FIR filter Design using window Method
Depending upon the value of passband attenuation and stopband attenuation, appropriate window function was chosen from Hanning, Hamming, Blackman, Rectangular and Barlett.We have implemented the code in Scilab. In case of FIR filter the phase response of the filter varies linearly with the frequency thus the output of the filter is delayed version of the input by some constant and there is no distortion in the output.
Depending upon the value of passband attenuation and stopband attenuation, appropriate window function was chosen from Hanning, Hamming, Blackman, Rectangular and Barlett.We have implemented the code in Scilab. In case of FIR filter the phase response of the filter varies linearly with the frequency thus the output of the filter is delayed version of the input by some constant and there is no distortion in the output.
What is the role of window in design of FIR filter ?
ReplyDeleteFIR filter is designed by truncating infinite samples of hd[n] by using window function. Examples of window function are rectangular, barnet hamming, hanning and blackman
DeleteWhy a rectangular window is not prefered in filter design ?
ReplyDeleteRectangular window fucntion is not used as it has the lowest stopband attenuation.The stopband attenuation of rectangular window fucntion is only 21dB
ReplyDeleteWhat is the effect of windowing on W e^(jw)?
ReplyDeleteDiscontinuities in H(e^jw) are converted into transition bands between values on either sides of discontinuity
DeleteSelection of window function depends on requirement of stop band attenuation.Of all, Blackman window function is most preferred because of highest stop band attenuation of 74db
ReplyDeleteYes Blackman has the maximum amount of stopband attenuation
DeleteThe trick is to select the window function that will give a filter with the correct transition width and attenuation in stopband.
ReplyDeleteYes thanks for the information
DeleteAttenuation of the side lobes is an important factor.
ReplyDeleteYes.
Deletewindow selection is done upon requirement of passband attenuation
ReplyDeleteIt also depends upon the requirement of stopband attenuation. Greater the stopband better the window function
Delete