mirror of https://gerrit.osmocom.org/libosmocore
3869 lines
101 KiB
C
3869 lines
101 KiB
C
/*
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* (C) 2013 by Andreas Eversberg <jolly@eversberg.eu>
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* (C) 2015 by Alexander Chemeris <Alexander.Chemeris@fairwaves.co>
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* (C) 2016 by Tom Tsou <tom.tsou@ettus.com>
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* (C) 2017 by Harald Welte <laforge@gnumonks.org>
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*
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* All Rights Reserved
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*
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* SPDX-License-Identifier: GPL-2.0+
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <string.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <osmocom/core/bits.h>
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#include <osmocom/core/conv.h>
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#include <osmocom/core/utils.h>
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#include <osmocom/core/crcgen.h>
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#include <osmocom/core/endian.h>
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#include <osmocom/gsm/protocol/gsm_44_060.h>
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#include <osmocom/gsm/protocol/gsm_04_08.h>
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#include <osmocom/gsm/gsm0503.h>
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#include <osmocom/codec/codec.h>
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#include <osmocom/coding/gsm0503_interleaving.h>
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#include <osmocom/coding/gsm0503_mapping.h>
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#include <osmocom/coding/gsm0503_tables.h>
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#include <osmocom/coding/gsm0503_coding.h>
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#include <osmocom/coding/gsm0503_parity.h>
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#include <osmocom/coding/gsm0503_amr_dtx.h>
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/*! \mainpage libosmocoding Documentation
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*
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* \section sec_intro Introduction
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* This library is a collection of definitions, tables and functions
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* implementing the GSM/GPRS/EGPRS channel coding (and decoding) as
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* specified in 3GPP TS 05.03 / 45.003.
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*
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* libosmocoding is developed as part of the Osmocom (Open Source Mobile
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* Communications) project, a community-based, collaborative development
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* project to create Free and Open Source implementations of mobile
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* communications systems. For more information about Osmocom, please
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* see https://osmocom.org/
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*
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* \section sec_copyright Copyright and License
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* Copyright © 2013 by Andreas Eversberg\n
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* Copyright © 2015 by Alexander Chemeris\n
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* Copyright © 2016 by Tom Tsou\n
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* Documentation Copyright © 2017 by Harald Welte\n
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* All rights reserved. \n\n
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* The source code of libosmocoding is licensed under the terms of the GNU
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* General Public License as published by the Free Software Foundation;
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* either version 2 of the License, or (at your option) any later
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* version.\n
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* See <http://www.gnu.org/licenses/> or COPYING included in the source
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* code package istelf.\n
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* The information detailed here is provided AS IS with NO WARRANTY OF
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* ANY KIND, INCLUDING THE WARRANTY OF DESIGN, MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE.
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* \n\n
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*
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* \section sec_tracker Homepage + Issue Tracker
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* libosmocoding is distributed as part of libosmocore and shares its
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* project page at http://osmocom.org/projects/libosmocore
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*
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* An Issue Tracker can be found at
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* https://osmocom.org/projects/libosmocore/issues
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*
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* \section sec_contact Contact and Support
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* Community-based support is available at the OpenBSC mailing list
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* <http://lists.osmocom.org/mailman/listinfo/openbsc>\n
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* Commercial support options available upon request from
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* <http://sysmocom.de/>
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*/
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/*! \addtogroup coding
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* @{
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*
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* GSM TS 05.03 coding
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*
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* This module is the "master module" of libosmocoding. It uses the
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* various other modules (mapping, parity, interleaving) in order to
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* implement the complete channel coding (and decoding) chain for the
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* various channel types as defined in TS 05.03 / 45.003.
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*
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* \file gsm0503_coding.c */
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/*
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* EGPRS coding limits
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*/
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/* Max header size with parity bits */
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#define EGPRS_HDR_UPP_MAX 54
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/* Max encoded header size */
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#define EGPRS_HDR_C_MAX 162
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/* Max punctured header size */
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#define EGPRS_HDR_HC_MAX 160
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/* Max data block size with parity bits */
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#define EGPRS_DATA_U_MAX 612
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/* Max encoded data block size */
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#define EGPRS_DATA_C_MAX 1836
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/* Max single block punctured data size */
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#define EGPRS_DATA_DC_MAX 1248
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/* Dual block punctured data size */
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#define EGPRS_DATA_C1 612
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#define EGPRS_DATA_C2 EGPRS_DATA_C1
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/*! union across the three different EGPRS Uplink header types */
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union gprs_rlc_ul_hdr_egprs {
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struct gprs_rlc_ul_header_egprs_1 type1;
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struct gprs_rlc_ul_header_egprs_2 type2;
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struct gprs_rlc_ul_header_egprs_3 type3;
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};
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/*! union across the three different EGPRS Downlink header types */
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union gprs_rlc_dl_hdr_egprs {
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struct gprs_rlc_dl_header_egprs_1 type1;
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struct gprs_rlc_dl_header_egprs_2 type2;
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struct gprs_rlc_dl_header_egprs_3 type3;
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};
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/*! Structure describing a Modulation and Coding Scheme */
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struct gsm0503_mcs_code {
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/*! Modulation and Coding Scheme (MSC) number */
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uint8_t mcs;
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/*! Length of Uplink Stealing Flag (USF) in bits */
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uint8_t usf_len;
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/* Header coding */
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/*! Length of header (bits) */
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uint8_t hdr_len;
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/*! Length of header convolutional code */
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uint8_t hdr_code_len;
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/*! Length of header code puncturing sequence */
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uint8_t hdr_punc_len;
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/*! header convolutional code */
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const struct osmo_conv_code *hdr_conv;
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/*! header puncturing sequence */
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const uint8_t *hdr_punc;
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/* Data coding */
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/*! length of data (bits) */
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uint16_t data_len;
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/*! length of data convolutional code */
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uint16_t data_code_len;
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/*! length of data code puncturing sequence */
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uint16_t data_punc_len;
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/*! data convolutional code */
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const struct osmo_conv_code *data_conv;
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/*! data puncturing sequences */
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const uint8_t *data_punc[3];
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};
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/*
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* EGPRS UL coding parameters
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*/
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const struct gsm0503_mcs_code gsm0503_mcs_ul_codes[EGPRS_NUM_MCS] = {
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{
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.mcs = EGPRS_MCS0,
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},
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{
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.mcs = EGPRS_MCS1,
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.hdr_len = 31,
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.hdr_code_len = 117,
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.hdr_punc_len = 80,
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.hdr_conv = &gsm0503_mcs1_ul_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_ul_hdr,
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.data_len = 178,
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.data_code_len = 588,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs1,
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.data_punc = {
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gsm0503_puncture_mcs1_p1,
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gsm0503_puncture_mcs1_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS2,
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.hdr_len = 31,
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.hdr_code_len = 117,
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.hdr_punc_len = 80,
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.hdr_conv = &gsm0503_mcs1_ul_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_ul_hdr,
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.data_len = 226,
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.data_code_len = 732,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs2,
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.data_punc = {
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gsm0503_puncture_mcs2_p1,
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gsm0503_puncture_mcs2_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS3,
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.hdr_len = 31,
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.hdr_code_len = 117,
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.hdr_punc_len = 80,
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.hdr_conv = &gsm0503_mcs1_ul_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_ul_hdr,
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.data_len = 298,
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.data_code_len = 948,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs3,
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.data_punc = {
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gsm0503_puncture_mcs3_p1,
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gsm0503_puncture_mcs3_p2,
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gsm0503_puncture_mcs3_p3,
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},
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},
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{
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.mcs = EGPRS_MCS4,
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.hdr_len = 31,
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.hdr_code_len = 117,
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.hdr_punc_len = 80,
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.hdr_conv = &gsm0503_mcs1_ul_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_ul_hdr,
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.data_len = 354,
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.data_code_len = 1116,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs4,
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.data_punc = {
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gsm0503_puncture_mcs4_p1,
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gsm0503_puncture_mcs4_p2,
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gsm0503_puncture_mcs4_p3,
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},
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},
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{
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.mcs = EGPRS_MCS5,
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.hdr_len = 37,
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.hdr_code_len = 135,
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.hdr_punc_len = 136,
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.hdr_conv = &gsm0503_mcs5_ul_hdr,
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.hdr_punc = NULL,
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.data_len = 450,
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.data_code_len = 1404,
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.data_punc_len = 1248,
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.data_conv = &gsm0503_mcs5,
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.data_punc = {
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gsm0503_puncture_mcs5_p1,
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gsm0503_puncture_mcs5_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS6,
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.hdr_len = 37,
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.hdr_code_len = 135,
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.hdr_punc_len = 136,
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.hdr_conv = &gsm0503_mcs5_ul_hdr,
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.hdr_punc = NULL,
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.data_len = 594,
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.data_code_len = 1836,
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.data_punc_len = 1248,
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.data_conv = &gsm0503_mcs6,
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.data_punc = {
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gsm0503_puncture_mcs6_p1,
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gsm0503_puncture_mcs6_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS7,
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.hdr_len = 46,
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.hdr_code_len = 162,
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.hdr_punc_len = 160,
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.hdr_conv = &gsm0503_mcs7_ul_hdr,
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.hdr_punc = gsm0503_puncture_mcs7_ul_hdr,
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.data_len = 900,
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.data_code_len = 1404,
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.data_punc_len = 612,
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.data_conv = &gsm0503_mcs7,
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.data_punc = {
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gsm0503_puncture_mcs7_p1,
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gsm0503_puncture_mcs7_p2,
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gsm0503_puncture_mcs7_p3,
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}
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},
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{
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.mcs = EGPRS_MCS8,
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.hdr_len = 46,
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.hdr_code_len = 162,
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.hdr_punc_len = 160,
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.hdr_conv = &gsm0503_mcs7_ul_hdr,
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.hdr_punc = gsm0503_puncture_mcs7_ul_hdr,
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.data_len = 1092,
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.data_code_len = 1692,
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.data_punc_len = 612,
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.data_conv = &gsm0503_mcs8,
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.data_punc = {
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gsm0503_puncture_mcs8_p1,
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gsm0503_puncture_mcs8_p2,
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gsm0503_puncture_mcs8_p3,
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}
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},
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{
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.mcs = EGPRS_MCS9,
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.hdr_len = 46,
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.hdr_code_len = 162,
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.hdr_punc_len = 160,
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.hdr_conv = &gsm0503_mcs7_ul_hdr,
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.hdr_punc = gsm0503_puncture_mcs7_ul_hdr,
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.data_len = 1188,
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.data_code_len = 1836,
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.data_punc_len = 612,
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.data_conv = &gsm0503_mcs9,
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.data_punc = {
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gsm0503_puncture_mcs9_p1,
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gsm0503_puncture_mcs9_p2,
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gsm0503_puncture_mcs9_p3,
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}
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},
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};
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/*
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* EGPRS DL coding parameters
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*/
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const struct gsm0503_mcs_code gsm0503_mcs_dl_codes[EGPRS_NUM_MCS] = {
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{
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.mcs = EGPRS_MCS0,
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},
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{
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.mcs = EGPRS_MCS1,
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.usf_len = 3,
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.hdr_len = 28,
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.hdr_code_len = 108,
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.hdr_punc_len = 68,
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.hdr_conv = &gsm0503_mcs1_dl_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_dl_hdr,
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.data_len = 178,
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.data_code_len = 588,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs1,
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.data_punc = {
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gsm0503_puncture_mcs1_p1,
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gsm0503_puncture_mcs1_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS2,
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.usf_len = 3,
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.hdr_len = 28,
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.hdr_code_len = 108,
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.hdr_punc_len = 68,
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.hdr_conv = &gsm0503_mcs1_dl_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_dl_hdr,
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.data_len = 226,
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.data_code_len = 732,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs2,
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.data_punc = {
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gsm0503_puncture_mcs2_p1,
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gsm0503_puncture_mcs2_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS3,
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.usf_len = 3,
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.hdr_len = 28,
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.hdr_code_len = 108,
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.hdr_punc_len = 68,
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.hdr_conv = &gsm0503_mcs1_dl_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_dl_hdr,
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.data_len = 298,
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.data_code_len = 948,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs3,
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.data_punc = {
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gsm0503_puncture_mcs3_p1,
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gsm0503_puncture_mcs3_p2,
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gsm0503_puncture_mcs3_p3,
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},
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},
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{
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.mcs = EGPRS_MCS4,
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.usf_len = 3,
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.hdr_len = 28,
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.hdr_code_len = 108,
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.hdr_punc_len = 68,
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.hdr_conv = &gsm0503_mcs1_dl_hdr,
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.hdr_punc = gsm0503_puncture_mcs1_dl_hdr,
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.data_len = 354,
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.data_code_len = 1116,
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.data_punc_len = 372,
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.data_conv = &gsm0503_mcs4,
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.data_punc = {
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gsm0503_puncture_mcs4_p1,
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gsm0503_puncture_mcs4_p2,
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gsm0503_puncture_mcs4_p3,
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},
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},
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{
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.mcs = EGPRS_MCS5,
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.usf_len = 3,
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.hdr_len = 25,
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.hdr_code_len = 99,
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.hdr_punc_len = 100,
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.hdr_conv = &gsm0503_mcs5_dl_hdr,
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.hdr_punc = NULL,
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.data_len = 450,
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.data_code_len = 1404,
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.data_punc_len = 1248,
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.data_conv = &gsm0503_mcs5,
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.data_punc = {
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gsm0503_puncture_mcs5_p1,
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gsm0503_puncture_mcs5_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS6,
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.usf_len = 3,
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.hdr_len = 25,
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.hdr_code_len = 99,
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.hdr_punc_len = 100,
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.hdr_conv = &gsm0503_mcs5_dl_hdr,
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.hdr_punc = NULL,
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.data_len = 594,
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.data_code_len = 1836,
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.data_punc_len = 1248,
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.data_conv = &gsm0503_mcs6,
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.data_punc = {
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gsm0503_puncture_mcs6_p1,
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gsm0503_puncture_mcs6_p2,
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NULL,
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},
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},
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{
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.mcs = EGPRS_MCS7,
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.usf_len = 3,
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.hdr_len = 37,
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.hdr_code_len = 135,
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.hdr_punc_len = 124,
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.hdr_conv = &gsm0503_mcs7_dl_hdr,
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.hdr_punc = gsm0503_puncture_mcs7_dl_hdr,
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.data_len = 900,
|
|
.data_code_len = 1404,
|
|
.data_punc_len = 612,
|
|
.data_conv = &gsm0503_mcs7,
|
|
.data_punc = {
|
|
gsm0503_puncture_mcs7_p1,
|
|
gsm0503_puncture_mcs7_p2,
|
|
gsm0503_puncture_mcs7_p3,
|
|
}
|
|
},
|
|
{
|
|
.mcs = EGPRS_MCS8,
|
|
.usf_len = 3,
|
|
.hdr_len = 37,
|
|
.hdr_code_len = 135,
|
|
.hdr_punc_len = 124,
|
|
.hdr_conv = &gsm0503_mcs7_dl_hdr,
|
|
.hdr_punc = gsm0503_puncture_mcs7_dl_hdr,
|
|
|
|
.data_len = 1092,
|
|
.data_code_len = 1692,
|
|
.data_punc_len = 612,
|
|
.data_conv = &gsm0503_mcs8,
|
|
.data_punc = {
|
|
gsm0503_puncture_mcs8_p1,
|
|
gsm0503_puncture_mcs8_p2,
|
|
gsm0503_puncture_mcs8_p3,
|
|
}
|
|
},
|
|
{
|
|
.mcs = EGPRS_MCS9,
|
|
.usf_len = 3,
|
|
.hdr_len = 37,
|
|
.hdr_code_len = 135,
|
|
.hdr_punc_len = 124,
|
|
.hdr_conv = &gsm0503_mcs7_dl_hdr,
|
|
.hdr_punc = gsm0503_puncture_mcs7_dl_hdr,
|
|
|
|
.data_len = 1188,
|
|
.data_code_len = 1836,
|
|
.data_punc_len = 612,
|
|
.data_conv = &gsm0503_mcs9,
|
|
.data_punc = {
|
|
gsm0503_puncture_mcs9_p1,
|
|
gsm0503_puncture_mcs9_p2,
|
|
gsm0503_puncture_mcs9_p3,
|
|
}
|
|
},
|
|
};
|
|
|
|
/*! Convolutional Decode + compute BER for punctured codes
|
|
* \param[in] code Description of Convolutional Code
|
|
* \param[in] input Input soft-bits (-127...127)
|
|
* \param[out] output bits
|
|
* \param[out] n_errors Number of bit-errors
|
|
* \param[out] n_bits_total Number of bits
|
|
* \param[in] data_punc Puncturing mask array. Can be NULL.
