v32_diffcoding.m

matlab 代码,实现了ITU-T V.32建议的 modem 整体仿真实现。

function[Y2,Y1]=v32_diffcoding(Q2,Q1)
%设初始状态为Y2=0，Y1=0
if Q2(1)==0&&Q1(1)==0
    Y2(1)=0;Y1(1)=0;
elseif Q2(1)==1&&Q1(1)==0
    Y2(1)=1;Y1(1)=0;
elseif Q2(1)==0&&Q1(1)==1
    Y2(1)=0;Y1(1)=1;
elseif Q2(1)==1&&Q1(1)==1
    Y2(1)=1;Y1(1)=1;
end

for k=2:length(Q2)
    if (Q2(k)==0&&Q1(k)==0&&Y2(k-1)==0&&Y1(k-1)==0)||(Q2(k)==1&&Q1(k)==0&&Y2(k-1)==1&&Y1(k-1)==0)||(Q2(k)==0&&Q1(k)==1&&Y2(k-1)==1&&Y1(k-1)==1)||(Q2(k)==1&&Q1(k)==1&&Y2(k-1)==0&&Y1(k-1)==1)
        Y2(k)=0;Y1(k)=0;
    end
    if (Q2(k)==0&&Q1(k)==0&&Y2(k-1)==1&&Y1(k-1)==0)||(Q2(k)==1&&Q1(k)==0&&Y2(k-1)==0&&Y1(k-1)==0)||(Q2(k)==0&&Q1(k)==1&&Y2(k-1)==0&&Y1(k-1)==1)||(Q2(k)==1&&Q1(k)==1&&Y2(k-1)==1&&Y1(k-1)==1)
        Y2(k)=1;Y1(k)=0;
    end    
    if (Q2(k)==0&&Q1(k)==0&&Y2(k-1)==0&&Y1(k-1)==1)||(Q2(k)==1&&Q1(k)==0&&Y2(k-1)==1&&Y1(k-1)==1)||(Q2(k)==0&&Q1(k)==1&&Y2(k-1)==0&&Y1(k-1)==0)||(Q2(k)==1&&Q1(k)==1&&Y2(k-1)==1&&Y1(k-1)==0)
        Y2(k)=0;Y1(k)=1;
    end
    if (Q2(k)==0&&Q1(k)==0&&Y2(k-1)==1&&Y1(k-1)==1)||(Q2(k)==1&&Q1(k)==0&&Y2(k-1)==0&&Y1(k-1)==1)||(Q2(k)==0&&Q1(k)==1&&Y2(k-1)==1&&Y1(k-1)==0)||(Q2(k)==1&&Q1(k)==1&&Y2(k-1)==0&&Y1(k-1)==0)
        Y2(k)=1;Y1(k)=1;
    end
end