FastFurierTransform

function [result] = func8v2_FFT(signal)
    N = length(signal);
    result = zeros(1, N);

    if N == 2
        result(1) = signal(1) + signal(2);
        result(2) = signal(1) - signal(2);
    else
        left = signal(1:N/2);
        right = signal(N/2+1:end);

        k = 0:N/2-1;
        W = RotateKoef(k, N);
        f = (left + right);
        g = (left - right) .* W;

        f = func8v2_FFT(f);
        g = func8v2_FFT(g);

        result(1:2:end) = f;
        result(2:2:end) = g;
    end
end