|
|
*/
|
|
static int osmo_conv_decode_ber_punctured(const struct osmo_conv_code *code,
|
|
const sbit_t *input, ubit_t *output,
|
|
int *n_errors, int *n_bits_total,
|
|
const uint8_t *data_punc)
|
|
{
|
|
int res, coded_len;
|
|
ubit_t recoded[EGPRS_DATA_C_MAX];
|
|
|
|
res = osmo_conv_decode(code, input, output);
|
|
|
|
if (!n_bits_total && !n_errors)
|
|
return res;
|
|
|
|
coded_len = osmo_conv_encode(code, output, recoded);
|
|
OSMO_ASSERT(ARRAY_SIZE(recoded) >= coded_len);
|
|
|
|
/* Count bit errors */
|
|
if (n_errors) {
|
|
*n_errors = 0;
|
|
for (unsigned int i = 0; i < coded_len; i++) {
|
|
/* punctured bits do not count as bit errors */
|
|
if (data_punc != NULL && data_punc[i])
|
|
continue;
|
|
if (recoded[i] == 1 && input[i] < 0)
|
|
continue;
|
|
if (recoded[i] == 0 && input[i] > 0)
|
|
continue;
|
|
*n_errors += 1;
|
|
}
|
|
}
|
|
|
|
if (n_bits_total)
|
|
*n_bits_total = coded_len;
|
|
|
|
return res;
|
|
}
|
|
|
|
/*! Convolutional Decode + compute BER for non-punctured codes
|
|
* \param[in] code Description of Convolutional Code
|
|
* \param[in] input Input soft-bits (-127...127)
|
|
* \param[out] output bits
|
|
* \param[out] n_errors Number of bit-errors
|
|
* \param[out] n_bits_total Number of bits
|
|
*/
|
|
static int osmo_conv_decode_ber(const struct osmo_conv_code *code,
|
|
const sbit_t *input, ubit_t *output,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
return osmo_conv_decode_ber_punctured(code, input, output,
|
|
n_errors, n_bits_total, NULL);
|
|
}
|
|
|
|
/*! convenience wrapper for decoding coded bits
|
|
* \param[out] l2_data caller-allocated buffer for L2 Frame
|
|
* \param[in] cB 456 coded (soft) bits as per TS 05.03 4.1.3
|
|
* \param[out] n_errors Number of detected errors
|
|
* \param[out] n_bits_total Number of total coded bits
|
|
* \returns 0 on success; -1 on CRC error */
|
|
static int _xcch_decode_cB(uint8_t *l2_data, const sbit_t *cB,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
ubit_t conv[224];
|
|
int rv;
|
|
|
|
osmo_conv_decode_ber(&gsm0503_xcch, cB,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40,
|
|
conv, 184, conv + 184);
|
|
if (rv)
|
|
return -1;
|
|
|
|
osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! convenience wrapper for encoding to coded bits
|
|
* \param[out] cB caller-allocated buffer for 456 coded bits as per TS 05.03 4.1.3
|
|
* \param[in] l2_data to-be-encoded L2 Frame
|
|
* \returns 0 */
|
|
static int _xcch_encode_cB(ubit_t *cB, const uint8_t *l2_data)
|
|
{
|
|
ubit_t conv[224];
|
|
|
|
osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1);
|
|
|
|
osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, conv + 184);
|
|
|
|
osmo_conv_encode(&gsm0503_xcch, conv, cB);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* GSM xCCH block transcoding
|
|
*/
|
|
|
|
/*! Decoding of xCCH data from bursts to L2 frame
|
|
* \param[out] l2_data caller-allocated output data buffer
|
|
* \param[in] bursts four GSM bursts in soft-bits
|
|
* \param[out] n_errors Number of detected errors
|
|
* \param[out] n_bits_total Number of total coded bits
|
|
*/
|
|
int gsm0503_xcch_decode(uint8_t *l2_data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[456], cB[456];
|
|
int i;
|
|
|
|
for (i = 0; i < 4; i++)
|
|
gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, NULL);
|
|
|
|
gsm0503_xcch_deinterleave(cB, iB);
|
|
|
|
return _xcch_decode_cB(l2_data, cB, n_errors, n_bits_total);
|
|
}
|
|
|
|
/*! Encoding of xCCH data from L2 frame to bursts
|
|
* \param[out] bursts caller-allocated burst data (unpacked bits)
|
|
* \param[in] l2_data L2 input data (MAC block)
|
|
* \returns 0
|
|
*/
|
|
int gsm0503_xcch_encode(ubit_t *bursts, const uint8_t *l2_data)
|
|
{
|
|
ubit_t iB[456], cB[456], hl = 1, hn = 1;
|
|
int i;
|
|
|
|
_xcch_encode_cB(cB, l2_data);
|
|
|
|
gsm0503_xcch_interleave(cB, iB);
|
|
|
|
for (i = 0; i < 4; i++)
|
|
gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], &hl, &hn);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* EGPRS PDTCH UL block decoding
|
|
*/
|
|
|
|
/*
|
|
* Type 3 - MCS-1,2,3,4
|
|
* Unmapping and deinterleaving
|
|
*/
|
|
static int egprs_type3_unmap(const sbit_t *bursts, sbit_t *hc, sbit_t *dc)
|
|
{
|
|
int i;
|
|
sbit_t iB[456], q[8];
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116],
|
|
q + i * 2, q + i * 2 + 1);
|
|
}
|
|
|
|
gsm0503_mcs1_ul_deinterleave(hc, dc, iB);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Type 2 - MCS-5,6
|
|
* Unmapping and deinterleaving
|
|
*/
|
|
static int egprs_type2_unmap(const sbit_t *bursts, sbit_t *hc, sbit_t *dc)
|
|
{
|
|
int i;
|
|
sbit_t burst[348];
|
|
sbit_t hi[EGPRS_HDR_HC_MAX];
|
|
sbit_t di[EGPRS_DATA_DC_MAX];
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
memcpy(burst, &bursts[i * 348], 348);
|
|
|
|
gsm0503_mcs5_burst_swap(burst);
|
|
gsm0503_mcs5_ul_burst_unmap(di, burst, hi, i);
|
|
}
|
|
|
|
gsm0503_mcs5_ul_deinterleave(hc, dc, hi, di);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Type 1 - MCS-7,8,9
|
|
* Unmapping and deinterleaving - Note that MCS-7 interleaver is unique
|
|
*/
|
|
static int egprs_type1_unmap(const sbit_t *bursts, sbit_t *hc,
|
|
sbit_t *c1, sbit_t *c2, int msc)
|
|
{
|
|
int i;
|
|
sbit_t burst[348];
|
|
sbit_t hi[EGPRS_HDR_HC_MAX];
|
|
sbit_t di[EGPRS_DATA_C1 * 2];
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
memcpy(burst, &bursts[i * 348], 348);
|
|
|
|
gsm0503_mcs5_burst_swap(burst);
|
|
gsm0503_mcs7_ul_burst_unmap(di, burst, hi, i);
|
|
}
|
|
|
|
if (msc == EGPRS_MCS7)
|
|
gsm0503_mcs7_ul_deinterleave(hc, c1, c2, hi, di);
|
|
else
|
|
gsm0503_mcs8_ul_deinterleave(hc, c1, c2, hi, di);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Decode EGPRS UL header section
|
|
*
|
|
* 1. Depuncture
|
|
* 2. Convolutional decoding
|
|
* 3. CRC check
|
|
*/
|
|
static int _egprs_decode_hdr(const sbit_t *hc, int mcs,
|
|
union gprs_rlc_ul_hdr_egprs *hdr)
|
|
{
|
|
sbit_t C[EGPRS_HDR_C_MAX];
|
|
ubit_t upp[EGPRS_HDR_UPP_MAX];
|
|
int i, j, rc;
|
|
const struct gsm0503_mcs_code *code;
|
|
|
|
code = &gsm0503_mcs_ul_codes[mcs];
|
|
|
|
/* Skip depuncturing on MCS-5,6 header */
|
|
if ((mcs == EGPRS_MCS5) || (mcs == EGPRS_MCS6)) {
|
|
memcpy(C, hc, code->hdr_code_len);
|
|
goto hdr_conv_decode;
|
|
}
|
|
|
|
if (!code->hdr_punc) {
|
|
/* Invalid MCS-X header puncture matrix */
|
|
return -1;
|
|
}
|
|
|
|
i = code->hdr_code_len - 1;
|
|
j = code->hdr_punc_len - 1;
|
|
|
|
for (; i >= 0; i--) {
|
|
if (!code->hdr_punc[i])
|
|
C[i] = hc[j--];
|
|
else
|
|
C[i] = 0;
|
|
}
|
|
|
|
hdr_conv_decode:
|
|
osmo_conv_decode_ber(code->hdr_conv, C, upp, NULL, NULL);
|
|
rc = osmo_crc8gen_check_bits(&gsm0503_mcs_crc8_hdr, upp,
|
|
code->hdr_len, upp + code->hdr_len);
|
|
if (rc)
|
|
return -1;
|
|
|
|
osmo_ubit2pbit_ext((pbit_t *) hdr, 0, upp, 0, code->hdr_len, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Blind MCS header decoding based on burst length and CRC validation.
|
|
* Ignore 'q' value coding identification. This approach provides
|
|
* the strongest chance of header recovery.
|
|
*/
|
|
static int egprs_decode_hdr(union gprs_rlc_ul_hdr_egprs *hdr,
|
|
const sbit_t *bursts, uint16_t nbits)
|
|
{
|
|
int rc;
|
|
sbit_t hc[EGPRS_HDR_HC_MAX];
|
|
|
|
if (nbits == GSM0503_GPRS_BURSTS_NBITS) {
|
|
/* MCS-1,2,3,4 */
|
|
egprs_type3_unmap(bursts, hc, NULL);
|
|
rc = _egprs_decode_hdr(hc, EGPRS_MCS1, hdr);
|
|
if (!rc)
|
|
return EGPRS_HDR_TYPE3;
|
|
} else if (nbits == GSM0503_EGPRS_BURSTS_NBITS) {
|
|
/* MCS-5,6 */
|
|
egprs_type2_unmap(bursts, hc, NULL);
|
|
rc = _egprs_decode_hdr(hc, EGPRS_MCS5, hdr);
|
|
if (!rc)
|
|
return EGPRS_HDR_TYPE2;
|
|
|
|
/* MCS-7,8,9 */
|
|
egprs_type1_unmap(bursts, hc, NULL, NULL, EGPRS_MCS7);
|
|
rc = _egprs_decode_hdr(hc, EGPRS_MCS7, hdr);
|
|
if (!rc)
|
|
return EGPRS_HDR_TYPE1;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Parse EGPRS UL header for coding and puncturing scheme (CPS)
|
|
*
|
|
* Type 1 - MCS-7,8,9
|
|
* Type 2 - MCS-5,6
|
|
* Type 3 - MCS-1,2,3,4
|
|
*/
|
|
static int egprs_parse_ul_cps(struct egprs_cps *cps,
|
|
union gprs_rlc_ul_hdr_egprs *hdr, int type)
|
|
{
|
|
uint8_t bits;
|
|
|
|
switch (type) {
|
|
case EGPRS_HDR_TYPE1:
|
|
bits = hdr->type1.cps;
|
|
break;
|
|
case EGPRS_HDR_TYPE2:
|
|
bits = (hdr->type2.cps_lo << 2) | hdr->type2.cps_hi;
|
|
break;
|
|
case EGPRS_HDR_TYPE3:
|
|
bits = (hdr->type3.cps_lo << 2) | hdr->type3.cps_hi;
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
return egprs_get_cps(cps, type, bits);
|
|
}
|
|
|
|
/*
|
|
* Decode EGPRS UL data section
|
|
*
|
|
* 1. Depuncture
|
|
* 2. Convolutional decoding
|
|
* 3. CRC check
|
|
* 4. Block combining (MCS-7,8,9 only)
|
|
*/
|
|
static int egprs_decode_data(uint8_t *l2_data, const sbit_t *c,
|
|
int mcs, int p, int blk, int *n_errors, int *n_bits_total)
|
|
{
|
|
ubit_t u[EGPRS_DATA_U_MAX];
|
|
sbit_t C[EGPRS_DATA_C_MAX];
|
|
|
|
int i, j, rc, data_len;
|
|
const struct gsm0503_mcs_code *code;
|
|
|
|
if (blk && mcs < EGPRS_MCS7) {
|
|
/* Invalid MCS-X block state */
|
|
return -1;
|
|
}
|
|
|
|
code = &gsm0503_mcs_ul_codes[mcs];
|
|
if (!code->data_punc[p]) {
|
|
/* Invalid MCS-X data puncture matrix */
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* MCS-1,6 - single block processing
|
|
* MCS-7,9 - dual block processing
|
|
*/
|
|
if (mcs >= EGPRS_MCS7)
|
|
data_len = code->data_len / 2;
|
|
else
|
|
data_len = code->data_len;
|
|
|
|
i = code->data_code_len - 1;
|
|
j = code->data_punc_len - 1;
|
|
|
|
for (; i >= 0; i--) {
|
|
if (!code->data_punc[p][i])
|
|
C[i] = c[j--];
|
|
else
|
|
C[i] = 0;
|
|
}
|
|
|
|
osmo_conv_decode_ber_punctured(code->data_conv, C, u,
|
|
n_errors, n_bits_total, code->data_punc[p]);
|
|
rc = osmo_crc16gen_check_bits(&gsm0503_mcs_crc12, u,
|
|
data_len, u + data_len);
|
|
if (rc)
|
|
return -1;
|
|
|
|
/* Offsets output pointer on the second block of Type 1 MCS */
|
|
osmo_ubit2pbit_ext(l2_data, code->hdr_len + blk * data_len,
|
|
u, 0, data_len, 1);
|
|
|
|
/* Return the number of bytes required for the bit message */
|
|
return OSMO_BYTES_FOR_BITS(code->hdr_len + code->data_len);
|
|
}
|
|
|
|
/*! Decode EGPRS UL message
|
|
* 1. Header section decoding
|
|
* 2. Extract CPS settings
|
|
* 3. Burst unmapping and deinterleaving
|
|
* 4. Data section decoding
|
|
* \param[out] l2_data caller-allocated buffer for L2 Frame
|
|
* \param[in] bursts burst input data as soft unpacked bits
|
|
* \param[in] nbits number of bits in \a bursts
|
|
* \param usf_p Uplink State Flag, FIXME: not implemented
|
|
* \param[out] n_errors number of detected bit-errors
|
|
* \param[out] n_bits_total total number of decoded bits
|
|
* \returns number of bytes decoded; negative on error */
|
|
int gsm0503_pdtch_egprs_decode(uint8_t *l2_data, const sbit_t *bursts, uint16_t nbits,
|
|
uint8_t *usf_p, int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t dc[EGPRS_DATA_DC_MAX];
|
|
sbit_t c1[EGPRS_DATA_C1], c2[EGPRS_DATA_C2];
|
|
int type, rc;
|
|
struct egprs_cps cps;
|
|
union gprs_rlc_ul_hdr_egprs *hdr;
|
|
|
|
if (n_errors)
|
|
*n_errors = 0;
|
|
if (n_bits_total)
|
|
*n_bits_total = 0;
|
|
|
|
if ((nbits != GSM0503_GPRS_BURSTS_NBITS) &&
|
|
(nbits != GSM0503_EGPRS_BURSTS_NBITS)) {
|
|
/* Invalid EGPRS bit length */
|
|
return -EOVERFLOW;
|
|
}
|
|
|
|
hdr = (union gprs_rlc_ul_hdr_egprs *) l2_data;
|
|
type = egprs_decode_hdr(hdr, bursts, nbits);
|
|
if (egprs_parse_ul_cps(&cps, hdr, type) < 0)
|
|
return -EIO;
|
|
|
|
switch (cps.mcs) {
|
|
case EGPRS_MCS0:
|
|
return -ENOTSUP;
|
|
case EGPRS_MCS1:
|
|
case EGPRS_MCS2:
|
|
case EGPRS_MCS3:
|
|
case EGPRS_MCS4:
|
|
egprs_type3_unmap(bursts, NULL, dc);
|
|
break;
|
|
case EGPRS_MCS5:
|
|
case EGPRS_MCS6:
|
|
egprs_type2_unmap(bursts, NULL, dc);
|
|
break;
|
|
case EGPRS_MCS7:
|
|
case EGPRS_MCS8:
|
|
case EGPRS_MCS9:
|
|
egprs_type1_unmap(bursts, NULL, c1, c2, cps.mcs);
|
|
break;
|
|
default:
|
|
/* Invalid MCS-X */
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Decode MCS-X block, where X = cps.mcs */
