% function [b,k] = fir_rc(fa, T, N, alpha)
% Raised Cosine FIR-Filter

function [b,k] = fir_rc(fa, T, alpha, N)

n = -(N-1)/2:1:(N-1)/2;
t = n/fa;

nom = sinc(t/T).*cos(pi*alpha*t/T);
denom = (1 - (2*alpha*t/T).^2);

% Find zero elements
ze = find(abs(alpha*t/T) == 0.5);

nom(ze) = pi/4 * sinc(t(ze)./T);
denom(ze) = 1;

b = (nom./denom).*blackman(N)';
k = 1 /sum(b);