I am trying to calculate the unit vector and standard deviation of the signal. I hope everyone can give me ideas. Here is my scenario: I have 2 rx channels: - f is channel 1 with the length 1x256 complex, then FFT. - g is channel 2 with the length 1x256 complex, then FFT. - from f and g, I can calculate the spectrum density S_fg = f * conj(g), with the length 1x256 complex S_fg = f * conj(g) t_0 = 1 / f_0; r_0 = t_0 / (2 * pi); delay = angle(S_fg) * r_0 * 1e12; % in pico second d = median(delay); since I have those parameters, How can i calculate the unit vector (x,y), and standard deviation? The unit vector maybe calculated by the equation: x = 1*cos(delay); % 1x256 y = 1*sin(delay); % 1x256 but I do not know how to get the standard deviation? Hope anyone can help?