|
|
if (cps.mcs < EGPRS_MCS7) {
|
|
rc = egprs_decode_data(l2_data, dc, cps.mcs, cps.p[0],
|
|
0, n_errors, n_bits_total);
|
|
if (rc < 0)
|
|
return -EFAULT;
|
|
} else {
|
|
/* Bit counters for the second block */
|
|
int n_errors2, n_bits_total2;
|
|
|
|
/* MCS-7,8,9 block 1 */
|
|
rc = egprs_decode_data(l2_data, c1, cps.mcs, cps.p[0],
|
|
0, n_errors, n_bits_total);
|
|
if (rc < 0)
|
|
return -EFAULT;
|
|
|
|
/* MCS-7,8,9 block 2 */
|
|
rc = egprs_decode_data(l2_data, c2, cps.mcs, cps.p[1],
|
|
1, &n_errors2, &n_bits_total2);
|
|
if (n_errors)
|
|
*n_errors += n_errors2;
|
|
if (n_bits_total)
|
|
*n_bits_total += n_bits_total2;
|
|
if (rc < 0)
|
|
return -EFAULT;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* GSM PDTCH block transcoding
|
|
*/
|
|
|
|
/*! Decode GPRS PDTCH
|
|
* \param[out] l2_data caller-allocated buffer for L2 Frame
|
|
* \param[in] bursts burst input data as soft unpacked bits
|
|
* \param[out] usf_p Uplink State Flag, only relevant for DL blocks
|
|
* \param[out] n_errors number of detected bit-errors
|
|
* \param[out] n_bits_total total number of decoded bits
|
|
* \returns number of bytes decoded; negative on error */
|
|
int gsm0503_pdtch_decode(uint8_t *l2_data, const sbit_t *bursts, uint8_t *usf_p,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[456], cB[676], hl_hn[8];
|
|
ubit_t conv[456];
|
|
int i, j, k, rv, best = 0, cs = 0, usf = 0; /* make GCC happy */
|
|
|
|
for (i = 0; i < 4; i++)
|
|
gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116],
|
|
hl_hn + i * 2, hl_hn + i * 2 + 1);
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
for (j = 0, k = 0; j < 8; j++)
|
|
k += abs(((int)gsm0503_pdtch_hl_hn_sbit[i][j]) - ((int)hl_hn[j]));
|
|
|
|
if (i == 0 || k < best) {
|
|
best = k;
|
|
cs = i + 1;
|
|
}
|
|
}
|
|
|
|
gsm0503_xcch_deinterleave(cB, iB);
|
|
|
|
switch (cs) {
|
|
case 1:
|
|
osmo_conv_decode_ber(&gsm0503_xcch, cB,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
/* the three USF bits d(0),d(1),d(2) are *not* precoded */
|
|
if (usf_p)
|
|
*usf_p = (conv[0] << 2) | (conv[1] << 1) | (conv[2] << 0);
|
|
|
|
rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40,
|
|
conv, 184, conv + 184);
|
|
if (rv)
|
|
return -1;
|
|
|
|
osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1);
|
|
|
|
return 23;
|
|
case 2:
|
|
/* reorder, set punctured bits to 0 (unknown state) */
|
|
for (i = 587, j = 455; i >= 0; i--) {
|
|
if (!gsm0503_puncture_cs2[i])
|
|
cB[i] = cB[j--];
|
|
else
|
|
cB[i] = 0;
|
|
}
|
|
|
|
/* decode as if puncturing was not employed (note '_np') */
|
|
osmo_conv_decode_ber_punctured(&gsm0503_cs2_np, cB, conv,
|
|
n_errors, NULL,
|
|
gsm0503_puncture_cs2);
|
|
/* indicate the actual amount of coded bits (excluding punctured ones) */
|
|
if (n_bits_total != NULL)
|
|
*n_bits_total = 456;
|
|
|
|
/* 5.1.2.2 a) the three USF bits d(0),d(1),d(2) are precoded into six bits */
|
|
for (i = 0; i < 8; i++) {
|
|
for (j = 0, k = 0; j < 6; j++)
|
|
k += abs(((int)gsm0503_usf2six[i][j]) - ((int)conv[j]));
|
|
|
|
if (i == 0 || k < best) {
|
|
best = k;
|
|
usf = i;
|
|
}
|
|
}
|
|
|
|
conv[3] = usf & 1;
|
|
conv[4] = (usf >> 1) & 1;
|
|
conv[5] = (usf >> 2) & 1;
|
|
if (usf_p)
|
|
*usf_p = usf;
|
|
|
|
rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16,
|
|
conv + 3, 271, conv + 3 + 271);
|
|
if (rv)
|
|
return -1;
|
|
|
|
osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 271, 1);
|
|
|
|
return 34;
|
|
case 3:
|
|
/* reorder, set punctured bits to 0 (unknown state) */
|
|
for (i = 675, j = 455; i >= 0; i--) {
|
|
if (!gsm0503_puncture_cs3[i])
|
|
cB[i] = cB[j--];
|
|
else
|
|
cB[i] = 0;
|
|
}
|
|
|
|
/* decode as if puncturing was not employed (note '_np') */
|
|
osmo_conv_decode_ber_punctured(&gsm0503_cs3_np, cB, conv,
|
|
n_errors, NULL,
|
|
gsm0503_puncture_cs3);
|
|
/* indicate the actual amount of coded bits (excluding punctured ones) */
|
|
if (n_bits_total != NULL)
|
|
*n_bits_total = 456;
|
|
|
|
/* 5.1.3.2 a) the three USF bits d(0),d(1),d(2) are precoded into six bits */
|
|
for (i = 0; i < 8; i++) {
|
|
for (j = 0, k = 0; j < 6; j++)
|
|
k += abs(((int)gsm0503_usf2six[i][j]) - ((int)conv[j]));
|
|
|
|
if (i == 0 || k < best) {
|
|
best = k;
|
|
usf = i;
|
|
}
|
|
}
|
|
|
|
conv[3] = usf & 1;
|
|
conv[4] = (usf >> 1) & 1;
|
|
conv[5] = (usf >> 2) & 1;
|
|
if (usf_p)
|
|
*usf_p = usf;
|
|
|
|
rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16,
|
|
conv + 3, 315, conv + 3 + 315);
|
|
if (rv)
|
|
return -1;
|
|
|
|
osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 315, 1);
|
|
|
|
return 40;
|
|
case 4:
|
|
for (i = 12; i < 456; i++)
|
|
conv[i] = (cB[i] < 0) ? 1 : 0;
|
|
|
|
/* 5.1.4.2 a) the three USF bits d(0),d(1),d(2) are precoded into twelve bits */
|
|
for (i = 0; i < 8; i++) {
|
|
for (j = 0, k = 0; j < 12; j++)
|
|
k += abs(((int)gsm0503_usf2twelve_sbit[i][j]) - ((int)cB[j]));
|
|
|
|
if (i == 0 || k < best) {
|
|
best = k;
|
|
usf = i;
|
|
}
|
|
}
|
|
|
|
conv[9] = usf & 1;
|
|
conv[10] = (usf >> 1) & 1;
|
|
conv[11] = (usf >> 2) & 1;
|
|
if (usf_p)
|
|
*usf_p = usf;
|
|
|
|
rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16,
|
|
conv + 9, 431, conv + 9 + 431);
|
|
if (rv) {
|
|
*n_bits_total = 456 - 12;
|
|
*n_errors = *n_bits_total;
|
|
return -1;
|
|
}
|
|
|
|
*n_bits_total = 456 - 12;
|
|
*n_errors = 0;
|
|
|
|
osmo_ubit2pbit_ext(l2_data, 0, conv, 9, 431, 1);
|
|
|
|
return 54;
|
|
default:
|
|
*n_bits_total = 0;
|
|
*n_errors = 0;
|
|
break;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* EGPRS PDTCH DL block encoding
|
|
*/
|
|
static int egprs_type3_map(ubit_t *bursts, const ubit_t *hc, const ubit_t *dc, int usf)
|
|
{
|
|
int i;
|
|
ubit_t iB[456];
|
|
const ubit_t *hl_hn = gsm0503_pdtch_hl_hn_ubit[3];
|
|
|
|
gsm0503_mcs1_dl_interleave(gsm0503_usf2twelve_ubit[usf], hc, dc, iB);
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116],
|
|
hl_hn + i * 2, hl_hn + i * 2 + 1);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int egprs_type2_map(ubit_t *bursts, const ubit_t *hc, const ubit_t *dc, int usf)
|
|
{
|
|
int i;
|
|
const ubit_t *up;
|
|
ubit_t hi[EGPRS_HDR_HC_MAX];
|
|
ubit_t di[EGPRS_DATA_DC_MAX];
|
|
|
|
gsm0503_mcs5_dl_interleave(hc, dc, hi, di);
|
|
up = gsm0503_mcs5_usf_precode_table[usf];
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_mcs5_dl_burst_map(di, &bursts[i * 348], hi, up, i);
|
|
gsm0503_mcs5_burst_swap((sbit_t *) &bursts[i * 348]);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int egprs_type1_map(ubit_t *bursts, const ubit_t *hc,
|
|
const ubit_t *c1, const ubit_t *c2, int usf, int mcs)
|
|
{
|
|
int i;
|
|
const ubit_t *up;
|
|
ubit_t hi[EGPRS_HDR_HC_MAX];
|
|
ubit_t di[EGPRS_DATA_C1 * 2];
|
|
|
|
if (mcs == EGPRS_MCS7)
|
|
gsm0503_mcs7_dl_interleave(hc, c1, c2, hi, di);
|
|
else
|
|
gsm0503_mcs8_dl_interleave(hc, c1, c2, hi, di);
|
|
|
|
up = gsm0503_mcs5_usf_precode_table[usf];
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_mcs7_dl_burst_map(di, &bursts[i * 348], hi, up, i);
|
|
gsm0503_mcs5_burst_swap((sbit_t *) &bursts[i * 348]);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int egprs_encode_hdr(ubit_t *hc, const uint8_t *l2_data, int mcs)
|
|
{
|
|
int i, j;
|
|
ubit_t upp[EGPRS_HDR_UPP_MAX], C[EGPRS_HDR_C_MAX];
|
|
const struct gsm0503_mcs_code *code;
|
|
|
|
code = &gsm0503_mcs_dl_codes[mcs];
|
|
|
|
osmo_pbit2ubit_ext(upp, 0, l2_data, code->usf_len, code->hdr_len, 1);
|
|
osmo_crc8gen_set_bits(&gsm0503_mcs_crc8_hdr, upp,
|
|
code->hdr_len, upp + code->hdr_len);
|
|
|
|
osmo_conv_encode(code->hdr_conv, upp, C);
|
|
|
|
/* MCS-5,6 header direct puncture instead of table */
|
|
if ((mcs == EGPRS_MCS5) || (mcs == EGPRS_MCS6)) {
|
|
memcpy(hc, C, code->hdr_code_len);
|
|
hc[99] = hc[98];
|
|
return 0;
|
|
}
|
|
|
|
if (!code->hdr_punc) {
|
|
/* Invalid MCS-X header puncture matrix */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0, j = 0; i < code->hdr_code_len; i++) {
|
|
if (!code->hdr_punc[i])
|
|
hc[j++] = C[i];
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int egprs_encode_data(ubit_t *c, const uint8_t *l2_data,
|
|
int mcs, int p, int blk)
|
|
{
|
|
int i, j, data_len;
|
|
ubit_t u[EGPRS_DATA_U_MAX], C[EGPRS_DATA_C_MAX];
|
|
const struct gsm0503_mcs_code *code;
|
|
|
|
code = &gsm0503_mcs_dl_codes[mcs];
|
|
|
|
/*
|
|
* Dual block - MCS-7,8,9
|
|
* Single block - MCS-1,2,3,4,5,6
|
|
*/
|
|
if (mcs >= EGPRS_MCS7)
|
|
data_len = code->data_len / 2;
|
|
else
|
|
data_len = code->data_len;
|
|
|
|
osmo_pbit2ubit_ext(u, 0, l2_data,
|
|
code->usf_len + code->hdr_len + blk * data_len, data_len, 1);
|
|
|
|
osmo_crc16gen_set_bits(&gsm0503_mcs_crc12, u, data_len, u + data_len);
|
|
|
|
osmo_conv_encode(code->data_conv, u, C);
|
|
|
|
if (!code->data_punc[p]) {
|
|
/* Invalid MCS-X data puncture matrix */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0, j = 0; i < code->data_code_len; i++) {
|
|
if (!code->data_punc[p][i])
|
|
c[j++] = C[i];
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Parse EGPRS DL header for coding and puncturing scheme (CPS)
|
|
*
|
|
* Type 1 - MCS-7,8,9
|
|
* Type 2 - MCS-5,6
|
|
* Type 3 - MCS-1,2,3,4
|
|
*/
|
|
static int egprs_parse_dl_cps(struct egprs_cps *cps,
|
|
const union gprs_rlc_dl_hdr_egprs *hdr, int type)
|
|
{
|
|
uint8_t bits;
|
|
|
|
switch (type) {
|
|
case EGPRS_HDR_TYPE1:
|
|
bits = hdr->type1.cps;
|
|
break;
|
|
case EGPRS_HDR_TYPE2:
|
|
bits = hdr->type2.cps;
|
|
break;
|
|
case EGPRS_HDR_TYPE3:
|
|
bits = hdr->type3.cps;
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
return egprs_get_cps(cps, type, bits);
|
|
}
|
|
|
|
/*! EGPRS DL message encoding
|
|
* \param[out] bursts caller-allocated buffer for unpacked burst bits
|
|
* \param[in] l2_data L2 (MAC) block to be encoded
|
|
* \param[in] l2_len length of l2_data in bytes, used to determine MCS
|
|
* \returns number of bits encoded; negative on error */
|
|
int gsm0503_pdtch_egprs_encode(ubit_t *bursts,
|
|
const uint8_t *l2_data, uint8_t l2_len)
|
|
{
|
|
ubit_t hc[EGPRS_DATA_C_MAX], dc[EGPRS_DATA_DC_MAX];
|
|
ubit_t c1[EGPRS_DATA_C1], c2[EGPRS_DATA_C2];
|
|
uint8_t mcs;
|
|
struct egprs_cps cps;
|
|
union gprs_rlc_dl_hdr_egprs *hdr;
|
|
|
|
switch (l2_len) {
|
|
case 27:
|
|
mcs = EGPRS_MCS1;
|
|
break;
|
|
case 33:
|
|
mcs = EGPRS_MCS2;
|
|
break;
|
|
case 42:
|
|
mcs = EGPRS_MCS3;
|
|
break;
|
|
case 49:
|
|
mcs = EGPRS_MCS4;
|
|
break;
|
|
case 60:
|
|
mcs = EGPRS_MCS5;
|
|
break;
|
|
case 78:
|
|
mcs = EGPRS_MCS6;
|
|
break;
|
|
case 118:
|
|
mcs = EGPRS_MCS7;
|
|
break;
|
|
case 142:
|
|
mcs = EGPRS_MCS8;
|
|
break;
|
|
case 154:
|
|
mcs = EGPRS_MCS9;
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
/* Read header for USF and puncturing matrix selection. */
|
|
hdr = (union gprs_rlc_dl_hdr_egprs *) l2_data;
|
|
|
|
switch (mcs) {
|
|
case EGPRS_MCS1:
|
|
case EGPRS_MCS2:
|
|
case EGPRS_MCS3:
|
|
case EGPRS_MCS4:
|
|
/* Check for valid CPS and matching MCS to message size */
|
|
if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE3) < 0) ||
|
|
(cps.mcs != mcs))
|
|
goto bad_header;
|
|
|
|
egprs_encode_hdr(hc, l2_data, mcs);
|
|
egprs_encode_data(dc, l2_data, mcs, cps.p[0], 0);
|
|
egprs_type3_map(bursts, hc, dc, hdr->type3.usf);
|
|
break;
|
|
case EGPRS_MCS5:
|
|
case EGPRS_MCS6:
|
|
if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE2) < 0) ||
|
|
(cps.mcs != mcs))
|
|
goto bad_header;
|
|
|
|
egprs_encode_hdr(hc, l2_data, mcs);
|
|
egprs_encode_data(dc, l2_data, mcs, cps.p[0], 0);
|
|
egprs_type2_map(bursts, hc, dc, hdr->type2.usf);
|
|
break;
|
|
case EGPRS_MCS7:
|
|
case EGPRS_MCS8:
|
|
case EGPRS_MCS9:
|
|
if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE1) < 0) ||
|
|
(cps.mcs != mcs))
|
|
goto bad_header;
|
|
|
|
egprs_encode_hdr(hc, l2_data, mcs);
|
|
egprs_encode_data(c1, l2_data, mcs, cps.p[0], 0);
|
|
egprs_encode_data(c2, l2_data, mcs, cps.p[1], 1);
|
|
egprs_type1_map(bursts, hc, c1, c2, hdr->type1.usf, mcs);
|
|
break;
|
|
}
|
|
|
|
return mcs >= EGPRS_MCS5 ?
