📄 turbo_code_log_map.c
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/*----------------------------------------------------------
* Copyright (c) 2003, 北京邮电大学移动通信实验室
* All rights reserved.
*
* 文件名称：turbo_code_Log_MAP.c
* 文件标识：
* 摘 要：Turbo编译码实现函数文件.
*
* 当前版本：1.0
* 作 者：张鹏
* 完成日期：2003年12月1日
----------------------------------------------------------*/
#include "turbo_code_Log_MAP.h"
/*==================================================*/
/* Log-MAP算法用到的查找表 */
const double lookup_index_Log_MAP[16] = {0.0, 0.08824, 0.19587, 0.31026, 0.43275, 0.56508,
0.70963, 0.86972, 1.0502, 1.2587, 1.5078, 1.8212,
2.2522, 2.9706, 3.6764, 4.3758};
const double lookup_table_Log_MAP[16] = {0.69315, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35,
0.3, 0.25, 0.2, 0.15, 0.1, 0.05, 0.025, 0.0125};
/* CDMA2000中Turbo码所使用的交织器要使用该查找表。
各列分别对应于N＝4，5，6，7，8，9，10。N>=log2(Nturbo)-5。*/
const int lookuptable_cdma2000[7][32] =
{{5,15,5,15,1,9,9,15,13,15,7,11,15,3,15,5,13,15,9,3,1,3,15,1,13,1,9,15,11,3,15,5},
{27,3,1,15,13,17,23,13,9,3,15,3,13,1,13,29,21,19,1,3,29,17,25,29,9,13,23,13,13,1,13,13},
{3,27,15,13,29,5,1,31,3,9,15,31,17,5,39,1,19,27,15,13,45,5,33,15,13,9,15,31,17,5,15,33},
{15,127,89,1,31,15,61,47,127,17,119,15,57,123,95,5,85,17,55,57,15,41,93,87,63,15,13,15,81,57,31,69},
{3,1,5,83,19,179,19,99,23,1,3,13,13,3,17,1,63,131,17,131,211,173,231,171,23,147,243,213,189,51,15,67},
{13,335,87,15,15,1,333,11,13,1,121,155,1,175,421,5,509,215,47,425,295,229,427,83,409,387,193,57,501,313,489,391},
{1,349,303,721,973,703,761,327,453,95,241,187,497,909,769,349,71,557,197,499,409,259,335,253,677,717,313,757,189,15,75,163}};
/*==================================================*/
/* 与生成阵相关的参数 */
const int M_num_reg = COLUMN_OF_G-1; /* 寄存器数 */
const int n_states = 8; /* 状态数:2的M_num_reg次幂 */
/*==================================================*/
extern double *alpha_channel;
/*---------------------------------------------------------------
函数:
TurboCodingTraffic(int *trafficflow_source, int *coded_trafficflow_source,
int *traffic_source_length)
介绍:
Turbo码业务信息编码函数.
参数:
输入参数: trafficflow_source - 源bit序列首址.
traffic_source_length - 源bit序列长度.
输出参数: coded_trafficflow_source - 编码后的序列首址.
