libosmocore/src/coding
Vadim Yanitskiy 9e713f3828 coding: fix bit ordering in 11-bit RACH coding functions
According to 3GPP TS 44.004, figure 7.4a.b, the format of 11-bit
RACH uplink / Uplink access burst block is as defined follows:

  <---------------------------------------------------

      8     7     6     5     4     3     2     1
  +--------------------------------------------------+
  |  11 bit RACH uplink / Uplink access burst block  | OCT1
  +--------------------------------------------------+
                                 |                   | OCT2
                                 +-------------------+

As was (correctly) assumed in [1], the bit ordering in 11-bit RACH
coding functions is wrong. The problem is that neither of generic
functions from bit16gen.h can be used to load / store the RA11
value (regardless of the endianness), because they assume that
the payload is 16 bit long.

With this patch applied, RA11 values from [1] look correct:

  < EGPRS Packet channel request message content > ::=
    < Signalling : 110011  < RandomBits : 00111 > > |
    < Signalling : 110011  < RandomBits : 00110 > > |
    < Signalling : 110011  < RandomBits : 01111 > > |
    < Signalling : 110011  < RandomBits : 01100 > > |
    < Signalling : 110011  < RandomBits : 00111 > > |
    < Signalling : 110011  < RandomBits : 10110 > > ;

[1] Id80e471d252b9416217b56f4c8c0a8f5f1289fee

Change-Id: I43d30611dd69f77f2b3b46f4b56056a8891d3c24
Related: OS#1548
2020-04-01 01:09:31 +07:00
..
Makefile.am osmo-release.sh: Drop whitespace after = when parsing LIBVERSION 2019-08-06 17:58:28 +02:00
gsm0503_coding.c coding: fix bit ordering in 11-bit RACH coding functions 2020-04-01 01:09:31 +07:00
gsm0503_interleaving.c Fix/Update copyright notices; Add SPDX annotation 2017-11-13 01:35:12 +09:00
gsm0503_mapping.c coding: move eB adjustement to appropriate place 2018-01-05 10:12:35 +00:00
gsm0503_parity.c parity: add amr crc14 definition 2020-03-09 13:40:27 +01:00
gsm0503_tables.c Fix/Update copyright notices; Add SPDX annotation 2017-11-13 01:35:12 +09:00
libosmocoding.map parity: add amr crc14 definition 2020-03-09 13:40:27 +01:00