|
|
GSM0503_EGPRS_BURSTS_NBITS : GSM0503_GPRS_BURSTS_NBITS;
|
|
|
|
bad_header:
|
|
/* Invalid EGPRS MCS-X header */
|
|
return -1;
|
|
}
|
|
|
|
/*! GPRS DL message encoding
|
|
* \param[out] bursts caller-allocated buffer for unpacked burst bits
|
|
* \param[in] l2_data L2 (MAC) block to be encoded
|
|
* \param[in] l2_len length of l2_data in bytes, used to determine CS
|
|
* \returns number of bits encoded; negative on error */
|
|
int gsm0503_pdtch_encode(ubit_t *bursts, const uint8_t *l2_data, uint8_t l2_len)
|
|
{
|
|
ubit_t iB[456], cB[676];
|
|
const ubit_t *hl_hn;
|
|
ubit_t conv[334];
|
|
int i, j, usf;
|
|
|
|
switch (l2_len) {
|
|
case 23:
|
|
osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1);
|
|
|
|
osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, conv + 184);
|
|
|
|
osmo_conv_encode(&gsm0503_xcch, conv, cB);
|
|
|
|
hl_hn = gsm0503_pdtch_hl_hn_ubit[0];
|
|
|
|
break;
|
|
case 34:
|
|
osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 271, 1);
|
|
usf = l2_data[0] & 0x7;
|
|
|
|
osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv + 3,
|
|
271, conv + 3 + 271);
|
|
|
|
memcpy(conv, gsm0503_usf2six[usf], 6);
|
|
|
|
osmo_conv_encode(&gsm0503_cs2_np, conv, cB);
|
|
|
|
for (i = 0, j = 0; i < 588; i++)
|
|
if (!gsm0503_puncture_cs2[i])
|
|
cB[j++] = cB[i];
|
|
|
|
hl_hn = gsm0503_pdtch_hl_hn_ubit[1];
|
|
|
|
break;
|
|
case 40:
|
|
osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 315, 1);
|
|
usf = l2_data[0] & 0x7;
|
|
|
|
osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv + 3,
|
|
315, conv + 3 + 315);
|
|
|
|
memcpy(conv, gsm0503_usf2six[usf], 6);
|
|
|
|
osmo_conv_encode(&gsm0503_cs3_np, conv, cB);
|
|
|
|
for (i = 0, j = 0; i < 676; i++)
|
|
if (!gsm0503_puncture_cs3[i])
|
|
cB[j++] = cB[i];
|
|
|
|
hl_hn = gsm0503_pdtch_hl_hn_ubit[2];
|
|
|
|
break;
|
|
case 54:
|
|
osmo_pbit2ubit_ext(cB, 9, l2_data, 0, 431, 1);
|
|
usf = l2_data[0] & 0x7;
|
|
|
|
osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, cB + 9,
|
|
431, cB + 9 + 431);
|
|
|
|
memcpy(cB, gsm0503_usf2twelve_ubit[usf], 12);
|
|
|
|
hl_hn = gsm0503_pdtch_hl_hn_ubit[3];
|
|
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
gsm0503_xcch_interleave(cB, iB);
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116],
|
|
hl_hn + i * 2, hl_hn + i * 2 + 1);
|
|
}
|
|
|
|
return GSM0503_GPRS_BURSTS_NBITS;
|
|
}
|
|
|
|
/*
|
|
* GSM TCH/F FR/EFR transcoding
|
|
*/
|
|
|
|
/*! assemble a FR codec frame in format as used inside RTP
|
|
* \param[out] tch_data Codec frame in RTP format
|
|
* \param[in] b_bits Codec frame in 'native' format
|
|
* \param[in] net_order FIXME */
|
|
static void tch_fr_reassemble(uint8_t *tch_data,
|
|
const ubit_t *b_bits, int net_order)
|
|
{
|
|
int i, j, k, l, o;
|
|
|
|
tch_data[0] = 0xd << 4;
|
|
memset(tch_data + 1, 0, 32);
|
|
|
|
if (net_order) {
|
|
for (i = 0, j = 4; i < 260; i++, j++)
|
|
tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7)));
|
|
|
|
return;
|
|
}
|
|
|
|
/* reassemble d-bits */
|
|
i = 0; /* counts bits */
|
|
j = 4; /* counts output bits */
|
|
k = gsm0503_gsm_fr_map[0]-1; /* current number bit in element */
|
|
l = 0; /* counts element bits */
|
|
o = 0; /* offset input bits */
|
|
while (i < 260) {
|
|
tch_data[j >> 3] |= (b_bits[k + o] << (7 - (j & 7)));
|
|
if (--k < 0) {
|
|
o += gsm0503_gsm_fr_map[l];
|
|
k = gsm0503_gsm_fr_map[++l]-1;
|
|
}
|
|
i++;
|
|
j++;
|
|
}
|
|
}
|
|
|
|
static void tch_fr_disassemble(ubit_t *b_bits,
|
|
const uint8_t *tch_data, int net_order)
|
|
{
|
|
int i, j, k, l, o;
|
|
|
|
if (net_order) {
|
|
for (i = 0, j = 4; i < 260; i++, j++)
|
|
b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1;
|
|
|
|
return;
|
|
}
|
|
|
|
i = 0; /* counts bits */
|
|
j = 4; /* counts input bits */
|
|
k = gsm0503_gsm_fr_map[0] - 1; /* current number bit in element */
|
|
l = 0; /* counts element bits */
|
|
o = 0; /* offset output bits */
|
|
while (i < 260) {
|
|
b_bits[k + o] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1;
|
|
if (--k < 0) {
|
|
o += gsm0503_gsm_fr_map[l];
|
|
k = gsm0503_gsm_fr_map[++l] - 1;
|
|
}
|
|
i++;
|
|
j++;
|
|
}
|
|
}
|
|
|
|
/* assemble a HR codec frame in the canonical format of ETSI TS 101 318 */
|
|
static void tch_hr_reassemble(uint8_t *tch_data, const ubit_t *b_bits)
|
|
{
|
|
int i;
|
|
|
|
memset(tch_data, 0, GSM_HR_BYTES);
|
|
for (i = 0; i < 112; i++)
|
|
tch_data[i >> 3] |= (b_bits[i] << (7 - (i & 7)));
|
|
}
|
|
|
|
static void tch_hr_disassemble(ubit_t *b_bits, const uint8_t *tch_data)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 112; i++)
|
|
b_bits[i] = (tch_data[i >> 3] >> (7 - (i & 7))) & 1;
|
|
}
|
|
|
|
/* assemble a EFR codec frame in format as used inside RTP */
|
|
static void tch_efr_reassemble(uint8_t *tch_data, const ubit_t *b_bits)
|
|
{
|
|
int i, j;
|
|
|
|
tch_data[0] = 0xc << 4;
|
|
memset(tch_data + 1, 0, 30);
|
|
|
|
for (i = 0, j = 4; i < 244; i++, j++)
|
|
tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7)));
|
|
}
|
|
|
|
static void tch_efr_disassemble(ubit_t *b_bits, const uint8_t *tch_data)
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0, j = 4; i < 244; i++, j++)
|
|
b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1;
|
|
}
|
|
|
|
/* assemble a AMR codec frame in format as used inside RTP */
|
|
static void tch_amr_reassemble(uint8_t *tch_data, const ubit_t *d_bits, int len)
|
|
{
|
|
int i, j;
|
|
|
|
memset(tch_data, 0, (len + 7) >> 3);
|
|
|
|
for (i = 0, j = 0; i < len; i++, j++)
|
|
tch_data[j >> 3] |= (d_bits[i] << (7 - (j & 7)));
|
|
}
|
|
|
|
static void tch_amr_disassemble(ubit_t *d_bits, const uint8_t *tch_data, int len)
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0, j = 0; i < len; i++, j++)
|
|
d_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1;
|
|
}
|
|
|
|
/* Append STI and MI bits to the SID_UPDATE frame, see also
|
|
* 3GPP TS 26.101, chapter 4.2.3 AMR Core Frame with comfort noise bits */
|
|
static void tch_amr_sid_update_append(ubit_t *sid_update, uint8_t sti, uint8_t mi)
|
|
{
|
|
/* Zero out the space that had been used by the CRC14 */
|
|
memset(sid_update + 35, 0, 14);
|
|
|
|
/* Append STI and MI parameters */
|
|
sid_update[35] = sti & 1;
|
|
sid_update[36] = mi & 1;
|
|
sid_update[37] = mi >> 1 & 1;
|
|
sid_update[38] = mi >> 2 & 1;
|
|
}
|
|
|
|
/* Extract a SID UPDATE fram the sbits of an FR AMR frame */
|
|
static void extract_afs_sid_update(sbit_t *sid_update, const sbit_t *sbits)
|
|
{
|
|
|
|
unsigned int i;
|
|
|
|
sbits += 32;
|
|
|
|
for (i = 0; i < 53; i++) {
|
|
sid_update[0] = sbits[0];
|
|
sid_update[1] = sbits[1];
|
|
sid_update[2] = sbits[2];
|
|
sid_update[3] = sbits[3];
|
|
sid_update += 4;
|
|
sbits += 8;
|
|
}
|
|
|
|
}
|
|
|
|
/* re-arrange according to TS 05.03 Table 2 (receiver) */
|
|
static void tch_fr_d_to_b(ubit_t *b_bits, const ubit_t *d_bits)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 260; i++)
|
|
b_bits[gsm610_bitorder[i]] = d_bits[i];
|
|
}
|
|
|
|
/* re-arrange according to TS 05.03 Table 2 (transmitter) */
|
|
static void tch_fr_b_to_d(ubit_t *d_bits, const ubit_t *b_bits)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 260; i++)
|
|
d_bits[i] = b_bits[gsm610_bitorder[i]];
|
|
}
|
|
|
|
/* re-arrange according to TS 05.03 Table 3a (receiver) */
|
|
static void tch_hr_d_to_b(ubit_t *b_bits, const ubit_t *d_bits)
|
|
{
|
|
int i;
|
|
|
|
const uint16_t *map;
|
|
|
|
if (!d_bits[93] && !d_bits[94])
|
|
map = gsm620_unvoiced_bitorder;
|
|
else
|
|
map = gsm620_voiced_bitorder;
|
|
|
|
for (i = 0; i < 112; i++)
|
|
b_bits[map[i]] = d_bits[i];
|
|
}
|
|
|
|
/* re-arrange according to TS 05.03 Table 3a (transmitter) */
|
|
static void tch_hr_b_to_d(ubit_t *d_bits, const ubit_t *b_bits)
|
|
{
|
|
int i;
|
|
const uint16_t *map;
|
|
|
|
if (!b_bits[34] && !b_bits[35])
|
|
map = gsm620_unvoiced_bitorder;
|
|
else
|
|
map = gsm620_voiced_bitorder;
|
|
|
|
for (i = 0; i < 112; i++)
|
|
d_bits[i] = b_bits[map[i]];
|
|
}
|
|
|
|
/* re-arrange according to TS 05.03 Table 6 (receiver) */
|
|
static void tch_efr_d_to_w(ubit_t *b_bits, const ubit_t *d_bits)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 260; i++)
|
|
b_bits[gsm660_bitorder[i]] = d_bits[i];
|
|
}
|
|
|
|
/* re-arrange according to TS 05.03 Table 6 (transmitter) */
|
|
static void tch_efr_w_to_d(ubit_t *d_bits, const ubit_t *b_bits)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 260; i++)
|
|
d_bits[i] = b_bits[gsm660_bitorder[i]];
|
|
}
|
|
|
|
/* extract the 65 protected class1a+1b bits */
|
|
static void tch_efr_protected(const ubit_t *s_bits, ubit_t *b_bits)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 65; i++)
|
|
b_bits[i] = s_bits[gsm0503_gsm_efr_protected_bits[i] - 1];
|
|
}
|
|
|
|
static void tch_fr_unreorder(ubit_t *d, ubit_t *p, const ubit_t *u)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 91; i++) {
|
|
d[i << 1] = u[i];
|
|
d[(i << 1) + 1] = u[184 - i];
|
|
}
|
|
|
|
for (i = 0; i < 3; i++)
|
|
p[i] = u[91 + i];
|
|
}
|
|
|
|
static void tch_fr_reorder(ubit_t *u, const ubit_t *d, const ubit_t *p)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 91; i++) {
|
|
u[i] = d[i << 1];
|
|
u[184 - i] = d[(i << 1) + 1];
|
|
}
|
|
|
|
for (i = 0; i < 3; i++)
|
|
u[91 + i] = p[i];
|
|
}
|
|
|
|
static void tch_hr_unreorder(ubit_t *d, ubit_t *p, const ubit_t *u)
|
|
{
|
|
memcpy(d, u, 95);
|
|
memcpy(p, u + 95, 3);
|
|
}
|
|
|
|
static void tch_hr_reorder(ubit_t *u, const ubit_t *d, const ubit_t *p)
|
|
{
|
|
memcpy(u, d, 95);
|
|
memcpy(u + 95, p, 3);
|
|
}
|
|
|
|
static void tch_efr_reorder(ubit_t *w, const ubit_t *s, const ubit_t *p)
|
|
{
|
|
memcpy(w, s, 71);
|
|
w[71] = w[72] = s[69];
|
|
memcpy(w + 73, s + 71, 50);
|
|
w[123] = w[124] = s[119];
|
|
memcpy(w + 125, s + 121, 53);
|
|
w[178] = w[179] = s[172];
|
|
memcpy(w + 180, s + 174, 50);
|
|
w[230] = w[231] = s[222];
|
|
memcpy(w + 232, s + 224, 20);
|
|
memcpy(w + 252, p, 8);
|
|
}
|
|
|
|
static void tch_efr_unreorder(ubit_t *s, ubit_t *p, const ubit_t *w)
|
|
{
|
|
int sum;
|
|
|
|
memcpy(s, w, 71);
|
|
sum = s[69] + w[71] + w[72];
|
|
s[69] = (sum >= 2);
|
|
memcpy(s + 71, w + 73, 50);
|
|
sum = s[119] + w[123] + w[124];
|
|
s[119] = (sum >= 2);
|
|
memcpy(s + 121, w + 125, 53);
|
|
sum = s[172] + w[178] + w[179];
|
|
s[172] = (sum >= 2);
|
|
memcpy(s + 174, w + 180, 50);
|
|
sum = s[222] + w[230] + w[231];
|
|
s[222] = (sum >= 2);
|
|
memcpy(s + 224, w + 232, 20);
|
|
memcpy(p, w + 252, 8);
|
|
}
|
|
|
|
static void tch_amr_merge(ubit_t *u, const ubit_t *d, const ubit_t *p, int len, int prot)
|
|
{
|
|
memcpy(u, d, prot);
|
|
memcpy(u + prot, p, 6);
|
|
memcpy(u + prot + 6, d + prot, len - prot);
|
|
}
|
|
|
|
static void tch_amr_unmerge(ubit_t *d, ubit_t *p, const ubit_t *u, int len, int prot)
|
|
{
|
|
memcpy(d, u, prot);
|
|
memcpy(p, u + prot, 6);
|
|
memcpy(d + prot, u + prot + 6, len - prot);
|
|
}
|
|
|
|
/*! Perform channel decoding of a FR/EFR channel according TS 05.03
|
|
* \param[out] tch_data Codec frame in RTP payload format
|
|
* \param[in] bursts buffer containing the symbols of 8 bursts
|
|
* \param[in] net_order FIXME
|
|
* \param[in] efr Is this channel using EFR (1) or FR (0)
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \returns length of bytes used in \a tch_data output buffer; negative on error */
|
|
int gsm0503_tch_fr_decode(uint8_t *tch_data, const sbit_t *bursts,
|
|
int net_order, int efr, int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[912], cB[456], h;
|
|
ubit_t conv[185], s[244], w[260], b[65], d[260], p[8];
|
|
int i, rv, len, steal = 0;
|
|
|
|
/* map from 8 bursts to interleaved data bits (iB) */
|
|
for (i = 0; i < 8; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114],
|
|
&bursts[i * 116], &h, i >> 2);
|
|
steal -= h;
|
|
}
|
|
/* we now have the bits of the four bursts (interface 4 in
|
|
* Figure 1a of TS 05.03 */
|
|
|
|
gsm0503_tch_fr_deinterleave(cB, iB);
|
|
/* we now have the coded bits c(B): interface 3 in Fig. 1a */
|
|
|
|
if (steal > 0) {
|
|
rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total);
|
|
if (rv) {
|
|
/* Error decoding FACCH frame */
|
|
return -1;
|
|
}
|
|
|
|
return GSM_MACBLOCK_LEN;
|
|
}
|
|
|
|
osmo_conv_decode_ber(&gsm0503_tch_fr, cB, conv, n_errors, n_bits_total);
|
|
/* we now have the data bits 'u': interface 2 in Fig. 1a */
|
|
|
|
/* input: 'conv', output: d[ata] + p[arity] */
|
|
tch_fr_unreorder(d, p, conv);
|
|
|
|
for (i = 0; i < 78; i++)
|
|
d[i + 182] = (cB[i + 378] < 0) ? 1 : 0;
|
|
|
|
/* check if parity of first 50 (class 1) 'd'-bits match 'p' */
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d, 50, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for the FR part of an EFR/FR frame */
|
|
return -1;
|
|
}
|
|
|
|
if (efr) {
|
|
tch_efr_d_to_w(w, d);
|
|
/* we now have the preliminary-coded bits w(k) */
|
|
|
|
tch_efr_unreorder(s, p, w);
|
|
/* we now have the data delivered to the preliminary
|
|
* channel encoding unit s(k) */
|
|
|
|
/* extract the 65 most important bits according TS 05.03 3.1.1.1 */
|
|
tch_efr_protected(s, b);
|
|
|
|
/* perform CRC-8 on 65 most important bits (50 bits of
|
|
* class 1a + 15 bits of class 1b) */
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_tch_efr_crc8, b, 65, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for the EFR part of an EFR frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_efr_reassemble(tch_data, s);
|
|
|
|
len = GSM_EFR_BYTES;
|
|
} else {
|
|
tch_fr_d_to_b(w, d);
|
|
|
|
tch_fr_reassemble(tch_data, w, net_order);
|
|
|
|
len = GSM_FR_BYTES;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
/*! Perform channel encoding on a TCH/FS channel according to TS 05.03
|
|
* \param[out] bursts caller-allocated output buffer for bursts bits
|
|
* \param[in] tch_data Codec input data in RTP payload format
|
|
* \param[in] len Length of \a tch_data in bytes
|
|
* \param[in] net_order FIXME
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_fr_encode(ubit_t *bursts, const uint8_t *tch_data,
|
|
int len, int net_order)
|
|
{
|
|
ubit_t iB[912], cB[456], h;
|
|
ubit_t conv[185], w[260], b[65], s[244], d[260], p[8];
|
|
int i;
|
|
|
|
switch (len) {
|
|
case GSM_EFR_BYTES: /* TCH EFR */
|
|
tch_efr_disassemble(s, tch_data);
|
|
tch_efr_protected(s, b);
|
|
osmo_crc8gen_set_bits(&gsm0503_tch_efr_crc8, b, 65, p);
|
|
tch_efr_reorder(w, s, p);
|
|
tch_efr_w_to_d(d, w);
|
|
goto coding_efr_fr;
|
|
case GSM_FR_BYTES: /* TCH FR */
|
|
tch_fr_disassemble(w, tch_data, net_order);
|
|
tch_fr_b_to_d(d, w);
|
|
coding_efr_fr:
|
|
osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d, 50, p);
|
|
tch_fr_reorder(conv, d, p);
|
|
memcpy(cB + 378, d + 182, 78);
|
|
osmo_conv_encode(&gsm0503_tch_fr, conv, cB);
|
|
h = 0;
|
|
break;
|
|
case 0: /* no data, induce BFI in the receiver */
|
|
/* Do the same thing that sysmoBTS PHY does when fed a 0-length
|
|
* payload for DL: set all u(k) bits to 0, and do the same
|
|
* with all class 2 bits. This operation is NOT the same as
|
|
* an FR codec frame of all zero bits: with all-zeros d(k) input
|
|
