WuYufei的Turbo编译码c语言实现

以下是WuYufei的Turbo编码和译码的C语言实现：

Turbo编码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define N 1024
#define K 512
#define M 4
#define PUNCTURE 3

int main()
{
    int i, j, k;
    int input[N];
    int output[K];
    int state1, state2, state3;
    int out1, out2, out3;
    int temp1, temp2, temp3;
    int *ptr;
    int puncture[PUNCTURE] = {1, 2, 3};

    //输入比特流
    printf("Input bit stream:\n");
    for(i = 0; i < N; i++)
        scanf("%d", &input[i]);

    //初始化状态
    state1 = 0;
    state2 = 0;
    state3 = 0;

    //Turbo码编码
    for(i = 0; i < K; i += 2)
    {
        //第一个卷积码器
        temp1 = (state1 << 1) | input[i];
        temp2 = (state2 << 1) | input[i + 1];
        out1 = (temp1 ^ temp2) & 1;
        state1 = (temp1 >> 1) & 7;
        state2 = (temp2 >> 1) & 7;

        //第二个卷积码器
        temp1 = (state2 << 1) | input[i];
        temp2 = (state3 << 1) | input[i + 1];
        out2 = (temp1 ^ temp2) & 1;
        state2 = (temp1 >> 1) & 7;
        state3 = (temp2 >> 1) & 7;

        //交织器
        ptr = output + i;
        *ptr = out1;
        *(ptr + 1) = out2;

        //打孔
        for(j = 0; j < PUNCTURE; j++)
        {
            if(i + puncture[j] < K)
                *(ptr + puncture[j]) = -1;
        }
    }

    //输出编码比特流
    printf("Output code bit stream:\n");
    for(i = 0; i < K; i++)
    {
        if(output[i] == -1)
            printf("-");
        else
            printf("%d", output[i]);
    }
    printf("\n");

    return 0;
}

Turbo译码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define N 1024
#define K 512
#define M 4
#define PUNCTURE 3
#define SOFT_DECISION 1

int main()
{
    int i, j, k;
    int input[K];
    int output[N];
    int state1, state2, state3;
    int out1, out2, out3;
    int temp1, temp2, temp3;
    int *ptr;
    int puncture[PUNCTURE] = {1, 2, 3};

    //输入编码比特流
    printf("Input code bit stream:\n");
    for(i = 0; i < K; i++)
    {
        char c = getchar();
        while(c == '\n' || c == '\r' || c == ' ')
            c = getchar();
        if(c == '-')
            input[i] = -1;
        else
            input[i] = c - '0';
    }

    //初始化状态
    state1 = 0;
    state2 = 0;
    state3 = 0;

    //Turbo码译码
    for(i = 0; i < N; i++)
    {
        //第一个卷积码器
        temp1 = (state1 << 1) | input[2 * (i % K)];
        temp2 = (state2 << 1) | input[2 * (i % K) + 1];
        out1 = (temp1 ^ temp2) & 1;
        state1 = (temp1 >> 1) & 7;
        state2 = (temp2 >> 1) & 7;

        //第二个卷积码器
        temp1 = (state2 << 1) | input[2 * (i % K)];
        temp2 = (state3 << 1) | input[2 * (i % K) + 1];
        out2 = (temp1 ^ temp2) & 1;
        state2 = (temp1 >> 1) & 7;
        state3 = (temp2 >> 1) & 7;

        //交织器
        ptr = output + i;
        *ptr = out1;
        *(ptr + M) = out2;

        //打孔
        for(j = 0; j < PUNCTURE; j++)
        {
            if(i % M == puncture[j])
                *(ptr - M + puncture[j]) = -1;
        }
    }

    //输出译码比特流
    printf("Output decoded bit stream:\n");
    for(i = 0; i < N; i++)
    {
        if(output[i] == -1)
            printf("-");
        else
            printf("%d", output[i]);
    }
    printf("\n");

    return 0;
}

其中，Turbo编码和Turbo译码的区别在于输入的数据不同，Turbo编码输入原始比特流，Turbo译码输入编码比特流。同时，在Turbo译码中，还需要对输入的编码比特流进行去打孔和交织处理，以还原出原始比特流。