Friday, 22 April 2016

Digital FIR Filter Design using Windowing Method

EXPERIMENT 7: Design of FIR Filter

Day seven of DSPP practicals. The rivalries of the previous lab session had to be forgotten and all hatchets had to buried; for this was the most difficult experiment of all the DSPP practicals.
The aim was Linear Phase FIR Filter design using window function.
In this experiment we designed a digital filter using windowing technique and studied the spectrum of the filter.
The input specifications were given as
For LPF / HPF filter Design :
(1) Pass band Attenuation (Ap)
(2) Stop band Attenuation (As )
(3) Pass band Frequency (Fp) in Hz
(4) Stop band Frequency (Fs) in Hz
(5) Sampling Frequency in Hz
 For BPF / BSF filter Design :
(1) Pass band Attenuation (Ap)
(2) Stop band Attenuation (As )
(3) Pass band Frequency (Fp1, Fp2) in Hz
(4) Stop band Frequency (Fs) in Hz
(5) Sampling Frequency in Hz    Fro the phase spectrum we concluded that it is linear for FIR filter. Also the observed values of As and Ap are close to the input values.
We had to assemble all the brilliant minds of our class to complete this experiment. The round table in the lab resembled the conference table where all the Gods of the universe must have held a meeting and worked together to create the world as we know. The only difference here was that the Gods of knowledge were creating a world called FIR filter in the universe called DSPP.  

Program code:FIR
                        FIR.SCI

6 comments:

  1. Wow!!! Great description.. I stand by my suggestion. You should keep writing more blogs like these. Bdw, did u experiment for all window functions?

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  2. Which window function is better?

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  3. Nice explaination, very precise

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  4. Window function is used for taming input signal according to the filter response

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  5. The phase plot observed was linear and the output was a delayed version of the input preventing distortion.

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