返回值:
无
---------------------------------------------------------------*/
void TurboCodingTraffic(int *trafficflow_source, float *coded_trafficflow_source,
int *traffic_source_length)
{
int i; /* 循环变量 */
int *temp_send = NULL;
int *send = NULL; /* 发送序列首址 */
int *send_punc = NULL; /* 打孔后的发送序列首址 */
int length_info = *traffic_source_length; /* 信息位长度 */
/*
switch( length_info/320 )
{
case 1:
case 2:
case 4:
break;
default:
{
printf("Wrong frame length!\n");
exit(1);
}
}
*/
/* 申请内存 */
if ((send=(int *)malloc((3*length_info+4*M_num_reg)*sizeof(int)))==NULL)
{
printf("\n fail to allocate memory of send \n");
exit(1);
}
if ((send_punc=(int *)malloc(2*length_info*sizeof(int)))==NULL)
{
printf("\n fail to allocate memory of send_punc \n");
exit(1);
}
/* 生成随机交织器下标 */
if (TYPE_INTERLEAVER == 2)
{
gen_rand_index(length_info, 1);
}
encoderm_turbo(trafficflow_source, send, length_info, 1); /* 编码,BPSK调制 */
temp_send = send;
if (TURBO_PUNCTURE) /* 打孔 */
{
puncture(send, 3*length_info+4*M_num_reg, send_punc, 3, length_info/4, 4);
temp_send = send_punc;
}
/* 写输出序列 */
for (i=0; i<((3-TURBO_PUNCTURE)*length_info+4*M_num_reg*(1-TURBO_PUNCTURE)); i++)
{
*(coded_trafficflow_source+i) = (float) *(temp_send+i);
}
/* 修改数据长度变量 */
*traffic_source_length = (3-TURBO_PUNCTURE)*length_info+4*M_num_reg*(1-TURBO_PUNCTURE);
free(send);
free(send_punc);
}
/*---------------------------------------------------------------
函数:
void TurboDecodingTraffic(double *trafficflow_for_decode, int *trafficflow_decoded,
int *trafficflow_length, double EbN0dB)
介绍:
Turbo码业务信息译码函数.
参数:
输入参数: trafficflow_for_decode - 输入序列首址.
trafficflow_length - 输入序列长度.
EbN0dB - 信噪比.
输出参数: trafficflow_decoded - 译码后的序列首址.
返回值:
无
---------------------------------------------------------------*/
void TurboDecodingTraffic(float *trafficflow_for_decodeA,float *trafficflow_for_decodeB,float *trafficflow_for_decodeAB, int *trafficflow_decodedAB, int *trafficflow_length, float EbN0dB)
{
int i; /* 循环变量 */
int length_info, length_total; /* 信息位长和总长度 */
int length_infoAB, length_totalAB;
int iteration; /* 叠代循环变量 */
/* 接收数据 */
double *yk_turboA = NULL; /* 包含ys和yp */
double *yk_turboB = NULL;
double *yk_turboAB = NULL;
double *infoAB = NULL;
double *interleavedAB = NULL;
double *La_turboA, *Le_turboA, *LLR_all_turboA, *La_turboB, *Le_turboB, *LLR_all_turboB; /* 外信息和似然比 */
double *La_turboAB, *Le_turboAB, *LLR_all_turboAB;
int *tempout=NULL;
double en_rate = (double)pow(10, EbN0dB*0.1);
double Lc_turbo = 4*en_rate/3; /* 信道可靠性值 */
/* 计算信息位长度 */
length_info = *trafficflow_length;
length_infoAB = (*(trafficflow_length))*2;
/* 总长度 */
length_total = length_info+M_num_reg;
length_totalAB = length_infoAB+M_num_reg;
/* 申请内存 */
if ((yk_turboA=(double *)malloc(2*length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of yk_turbo \n");
exit(1);
}
if ((yk_turboB=(double *)malloc(2*length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of yk_turbo \n");
exit(1);
}
if ((yk_turboAB=(double *)malloc(2*length_totalAB*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of yk_turbo \n");
exit(1);
}
if ((infoAB=(double *)malloc(length_infoAB*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of yk_turbo \n");
exit(1);
}
