pr2_55.m

Spread Spectrum and CDMA Principles and Applications 书籍和代码

%Problem 2.55;
%Simulating time-compression for LFM pulse;

clear all; close all;
t=[0:0.001:1];  t1=[0:0.001:2]; %time scale;
WD=10; %set frequency deviation 
S=exp(i*pi*t.^2.*WD); %signal complex envelope;
Sbp=imag(S.*exp(i*2*pi.*t*50)); SI=[Sbp zeros(1,1000)]; %input LFM signal;
subplot(211); plot(t1,SI); ylim([-1.2 1.2]); grid;  ylabel('MF input'); %plotting input;
SO1=xcorr(S)/1001; %complex envelope at the matched filter output;
SO=real(SO1.*exp(i*2*pi*(t1-1)*50)); %complete bandpass signal at the matched filter output;;
subplot(212); plot(t1,SO); ylim([-1.2 1.2]); grid; xlabel('t/T'); ylabel('MF output');