In this experiment we used windowing method to design the digital FIR filter.
FIR filters if compared to IIR filters,its phase response is linear which is not the case in IIR filters.
In this method , FIR filter is designed by truncating infinite samples oh hd[n] using a window function. Linear phase FIR filter with impulse response h[n] is then given by h[n]=hd[n].w[n] where w[n] is an appropriate window function.
The written program finds an appropriate window function by comparing the entered value of Stopband attenuation(As) with the stored values in the program. Then using that particular window function it calculates value of h[n].
FIR filters if compared to IIR filters,its phase response is linear which is not the case in IIR filters.
In this method , FIR filter is designed by truncating infinite samples oh hd[n] using a window function. Linear phase FIR filter with impulse response h[n] is then given by h[n]=hd[n].w[n] where w[n] is an appropriate window function.
The written program finds an appropriate window function by comparing the entered value of Stopband attenuation(As) with the stored values in the program. Then using that particular window function it calculates value of h[n].
The output obtained is always symmetric.
ReplyDeleteWindowing function is helpful for optimum design since the appropriate window function is chosen using value of As from the input
ReplyDeleteWhich windowing method did you use?
ReplyDeleteI used blackman window.For more info
DeleteRefer this: https://www.dsprelated.com/freebooks/mdft/Use_Blackman_Window.html
well explained
ReplyDeleteWhat is the selection criteria for window function?
ReplyDeleteIt depends upon the characteristics you want in the magnitude response of the filter while implementation.
DeleteRefer this for more info:
https://www.ee.iitb.ac.in/~esgroup/es_mtech02_sem/es02_sem_rep_arojit.pdf
Distortion is very low since, FIR is a Linear phase filter
ReplyDeletewell done shivam
ReplyDeleteIn FIR filters, if order increases, the number of side lobes increase. Side lobes should be avoided as the stopband attenuation is non-uniform.
ReplyDeleteAs we go from rectangular window function to hanning window, we get smoother response which reduces Gibbs phenomenon.
ReplyDelete