How to extend g0=exprnd(1,1e6,1); from SISO to MISO,SIMO or MIMO,

Hi

I have to select best channel condition i need help to know how g0=exprnd(1,1e6,1); which is currently being used as SISO how possibly be extended for multiple antenna's and when i try to calculate ergodic capacity its not working.

for g=1:100

% Generates Channel fading states randomly

g0=exprnd(1,1e6,1); P1(g)=Bla Bla SINR(:,g)=(Bla Bla).*g0); end for S=1:length(SINR)

    % Ergodic Capacity Over Rayleigh fading channel
    C_Ral=mean(log2(1+SINR(:,S)));

end

Cheers