文档介绍：1、卷积码编码function[output]=cnv_encd(input)%v_encd(g,k0,input)卷积码编码函数%g生成矩阵%k0输入码长%input输入信源序列%output输出卷积编码序列g=[111;101];编码矩阵k0=1;input=[1101];ifrem(length(input),k0)>0input=[input,zeros(size(1:k0-rem(length(input),k0)))];endn=length(input)/k0;ifrem(size(g,2),k0)>0error('Error,gisnotoftherightsize.')endli=size(g,2)/k0;n0=size(g,1);u=[zeros(size(1:(li-1)*k0)),input,zeros(size(1:(li-1)*k0))];u1=u(li*k0:-1:1);fori=1:n+li-2u1=[u1,u((i+li)*k0:-1:i*k0+1)];enduu=reshape(u1,li*k0,n+li-1);output=reshape(rem(g*uu,2),1,n0*(n+li-1));2、Viterbi译码程序1)functiony=bin2deci(x)l=length(x);y=(l-1:-1:0);y=2.^y;y=x*y';2)functiony=deci2bin(x,l)y=zeros(1,l);i=1;whilex>=0&i<=ly(i)=rem(x,2);x=(x-y(i))/2;i=i+1;endy=y(l:-1:1);3)functiondistance=metric(x,y)ifx==ydistance=0;elsedistance=1;end4)function[next_state,memory_contents]=nxt_stat(current_state,input,L,k)binary_state=deci2bin(current_state,k*(L-1));binary_input=deci2bin(input,k);next_state_binary=[binary_input,binary_state(1:(L-2)*k)];next_state=bin2deci(next_state_binary);memory_contents=[binary_input,binary_state];5)function[decoder_output,survivor_state,cumulated_metric]=viterbi(channel,snr_db)G=[111;101];%G卷积编码矩阵,如(2,1,3)卷积码生成矩阵[111;101],可以根据自己的需要输入编码矩阵k=1;%k信息源输入端口数k=1channel=[1**********];%信源编码snr_db=6;%信噪比,可以通过调节信噪比大小观察viterbi译码的性能%bpsk调制channel_output=bpsk(channel,snr_db);%调用bpsk函数,得到信道编码n=size(G,1);%n编码输出端口数量,(2,1,3)中n=2ifrem(size(G,2),k)~=0%当G列数不是k的整数倍时error('SizeofGandkdonotagree')%发出出错信息endifrem(size(channel_output,2),n)~=0%当输出量元素个数不是输出端口的整数倍时error('channeloutputnotoftherightsize')endN=size(G,2)/k;%得出移位数,即寄存器的个数M=2^k;number_of_states=2^(k*(N-1));%状态数forj=0:number_of_states-1%j表示当前寄存器组的状态因为状态是从零%开始的,所以循环从0到number_of_states-1form=0:M-1%m为从k个输入端的信号组成的状态,总的状%态数为2^k,所以循环从0到2^k-1%nxt_stat完成从当前的状态和输入的矢量得出下寄存器组的一个状态[next_state,memory_contents]=nxt_stat(j,m,N,k);%调用nxt_stat函数input(j+1,next_state+1)=m;branch_output=rem(memory_contents*G',2);nextstate(j+1,m+1)=next_state;output(j+1,m+1)=bin2deci(branch_output);endend%state_metric数组用于记录译码过程在每