Changes between Version 34 and Version 35 of Other/Summer/2020/FPGAspectrum

Timestamp:

Jul 30, 2020, 12:26:07 AM (4 years ago)

Author:

rgd51

Comment:

—

Other/Summer/2020/FPGAspectrum

@@ -329 +329 @@
 }}}
 
+
+== Matched Filter ==
+{{{#!matlab
+% Zhuohuan Li
+% Sid Mandayam
+
+antenna = phased.IsotropicAntennaElement('FrequencyRange',[5e9 15e9]);
+transmitter = phased.Transmitter('Gain',20,'InUseOutputPort',true);
+fc = 10e9;
+target = phased.RadarTarget('Model','Nonfluctuating',...
+   'MeanRCS',1,'OperatingFrequency',fc);
+txloc = [0;0;0];
+tgtloc = [5000;5000;10];
+transmitterplatform = phased.Platform('InitialPosition',txloc);
+targetplatform = phased.Platform('InitialPosition',tgtloc);
+[tgtrng,tgtang] = rangeangle(targetplatform.InitialPosition,...
+   transmitterplatform.InitialPosition);waveform = phased.RectangularWaveform('PulseWidth',25e-6,...
+   'OutputFormat','Pulses','PRF',10e3,'NumPulses',1);
+c = physconst('LightSpeed');
+maxrange = c/(2*waveform.PRF);
+SNR = npwgnthresh(1e-6,1,'noncoherent');
+Pt = radareqpow(c/fc,maxrange,SNR,...
+   waveform.PulseWidth,'RCS',target.MeanRCS,'Gain',transmitter.Gain);transmitter.PeakPower = Pt;radiator = phased.Radiator('PropagationSpeed',c,...
+   'OperatingFrequency',fc,'Sensor',antenna);
+channel = phased.FreeSpace('PropagationSpeed',c,...
+   'OperatingFrequency',fc,'TwoWayPropagation',false);
+collector = phased.Collector('PropagationSpeed',c,...
+   'OperatingFrequency',fc,'Sensor',antenna);
+receiver = phased.ReceiverPreamp('NoiseFigure',0,...
+   'EnableInputPort',true,'SeedSource','Property','Seed',2e3);
+filter = phased.MatchedFilter(...
+   'Coefficients',getMatchedFilter(waveform),...
+   'GainOutputPort',true);wf = waveform();
+[wf,txstatus] = transmitter(wf);
+wf = radiator(wf,tgtang);
+wf = channel(wf,txloc,tgtloc,[0;0;0],[0;0;0]);
+wf = target(wf);
+wf = channel(wf,tgtloc,txloc,[0;0;0],[0;0;0]);
+wf = collector(wf,tgtang);
+rx_puls = receiver(wf,~txstatus);
+[mf_puls,mfgain] = filter(rx_puls);
+Gd = length(filter.Coefficients)-1;mf_puls=[mf_puls(Gd+1:end); mf_puls(1:Gd)]; % main line of matched filter
+subplot(2,1,1)
+t = unigrid(0,1e-6,1e-4,'[)');
+rangegates = c.*t;
+rangegates = rangegates/2; % end with this lineplot(rangegates,abs(rx_puls))
+title('Received Pulse')
+xlabel('Meters')
+ylabel('Amplitude')
+hold on
+plot([tgtrng, tgtrng], [0 max(abs(rx_puls))],'r')
+subplot(2,1,2)
+plot(rangegates,abs(mf_puls))
+title('After Matched Filter')
+xlabel('Meters')
+ylabel('Amplitude')
+hold on
+plot([tgtrng, tgtrng], [0 max(abs(mf_puls))],'r')
+hold off
+}}}
+