# How to express random signal in MATLAB which is transmitted from transmitter to receiver

I am trying to model a random transmitted signal between transmitter (source) to receiver.

Specifically, the transmitter has $$N_s = 1$$ antenna and receiver has $$N_r = 2$$ antennas.

My query is that I am having doubt in writing MATLAB code for this system. I had written the code in two ways. So could any one pls tell whether the code written in (1) is correct or code written in (2) is correct.

xs = sqrt(v_S/2)*(randn(N_s,N_r)+1i*randn(N_s,N_r)); % ----(1)


where v_s is variance of transmitted signal such that v_s = 1, N_s and N_r are antennas at transmitter and receiver respectively.

xs = sqrt(v_S/2)*(randn(1,1)+1i*randn(1,1)); % ----(2)


Any help in this regard will be highly appreciated.

• The variance of the transmitted signal v_S is completely unrelated to the variance of the noise at each receiver.
– MBaz
Oct 21, 2023 at 2:43
• Ok... Thank u sir...but in many MATLAB codes I have seen the same way of modelling the signal Oct 21, 2023 at 18:07