if ((interleavedAB=(double *)malloc(length_infoAB*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of yk_turbo \n");
exit(1);
}
if ((La_turboA=(double *)malloc(length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of La_turbo \n");
exit(1);
}
if ((Le_turboA=(double *)malloc(length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of Le_turbo \n");
exit(1);
}
if ((LLR_all_turboA=(double *)malloc(length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of LLR_all_turbo \n");
exit(1);
}
if ((La_turboB=(double *)malloc(length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of La_turbo \n");
exit(1);
}
if ((Le_turboB=(double *)malloc(length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of Le_turbo \n");
exit(1);
}
if ((LLR_all_turboB=(double *)malloc(length_total*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of LLR_all_turbo \n");
exit(1);
}
if ((La_turboAB=(double *)malloc(length_totalAB*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of La_turbo \n");
exit(1);
}
if ((Le_turboAB=(double *)malloc(length_totalAB*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of Le_turbo \n");
exit(1);
}
if ((LLR_all_turboAB=(double *)malloc(length_totalAB*sizeof(double)))==NULL)
{
printf("\n fail to allocate memory of LLR_all_turbo \n");
exit(1);
}
if ((tempout=(int *)malloc(length_totalAB*sizeof(int)))==NULL)
{
printf("\n fail to allocate memory of tempout \n");
exit(1);
}
/* 乘信道衰落 */
/*
for (i=0; i<2*length_total; i++)
{
*(yk_turboA+i) =(double)( *(yk_turboA+i)*(1+TYPE_CHANNEL)*(*(alpha_channel+i)));
*(yk_turboB+i) =(double)( *(yk_turboB+i)*(1+TYPE_CHANNEL)*(*(alpha_channel+i)));
}
for (i=0; i<2*length_totalAB; i++)
{
*(yk_turboAB+i) =(double)( *(yk_turboAB+i)*(1+TYPE_CHANNEL)*(*(alpha_channel+i)));
}*/
for (i=0; i<2*length_total; i++)
{
*(yk_turboA+i)=(double)(*(trafficflow_for_decodeA+i));
*(yk_turboB+i)=(double)(*(trafficflow_for_decodeB+i));
}
comboinfoAB(infoAB,yk_turboA,yk_turboB);
interleave_double(infoAB, interleavedAB, TYPE_INTERLEAVER, length_infoAB, 1);
for (i=0; i<length_infoAB; i++)
{
*(yk_turboAB+2*i)=(double)(*(interleavedAB+i));
*(yk_turboAB+2*i+1)=(double)(*(trafficflow_for_decodeAB+i));
}
for (i=4*length_info; i<2*length_totalAB;i++)
{
*(yk_turboAB+i)=(double)(*(trafficflow_for_decodeAB+i-length_infoAB));
}
// for (i=0; i<2*length_total; i++)
// {
// *(yk_turboA+i) =(double)( *(yk_turboA+i)*(1+TYPE_CHANNEL));
// *(yk_turboB+i) =(double)( *(yk_turboB+i)*(1+TYPE_CHANNEL));
// }
// for (i=0; i<2*length_totalAB; i++)
// {
// *(yk_turboAB+i) =(double)( *(yk_turboAB+i)*(1+TYPE_CHANNEL));
// }
/* scale数据 */
// for (i=0; i<2*length_total; i++)
// {
// *(yk_turboA+i) = (double)( *(yk_turboA+i) * Lc_turbo *0.5 );
// *(yk_turboB+i) = (double)( *(yk_turboB+i) * Lc_turbo *0.5 );
// }
// for (i=0; i<2*length_totalAB; i++)
// {
// *(yk_turboAB+i) = (double)( *(yk_turboAB+i) * Lc_turbo *0.5 );
// }
/* 初始化外信息和似然信息 */
for (i=0; i<length_total; i++)
{
*(La_turboA+i) = *(Le_turboA+i) = *(LLR_all_turboA+i) = 0;
*(La_turboB+i) = *(Le_turboB+i) = *(LLR_all_turboB+i) = 0;
}
for (i=0; i<length_totalAB; i++)
{
*(La_turboAB+i) = *(Le_turboAB+i) = *(LLR_all_turboAB+i) = 0;
}
for (iteration=0; iteration<N_ITERATION; iteration++) /* 开始叠代 */
{
/* 译码器1: */
/* 解交织来自译码器2的外信息 */
