diff options
Diffstat (limited to 'lib/decoding/osmocom/coding/gsm0503_coding.c')
| -rw-r--r-- | lib/decoding/osmocom/coding/gsm0503_coding.c | 492 |
1 files changed, 401 insertions, 91 deletions
diff --git a/lib/decoding/osmocom/coding/gsm0503_coding.c b/lib/decoding/osmocom/coding/gsm0503_coding.c index afbba88..3812c9f 100644 --- a/lib/decoding/osmocom/coding/gsm0503_coding.c +++ b/lib/decoding/osmocom/coding/gsm0503_coding.c @@ -2,9 +2,12 @@ * (C) 2013 by Andreas Eversberg <jolly@eversberg.eu> * (C) 2015 by Alexander Chemeris <Alexander.Chemeris@fairwaves.co> * (C) 2016 by Tom Tsou <tom.tsou@ettus.com> + * (C) 2017 by Harald Welte <laforge@gnumonks.org> * * All Rights Reserved * + * SPDX-License-Identifier: GPL-2.0+ + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -24,31 +27,83 @@ #include <stdint.h> #include <string.h> #include <stdlib.h> - -#ifdef __cplusplus -extern "C" { -#endif +#include <errno.h> #include <osmocom/core/bits.h> #include <osmocom/core/conv.h> -#include <osmocom/core/utils.h> +//#include <osmocom/core/utils.h> #include <osmocom/core/crcgen.h> #include <osmocom/core/endian.h> -#include <osmocom/gsm/protocol/gsm_04_08.h> -#include "gsm0503.h" +//#include <osmocom/gsm/protocol/gsm_04_08.h> +#include <osmocom/gprs/protocol/gsm_04_60.h> +#include <osmocom/gprs/gprs_rlc.h> + +#include <osmocom/gsm/gsm0503.h> #include <osmocom/codec/codec.h> -#include "gsm0503_interleaving.h" -#include "gsm0503_mapping.h" -#include "gsm0503_tables.h" -#include "gsm0503_coding.h" -#include "gsm0503_parity.h" +#include <osmocom/coding/gsm0503_interleaving.h> +#include <osmocom/coding/gsm0503_mapping.h> +#include <osmocom/coding/gsm0503_tables.h> +#include <osmocom/coding/gsm0503_coding.h> +#include <osmocom/coding/gsm0503_parity.h> + +/*! \mainpage libosmocoding Documentation + * + * \section sec_intro Introduction + * This library is a collection of definitions, tables and functions + * implementing the GSM/GPRS/EGPRS channel coding (and decoding) as + * specified in 3GPP TS 05.03 / 45.003. + * + * libosmocoding is developed as part of the Osmocom (Open Source Mobile + * Communications) project, a community-based, collaborative development + * project to create Free and Open Source implementations of mobile + * communications systems. For more information about Osmocom, please + * see https://osmocom.org/ + * + * \section sec_copyright Copyright and License + * Copyright © 2013 by Andreas Eversberg\n + * Copyright © 2015 by Alexander Chemeris\n + * Copyright © 2016 by Tom Tsou\n + * Documentation Copyright © 2017 by Harald Welte\n + * All rights reserved. \n\n + * The source code of libosmocoding is licensed under the terms of the GNU + * General Public License as published by the Free Software Foundation; + * either version 2 of the License, or (at your option) any later + * version.\n + * See <http://www.gnu.org/licenses/> or COPYING included in the source + * code package istelf.\n + * The information detailed here is provided AS IS with NO WARRANTY OF + * ANY KIND, INCLUDING THE WARRANTY OF DESIGN, MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. + * \n\n + * + * \section sec_tracker Homepage + Issue Tracker + * libosmocoding is distributed as part of libosmocore and shares its + * project page at http://osmocom.org/projects/libosmocore + * + * An Issue Tracker can be found at + * https://osmocom.org/projects/libosmocore/issues + * + * \section sec_contact Contact and Support + * Community-based support is available at the OpenBSC mailing list + * <http://lists.osmocom.org/mailman/listinfo/openbsc>\n + * Commercial support options available upon request from + * <http://sysmocom.de/> + */ -#ifdef __cplusplus -} -#endif +/*! \addtogroup coding + * @{ + * + * GSM TS 05.03 coding + * + * This module is the "master module" of libosmocoding. It uses the + * various other modules (mapping, parity, interleaving) in order to + * implement the complete channel coding (and decoding) chain for the + * various channel types as defined in TS 05.03 / 45.003. + * + * \file