Digital Signal Processing Reference
In-Depth Information
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(a) Sample
(b) Sample
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(c) Sample
(d) Sample
(e) Sample
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(f) Sample
Figure 3.28:
(a) Eight-sample impulse response; (b) Chirp, with second subsequence of eight samples
marked; (c) Eight-sample impulse response padded with another eight zeros; (d) Second eight-sample
subsequence from (b), padded with zeros; (e) First 15 samples of circular convolution of (c) and (d),
performed using DFTs; (f ) Result from (e), after being added to previous result, giving a valid linear
convolution up to sample 16.
which yields the sequence [1,3,2,0]. The second convolution is stated in m-code as
SecConv = real(ifft(fft([1,1,0,0]).*fft([3,4,0,0])))
which results in the sequence [3,7,4,0] which is then added to the first sequence, but shifted to the right
two samples:
1320
3740
13574
This can be checked using the call
y = conv([1,1], [1,2,3,4])
which yields the identical result.
