109 lines
4.1 KiB
C
109 lines
4.1 KiB
C
/*
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* SpanDSP - a series of DSP components for telephony
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*
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* private/v17tx.h - ITU V.17 modem transmit part
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*
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* Written by Steve Underwood <steveu@coppice.org>
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*
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* Copyright (C) 2004 Steve Underwood
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*
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* All rights reserved.
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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 Lesser General Public License version 2.1,
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* as published by the Free Software Foundation.
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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 Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/*! \file */
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#if !defined(_SPANDSP_PRIVATE_V17TX_H_)
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#define _SPANDSP_PRIVATE_V17TX_H_
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/*! The number of taps in the pulse shaping/bandpass filter */
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#define V17_TX_FILTER_STEPS 9
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/*!
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V.17 modem transmit side descriptor. This defines the working state for a
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single instance of a V.17 modem transmitter.
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*/
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struct v17_tx_state_s
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{
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/*! \brief The bit rate of the modem. Valid values are 4800, 7200 and 9600. */
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int bit_rate;
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/*! \brief The callback function used to get the next bit to be transmitted. */
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get_bit_func_t get_bit;
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/*! \brief A user specified opaque pointer passed to the get_bit function. */
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void *get_bit_user_data;
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/*! \brief The callback function used to report modem status changes. */
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modem_status_func_t status_handler;
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/*! \brief A user specified opaque pointer passed to the status function. */
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void *status_user_data;
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#if defined(SPANDSP_USE_FIXED_POINT)
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/*! \brief The gain factor needed to achieve the specified output power. */
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int16_t gain;
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/*! \brief A pointer to the constellation currently in use. */
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const complexi16_t *constellation;
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/*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
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int16_t rrc_filter_re[V17_TX_FILTER_STEPS];
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int16_t rrc_filter_im[V17_TX_FILTER_STEPS];
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#else
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/*! \brief The gain factor needed to achieve the specified output power. */
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float gain;
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/*! \brief A pointer to the constellation currently in use. */
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const complexf_t *constellation;
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/*! \brief The root raised cosine (RRC) pulse shaping filter buffer. */
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float rrc_filter_re[V17_TX_FILTER_STEPS];
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float rrc_filter_im[V17_TX_FILTER_STEPS];
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#endif
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/*! \brief Current offset into the RRC pulse shaping filter buffer. */
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int rrc_filter_step;
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/*! \brief The current state of the differential encoder. */
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int diff;
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/*! \brief The current state of the convolutional encoder. */
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int convolution;
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/*! \brief The code number for the current position in the constellation. */
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int constellation_state;
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/*! \brief The register for the data scrambler. */
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uint32_t scramble_reg;
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/*! \brief Scrambler tap */
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int scrambler_tap;
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/*! \brief TRUE if transmitting the training sequence. FALSE if transmitting user data. */
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int in_training;
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/*! \brief TRUE if the short training sequence is to be used. */
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int short_train;
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/*! \brief A counter used to track progress through sending the training sequence. */
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int training_step;
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/*! \brief The current phase of the carrier (i.e. the DDS parameter). */
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uint32_t carrier_phase;
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/*! \brief The update rate for the phase of the carrier (i.e. the DDS increment). */
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int32_t carrier_phase_rate;
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/*! \brief The current fractional phase of the baud timing. */
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int baud_phase;
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/*! \brief The current number of data bits per symbol. This does not include
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the redundant bit. */
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int bits_per_symbol;
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/*! \brief The get_bit function in use at any instant. */
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get_bit_func_t current_get_bit;
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/*! \brief Error and flow logging control */
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logging_state_t logging;
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};
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#endif
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/*- End of file ------------------------------------------------------------*/
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