www.gusucode.com > phased 案例源码 matlab代码程序 > phased/DechirpFMCWSignalExample.m

    %% Dechirp FMCW Signal  
% Dechirp a delayed FMCW signal, and plot the spectrum before and after
% dechirping.   

% Copyright 2015 The MathWorks, Inc.


%% 
% Create an FMCW signal. 
Fs = 2e5; Tm = 0.001;
hwav = phased.FMCWWaveform('SampleRate',Fs,'SweepTime',Tm);
xref = step(hwav);  

%% 
% Dechirp a delayed copy of the signal. 
x = [zeros(10,1); xref(1:end-10)];
y = dechirp(x,xref);  

%% 
% Plot the spectrum before dechirping. 
[Pxx,F] = periodogram(x,[],1024,Fs,'centered');
plot(F/1000,10*log10(Pxx)); grid;
xlabel('Frequency (kHz)');
ylabel('Power/Frequency (dB/Hz)');
title('Periodogram Power Spectral Density Estimate Before Dechirping');
%% 
% Plot the spectrum after dechirping.
[Pyy,F] = periodogram(y,[],1024,Fs,'centered');
plot(F/1000,10*log10(Pyy));
xlabel('Frequency (kHz)');
ylabel('Power/Frequency (dB/Hz)');
ylim([-100 -30]); grid
title('Periodogram Power Spectral Density Estimate After Dechirping');