* the CRC3 function will produce 111 output, whereas we
|
|
* transmit 000 in those parity bits too. The result will be
|
|
* an induced BFI (bad frame indication) condition in the
|
|
* receiver, for both TCH/FS and TCH/EFS decoders. */
|
|
memset(conv, 0, sizeof(conv));
|
|
memset(cB + 378, 0, 78);
|
|
osmo_conv_encode(&gsm0503_tch_fr, conv, cB);
|
|
h = 0;
|
|
break;
|
|
case GSM_MACBLOCK_LEN: /* FACCH */
|
|
_xcch_encode_cB(cB, tch_data);
|
|
h = 1;
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
gsm0503_tch_fr_interleave(cB, iB);
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
gsm0503_tch_burst_map(&iB[i * 114],
|
|
&bursts[i * 116], &h, i >> 2);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Perform channel decoding of a HR(v1) channel according TS 05.03
|
|
* \param[out] tch_data Codec frame in TS 101 318 canonical format
|
|
* \param[in] bursts buffer containing the symbols of 6 bursts
|
|
* \param[in] odd Odd (1) or even (0) frame number
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \returns length of bytes used in \a tch_data output buffer; negative on error */
|
|
int gsm0503_tch_hr_decode2(uint8_t *tch_data, const sbit_t *bursts, int odd,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[912], cB[456], h;
|
|
ubit_t conv[98], b[112], d[112], p[3];
|
|
int i, rv, steal = 0;
|
|
|
|
/* Only unmap the stealing bits */
|
|
if (!odd) {
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0);
|
|
steal -= h;
|
|
}
|
|
|
|
for (i = 2; i < 6; i++) {
|
|
gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1);
|
|
steal -= h;
|
|
}
|
|
}
|
|
|
|
/* If we found a stole FACCH, but only at correct alignment */
|
|
if (steal > 0) {
|
|
for (i = 0; i < 6; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114],
|
|
&bursts[i * 116], NULL, i >> 2);
|
|
}
|
|
|
|
for (i = 2; i < 4; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114 + 456],
|
|
&bursts[i * 116], NULL, 1);
|
|
}
|
|
|
|
gsm0503_tch_fr_deinterleave(cB, iB);
|
|
|
|
rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total);
|
|
if (rv) {
|
|
/* Error decoding FACCH frame */
|
|
return -1;
|
|
}
|
|
|
|
return GSM_MACBLOCK_LEN;
|
|
}
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114],
|
|
&bursts[i * 116], NULL, i >> 1);
|
|
}
|
|
|
|
gsm0503_tch_hr_deinterleave(cB, iB);
|
|
|
|
osmo_conv_decode_ber(&gsm0503_tch_hr, cB, conv, n_errors, n_bits_total);
|
|
|
|
tch_hr_unreorder(d, p, conv);
|
|
|
|
for (i = 0; i < 17; i++)
|
|
d[i + 95] = (cB[i + 211] < 0) ? 1 : 0;
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an HR frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_hr_d_to_b(b, d);
|
|
|
|
tch_hr_reassemble(tch_data, b);
|
|
|
|
return GSM_HR_BYTES;
|
|
}
|
|
|
|
/*! Perform channel decoding of a HR(v1) channel according TS 05.03,
|
|
* deprecated legacy API.
|
|
* \param[out] tch_data Codec frame in pseudo-RFC5993 format
|
|
* \param[in] bursts buffer containing the symbols of 6 bursts
|
|
* \param[in] odd Odd (1) or even (0) frame number
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \returns length of bytes used in \a tch_data output buffer; negative on error
|
|
*
|
|
* The HR1 codec frame format returned by this function is pseudo-RFC5993,
|
|
* not true RFC 5993, as there is no SID classification being done
|
|
* and the FT bits in the ToC octet are always set to 0 - but this
|
|
* arguably-bogus format is the legacy public API.
|
|
*/
|
|
int gsm0503_tch_hr_decode(uint8_t *tch_data, const sbit_t *bursts, int odd,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
int rc;
|
|
|
|
rc = gsm0503_tch_hr_decode2(tch_data, bursts, odd, n_errors,
|
|
n_bits_total);
|
|
if (rc != GSM_HR_BYTES)
|
|
return rc;
|
|
memmove(tch_data + 1, tch_data, GSM_HR_BYTES);
|
|
tch_data[0] = 0x00; /* FT=0, note absence of SID classification */
|
|
return GSM_HR_BYTES_RTP_RFC5993;
|
|
}
|
|
|
|
/*! Perform channel encoding on a TCH/HS channel according to TS 05.03
|
|
* \param[out] bursts caller-allocated output buffer for bursts bits
|
|
* \param[in] tch_data Codec input data in RTP payload format
|
|
* \param[in] len Length of \a tch_data in bytes
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_hr_encode(ubit_t *bursts, const uint8_t *tch_data, int len)
|
|
{
|
|
ubit_t iB[912], cB[456], h;
|
|
ubit_t conv[98], b[112], d[112], p[3];
|
|
int i;
|
|
|
|
switch (len) {
|
|
case GSM_HR_BYTES_RTP_RFC5993: /* TCH HR with RFC 5993 prefix */
|
|
tch_data++;
|
|
/* fall-through */
|
|
case GSM_HR_BYTES: /* TCH HR in "pure" form */
|
|
tch_hr_disassemble(b, tch_data);
|
|
tch_hr_b_to_d(d, b);
|
|
osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p);
|
|
tch_hr_reorder(conv, d, p);
|
|
memcpy(cB + 211, d + 95, 17);
|
|
hr_conv_coding:
|
|
osmo_conv_encode(&gsm0503_tch_hr, conv, cB);
|
|
h = 0;
|
|
gsm0503_tch_hr_interleave(cB, iB);
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_tch_burst_map(&iB[i * 114],
|
|
&bursts[i * 116], &h, i >> 1);
|
|
}
|
|
break;
|
|
case 0: /* no data, induce BFI in the receiver */
|
|
/* see comments in gsm0503_tch_fr_encode() - same deal here */
|
|
memset(conv, 0, sizeof(conv));
|
|
memset(cB + 211, 0, 17);
|
|
goto hr_conv_coding;
|
|
case GSM_MACBLOCK_LEN: /* FACCH */
|
|
_xcch_encode_cB(cB, tch_data);
|
|
h = 1;
|
|
gsm0503_tch_fr_interleave(cB, iB);
|
|
for (i = 0; i < 6; i++) {
|
|
gsm0503_tch_burst_map(&iB[i * 114],
|
|
&bursts[i * 116], &h, i >> 2);
|
|
}
|
|
for (i = 2; i < 4; i++) {
|
|
gsm0503_tch_burst_map(&iB[i * 114 + 456],
|
|
&bursts[i * 116], &h, 1);
|
|
}
|
|
break;
|
|
default:
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* TCH/AFS: parse codec ID (CMI or CMC/CMR) from coded in-band data (16 bit) */
|
|
static uint8_t gsm0503_tch_afs_decode_inband(const sbit_t *cB)
|
|
{
|
|
unsigned int id = 0, best = 0;
|
|
unsigned int i, j, k;
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
/* FIXME: why not using remaining (16 - 8) soft-bits here? */
|
|
for (j = 0, k = 0; j < 8; j++)
|
|
k += abs(((int)gsm0503_afs_ic_sbit[i][j]) - ((int)cB[j]));
|
|
|
|
if (i == 0 || k < best) {
|
|
best = k;
|
|
id = i;
|
|
}
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/AFS channel according TS 05.03
|
|
* \param[out] tch_data Codec frame in RTP payload format
|
|
* \param[in] bursts buffer containing the symbols of 8 bursts
|
|
* \param[in] codec_mode_req is this CMR (1) or CMC (0)
|
|
* \param[in] codec array of active codecs (active codec set)
|
|
* \param[in] codecs number of codecs in \a codec
|
|
* \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise
|
|
* \param[out] cmr Output in \a codec_mode_req = 1
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3])
|
|
* codec out of range; negative on error
|
|
*/
|
|
int gsm0503_tch_afs_decode(uint8_t *tch_data, const sbit_t *bursts,
|
|
int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft,
|
|
uint8_t *cmr, int *n_errors, int *n_bits_total)
|
|
{
|
|
return gsm0503_tch_afs_decode_dtx(tch_data, bursts, codec_mode_req,
|
|
codec, codecs, ft, cmr, n_errors,
|
|
n_bits_total, NULL);
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/AFS channel according TS 05.03
|
|
* \param[out] tch_data Codec frame in RTP payload format
|
|
* \param[in] bursts buffer containing the symbols of 8 bursts
|
|
* \param[in] codec_mode_req is this CMR (1) or CMC (0)
|
|
* \param[in] codec array of active codecs (active codec set)
|
|
* \param[in] codecs number of codecs in \a codec
|
|
* \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise
|
|
* \param[out] cmr Output in \a codec_mode_req = 1
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \param[inout] dtx DTX frame type output, previous DTX frame type input
|
|
* \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3])
|
|
* codec out of range; negative on error
|
|
*/
|
|
int gsm0503_tch_afs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts,
|
|
int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft,
|
|
uint8_t *cmr, int *n_errors, int *n_bits_total, uint8_t *dtx)
|
|
{
|
|
sbit_t iB[912], cB[456], h;
|
|
ubit_t d[244], p[6], conv[250];
|
|
int i, rv, len, steal = 0, id = -1;
|
|
*n_errors = 0; *n_bits_total = 0;
|
|
static ubit_t sid_first_dummy[64] = { 0 };
|
|
sbit_t sid_update_enc[256];
|
|
|
|
for (i=0; i<8; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], &h, i >> 2);
|
|
steal -= h;
|
|
}
|
|
|
|
gsm0503_tch_fr_deinterleave(cB, iB);
|
|
|
|
if (steal > 0) {
|
|
/* If not NULL, dtx indicates type of previously decoded TCH/AFS frame.
|
|
* It's normally updated by gsm0503_detect_afs_dtx_frame2(), which is not
|
|
* reached in case of FACCH. Reset it here to avoid FACCH/F frames being
|
|
* misinterpreted as AMR's special DTX frames. */
|
|
if (dtx != NULL)
|
|
*dtx = AMR_OTHER;
|
|
rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total);
|
|
if (rv) {
|
|
/* Error decoding FACCH frame */
|
|
return -1;
|
|
}
|
|
|
|
return GSM_MACBLOCK_LEN;
|
|
}
|
|
|
|
/* Determine the DTX frame type (SID_UPDATE, ONSET etc...) */
|
|
if (dtx) {
|
|
const enum gsm0503_amr_dtx_frames dtx_prev = *dtx;
|
|
|
|
*dtx = gsm0503_detect_afs_dtx_frame2(n_errors, n_bits_total, &id, cB);
|
|
|
|
switch (*dtx) {
|
|
case AMR_OTHER:
|
|
/* NOTE: The AFS_SID_UPDATE frame is splitted into
|
|
* two half rate frames. If the id marker frame
|
|
* (AFS_SID_UPDATE) is detected the following frame
|
|
* contains the actual comfort noised data part of
|
|
* (AFS_SID_UPDATE_CN). */
|
|
if (dtx_prev != AFS_SID_UPDATE)
|
|
break;
|
|
/* TODO: parse CMI _and_ CMC/CMR (16 + 16 bit) */
|
|
*dtx = AFS_SID_UPDATE_CN;
|
|
|
|
extract_afs_sid_update(sid_update_enc, cB);
|
|
osmo_conv_decode_ber(&gsm0503_tch_axs_sid_update,
|
|
sid_update_enc, conv, n_errors,
|
|
n_bits_total);
|
|
rv = osmo_crc16gen_check_bits(&gsm0503_amr_crc14, conv,
|
|
35, conv + 35);
|
|
if (rv != 0) {
|
|
/* Error checking CRC14 for an AMR SID_UPDATE frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_sid_update_append(conv, 1,
|
|
(codec_mode_req) ? codec[*ft]
|
|
: codec[id > 0 ? id : 0]);
|
|
tch_amr_reassemble(tch_data, conv, 39);
|
|
len = 5;
|
|
goto out;
|
|
case AFS_SID_FIRST: /* TODO: parse CMI or CMC/CMR (16 bit) */
|
|
tch_amr_sid_update_append(sid_first_dummy, 0,
|
|
(codec_mode_req) ? codec[*ft]
|
|
: codec[id > 0 ? id : 0]);
|
|
tch_amr_reassemble(tch_data, sid_first_dummy, 39);
|
|
len = 5;
|
|
goto out;
|
|
case AFS_SID_UPDATE: /* TODO: parse CMI _and_ CMC/CMR (16 + 16 bit) */
|
|
case AFS_ONSET:
|
|
len = 0;
|
|
goto out;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Parse codec ID (CMI or CMC/CMR) and check if it fits into range of codecs */
|
|
if ((id = gsm0503_tch_afs_decode_inband(&cB[0])) >= codecs) {
|
|
/* Codec mode out of range, return id */
|
|
return id;
|
|
}
|
|
|
|
switch ((codec_mode_req) ? codec[*ft] : codec[id]) {
|
|
case 7: /* TCH/AFS12.2 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_12_2, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 244, 81);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 81, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 12.2 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 244);
|
|
|
|
len = 31;
|
|
|
|
break;
|
|
case 6: /* TCH/AFS10.2 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_10_2, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 204, 65);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 65, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 10.2 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 204);
|
|
|
|
len = 26;
|
|
|
|
break;
|
|
case 5: /* TCH/AFS7.95 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_7_95, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 159, 75);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 75, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 7.95 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 159);
|
|
|
|
len = 20;
|
|
|
|
break;
|
|
case 4: /* TCH/AFS7.4 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_7_4, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 148, 61);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 7.4 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 148);
|
|
|
|
len = 19;
|
|
|
|
break;
|
|
case 3: /* TCH/AFS6.7 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_6_7, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 134, 55);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 6.7 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 134);
|
|
|
|
len = 17;
|
|
|
|
break;
|
|
case 2: /* TCH/AFS5.9 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_5_9, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 118, 55);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 5.9 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 118);
|
|
|
|
len = 15;
|
|
|
|
break;
|
|
case 1: /* TCH/AFS5.15 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_5_15, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 103, 49);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 5.15 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 103);
|
|
|
|
len = 13;
|
|
|
|
break;
|
|
case 0: /* TCH/AFS4.75 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_afs_4_75, cB + 8,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 95, 39);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 4.75 frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_reassemble(tch_data, d, 95);
|
|
|
|
len = 12;
|
|
|
|
break;
|
|
default:
|
|
/* Unknown frame type */
|
|
*n_bits_total = 448;
|
|
*n_errors = *n_bits_total;
|
|
return -1;
|
|
}
|
|
|
|
out:
|
|
/* Change codec request / indication, if frame is valid */
|
|
if (id != -1) {
|
|
if (codec_mode_req)
|
|
*cmr = id;
|
|
else
|
|
*ft = id;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
/*! Perform channel encoding on a TCH/AFS channel according to TS 05.03
|
|
* \param[out] bursts caller-allocated output buffer for bursts bits
|
|
* \param[in] tch_data Codec input data in RTP payload format
|
|
* \param[in] len Length of \a tch_data in bytes or 0 to generate a bad frame
|
|
* \param[in] codec_mode_req Use CMR (1) or FT (0)
|
|
* \param[in] codec Array of codecs (active codec set)
|
|
* \param[in] codecs Number of entries in \a codec
|
|
* \param[in] ft Frame Type to be used for encoding (index to \a codec)
|
|
* \param[in] cmr Codec Mode Request (used in codec_mode_req = 1 only)
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_afs_encode(ubit_t *bursts, const uint8_t *tch_data, int len,
|
|
int codec_mode_req, const uint8_t *codec, int codecs, uint8_t ft,
|
|
uint8_t cmr)
|
|
{
|
|
ubit_t iB[912], cB[456], h;
|
|
ubit_t d[244], p[6], conv[250];
|
|
int i;
|
|
uint8_t id;
|
|
|
|
if (len == GSM_MACBLOCK_LEN) { /* FACCH */
|
|
_xcch_encode_cB(cB, tch_data);
|
|
|
|
h = 1;
|
|
|
|
goto facch;
|
|
}
|
|
|
|
h = 0;
|
|
|
|
id = codec_mode_req ? cmr : ft;
|
|
if (OSMO_UNLIKELY(id >= ARRAY_SIZE(gsm0503_afs_ic_ubit)))
|
|
return -1;
|
|
if (OSMO_UNLIKELY(ft >= codecs))
|
|
return -1;
|
|
|
|
switch (codec[ft]) {
|
|
case 7: /* TCH/AFS12.2 */
|
|
if (!len) {
|
|
/* No data, induce BFI in the receiver by inverted CRC bits.
