crc encode.m

来自「AWGN信道下高斯噪声干扰下GPS编码译码系统性能仿真」· M 代码 · 共 42 行

function [B]=CRCen(X) 
G=[1 0 0 0 0 0 1 0 0 0 1 1 1 0 1 1 1 0 1 0 1 0 0 1];;
LG=length(G);
Z=zeros(1,LG-1);
B=[X,Z];
LB=length(B);

P=B(1:LG);
pointer=LG;
  
while pointer<=LB
        P=xor(P,G);
          if pointer==LB
               break;
          end     
         if sum(P)==0;
              for i=1:LG
                  pointer=pointer+1;
                  P(i)=B(pointer);
              end
               
         else
               for j=1:LG
                  if P(j)==1
                      k=j;
                           for i=1:LG+1-k
                              P(i)=P(k-1+i);
                           end
                      break;
                   end
                end
                if k>1
                    for i=LG-k+2:LG
                       pointer=pointer+1;
                       P(i)=B(pointer);
                    end
                end
                 
         end  
        
 end
 B(LB-LG+2:LB)=P(2:LG);