gsm0503_coding.c */ /* * EGPRS coding limits @@ -76,29 +131,49 @@ extern "C" { #define EGPRS_DATA_C1 612 #define EGPRS_DATA_C2 EGPRS_DATA_C1 -/* TS 101318 Chapter 5.1: 260 bits + 4bit sig */ -#define GSM_FR_BYTES 33 -/* TS 101318 Chapter 5.2: 112 bits, no sig */ -#define GSM_HR_BYTES 14 -/* TS 101318 Chapter 5.3: 244 bits + 4bit sig */ -#define GSM_EFR_BYTES 31 +/*! union across the three different EGPRS Uplink header types */ +union gprs_rlc_ul_hdr_egprs { + struct gprs_rlc_ul_header_egprs_1 type1; + struct gprs_rlc_ul_header_egprs_2 type2; + struct gprs_rlc_ul_header_egprs_3 type3; +}; + +/*! union across the three different EGPRS Downlink header types */ +union gprs_rlc_dl_hdr_egprs { + struct gprs_rlc_dl_header_egprs_1 type1; + struct gprs_rlc_dl_header_egprs_2 type2; + struct gprs_rlc_dl_header_egprs_3 type3; +}; +/*! Structure describing a Modulation and Coding Scheme */ struct gsm0503_mcs_code { + /*! Modulation and Coding Scheme (MSC) number */ uint8_t mcs; + /*! Length of Uplink Stealing Flag (USF) in bits */ uint8_t usf_len; /* Header coding */ + /*! Length of header (bits) */ uint8_t hdr_len; + /*! Length of header convolutional code */ uint8_t hdr_code_len; + /*! Length of header code puncturing sequence */ uint8_t hdr_punc_len; + /*! header convolutional code */ const struct osmo_conv_code *hdr_conv; + /*! header puncturing sequence */ const uint8_t *hdr_punc; /* Data coding */ + /*! length of data (bits) */ uint16_t data_len; + /*! length of data convolutional code */ uint16_t data_code_len; + /*! length of data code puncturing sequence */ uint16_t data_punc_len; + /*! data convolutional code */ const struct osmo_conv_code *data_conv; + /*! data puncturing sequences */ const uint8_t *data_punc[3]; }; @@ -113,7 +188,7 @@ static int osmo_conv_decode_ber(const struct osmo_conv_code *code, if (n_bits_total || n_errors) { coded_len = osmo_conv_encode(code, output, recoded); - OSMO_ASSERT(sizeof(recoded) / sizeof(recoded[0]) >= coded_len); + //OSMO_ASSERT(sizeof(recoded) / sizeof(recoded[0]) >= coded_len); } /* Count bit errors */ @@ -132,7 +207,13 @@ static int osmo_conv_decode_ber(const struct osmo_conv_code *code, return res; } -static int _xcch_decode_cB(uint8_t *l2_data, sbit_t *cB, +/*! 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]; @@ -151,7 +232,11 @@ static int _xcch_decode_cB(uint8_t *l2_data, sbit_t *cB, return 0; } -static int _xcch_encode_cB(ubit_t *cB, uint8_t *l2_data) +/*! 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[out] 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]; @@ -167,7 +252,14 @@ static int _xcch_encode_cB(ubit_t *cB, uint8_t *l2_data) /* * GSM xCCH block transcoding */ -int gsm0503_xcch_decode(uint8_t *l2_data, sbit_t *bursts, + +/*! 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]; @@ -181,7 +273,12 @@ int gsm0503_xcch_decode(uint8_t *l2_data, sbit_t *bursts, return _xcch_decode_cB(l2_data, cB, n_errors, n_bits_total); } -int gsm0503_xcch_encode(ubit_t *bursts, uint8_t *l2_data) +/*! 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; @@ -202,7 +299,14 @@ int gsm0503_xcch_encode(ubit_t *bursts, uint8_t *l2_data) * GSM PDTCH block transcoding */ -int gsm0503_pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p, +/*! 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 stealing flag + * \param[out] n_errors number of detected bit-errors + * \param[out] n_bits_total total number of dcoded bits + * \returns 0 on success; 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]; @@ -219,7 +323,7 @@ int gsm0503_pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p, if (i == 0 || k < best) { best = k; - cs = i+1; + cs = i + 1; } } @@ -246,7 +350,7 @@ int gsm0503_pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p, cB[i] = 0; } - osmo_conv_decode_ber(&gsm0503_cs2, cB, + osmo_conv_decode_ber(&gsm0503_cs2_np, cB, conv, n_errors, n_bits_total); for (i = 0; i < 8; i++) { @@ -281,7 +385,7 @@ int gsm0503_pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p, cB[i] = 0; } - osmo_conv_decode_ber(&gsm0503_cs3, cB, + osmo_conv_decode_ber(&gsm0503_cs3_np, cB, conv, n_errors, n_bits_total); for (i = 0; i < 8; i++) { @@ -351,7 +455,13 @@ int gsm0503_pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p, return -1; } -int gsm0503_pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len) + +/*! 