|
|
* The data bit are all 0, so the correct parity bits would be 111111. */
|
|
memset(d, 0, 244);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 31)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 244);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 81, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 244, 81);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_12_2, conv, cB + 8);
|
|
|
|
break;
|
|
case 6: /* TCH/AFS10.2 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 204);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 26)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 204);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 65, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 204, 65);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_10_2, conv, cB + 8);
|
|
|
|
break;
|
|
case 5: /* TCH/AFS7.95 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 159);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 20)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 159);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 75, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 159, 75);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_7_95, conv, cB + 8);
|
|
|
|
break;
|
|
case 4: /* TCH/AFS7.4 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 148);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 19)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 148);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 148, 61);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_7_4, conv, cB + 8);
|
|
|
|
break;
|
|
case 3: /* TCH/AFS6.7 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 134);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 17)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 134);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 134, 55);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_6_7, conv, cB + 8);
|
|
|
|
break;
|
|
case 2: /* TCH/AFS5.9 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 118);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 15)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 118);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 118, 55);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_5_9, conv, cB + 8);
|
|
|
|
break;
|
|
case 1: /* TCH/AFS5.15 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 103);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 13)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 103);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 103, 49);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_5_15, conv, cB + 8);
|
|
|
|
break;
|
|
case 0: /* TCH/AFS4.75 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 95);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 12)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 95);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 95, 39);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_afs_4_75, conv, cB + 8);
|
|
|
|
break;
|
|
default:
|
|
/* FIXME: FT %ft is not supported */
|
|
return -1;
|
|
}
|
|
|
|
memcpy(cB, gsm0503_afs_ic_ubit[id], 8);
|
|
|
|
facch:
|
|
gsm0503_tch_fr_interleave(cB, iB);
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
gsm0503_tch_burst_map(&iB[i * 114],
|
|
&bursts[i * 116], &h, i >> 2);
|
|
}
|
|
|
|
return 0;
|
|
|
|
invalid_length:
|
|
/* FIXME: payload length %len does not comply with codec type %ft */
|
|
return -1;
|
|
}
|
|
|
|
/* TCH/AHS: parse codec ID (CMI or CMC/CMR) from coded in-band data (16 bit) */
|
|
static uint8_t gsm0503_tch_ahs_decode_inband(const sbit_t *cB)
|
|
{
|
|
unsigned int id = 0, best = 0;
|
|
unsigned int i, j, k;
|
|
|
|
for (i = 0, k = 0; i < 4; i++) {
|
|
/* FIXME: why not using remaining (16 - 4) soft-bits here? */
|
|
for (j = 0, k = 0; j < 4; j++)
|
|
k += abs(((int)gsm0503_ahs_ic_sbit[i][j]) - ((int)cB[j]));
|
|
|
|
if (i == 0 || k < best) {
|
|
best = k;
|
|
id = i;
|
|
}
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/AHS channel according TS 05.03
|
|
* \param[out] tch_data Codec frame in RTP payload format
|
|
* \param[in] bursts buffer containing the symbols of 6 bursts
|
|
* \param[in] odd Is this an odd (1) or even (0) frame number?
|
|
* \param[in] codec_mode_req is this CMR (1) or CMC (0)
|
|
* \param[in] codec array of active codecs (active codec set)
|
|
* \param[in] codecs number of codecs in \a codec
|
|
* \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise
|
|
* \param[out] cmr Output in \a codec_mode_req = 1
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3])
|
|
* codec out of range; negative on error
|
|
*/
|
|
int gsm0503_tch_ahs_decode(uint8_t *tch_data, const sbit_t *bursts, int odd,
|
|
int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft,
|
|
uint8_t *cmr, int *n_errors, int *n_bits_total)
|
|
{
|
|
return gsm0503_tch_ahs_decode_dtx(tch_data, bursts, odd, codec_mode_req,
|
|
codec, codecs, ft, cmr, n_errors,
|
|
n_bits_total, NULL);
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/AHS channel according TS 05.03
|
|
* \param[out] tch_data Codec frame in RTP payload format
|
|
* \param[in] bursts buffer containing the symbols of 6 bursts
|
|
* \param[in] odd Is this an odd (1) or even (0) frame number?
|
|
* \param[in] codec_mode_req is this CMR (1) or CMC (0)
|
|
* \param[in] codec array of active codecs (active codec set)
|
|
* \param[in] codecs number of codecs in \a codec
|
|
* \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise
|
|
* \param[out] cmr Output in \a codec_mode_req = 1
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \param[inout] dtx DTX frame type output, previous DTX frame type input
|
|
* \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3])
|
|
* codec out of range; negative on error
|
|
*/
|
|
int gsm0503_tch_ahs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, int odd,
|
|
int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft,
|
|
uint8_t *cmr, int *n_errors, int *n_bits_total, uint8_t *dtx)
|
|
{
|
|
sbit_t iB[912], cB[456], h;
|
|
ubit_t d[244], p[6], conv[135];
|
|
int i, rv, len, steal = 0, id = -1;
|
|
static ubit_t sid_first_dummy[64] = { 0 };
|
|
|
|
/* only unmap the stealing bits */
|
|
if (!odd) {
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0);
|
|
steal -= h;
|
|
}
|
|
for (i = 2; i < 5; i++) {
|
|
gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1);
|
|
steal -= h;
|
|
}
|
|
}
|
|
|
|
/* if we found a stole FACCH, but only at correct alignment */
|
|
if (steal > 0) {
|
|
/* If not NULL, dtx indicates type of previously decoded TCH/AHS frame.
|
|
* It's normally updated by gsm0503_detect_ahs_dtx_frame2(), which is not
|
|
* reached in case of FACCH. Reset it here to avoid FACCH/H frames being
|
|
* misinterpreted as AMR's special DTX frames. */
|
|
if (dtx != NULL)
|
|
*dtx = AMR_OTHER;
|
|
|
|
for (i = 0; i < 6; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114],
|
|
&bursts[i * 116], NULL, i >> 2);
|
|
}
|
|
|
|
for (i = 2; i < 4; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114 + 456],
|
|
&bursts[i * 116], NULL, 1);
|
|
}
|
|
|
|
gsm0503_tch_fr_deinterleave(cB, iB);
|
|
|
|
rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total);
|
|
if (rv) {
|
|
/* Error decoding FACCH frame */
|
|
return -1;
|
|
}
|
|
|
|
return GSM_MACBLOCK_LEN;
|
|
}
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
gsm0503_tch_burst_unmap(&iB[i * 114],
|
|
&bursts[i * 116], NULL, i >> 1);
|
|
}
|
|
|
|
gsm0503_tch_hr_deinterleave(cB, iB);
|
|
|
|
/* Determine the DTX frame type (SID_UPDATE, ONSET etc...) */
|
|
if (dtx) {
|
|
int n_bits_total_sid;
|
|
int n_errors_sid;
|
|
|
|
*dtx = gsm0503_detect_ahs_dtx_frame2(n_errors, n_bits_total, &id, cB);
|
|
/* TODO: detect and handle AHS_SID_UPDATE + AHS_SID_UPDATE_INH */
|
|
|
|
switch (*dtx) {
|
|
case AHS_SID_UPDATE: /* TODO: parse CMI _and_ CMC/CMR (16 + 16 bit) */
|
|
/* cB[] contains 16 bits of coded in-band data and 212 bits containing
|
|
* the identification marker. We need to unmap/deinterleave 114 odd
|
|
* bits from the last two blocks, 114 even bits from the first two
|
|
* blocks and combine them together. */
|
|
gsm0503_tch_burst_unmap(&iB[0 * 114], &bursts[2 * 116], NULL, 0);
|
|
gsm0503_tch_burst_unmap(&iB[1 * 114], &bursts[3 * 116], NULL, 0);
|
|
gsm0503_tch_burst_unmap(&iB[2 * 114], &bursts[0 * 116], NULL, 1);
|
|
gsm0503_tch_burst_unmap(&iB[3 * 114], &bursts[1 * 116], NULL, 1);
|
|
gsm0503_tch_hr_deinterleave(cB, iB);
|
|
|
|
/* cB[] is expected to contain 16 bits of coded in-band data and
|
|
* 212 bits containing the coded data (53 bits coded at 1/4 rate). */
|
|
*dtx = AHS_SID_UPDATE_CN;
|
|
|
|
osmo_conv_decode_ber(&gsm0503_tch_axs_sid_update,
|
|
cB + 16, conv, &n_errors_sid,
|
|
&n_bits_total_sid);
|
|
/* gsm0503_detect_ahs_dtx_frame2() calculates BER for the marker,
|
|
* osmo_conv_decode_ber() calculates BER for the coded data. */
|
|
if (n_errors != NULL)
|
|
*n_errors += n_errors_sid;
|
|
if (n_bits_total != NULL)
|
|
*n_bits_total += n_bits_total_sid;
|
|
rv = osmo_crc16gen_check_bits(&gsm0503_amr_crc14, conv,
|
|
35, conv + 35);
|
|
if (rv != 0) {
|
|
/* Error checking CRC14 for an AMR SID_UPDATE frame */
|
|
return -1;
|
|
}
|
|
|
|
tch_amr_sid_update_append(conv, 1,
|
|
(codec_mode_req) ? codec[*ft]
|
|
: codec[id > 0 ? id : 0]);
|
|
tch_amr_reassemble(tch_data, conv, 39);
|
|
len = 5;
|
|
goto out;
|
|
case AHS_SID_FIRST_P2:
|
|
tch_amr_sid_update_append(sid_first_dummy, 0,
|
|
(codec_mode_req) ? codec[*ft]
|
|
: codec[id > 0 ? id : 0]);
|
|
tch_amr_reassemble(tch_data, sid_first_dummy, 39);
|
|
len = 5;
|
|
goto out;
|
|
case AHS_ONSET:
|
|
case AHS_SID_FIRST_INH: /* TODO: parse CMI or CMC/CMR (16 bit) */
|
|
case AHS_SID_UPDATE_INH: /* TODO: parse CMI or CMC/CMR (16 bit) */
|
|
case AHS_SID_FIRST_P1: /* TODO: parse CMI or CMC/CMR (16 bit) */
|
|
len = 0;
|
|
goto out;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Parse codec ID (CMI or CMC/CMR) and check if it fits into range of codecs */
|
|
if ((id = gsm0503_tch_ahs_decode_inband(&cB[0])) >= codecs) {
|
|
/* Codec mode out of range, return id */
|
|
return id;
|
|
}
|
|
|
|
switch ((codec_mode_req) ? codec[*ft] : codec[id]) {
|
|
case 5: /* TCH/AHS7.95 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_ahs_7_95, cB + 4,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 123, 67);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 67, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 7.95 frame */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < 36; i++)
|
|
d[i + 123] = (cB[i + 192] < 0) ? 1 : 0;
|
|
|
|
tch_amr_reassemble(tch_data, d, 159);
|
|
|
|
len = 20;
|
|
|
|
break;
|
|
case 4: /* TCH/AHS7.4 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_ahs_7_4, cB + 4,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 120, 61);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 7.4 frame */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < 28; i++)
|
|
d[i + 120] = (cB[i + 200] < 0) ? 1 : 0;
|
|
|
|
tch_amr_reassemble(tch_data, d, 148);
|
|
|
|
len = 19;
|
|
|
|
break;
|
|
case 3: /* TCH/AHS6.7 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_ahs_6_7, cB + 4,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 110, 55);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 6.7 frame */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < 24; i++)
|
|
d[i + 110] = (cB[i + 204] < 0) ? 1 : 0;
|
|
|
|
tch_amr_reassemble(tch_data, d, 134);
|
|
|
|
len = 17;
|
|
|
|
break;
|
|
case 2: /* TCH/AHS5.9 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_ahs_5_9, cB + 4,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 102, 55);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 5.9 frame */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < 16; i++)
|
|
d[i + 102] = (cB[i + 212] < 0) ? 1 : 0;
|
|
|
|
tch_amr_reassemble(tch_data, d, 118);
|
|
|
|
len = 15;
|
|
|
|
break;
|
|
case 1: /* TCH/AHS5.15 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_ahs_5_15, cB + 4,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 91, 49);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 5.15 frame */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < 12; i++)
|
|
d[i + 91] = (cB[i + 216] < 0) ? 1 : 0;
|
|
|
|
tch_amr_reassemble(tch_data, d, 103);
|
|
|
|
len = 13;
|
|
|
|
break;
|
|
case 0: /* TCH/AHS4.75 */
|
|
osmo_conv_decode_ber(&gsm0503_tch_ahs_4_75, cB + 4,
|
|
conv, n_errors, n_bits_total);
|
|
|
|
tch_amr_unmerge(d, p, conv, 83, 39);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p);
|
|
if (rv) {
|
|
/* Error checking CRC8 for an AMR 4.75 frame */
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < 12; i++)
|
|
d[i + 83] = (cB[i + 216] < 0) ? 1 : 0;
|
|
|
|
tch_amr_reassemble(tch_data, d, 95);
|
|
|
|
len = 12;
|
|
|
|
break;
|
|
default:
|
|
/* Unknown frame type */
|
|
*n_bits_total = 159;
|
|
*n_errors = *n_bits_total;
|
|
return -1;
|
|
}
|
|
|
|
out:
|
|
/* Change codec request / indication, if frame is valid */
|
|
if (id != -1) {
|
|
if (codec_mode_req)
|
|
*cmr = id;
|
|
else
|
|
*ft = id;
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
/*! Perform channel encoding on a TCH/AHS channel according to TS 05.03
|
|
* \param[out] bursts caller-allocated output buffer for bursts bits
|
|
* \param[in] tch_data Codec input data in RTP payload format
|
|
* \param[in] len Length of \a tch_data in bytes or 0 to generate a bad frame
|
|
* \param[in] codec_mode_req Use CMR (1) or FT (0)
|
|
* \param[in] codec Array of codecs (active codec set)
|
|
* \param[in] codecs Number of entries in \a codec
|
|
* \param[in] ft Frame Type to be used for encoding (index to \a codec)
|
|
* \param[in] cmr Codec Mode Request (used in codec_mode_req = 1 only)
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_ahs_encode(ubit_t *bursts, const uint8_t *tch_data, int len,
|
|
int codec_mode_req, const uint8_t *codec, int codecs, uint8_t ft,
|
|
uint8_t cmr)
|
|
{
|
|
ubit_t iB[912], cB[456], h;
|
|
ubit_t d[244], p[6], conv[135];
|
|
int i;
|
|
uint8_t id;
|
|
|
|
if (len == GSM_MACBLOCK_LEN) { /* FACCH */
|
|
_xcch_encode_cB(cB, tch_data);
|
|
|
|
h = 1;
|
|
|
|
gsm0503_tch_fr_interleave(cB, iB);
|
|
|
|
for (i = 0; i < 6; i++)
|
|
gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116],
|
|
&h, i >> 2);
|
|
for (i = 2; i < 4; i++)
|
|
gsm0503_tch_burst_map(&iB[i * 114 + 456],
|
|
&bursts[i * 116], &h, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
h = 0;
|
|
|
|
id = codec_mode_req ? cmr : ft;
|
|
if (OSMO_UNLIKELY(id >= ARRAY_SIZE(gsm0503_ahs_ic_ubit)))
|
|
return -1;
|
|
if (OSMO_UNLIKELY(ft >= codecs))
|
|
return -1;
|
|
|
|
switch (codec[ft]) {
|
|
case 5: /* TCH/AHS7.95 */
|
|
if (!len) {
|
|
/* No data, induce BFI in the receiver by inverted CRC bits.
