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Diffstat (limited to 'src/l1')
-rw-r--r-- | src/l1/conv.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/src/l1/conv.c b/src/l1/conv.c new file mode 100644 index 0000000..a418a88 --- /dev/null +++ b/src/l1/conv.c @@ -0,0 +1,144 @@ +/* GMR-1 convolutional coding */ +/* See GMR-1 05.003 (ETSI TS 101 376-5-3 V1.2.1) - Section 4.4 */ + +/* (C) 2011 by Sylvain Munaut <tnt@246tNt.com> + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/*! \addtogroup conv + * @{ + */ + +/*! \file conv.c + * \file Osmocom GMR-1 convolutional coding implementation + */ + +#include <stdint.h> + +#include <osmocom/core/conv.h> + + +/* All codes are K=5 and share the same next_state table */ +static const uint8_t gmr1_conv_next_state[][2] = { + { 0, 1 }, { 2, 3 }, { 4, 5 }, { 6, 7 }, + { 8, 9 }, { 10, 11 }, { 12, 13 }, { 14, 15 }, + { 0, 1 }, { 2, 3 }, { 4, 5 }, { 6, 7 }, + { 8, 9 }, { 10, 11 }, { 12, 13 }, { 14, 15 }, +}; + + +/* + * GMR-1 Rate 1/2 convolutional code + * + * g0(D) = 1 + D^3 + D^4 + * g1(D) = 1 + D + D^2 + D^4 + */ + +static const uint8_t gmr1_conv_12_next_output[][2] = { + { 0, 3 }, { 1, 2 }, { 1, 2 }, { 0, 3 }, + { 2, 1 }, { 3, 0 }, { 3, 0 }, { 2, 1 }, + { 3, 0 }, { 2, 1 }, { 2, 1 }, { 3, 0 }, + { 1, 2 }, { 0, 3 }, { 0, 3 }, { 1, 2 }, +}; + +/*! \brief GMR-1 rate 1/2 convolutional code */ +const struct osmo_conv_code gmr1_conv_12 = { + .N = 2, + .K = 5, + .len = 0, /* to be filled during specialization */ + .next_output = gmr1_conv_12_next_output, + .next_state = gmr1_conv_next_state, +}; + + +/* + * GMR-1 Rate 1/3 convolutional code + * + * g0(D) = 1 + D^2 + D^4 + * g1(D) = 1 + D + D^3 + D^4 + * g2(D) = 1 + D + D^2 + D^3 + D^4 + */ + +static const uint8_t gmr1_conv_13_next_output[][2] = { + { 0, 7 }, { 3, 4 }, { 5, 2 }, { 6, 1 }, + { 3, 4 }, { 0, 7 }, { 6, 1 }, { 5, 2 }, + { 7, 0 }, { 4, 3 }, { 2, 5 }, { 1, 6 }, + { 4, 3 }, { 7, 0 }, { 1, 6 }, { 2, 5 }, +}; + +/*! \brief GMR-1 rate 1/3 convolutional code */ +const struct osmo_conv_code gmr1_conv_13 = { + .N = 3, + .K = 5, + .len = 0, /* to be filled during specialization */ + .next_output = gmr1_conv_13_next_output, + .next_state = gmr1_conv_next_state, +}; + + +/* + * GMR-1 Rate 1/4 convolutional code + * + * g0(D) = 1 + D^3 + D^4 + * g1(D) = 1 + D + D^2 + D^4 + * g2(D) = 1 + D^2 + D^4 + * g3(D) = 1 + D + D^2 + D^3 + D^4 + */ + +static const uint8_t gmr1_conv_14_next_output[][2] = { + { 0, 15 }, { 5, 10 }, { 7, 8 }, { 2, 13 }, + { 9, 6 }, { 12, 3 }, { 14, 1 }, { 11, 4 }, + { 15, 0 }, { 10, 5 }, { 8, 7 }, { 13, 2 }, + { 6, 9 }, { 3, 12 }, { 1, 14 }, { 4, 11 }, +}; + +/*! \brief GMR-1 rate 1/4 convolutional code */ +const struct osmo_conv_code gmr1_conv_14 = { + .N = 4, + .K = 5, + .len = 0, /* to be filled during specialization */ + .next_output = gmr1_conv_14_next_output, + .next_state = gmr1_conv_next_state, +}; + + +/* + * GMR-1 Rate 1/5 convolutional code + * + * g0(D) = 1 + D^2 + D^4 + * g1(D) = 1 + D + D^3 + D^4 + * g2(D) = 1 + D + D^2 + D^3 + D^4 + * g3(D) = 1 + D^2 + D^3 + D^4 + * g4(D) = 1 + D + D^2 + D^4 + */ + +static const uint8_t gmr1_conv_15_next_output[][2] = { + { 0, 31 }, { 13, 18 }, { 23, 8 }, { 26, 5 }, + { 14, 17 }, { 3, 28 }, { 25, 6 }, { 20, 11 }, + { 31, 0 }, { 18, 13 }, { 8, 23 }, { 5, 26 }, + { 17, 14 }, { 28, 3 }, { 6, 25 }, { 11, 20 }, +}; + +/*! \brief GMR-1 rate 1/5 convolutional code */ +const struct osmo_conv_code gmr1_conv_15 = { + .N = 5, + .K = 5, + .len = 0, /* to be filled during specialization */ + .next_output = gmr1_conv_15_next_output, + .next_state = gmr1_conv_next_state, +}; + +/*! }@ */ |