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 0 on success; 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; @@ -378,7 +488,7 @@ int gsm0503_pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len) memcpy(conv, gsm0503_usf2six[usf], 6); - osmo_conv_encode(&gsm0503_cs2, conv, cB); + osmo_conv_encode(&gsm0503_cs2_np, conv, cB); for (i = 0, j = 0; i < 588; i++) if (!gsm0503_puncture_cs2[i]) @@ -396,7 +506,7 @@ int gsm0503_pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len) memcpy(conv, gsm0503_usf2six[usf], 6); - osmo_conv_encode(&gsm0503_cs3, conv, cB); + osmo_conv_encode(&gsm0503_cs3_np, conv, cB); for (i = 0, j = 0; i < 676; i++) if (!gsm0503_puncture_cs3[i]) @@ -435,8 +545,12 @@ int gsm0503_pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len) * 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, - ubit_t *b_bits, int net_order) + const ubit_t *b_bits, int net_order) { int i, j, k, l, o; @@ -468,7 +582,7 @@ static void tch_fr_reassemble(uint8_t *tch_data, } static void tch_fr_disassemble(ubit_t *b_bits, - uint8_t *tch_data, int net_order) + const uint8_t *tch_data, int net_order) { int i, j, k, l, o; @@ -495,7 +609,8 @@ static void tch_fr_disassemble(ubit_t *b_bits, } } -static void tch_hr_reassemble(uint8_t *tch_data, ubit_t *b_bits) +/* assemble a HR codec frame in format as used inside RTP */ +static void tch_hr_reassemble(uint8_t *tch_data, const ubit_t *b_bits) { int i, j; @@ -506,7 +621,7 @@ static void tch_hr_reassemble(uint8_t *tch_data, ubit_t *b_bits) tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); } -static void tch_hr_disassemble(ubit_t *b_bits, uint8_t *tch_data) +static void tch_hr_disassemble(ubit_t *b_bits, const uint8_t *tch_data) { int i, j; @@ -514,7 +629,8 @@ static void tch_hr_disassemble(ubit_t *b_bits, uint8_t *tch_data) b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; } -static void tch_efr_reassemble(uint8_t *tch_data, ubit_t *b_bits) +/* 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; @@ -525,7 +641,7 @@ static void tch_efr_reassemble(uint8_t *tch_data, ubit_t *b_bits) tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); } -static void tch_efr_disassemble(ubit_t *b_bits, uint8_t *tch_data) +static void tch_efr_disassemble(ubit_t *b_bits, const uint8_t *tch_data) { int i, j; @@ -533,7 +649,8 @@ static void tch_efr_disassemble(ubit_t *b_bits, uint8_t *tch_data) b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; } -static void tch_amr_reassemble(uint8_t *tch_data, ubit_t *d_bits, int len) +/* 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; @@ -543,7 +660,7 @@ static void tch_amr_reassemble(uint8_t *tch_data, ubit_t *d_bits, int len) tch_data[j >> 3] |= (d_bits[i] << (7 - (j & 7))); } -static void tch_amr_disassemble(ubit_t *d_bits, uint8_t *tch_data, int len) +static void tch_amr_disassemble(ubit_t *d_bits, const uint8_t *tch_data, int len) { int i, j; @@ -551,7 +668,8 @@ static void tch_amr_disassemble(ubit_t *d_bits, uint8_t *tch_data, int len) d_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; } -static void tch_fr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) +/* 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; @@ -559,7 +677,8 @@ static void tch_fr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) b_bits[gsm610_bitorder[i]] = d_bits[i]; } -static void tch_fr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) +/* 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; @@ -567,7 +686,8 @@ static void tch_fr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) d_bits[i] = b_bits[gsm610_bitorder[i]]; } -static void tch_hr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) +/* 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; @@ -582,7 +702,8 @@ static void