How do i simulate hybrid combining technique of Selection and Maximal Ratio Combining?

consider a hybrid technique that selects the maximum K (out of N) diversity branches, and combines them using maximal ratio combining How can we simulate the BER of a BPSK modulated signal for the case where N = 3 and k = 2, assuming an independent Rayleigh fading over the branches with E (|h^2|)=1 .