Closed-Form BER Expressions for BPSK Using MRC with Multiple Interferers in Arbitrarily Correlated Rayleigh Fading

An exact and closed-form expression for the average bit error rate (BER) of coherent binary phase-shift keying (BPSK) using maximal ratio combining (MRC) in the presence of multiple cochannel interfering users is derived for correlated Rayleigh fading. Under the assumption that the branch gains of the desired user signal and interfering signals experience correlated Rayleigh fading with the same correlation eigenvector matrix, as is the case for receiver diversity in an omnidirectional scattering environment, this BER expression is valid for arbitrary correlation structure such as 2-D and 3-D channel correlation models, and applys for an arbitrary number of interfering users and an arbitrary number of receiver antennas.