despread_spectrum.m

使用matlab程序实现了由随机序列到码元电平、m序列直接扩频解扩、qpsk调制解调

function [ij1 ij2 qj1 qj2]=despread_spectrum(m,iremodo,qremodo)
N=20;                                  %随机数点数20
td=0.1;
f0=3000;
wc=2e4*pi;
g=100;                                 %一个矩形电平采样点

[ij ijsum ij1]=jiekuozlp(m,iremodo);               
ij2=dpxs(g,ij1);
[qj qjsum qj1]=jiekuozlp(m,qremodo);
qj2=dpxs(g,qj1);
t=linspace(0,td,length(ij2));

figure(7);
subplot(211);
plot(t,ij2,'LineWidth',1.5);
grid on;
title('I Channel jiekuo');
axis([0 td -1.5 1.5]);               %画I通道解扩图
subplot(212);
plot(t,qj2,'LineWidth',1.5);
grid on;
title('Q Channel jiekuo');
axis([0 td -1.5 1.5]);              %画Q通道解扩图