Hi team,
I am trying to get the frequency response (H(z)) for the thiran filter using below. But I am stuck after getting the 'ak' value how to proceed to get the frequency response without inbuilt syntax ? Can you please help?
I used below code for calculating ak.
function [b,a] = thiran_1(D,N)
% [b,a] = thiran_1(D,N)
% b and a are numerator and denominator of H, respectively
% returns the order N Thiran allpass interpolation filter
% for delay D (samples).
a = zeros(1,N+1);
for k=0:N
ak = 1;
for n=0:N
if(D == N && k==0 && n==0)
ak=1;
else
ak = ak * (D-N+n)/(D-N+k+n);
end
a(k+1) = (-1)^k * nchoosek(N,k) * ak;
end
b = a(N+1:-1:1);
end
Ref:
[1] T. Laakso, V. Valimaki, “Splitting the Unit Delay”, IEEE Signal Processing Magazine, Vol. 13, No. 1, p.30-60, 1996.