|
|
* The data bit are all 0, so the correct parity bits would be 111111. */
|
|
memset(d, 0, 159);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 20)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 159);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 67, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 123, 67);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_ahs_7_95, conv, cB + 4);
|
|
|
|
memcpy(cB + 192, d + 123, 36);
|
|
|
|
break;
|
|
case 4: /* TCH/AHS7.4 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 148);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 19)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 148);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 120, 61);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_ahs_7_4, conv, cB + 4);
|
|
|
|
memcpy(cB + 200, d + 120, 28);
|
|
|
|
break;
|
|
case 3: /* TCH/AHS6.7 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 134);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 17)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 134);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 110, 55);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_ahs_6_7, conv, cB + 4);
|
|
|
|
memcpy(cB + 204, d + 110, 24);
|
|
|
|
break;
|
|
case 2: /* TCH/AHS5.9 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 118);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 15)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 118);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 102, 55);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_ahs_5_9, conv, cB + 4);
|
|
|
|
memcpy(cB + 212, d + 102, 16);
|
|
|
|
break;
|
|
case 1: /* TCH/AHS5.15 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 103);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 13)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 103);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 91, 49);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_ahs_5_15, conv, cB + 4);
|
|
|
|
memcpy(cB + 216, d + 91, 12);
|
|
|
|
break;
|
|
case 0: /* TCH/AHS4.75 */
|
|
if (!len) {
|
|
/* See comment above. */
|
|
memset(d, 0, 95);
|
|
memset(p, 0, 6);
|
|
} else {
|
|
if (len != 12)
|
|
goto invalid_length;
|
|
|
|
tch_amr_disassemble(d, tch_data, 95);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p);
|
|
}
|
|
|
|
tch_amr_merge(conv, d, p, 83, 39);
|
|
|
|
osmo_conv_encode(&gsm0503_tch_ahs_4_75, conv, cB + 4);
|
|
|
|
memcpy(cB + 216, d + 83, 12);
|
|
|
|
break;
|
|
default:
|
|
/* FIXME: FT %ft is not supported */
|
|
return -1;
|
|
}
|
|
|
|
memcpy(cB, gsm0503_ahs_ic_ubit[id], 4);
|
|
|
|
gsm0503_tch_hr_interleave(cB, iB);
|
|
|
|
for (i = 0; i < 4; i++)
|
|
gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i >> 1);
|
|
|
|
return 0;
|
|
|
|
invalid_length:
|
|
/* FIXME: payload length %len does not comply with codec type %ft */
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* GSM RACH transcoding
|
|
*/
|
|
|
|
/*
|
|
* GSM RACH apply BSIC to parity
|
|
*
|
|
* p(j) = p(j) xor b(j) j = 0, ..., 5
|
|
* b(0) = MSB of PLMN colour code
|
|
* b(5) = LSB of BS colour code
|
|
*/
|
|
static inline void rach_apply_bsic(ubit_t *d, uint8_t bsic, uint8_t start)
|
|
{
|
|
int i;
|
|
|
|
/* Apply it */
|
|
for (i = 0; i < 6; i++)
|
|
d[start + i] ^= ((bsic >> (5 - i)) & 1);
|
|
}
|
|
|
|
static inline int16_t rach_decode_ber(const sbit_t *burst, uint8_t bsic, bool is_11bit,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
ubit_t conv[17];
|
|
uint8_t ra[2] = { 0 }, nbits = is_11bit ? 11 : 8;
|
|
int rv;
|
|
|
|
osmo_conv_decode_ber(is_11bit ? &gsm0503_rach_ext : &gsm0503_rach, burst, conv,
|
|
n_errors, n_bits_total);
|
|
|
|
rach_apply_bsic(conv, bsic, nbits);
|
|
|
|
rv = osmo_crc8gen_check_bits(&gsm0503_rach_crc6, conv, nbits, conv + nbits);
|
|
if (rv)
|
|
return -1;
|
|
|
|
osmo_ubit2pbit_ext(ra, 0, conv, 0, nbits, 1);
|
|
|
|
return is_11bit ? ((ra[0] << 3) | (ra[1] & 0x07)) : ra[0];
|
|
}
|
|
|
|
/*! Decode the Extended (11-bit) RACH according to 3GPP TS 45.003
|
|
* \param[out] ra output buffer for RACH data
|
|
* \param[in] burst Input burst data
|
|
* \param[in] bsic BSIC used in this cell
|
|
* \returns 0 on success; negative on error (e.g. CRC error) */
|
|
int gsm0503_rach_ext_decode(uint16_t *ra, const sbit_t *burst, uint8_t bsic)
|
|
{
|
|
int16_t r = rach_decode_ber(burst, bsic, true, NULL, NULL);
|
|
|
|
if (r < 0)
|
|
return r;
|
|
|
|
*ra = r;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Decode the (8-bit) RACH according to TS 05.03
|
|
* \param[out] ra output buffer for RACH data
|
|
* \param[in] burst Input burst data
|
|
* \param[in] bsic BSIC used in this cell
|
|
* \returns 0 on success; negative on error (e.g. CRC error) */
|
|
int gsm0503_rach_decode(uint8_t *ra, const sbit_t *burst, uint8_t bsic)
|
|
{
|
|
int16_t r = rach_decode_ber(burst, bsic, false, NULL, NULL);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
*ra = r;
|
|
return 0;
|
|
}
|
|
|
|
/*! Decode the Extended (11-bit) RACH according to 3GPP TS 45.003
|
|
* \param[out] ra output buffer for RACH data
|
|
* \param[in] burst Input burst data
|
|
* \param[in] bsic BSIC used in this cell
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \returns 0 on success; negative on error (e.g. CRC error) */
|
|
int gsm0503_rach_ext_decode_ber(uint16_t *ra, const sbit_t *burst, uint8_t bsic,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
int16_t r = rach_decode_ber(burst, bsic, true, n_errors, n_bits_total);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
*ra = r;
|
|
return 0;
|
|
}
|
|
|
|
/*! Decode the (8-bit) RACH according to TS 05.03
|
|
* \param[out] ra output buffer for RACH data
|
|
* \param[in] burst Input burst data
|
|
* \param[in] bsic BSIC used in this cell
|
|
* \param[out] n_errors Number of detected bit errors
|
|
* \param[out] n_bits_total Total number of bits
|
|
* \returns 0 on success; negative on error (e.g. CRC error) */
|
|
int gsm0503_rach_decode_ber(uint8_t *ra, const sbit_t *burst, uint8_t bsic,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
int16_t r = rach_decode_ber(burst, bsic, false, n_errors, n_bits_total);
|
|
|
|
if (r < 0)
|
|
return r;
|
|
|
|
*ra = r;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Encode the (8-bit) RACH according to TS 05.03
|
|
* \param[out] burst Caller-allocated output burst buffer
|
|
* \param[in] ra Input RACH data
|
|
* \param[in] bsic BSIC used in this cell
|
|
* \returns 0 on success; negative on error */
|
|
int gsm0503_rach_encode(ubit_t *burst, const uint8_t *ra, uint8_t bsic)
|
|
{
|
|
return gsm0503_rach_ext_encode(burst, *ra, bsic, false);
|
|
}
|
|
|
|
/*! Encode the Extended (11-bit) or regular (8-bit) RACH according to 3GPP TS 45.003
|
|
* \param[out] burst Caller-allocated output burst buffer
|
|
* \param[in] ra11 Input RACH data
|
|
* \param[in] bsic BSIC used in this cell
|
|
* \param[in] is_11bit whether given RA is 11 bit or not
|
|
* \returns 0 on success; negative on error */
|
|
int gsm0503_rach_ext_encode(ubit_t *burst, uint16_t ra11, uint8_t bsic, bool is_11bit)
|
|
{
|
|
ubit_t conv[17];
|
|
uint8_t ra[2] = { 0 }, nbits = 8;
|
|
|
|
if (is_11bit) {
|
|
ra[0] = (uint8_t) (ra11 >> 3);
|
|
ra[1] = (uint8_t) (ra11 & 0x07);
|
|
nbits = 11;
|
|
} else
|
|
ra[0] = (uint8_t)ra11;
|
|
|
|
osmo_pbit2ubit_ext(conv, 0, ra, 0, nbits, 1);
|
|
|
|
osmo_crc8gen_set_bits(&gsm0503_rach_crc6, conv, nbits, conv + nbits);
|
|
|
|
rach_apply_bsic(conv, bsic, nbits);
|
|
|
|
osmo_conv_encode(is_11bit ? &gsm0503_rach_ext : &gsm0503_rach, conv, burst);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* GSM SCH transcoding
|
|
*/
|
|
|
|
/*! Decode the SCH according to TS 05.03
|
|
* \param[out] sb_info output buffer for SCH data
|
|
* \param[in] burst Input burst data
|
|
* \returns 0 on success; negative on error (e.g. CRC error) */
|
|
int gsm0503_sch_decode(uint8_t *sb_info, const sbit_t *burst)
|
|
{
|
|
ubit_t conv[35];
|
|
int rv;
|
|
|
|
osmo_conv_decode(&gsm0503_sch, burst, conv);
|
|
|
|
rv = osmo_crc16gen_check_bits(&gsm0503_sch_crc10, conv, 25, conv + 25);
|
|
if (rv)
|
|
return -1;
|
|
|
|
osmo_ubit2pbit_ext(sb_info, 0, conv, 0, 25, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Encode the SCH according to TS 05.03
|
|
* \param[out] burst Caller-allocated output burst buffer
|
|
* \param[in] sb_info Input SCH data
|
|
* \returns 0 on success; negative on error */
|
|
int gsm0503_sch_encode(ubit_t *burst, const uint8_t *sb_info)
|
|
{
|
|
ubit_t conv[35];
|
|
|
|
osmo_pbit2ubit_ext(conv, 0, sb_info, 0, 25, 1);
|
|
|
|
osmo_crc16gen_set_bits(&gsm0503_sch_crc10, conv, 25, conv + 25);
|
|
|
|
osmo_conv_encode(&gsm0503_sch, conv, burst);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* GSM CSD transcoding
|
|
*/
|
|
|
|
static inline void _tch_csd_burst_map(ubit_t *burst, const ubit_t *iB)
|
|
{
|
|
unsigned int i;
|
|
|
|
/* hu(B): copy *even* numbered bits if not stolen by FACCH */
|
|
if (burst[58] == 0) {
|
|
for (i = 0; i < 57; i += 2)
|
|
burst[i] |= iB[i];
|
|
for (i = 58; i < 114; i += 2)
|
|
burst[i + 2] |= iB[i];
|
|
}
|
|
|
|
/* hl(B): copy *odd* numbered bits if not stolen by FACCH */
|
|
if (burst[57] == 0) {
|
|
for (i = 1; i < 57; i += 2)
|
|
burst[i] |= iB[i];
|
|
for (i = 57; i < 114; i += 2)
|
|
burst[i + 2] |= iB[i];
|
|
}
|
|
}
|
|
|
|
/*! Perform channel encoding of a TCH/F9.6 channel as per section 3.3.
|
|
* \param[out] bursts Caller-allocated buffer for symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[in] data Data to be encoded (240 unpacked bits).
|
|
* \returns 0 in case of success; negative on error. */
|
|
int gsm0503_tch_fr96_encode(ubit_t *bursts, const ubit_t *data)
|
|
{
|
|
ubit_t iB[22 * 114], cB[4 * 114];
|
|
ubit_t conv[4 * 60 + 4];
|
|
|
|
/* 3.3.2 Block code: b1(60) + b2(60) + b3(60) + b4(60) + pad(4) */
|
|
memcpy(&conv[0], &data[0], 4 * 60);
|
|
/* pad(4) is set to 0 by osmo_conv_encode() below */
|
|
|
|
/* 3.3.3 Convolutional encoder */
|
|
osmo_conv_encode(&gsm0503_tch_f96, &conv[0], &cB[0]);
|
|
|
|
/* 3.3.4 Interleaving */
|
|
memset(&iB[0], 0, sizeof(iB));
|
|
gsm0503_tch_f96_interleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.3.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 22; i++)
|
|
_tch_csd_burst_map(&bursts[i * 116], &iB[i * 114]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/F9.6 channel as per section 3.3.
|
|
* \param[out] data Caller-allocated buffer for decoded data (240 unpacked bits).
|
|
* \param[in] bursts Buffer containing the symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[out] n_errors Number of detected bit errors.
|
|
* \param[out] n_bits_total Total number of bits.
|
|
* \returns Number of unpacked bits used in the output buffer; negative on error. */
|
|
int gsm0503_tch_fr96_decode(ubit_t *data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[22 * 114], cB[4 * 114];
|
|
ubit_t conv[4 * 60 + 4];
|
|
|
|
/* 3.3.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 22; i++) {
|
|
memcpy(&iB[i * 114], &bursts[i * 116], 57);
|
|
memcpy(&iB[i * 114 + 57], &bursts[i * 116 + 59], 57);
|
|
}
|
|
|
|
/* 3.3.4 Interleaving */
|
|
gsm0503_tch_f96_deinterleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.3.3 Convolutional encoder */
|
|
osmo_conv_decode_ber(&gsm0503_tch_f96, &cB[0], &conv[0], n_errors, n_bits_total);
|
|
|
|
/* 3.3.2 Block code: b1(60) + b2(60) + b3(60) + b4(60) + pad(4) */
|
|
memcpy(&data[0], &conv[0], 4 * 60);
|
|
|
|
return 4 * 60;
|
|
}
|
|
|
|
/*! Perform channel encoding of a TCH/F4.8 channel as per section 3.4.
|
|
* \param[out] bursts Caller-allocated buffer for symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[in] data Data to be encoded (120 unpacked bits).
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_fr48_encode(ubit_t *bursts, const ubit_t *data)
|
|
{
|
|
ubit_t iB[22 * 114], cB[4 * 114];
|
|
ubit_t conv[2 * 60 + 32];
|
|
|
|
/* 3.4.2 Block code:
|
|
*
|
|
* Sixteen bits equal to 0 are added to the 60 information bits, the result
|
|
* being a block of 76 bits, {u(0),u(1),...,u(75)}, with:
|
|
*
|
|
* u(19k+p) = d(15k+p) for k = 0,1,2,3 and p = 0,1,...,14;
|
|
* u(19k+p) = 0 for k = 0,1,2,3 and p = 15,16,17,18.
|
|
*
|
|
* Two such blocks forming a block of 152 bits: u1 + u2. */
|
|
for (unsigned int k = 0; k < 2 * 4; k++) {
|
|
memcpy(&conv[19 * k], &data[15 * k], 15);
|
|
memset(&conv[19 * k + 15], 0, 4);
|
|
}
|
|
|
|
/* 3.4.3 Convolutional encoder */
|
|
osmo_conv_encode(&gsm0503_tch_f48, &conv[0], &cB[0]);
|
|
|
|
/* 3.4.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */
|
|
memset(&iB[0], 0, sizeof(iB));
|
|
gsm0503_tch_f96_interleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.4.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 22; i++)
|
|
_tch_csd_burst_map(&bursts[i * 116], &iB[i * 114]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/F4.8 channel as per section 3.4.
|
|
* \param[out] data Caller-allocated buffer for decoded data (120 unpacked bits).
|
|
* \param[in] bursts Buffer containing the symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[out] n_errors Number of detected bit errors.
|
|
* \param[out] n_bits_total Total number of bits.
|
|
* \returns Number of unpacked bits used in the output buffer; negative on error. */
|
|
int gsm0503_tch_fr48_decode(ubit_t *data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[22 * 114], cB[4 * 114];
|
|
ubit_t conv[2 * 60 + 32];
|
|
|
|
/* 3.4.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 22; i++) {
|
|
memcpy(&iB[i * 114], &bursts[i * 116], 57);
|
|
memcpy(&iB[i * 114 + 57], &bursts[i * 116 + 59], 57);
|
|
}
|
|
|
|
/* 3.4.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */
|
|
gsm0503_tch_f96_deinterleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.4.3 Convolutional encoder */
|
|
osmo_conv_decode_ber(&gsm0503_tch_f48, &cB[0], &conv[0], n_errors, n_bits_total);
|
|
|
|
/* 3.4.2 Block code:
|
|
*
|
|
* Sixteen bits equal to 0 are added to the 60 information bits, the result
|
|
* being a block of 76 bits, {u(0),u(1),...,u(75)}, with:
|
|
*
|
|
* u(19k+p) = d(15k+p) for k = 0,1,2,3 and p = 0,1,...,14;
|
|
* u(19k+p) = 0 for k = 0,1,2,3 and p = 15,16,17,18.
|
|
*
|
|
* Two such blocks forming a block of 152 bits: u1 + u2. */
|
|
for (unsigned int k = 0; k < 2 * 4; k++)
|
|
memcpy(&data[15 * k], &conv[19 * k], 15);
|
|
|
|
return 2 * 60;
|
|
}
|
|
|
|
/*! Perform channel encoding of a TCH/H4.8 channel as per section 3.5.
|
|
* The algorithm is identical to TCH/F9.6, so it's just a wrapper.
|
|
* \param[out] bursts Caller-allocated buffer for symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[in] data Data to be encoded (240 unpacked bits).