de_interleave_double(La_turboAB, Le_turboAB, TYPE_INTERLEAVER, length_infoAB, 1);
doubledecombo(La_turboAB,La_turboA,La_turboB);
/* 结尾处赋0 */
for (i=length_info; i<length_total; i++)
{
*(La_turboA+i) = 0;
*(La_turboB+i) = 0;
}
/* Log-MAP算法 */
Log_MAP_decoder(yk_turboA, La_turboA, 1, LLR_all_turboA, length_total);
Log_MAP_decoder(yk_turboB, La_turboB, 1, LLR_all_turboB, length_total);
/* 计算外信息 */
for (i=0; i<length_total; i++)
{
*(Le_turboA+i) = *(LLR_all_turboA+i) - *(La_turboA+i) - 2*(*(yk_turboA+2*i));
*(Le_turboB+i) = *(LLR_all_turboB+i) - *(La_turboB+i) - 2*(*(yk_turboB+2*i));
}
doublecombo(Le_turboA,Le_turboB,Le_turboAB);
/* 译码器2: */
/* 交织来自译码器1的外信息 */
interleave_double(Le_turboAB, La_turboAB, TYPE_INTERLEAVER, length_infoAB, 1);
/* 结尾处赋0 */
for (i=length_infoAB; i<length_totalAB; i++)
{
*(La_turboAB+i) = 0;
}
/* Log-MAP算法 */
Log_MAP_decoder(yk_turboAB, La_turboAB, 1, LLR_all_turboAB, length_totalAB);
// for (i=0; i<length_totalAB; i++)
// {
// printf("%f ",*(LLR_all_turboAB+i));
// }
/* 计算外信息 */
for(i=0; i<length_totalAB; i++)
{
*(Le_turboAB+i) = *(LLR_all_turboAB+i) - *(La_turboAB+i) - (2-TYPE_CHANNEL)*(*(yk_turboAB+2*i));
}
/* 译码器2结束 */
}
/* 对全部似然比判决 */
decision(LLR_all_turboAB, length_totalAB, tempout);
/* 对判决比特解交织 */
de_interleave_int(trafficflow_decodedAB, tempout, TYPE_INTERLEAVER, length_infoAB, 1);
/* 修改长度变量 */
*trafficflow_length = length_info;
// free(receive_punc);
free(yk_turboA);
free(La_turboA);
free(Le_turboA);
free(LLR_all_turboA);
free(yk_turboB);
free(La_turboB);
free(Le_turboB);
free(LLR_all_turboB);
free(yk_turboAB);
free(La_turboAB);
free(Le_turboAB);
free(LLR_all_turboAB);
free(infoAB);
free(interleavedAB);
free(tempout);
}
/*---------------------------------------------------------------
函数:
void TurboCodingSupflow(int *supflow, double *coded_supflow, int *supflow_length)
介绍:
Turbo码补充信息编码函数.
参数:
输入参数: supflow - 源bit序列首址.
supflow_length - 源bit序列长度.
输出参数: coded_supflow - 编码后的序列首址.
返回值:
无
---------------------------------------------------------------*/
void TurboCodingSupflow(int *supflow, float *coded_supflow, int *supflow_length)
{
int i; /* 循环变量 */
int *temp_send = NULL;
int *send = NULL; /* 发送序列首址 */
int *send_punc = NULL; /* 打孔后的发送序列首址 */
int length_info = *supflow_length; /* 信息位长度 */
switch( length_info/320 )
{
case 1:
case 2:
case 4:
break;
default:
{
printf("Wrong frame length!\n");
exit(1);
break;
}
}
/* 申请内存 */
if ((send=(int *)malloc((3*length_info+4*M_num_reg)*sizeof(int)))==NULL)
{
printf("\n fail to allocate memory of send \n");
exit(1);
}
if ((send_punc=(int *)malloc(2*length_info*sizeof(int)))==NULL)
{
printf("\n fail to allocate memory of send_punc \n");
exit(1);
}
/* 生成随机交织器下标 */
if (TYPE_INTERLEAVER == 2)
{
gen_rand_index(length_info, 0);
}
encoderm_turbo(supflow, send, length_info, 0); /* 编码,BPSK调制 */
temp_send = send;
if (TURBO_PUNCTURE) /* 打孔 */
{
puncture(send, 3*length_info+4*M_num_reg, send_punc, 3, length_info/4, 4);
temp_send = send_punc;
}
/* 写输出序列 */
for (i=0; i<((3-TURBO_PUNCTURE)*length_info+4*M_num_reg*(1-TURBO_PUNCTURE)); i++)
{
*(coded_supflow+i) = (float) *(temp_send+i);
}
/* 修改数据长度变量 */
*supflow_length = (3-TURBO_PUNCTURE)*length_info+4*M_num_reg*(1-TURBO_PUNCTURE);
free(send);
free(send_punc);
}
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