Digital Signal Processing Reference
In-Depth Information
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(a) Imp Resp (Samp 0 to 63), Test Sig (Samp Time 0)
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(b) Sample
Figure 4.18:
(a) Non-time-reversed chirp as impulse response (samples 0 to 63), and incoming signal
(samples to left of sample 0); (b) Convolution sequence.
function LVFreqResp(tstSig, NoFreqs)
% LVFreqResp([1.9, 0, -0.9, 0, 1.9, 0, -3.2], 500)
NyqLim = length(tstSig)/2; LTS = length(tstSig);
t = [0:1:(LTS-1)]/(LTS); FR = [];
frVec = 0:NyqLim/(NoFreqs-1):NyqLim;
for Freq = frVec % FR via loop
testCorr = cos(2*pi*t*Freq) - j*sin(2*pi*t*Freq);
FR = [FR, sum(tstSig.*testCorr)];
end
% FR = exp(-j*(((2*pi*t)'*frVec)'))*(tstSig');
figure(9)
xvec = frVec/(frVec(length(frVec)));
plot(xvec,abs(FR));
xlabel('Normalized Frequency')
ylabel('Magnitude')
4.9
FREQUENCY SELECTIVITY
So far, we've seen that:
