bpskdet.m

交全面的给出了好几种调制解调方案的matlab代码,又ASK,BPSK,FSK,QAM等的源代码 对通信领域的研究人员很有帮助

function [xn,x]=bpskdet(y,Kmod,fs,fb,fc,rd);
%
% Usage:[xn,x]=bpskdet(y,Kmod,fs,fb,fc,rd);BBI
% 2000;Kmod=1表示BPSK解调,Kmod=2表示DPSK解调,xn为解调输出的二进制码流向量,x为解调输出的脉冲信号波形
if nargin<6; rd=0; end;
if nargin<5; fc=2; end;
if nargin<4; fb=1; end;
if nargin<3; fs=32;end; 
if nargin<2; Kmod=1;end;
if nargin<1; y=bpsk([0 0 1 1 1 0 0 1 0 1]);end;
dt=1/fs;t=0:dt:(length(y)-1)*dt;
x=y.*sin(2*pi*fc*t);
[b,a]=butter(2,2*fb/fs);
x=-filtfilt(b,a,x);
m=fs/fb;N=length(y)/m;n=(.75:1:N)*m;
xn=(sign(x(n))+1)/2;
if Kmod==1;
    tstr='BPSK';
elseif Kmod==2;
    xn=xor(xn,[rd xn(1:N-1)]);tstr='DPSK';
end;
%---------------------------------------------------
if nargout<1;
    c='bbbbbbbbrrrrrrrr';
    subplot(211);plot(t,y);title('Input');axis([0,35,-1,1]);
    subplot(212);plot(t,x,t,sign(x)*.5);axis([0,35,-1,1]);
    set(gca,'ygrid','on');v=axis;
    for i=1:N;
        ci=rem(i,16);ci=ci+(ci==0)*16;ci=c(ci);
        text((2*i-1)*m*dt/2,v(4)*.8,int2str(xn(i)),'color',ci);
    end;title('Output');
    set(gcf,'num','off','name',['Coherent Detection of',...
            'tstr ','blanks(10)','BBI 2000']);zoom xon;
end;