Friday, 22 April 2016

Frequency Sampling Method

In this experiment a digital FIR filter is designed using Frequency sampling method.In FSM we subsitute w=2(pi)k/n.5 parameters namely, Attenuation in both pass and stop bands in dB, pass band and stop band frequencies in Hertz and Sampling frequency in Hertz are taken from user. Once we obtain the desired frequency response, Hd[w], we can directly convert them into the frequency domain  using the conventional Discrete Fourier Transform algorithm, H[k]. The final output sequence, h[n] can be obtained by performing the  Inverse Discrete Fourier Transform algorithm. The final output sequence, h[n] is always symmetric about the point of symmetry i.e. N/2 . Discontinuity is observed in phase plot between lobes and also when the spectrum goes out of the range that is from -pi to +pi. 
Link:- FSM

6 comments:

  1. Phase spectrum is linear within the positive lobes of magnitude spectrum.

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  2. Unlike the window method, can this technique be used for any given magnitude response??

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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. Thank you for sharing your views.

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  5. computational efficiency is increased as signal is decomposed which makes calculation faster

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