Frequency sampling method is an alternative method to design FIR filter.
Frequency sampling method:
In this experiment various parameters such as passband attenuation, stop attenuation, passband frequency and stopband frequency and sampling frequency are passed as input. In this method the desired frequency response which is given as Hd(w) is sampled at w=2*pi*k/N where N is the length of the signal. The frequency sampled obtained are thus taken as DFT coefficients H[k].
FIR filter response is now obtained by taking Inverse Discrete Fourier Transform of H[k]. The results were verified by comparing the stopband and passband attenuation from the magnitude and phase spectrum which were plotted.
Frequency sampling method:
In this experiment various parameters such as passband attenuation, stop attenuation, passband frequency and stopband frequency and sampling frequency are passed as input. In this method the desired frequency response which is given as Hd(w) is sampled at w=2*pi*k/N where N is the length of the signal. The frequency sampled obtained are thus taken as DFT coefficients H[k].
FIR filter response is now obtained by taking Inverse Discrete Fourier Transform of H[k]. The results were verified by comparing the stopband and passband attenuation from the magnitude and phase spectrum which were plotted.
What is the advantage of this method ?
ReplyDeleteThe advantage of this method is that frequency sampling realization of filter is computationally more efficient than the direct form realization.
Deletewell written
ReplyDeleteThank you
DeleteIt is computationally more efficient because coefficients of H[k] becomes zero for w greater than cut off frequency. Thus only non - zero values are to be taken into consideration while obtaining h(n)
ReplyDeleteYes. Hence this method is simpler as compared to other methods
DeleteFrequency sampling technique is one of the easiest methods for designing a FIR filter moreover it is computationally faster.
ReplyDeleteYes because H[k] with zero co-efficient are eliminated
Deletealising may occur if nyquist criterion is not followed
ReplyDeleteHence the sampling frequency must be at least twice of that of highest frequency
DeleteFSM is used in the cases where desired response in known.
ReplyDeleteYes. Thanks for the Additional information
DeleteFSM is computationally more efficient because many samples in the input impulse function are zero. so less calculations are required for final output
ReplyDeleteYes. Thanks for the information
Deleteit would be more efficient if simulation results will also attached
ReplyDeleteFrequency sampling realization is computationally more efficient than direct form realization
ReplyDeleteYes because only non-zero coefficients are taken into consideration
ReplyDelete