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Frequency Sampling Method

Frequency Sampling Method

An FIR Filter can be designed using Frequency Sampling Method also. Attenuation in passband, attenuation in stop band and related frequencies were entered into the Scilab code. Conventional Discrete Fourier Transform algorithm was used to convert the obtained desired frequency response in the frequency domain. h[n] was obtained finally, by applying Inverse Discrete Fourier Transform algorithm. It was observed that the final output sequence h[n] was always symmetric about the point of symmetry (N/2). Phase spectrum is linear within the positive lobes of magnitude spectrum while a discontinuity is observed when the spectrum goes out of range (-pi to pi). 

Comments

  1. However it causes aliasing effects

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  2. Aliasing occurs only when the frequency spectrum is undersampled

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  3. Nyquist criterion must be satisfied

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