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_hr48_encode(ubit_t *bursts, const ubit_t *data)
|
|
{
|
|
return gsm0503_tch_fr96_encode(bursts, data);
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/H4.8 channel as per section 3.5.
|
|
* The algorithm is identical to TCH/F9.6, so it's just a wrapper.
|
|
* \param[out] data Caller-allocated buffer for decoded data (240 unpacked bits).
|
|
* \param[in] bursts Buffer containing the symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[out] n_errors Number of detected bit errors.
|
|
* \param[out] n_bits_total Total number of bits.
|
|
* \returns Number of unpacked bits used in the output buffer; negative on error. */
|
|
int gsm0503_tch_hr48_decode(ubit_t *data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
return gsm0503_tch_fr96_decode(data, bursts, n_errors, n_bits_total);
|
|
}
|
|
|
|
/*! Perform channel encoding of a TCH/F2.4 channel as per section 3.6.
|
|
* \param[out] bursts Caller-allocated buffer for symbols of 8 bursts,
|
|
* 8 * 2 * 58 == 928 bits total.
|
|
* \param[in] data Data to be encoded (72 unpacked bits).
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_fr24_encode(ubit_t *bursts, const ubit_t *data)
|
|
{
|
|
ubit_t iB[8 * 114], cB[4 * 114];
|
|
const ubit_t h = 0;
|
|
|
|
/* 3.6.{1-3} Block code and Convolutional encoder */
|
|
osmo_conv_encode(&gsm0503_tch_f24, &data[0], &cB[0]);
|
|
|
|
/* 3.6.4 Interleaving: as specified for the TCH/FS in subclause 3.1.3 */
|
|
gsm0503_tch_fr_interleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.6.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 8; i++)
|
|
gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i >> 2);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/F2.4 channel as per section 3.6.
|
|
* \param[out] data Caller-allocated buffer for decoded data (72 unpacked bits).
|
|
* \param[in] bursts Buffer containing the symbols of 8 bursts,
|
|
* 8 * 2 * 58 == 928 bits total.
|
|
* \param[out] n_errors Number of detected bit errors.
|
|
* \param[out] n_bits_total Total number of bits.
|
|
* \returns Number of unpacked bits used in the output buffer; negative on error. */
|
|
int gsm0503_tch_fr24_decode(ubit_t *data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[8 * 114], cB[4 * 114];
|
|
|
|
/* 3.6.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 8; i++)
|
|
gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, i >> 2);
|
|
|
|
/* 3.6.4 Interleaving: as specified for the TCH/FS in subclause 3.1.3 */
|
|
gsm0503_tch_fr_deinterleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.6.{1-3} Block code and Convolutional encoder */
|
|
osmo_conv_decode_ber(&gsm0503_tch_f24, &cB[0], &data[0], n_errors, n_bits_total);
|
|
|
|
return 72;
|
|
}
|
|
|
|
/*! Perform channel encoding of a TCH/H2.4 channel as per section 3.7.
|
|
* \param[out] bursts Caller-allocated buffer for symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[in] data Data to be encoded (144 unpacked bits).
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_hr24_encode(ubit_t *bursts, const ubit_t *data)
|
|
{
|
|
ubit_t iB[22 * 114], cB[4 * 114];
|
|
|
|
/* 3.7.{1-3} Block code and Convolutional encoder */
|
|
osmo_conv_encode(&gsm0503_tch_h24, &data[ 0], &cB[ 0]);
|
|
osmo_conv_encode(&gsm0503_tch_h24, &data[72], &cB[228]);
|
|
|
|
/* 3.7.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */
|
|
memset(&iB[0], 0, sizeof(iB));
|
|
gsm0503_tch_f96_interleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.7.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 22; i++)
|
|
_tch_csd_burst_map(&bursts[i * 116], &iB[i * 114]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Perform channel decoding of a TCH/H2.4 channel as per section 3.7.
|
|
* \param[out] data Caller-allocated buffer for decoded data (144 unpacked bits).
|
|
* \param[in] bursts Buffer containing the symbols of 22 bursts,
|
|
* 22 * 2 * 58 == 2552 bits total.
|
|
* \param[out] n_errors Number of detected bit errors.
|
|
* \param[out] n_bits_total Total number of bits.
|
|
* \returns Number of unpacked bits used in the output buffer; negative on error. */
|
|
int gsm0503_tch_hr24_decode(ubit_t *data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
int n_errors_l[2], n_bits_total_l[2];
|
|
sbit_t iB[22 * 114], cB[4 * 114];
|
|
|
|
/* 3.7.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
|
|
for (unsigned int i = 0; i < 22; i++) {
|
|
memcpy(&iB[i * 114], &bursts[i * 116], 57);
|
|
memcpy(&iB[i * 114 + 57], &bursts[i * 116 + 59], 57);
|
|
}
|
|
|
|
/* 3.7.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */
|
|
gsm0503_tch_f96_deinterleave(&cB[0], &iB[0]);
|
|
|
|
/* 3.7.{1-3} Block code and Convolutional encoder */
|
|
osmo_conv_decode_ber(&gsm0503_tch_h24, &cB[ 0], &data[ 0], &n_errors_l[0], &n_bits_total_l[0]);
|
|
osmo_conv_decode_ber(&gsm0503_tch_h24, &cB[228], &data[72], &n_errors_l[1], &n_bits_total_l[1]);
|
|
|
|
if (n_errors)
|
|
*n_errors = n_errors_l[0] + n_errors_l[1];
|
|
|
|
if (n_bits_total)
|
|
*n_bits_total = n_bits_total_l[0] + n_bits_total_l[1];
|
|
|
|
return 2 * 72;
|
|
}
|
|
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/*! Perform channel encoding of a TCH/F14.4 channel as per section 3.8.
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* \param[out] bursts Caller-allocated buffer for symbols of 22 bursts,
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* 22 * 2 * 58 == 2552 bits total.
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* \param[in] data Data to be encoded (290 unpacked bits).
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* \returns 0 in case of success; negative on error */
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int gsm0503_tch_fr144_encode(ubit_t *bursts, const ubit_t *data)
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{
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ubit_t iB[22 * 114], cB[4 * 114];
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ubit_t conv[290 + 4];
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/* 3.8.2 Block code: b(290) + pad(4) */
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memcpy(&conv[0], &data[0], 290);
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/* pad(4) is set to 0 by osmo_conv_encode() below */
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/* 3.8.3 Convolutional encoder */
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osmo_conv_encode(&gsm0503_tch_f144, &conv[0], &cB[0]);
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/* 3.8.4 Interleaving */
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memset(&iB[0], 0, sizeof(iB));
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gsm0503_tch_f96_interleave(&cB[0], &iB[0]);
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/* 3.8.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
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for (unsigned int i = 0; i < 22; i++)
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_tch_csd_burst_map(&bursts[i * 116], &iB[i * 114]);
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return 0;
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}
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/*! Perform channel decoding of a TCH/14.4 channel as per section 3.8.
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* \param[out] data Caller-allocated buffer for decoded data (290 unpacked bits).
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* \param[in] bursts Buffer containing the symbols of 22 bursts,
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* 22 * 2 * 58 == 2552 bits total.
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* \param[out] n_errors Number of detected bit errors.
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* \param[out] n_bits_total Total number of bits.
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* \returns Number of unpacked bits used in the output buffer; negative on error. */
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int gsm0503_tch_fr144_decode(ubit_t *data, const sbit_t *bursts,
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int *n_errors, int *n_bits_total)
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{
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sbit_t iB[22 * 114], cB[4 * 114];
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ubit_t conv[294];
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/* 3.8.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */
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for (unsigned int i = 0; i < 22; i++) {
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memcpy(&iB[i * 114], &bursts[i * 116], 57);
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memcpy(&iB[i * 114 + 57], &bursts[i * 116 + 59], 57);
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}
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/* 3.8.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */
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gsm0503_tch_f96_deinterleave(&cB[0], &iB[0]);
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/* 3.8.3 Convolutional encoder */
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osmo_conv_decode_ber(&gsm0503_tch_f144, &cB[0], &conv[0], n_errors, n_bits_total);
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/* 3.8.2 Block code: b(290) + pad(4) */
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memcpy(&data[0], &conv[0], 290);
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return 290;
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}
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/*
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* FACCH/[FH] transcoding
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*/
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/*! Perform channel encoding of a FACCH/F data as per section 4.2.
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* \param[out] bursts Caller-allocated buffer for symbols of 8 bursts,
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* 8 * 2 * 58 == 928 bits total.
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* \param[in] data FACCH MAC block to be encoded (GSM_MACBLOCK_LEN).
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* \returns 0 in case of success; negative on error */
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int gsm0503_tch_fr_facch_encode(ubit_t *bursts, const uint8_t *data)
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{
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ubit_t iB[8 * 114], cB[4 * 114];
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const ubit_t h = 1;
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/* 4.2.1-3 as specified for the SACCH in 4.1.1-3 */
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_xcch_encode_cB(&cB[0], &data[0]);
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/* 4.2.4 Interleaving: as specified for the TCH/FS in subclause 3.1.3 */
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gsm0503_tch_fr_interleave(&cB[0], &iB[0]);
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|
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/* 4.2.5 Mapping on a Burst:
|
|
* - hu(B)=1 the even numbered bits in the first 4 bursts and
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|
* - hl(B)=1 the odd numbered bits of the last 4 bursts are stolen. */
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for (unsigned int i = 0; i < 8; i++)
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gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i >> 2);
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return 0;
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}
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/*! Perform channel decoding of a FACCH/F data as per section 4.2.
|
|
* \param[out] data Caller-allocated buffer for decoded FACCH (GSM_MACBLOCK_LEN).
|
|
* \param[in] bursts Buffer containing the symbols of 8 bursts,
|
|
* 8 * 2 * 58 == 928 bits total.
|
|
* \param[out] n_errors Number of detected bit errors.
|
|
* \param[out] n_bits_total Total number of bits.
|
|
* \returns Number of bytes used in the output buffer; negative on error. */
|
|
int gsm0503_tch_fr_facch_decode(uint8_t *data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[8 * 114], cB[4 * 114];
|
|
int steal = 0;
|
|
|
|
/* FACCH decision: sum of 4 first hu(B) and 4 last hl(B) soft-bits */
|
|
for (unsigned int i = 0; i < 4; i++)
|
|
steal -= bursts[i * 116 + 58]; /* hu(B) */
|
|
for (unsigned int i = 4; i < 8; i++)
|
|
steal -= bursts[i * 116 + 57]; /* hl(B) */
|
|
if (steal <= 0)
|
|
return -1;
|
|
|
|
/* 4.2.5 Mapping on a Burst:
|
|
* - hu(B)=1 the even numbered bits in the first 4 bursts and
|
|
* - hl(B)=1 the odd numbered bits of the last 4 bursts are stolen. */
|
|
for (unsigned int i = 0; i < 8; i++)
|
|
gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, i >> 2);
|
|
|
|
/* 4.2.4 Interleaving: as specified for the TCH/FS in subclause 3.1.3 */
|
|
gsm0503_tch_fr_deinterleave(&cB[0], &iB[0]);
|
|
|
|
/* 4.2.1-3 as specified for the SACCH in 4.1.1-3 */
|
|
if (_xcch_decode_cB(&data[0], &cB[0], n_errors, n_bits_total) != 0)
|
|
return -1;
|
|
|
|
return GSM_MACBLOCK_LEN;
|
|
}
|
|
|
|
/*! Perform channel encoding of a FACCH/H data as per section 4.3.
|
|
* \param[out] bursts Caller-allocated buffer for symbols of 6 bursts,
|
|
* 6 * 2 * 58 == 696 bits total.
|
|
* \param[in] data FACCH MAC block to be encoded (GSM_MACBLOCK_LEN).
|
|
* \returns 0 in case of success; negative on error */
|
|
int gsm0503_tch_hr_facch_encode(ubit_t *bursts, const uint8_t *data)
|
|
{
|
|
ubit_t iB[8 * 114], cB[4 * 114];
|
|
const ubit_t h = 1;
|
|
|
|
/* 4.3.1-3 as specified for the SACCH in 4.1.1-3 */
|
|
_xcch_encode_cB(&cB[0], &data[0]);
|
|
|
|
/* 4.3.4 Interleaving */
|
|
gsm0503_tch_fr_interleave(&cB[0], &iB[0]);
|
|
|
|
/* 4.3.5 Mapping on a Burst:
|
|
* - hu(B)=1 the even numbered bits of the first 2 bursts,
|
|
* - hu(B)=1 & hl(B)=1 all bits of the middle 2 bursts and
|
|
* - hl(B)=1 the odd numbered bits of the last 2 bursts are stolen. */
|
|
for (unsigned int i = 0; i < 6; i++)
|
|
gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i >> 2);
|
|
for (unsigned int i = 2; i < 4; i++)
|
|
gsm0503_tch_burst_map(&iB[i * 114 + 456], &bursts[i * 116], &h, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Perform channel decoding of a FACCH/H data as per section 4.3.
|
|
* \param[out] data Caller-allocated buffer for decoded FACCH (GSM_MACBLOCK_LEN).
|
|
* \param[in] bursts Buffer containing the symbols of 6 bursts,
|
|
* 6 * 2 * 58 == 696 bits total.
|
|
* \param[out] n_errors Number of detected bit errors.
|
|
* \param[out] n_bits_total Total number of bits.
|
|
* \returns Number of bytes used in the output buffer; negative on error. */
|
|
int gsm0503_tch_hr_facch_decode(uint8_t *data, const sbit_t *bursts,
|
|
int *n_errors, int *n_bits_total)
|
|
{
|
|
sbit_t iB[8 * 114], cB[4 * 114];
|
|
int steal = 0;
|
|
|
|
/* FACCH decision: sum of 4 first hu(B) and 4 last hl(B) soft-bits */
|
|
for (unsigned int i = 0; i < 4; i++)
|
|
steal -= bursts[i * 116 + 58]; /* hu(B) */
|
|
for (unsigned int i = 2; i < 6; i++)
|
|
steal -= bursts[i * 116 + 57]; /* hl(B) */
|
|
if (steal <= 0)
|
|
return -1;
|
|
|
|
/* 4.3.5 Mapping on a Burst:
|
|
* - hu(B)=1 the even numbered bits of the first 2 bursts,
|
|
* - hu(B)=1 & hl(B)=1 all bits of the middle 2 bursts and
|
|
* - hl(B)=1 the odd numbered bits of the last 2 bursts are stolen. */
|
|
for (unsigned int i = 0; i < 6; i++)
|
|
gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, i >> 2);
|
|
for (unsigned int i = 2; i < 4; i++)
|
|
gsm0503_tch_burst_unmap(&iB[i * 114 + 456], &bursts[i * 116], NULL, 1);
|
|
|
|
/* 4.3.4 Interleaving */
|
|
gsm0503_tch_fr_deinterleave(&cB[0], &iB[0]);
|
|
|
|
/* 4.3.1-3 as specified for the SACCH in 4.1.1-3 */
|
|
if (_xcch_decode_cB(&data[0], &cB[0], n_errors, n_bits_total) != 0)
|
|
return -1;
|
|
|
|
return GSM_MACBLOCK_LEN;
|
|
}
|
|
|
|
/*! @} */
|