2014

这篇文章主要介绍了利用c语言实现卷积码编码器示例,需要的朋友可以参考下

实现(2, 1, 7)卷积码编码

信息序列1001 1010 1111 1100

生成序列g1 = 1011011;g2 = 1111001

初始状态全0.

以上参数可自行在main中修改。

/***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

#define LEN(array, len){len=sizeof(array)/sizeof(array[0]);}//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_ex[inf_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[i] = inf[i];

else

inf_ex[i] = 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[i];

int k;

for (k=0;k < m;k++)//Foreach registers

{

if (*(gen + L*j + k + 1) == 1)

out_tem += reg[k];//Mod op according to the generation sequence

}

out_tem %= 2;//Mod 2

output[i*n + j] = out_tem;

}

for (j=m - 1;j > 0;j--)//Register shift

{

reg[j] = reg[j - 1];

}

reg[0] = inf_ex[i];//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 gen[2][7]={{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(gen[0], 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[m];//Register

int i;//Index

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

{

reg[i] = init_s[i];

}

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[i]);

}

system("pause");

}