tch_hr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) b_bits[map[i]] = d_bits[i]; } -static void tch_hr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) +/* 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; @@ -596,7 +717,8 @@ static void tch_hr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) d_bits[i] = b_bits[map[i]]; } -static void tch_efr_d_to_w(ubit_t *b_bits, ubit_t *d_bits) +/* 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; @@ -604,7 +726,8 @@ static void tch_efr_d_to_w(ubit_t *b_bits, ubit_t *d_bits) b_bits[gsm660_bitorder[i]] = d_bits[i]; } -static void tch_efr_w_to_d(ubit_t *d_bits, ubit_t *b_bits) +/* 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; @@ -612,7 +735,8 @@ static void tch_efr_w_to_d(ubit_t *d_bits, ubit_t *b_bits) d_bits[i] = b_bits[gsm660_bitorder[i]]; } -static void tch_efr_protected(ubit_t *s_bits, ubit_t *b_bits) +/* extract the 65 protected class1a+1b bits */ +static void tch_efr_protected(const ubit_t *s_bits, ubit_t *b_bits) { int i; @@ -620,7 +744,7 @@ static void tch_efr_protected(ubit_t *s_bits, ubit_t *b_bits) b_bits[i] = s_bits[gsm0503_gsm_efr_protected_bits[i] - 1]; } -static void tch_fr_unreorder(ubit_t *d, ubit_t *p, ubit_t *u) +static void tch_fr_unreorder(ubit_t *d, ubit_t *p, const ubit_t *u) { int i; @@ -633,7 +757,7 @@ static void tch_fr_unreorder(ubit_t *d, ubit_t *p, ubit_t *u) p[i] = u[91 + i]; } -static void tch_fr_reorder(ubit_t *u, ubit_t *d, ubit_t *p) +static void tch_fr_reorder(ubit_t *u, const ubit_t *d, const ubit_t *p) { int i; @@ -646,19 +770,19 @@ static void tch_fr_reorder(ubit_t *u, ubit_t *d, ubit_t *p) u[91 + i] = p[i]; } -static void tch_hr_unreorder(ubit_t *d, ubit_t *p, ubit_t *u) +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, ubit_t *d, ubit_t *p) +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, ubit_t *s, ubit_t *p) +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]; @@ -672,55 +796,66 @@ static void tch_efr_reorder(ubit_t *w, ubit_t *s, ubit_t *p) memcpy(w + 252, p, 8); } -static void tch_efr_unreorder(ubit_t *s, ubit_t *p, ubit_t *w) +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); + s[69] = (sum >= 2); memcpy(s + 71, w + 73, 50); sum = s[119] + w[123] + w[124]; - s[119] = (sum > 2); + 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[220] + w[230] + w[231]; - s[222] = (sum > 2); + 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, ubit_t *d, ubit_t *p, int len, int prot) +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, - ubit_t *u, int len, int 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(p, u + prot, 6); memcpy(d + prot, u + prot + 6, len - prot); } -int gsm0503_tch_fr_decode(uint8_t *tch_data, sbit_t *bursts, +/*! 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 */ +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; - for (i=0; i<8; i++) { + /* 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); @@ -733,12 +868,15 @@ int gsm0503_tch_fr_decode(uint8_t *tch_data, sbit_t *bursts, } 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 */ @@ -747,11 +885,17 @@ int gsm0503_tch_fr_decode(uint8_t *tch_data, sbit_t *bursts, 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 */ @@ -772,7 +916,13 @@ int gsm0503_tch_fr_decode(uint8_t *tch_data, sbit_t *bursts, return len; } -int gsm0503_tch_fr_encode(ubit_t *bursts, uint8_t *tch_data, +/*! 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; @@ -830,7 +980,14 @@ coding_efr_fr: return 0; } -int gsm0503_tch_hr_decode(uint8_t *tch_data, sbit_t *bursts, int odd, +/*! Perform channel decoding of a HR(v1) 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] 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 */ +int gsm0503_tch_hr_decode(uint8_t *tch_data, const sbit_t *bursts, int odd, int *n_errors, int *n_bits_total) { sbit_t iB[912], cB[456], h; @@ -900,7 +1057,12 @@ int gsm0503_tch_hr_decode(uint8_t *tch_data, sbit_t *bursts, int odd, return 15; } -int gsm0503_tch_hr_encode(ubit_t *bursts, uint8_t *tch_data, int len) +/*! 