Friday, 22 April 2016

Exp-9 FIR using Frequency Sampling

This was our second last experiment on scilab, similar to the earlier one-FIR filter design using frequency sampling. The input specifications were taken as usual and the magnitude response was plotted.The basic concept of frequency sampling is sampling the desired frequency response Hd (ω) at ω=(2πk/N).
It is seen that as filter order increases, number of lobes in stop band also increases.Ripples in stop band were obtained of decreasing amplitude. Since, phase plot was linear, output will not be distorted. The phase plot of LPF and HPF were similar since order of both the filters is same.

For this experiment, we spoke to some seniors who did their pracs right behind us. They helped us getting the code right. We had a little bit of confusion regarding the phase and magnitude plot as google showed us plots which did not have limitation from (-pi,pi].Later it was sorted out. Term tests were over by this time but we were surely going to lose our grades as the week passed.
Codes at: google drive 


5 comments:

  1. try implementing for band stop and band pass filter too

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  2. We got same phase plot for LPF and HPF as order of the filter was same.

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  3. Wherever the lowest peak was observed in magnitude response, corresponding zero crossing was observed in phase response.

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  4. Frequency response is uniformly sampled at N points

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