Question

If M is the length of the filter, then at how many number of points, the error function is computed?

(a) 2M

(b) 4M

(c) 8M

(d) 16M

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Asked question is from Design of Optimum Equi Ripple Linear Phase FIR Filters topic in division Digital Filters Design of Digital Signal Processing

Answer 1

Right choice is (d) 16M

Explanation: Having the solution for P(ω), we can now compute the error function E(ω) from

E(ω)=W(ω)[Hdr(ω)-Hr(ω)]

on a dense set of frequency points. Usually, a number of points equal to 16M, where M is the length of the filter.