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]; @@ -937,12 +1099,12 @@ int gsm0503_tch_hr_encode(ubit_t *bursts, uint8_t *tch_data, int len) gsm0503_tch_fr_interleave(cB, iB); - for (i=0; i<6; i++) { + 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++) { + for (i = 2; i < 4; i++) { gsm0503_tch_burst_map(&iB[i * 114 + 456], &bursts[i * 116], &h, 1); } @@ -955,7 +1117,18 @@ int gsm0503_tch_hr_encode(ubit_t *bursts, uint8_t *tch_data, int len) return 0; } -int gsm0503_tch_afs_decode(uint8_t *tch_data, sbit_t *bursts, +/*! 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 length of bytes used in \a tch_data output buffer */ +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) { @@ -1150,7 +1323,17 @@ int gsm0503_tch_afs_decode(uint8_t *tch_data, sbit_t *bursts, return len; } -int gsm0503_tch_afs_encode(ubit_t *bursts, uint8_t *tch_data, int 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 + * \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, uint8_t *codec, int codecs, uint8_t ft, uint8_t cmr) { @@ -1310,7 +1493,19 @@ invalid_length: return -1; } -int gsm0503_tch_ahs_decode(uint8_t *tch_data, sbit_t *bursts, int odd, +/*! 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] 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 length of bytes used in \a tch_data output buffer */ +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) { @@ -1513,7 +1708,17 @@ int gsm0503_tch_ahs_decode(uint8_t *tch_data, sbit_t *bursts, int odd, return len; } -int gsm0503_tch_ahs_encode(ubit_t *bursts, uint8_t *tch_data, int 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 + * \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, uint8_t *codec, int codecs, uint8_t ft, uint8_t cmr) { @@ -1676,46 +1881,140 @@ invalid_length: * b(0) = MSB of PLMN colour code * b(5) = LSB of BS colour code */ -static int rach_apply_bsic(ubit_t *d, uint8_t bsic) +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[8 + i] ^= ((bsic >> (5 - i)) & 1); - - return 0; + d[start + i] ^= ((bsic >> (5 - i)) & 1); } -int gsm0503_rach_decode(uint8_t *ra, sbit_t *burst, uint8_t bsic) +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[14]; + ubit_t conv[17]; + uint8_t ra[2] = { 0 }, nbits = is_11bit ? 11 : 8; int rv; - osmo_conv_decode(&gsm0503_rach, burst, conv); + osmo_conv_decode_ber(is_11bit ? &gsm0503_rach_ext : &gsm0503_rach, burst, conv, + n_errors, n_bits_total); - rach_apply_bsic(conv, bsic); + rach_apply_bsic(conv, bsic, nbits); - rv = osmo_crc8gen_check_bits(&gsm0503_rach_crc6, conv, 8, conv + 8); + rv = osmo_crc8gen_check_bits(&gsm0503_rach_crc6, conv, nbits, conv + nbits); if (rv) return -1; - osmo_ubit2pbit_ext(ra, 0, conv, 0, 8, 1); + osmo_ubit2pbit_ext(ra, 0, conv, 0, nbits, 1); + + return is_11bit ? osmo_load16le(ra) : 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; } -int gsm0503_rach_encode(ubit_t *burst, uint8_t *ra, uint8_t bsic) +/*! 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[14]; + ubit_t conv[17]; + uint8_t ra[2] = { 0 }, nbits = 8; - osmo_pbit2ubit_ext(conv, 0, ra, 0, 8, 1); + if (is_11bit) { + osmo_store16le(ra11, ra); + nbits = 11; + } else + ra[0] = (uint8_t)ra11; - osmo_crc8gen_set_bits(&gsm0503_rach_crc6, conv, 8, conv + 8); + osmo_pbit2ubit_ext(conv, 0, ra, 0, nbits, 1); - rach_apply_bsic(conv, bsic); + osmo_crc8gen_set_bits(&gsm0503_rach_crc6, conv, nbits, conv + nbits); - osmo_conv_encode(&gsm0503_rach, conv, burst); + rach_apply_bsic(conv, bsic, nbits); + + osmo_conv_encode(is_11bit ? &gsm0503_rach_ext : &gsm0503_rach, conv, burst); return 0; } @@ -1723,7 +2022,12 @@ int gsm0503_rach_encode(ubit_t *burst, uint8_t *ra, uint8_t bsic) /* * GSM SCH transcoding */ -int gsm0503_sch_decode(uint8_t *sb_info, sbit_t *burst) + +/*! 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; @@ -1739,7 +2043,11 @@ int gsm0503_sch_decode(uint8_t *sb_info, sbit_t *burst) return 0; } -int gsm0503_sch_encode(ubit_t *burst, uint8_t *sb_info) +/*! 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]; @@ -1751,3 +2059,5 @@ int gsm0503_sch_encode(ubit_t *burst, uint8_t *sb_info) return 0; } + +/*! @} */ |