gusucode.com > 现代通信系统——使用MATLAB(+全部程序) > 现代通信系统——使用MATLAB(+全部程序)/现代通信系统——使用MATLAB(+全部程序)/Matlab 程序/Chapter7/ip_07_07.m
% MATLAB script for Illustrative Problem 7.7. echo on Tb=1; f1=1000/Tb; f2=f1+1/Tb; phi=pi/4; N=5000; % number of samples t=0:Tb/(N-1):Tb; u1=cos(2*pi*f1*t); u2=cos(2*pi*f2*t); % Assuming that u1 is transmitted, the received signal r is sgma=1; % noise variance for i=1:N, r(i)=cos(2*pi*f1*t(i)+phi)+gngauss(sgma); echo off; end; echo on ; % The correlator outputs are computed next. v1=sin(2*pi*f1*t); v2=sin(2*pi*f2*t); r1c(1)=r(1)*u1(1); r1s(1)=r(1)*v1(1); r2c(1)=r(1)*u2(1); r2s(1)=r(1)*v2(1); for k=2:N, r1c(k)=r1c(k-1)+r(k)*u1(k); r1s(k)=r1s(k-1)+r(k)*v1(k); r2c(k)=r2c(k-1)+r(k)*u2(k); r2s(k)=r2s(k-1)+r(k)*v2(k); echo off; end; echo on; % decision variables r1=r1c(5000)^2+r1s(5000)^2; r2=r2c(5000)^2+r2s(5000)^2; % Plotting commands follow.