利用c语言实现卷积码编码器示例

/***This is an simple example program of convolutional encoder.
   *The information sequence, the register initial states and the generation sequence
   *    can all be modified in the main function.
   */
#include<stdio.h>

#define LEN(array, len)len=sizeof(array)/sizeof(array0);//Size of array

int encoder(int **gen, int n, int L, int reg, int m, int inf, int inf_len, int output)
/*encoder(int **gen, int n, int L, int reg, int m, int inf, int inf_len, int output)
        *This function is a convolutional encoder.
        *gen     is the generation sequence, which is a two-dimension array,
         and it is a two-dimension pointer,
        *n       is the number of bits out the encoder at each clock cycle,
        *L       is for the constraight length,
        *reg     is for the shift registers,
        *m       is for the number of registers,
        *inf     is for the information sequence,
        *inf_len is for the inf length,
        *output  is for the output code.
*/

 int inf_exinf_len + m;

 int i,j;//Index

 for (i=0;i < inf_len + m;i++)//Extend the information sequence to include the last m bits
 
  if(i < inf_len)
   inf_ex = inf;
  else
   inf_ex = 0;
 
 for (i=0;i < inf_len + m;i++)//Foreach bit in extend information
 
  for (j=0;j < n;j++)//Output n bits at each clock cycle
  
      int out_tem=0;//Temp number
   if (*(gen + L*j) == 1)//Judge whether the next information bit should paticipate in the Mod op
                out_tem += inf_ex;

   int k;
   for (k=0;k < m;k++)//Foreach registers
   
    if (*(gen + L*j + k + 1) == 1)
     out_tem += reg;//Mod op according to the generation sequence
   
   out_tem %= 2;//Mod 2
   outputi*n + j = out_tem;
  

  for (j=m - 1;j > 0;j--)//Register shift
  
   reg = regj - 1;
  
  reg0 = inf_ex;//Input information bits into register
 

 return 1;

main()

 int inf=1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0;//Information sequence
 int inf_len;//Information length
 LEN(inf, inf_len);

 int gen27=1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1;//Generation sequence
 int n;//The number of bits out the encoder at each clock cycle
 int L;//Constraight length
 LEN(gen, n);
 LEN(gen0, L);
 int m=L - 1;//The number of shift registers

 int init_s=0, 0, 0, 0, 0, 0; //Initial states are all zero

 int reg;//Register

 int i;//Index

 for (i=0;i < m;i++)
   
        reg = init_s;
   

 int output_len=(inf_len + m)*n;//Output length, every bit of input can generate n bits of output sequence
 int output(inf_len + m)*n;//Output sequence
 encoder(gen, n, L, reg, m, inf, inf_len, output);//Encoder

 for (i=0;i < output_len;i++)
 
  printf("%d", output);
 
 system("pause");