BEP Analysis of MRT/MRC Diversity in Rayleigh Fading Channels

This letter analyzes the bit error probability (BEP) performance of multiple-input/multiple-output (MIMO) systems employing maximal ratio transmission/maximal ratio combining (MRT/MRC) diversity in Rayleigh fading channels, where the channels are known at the both transmitter and receiver. An exact closed-from expression for the BEP performances of square and rectangular quadrature amplitude modulation (QAM) is derived for systems with arbitrary number of transmit antennas and two receive antennas. Moreover, by approximating the probability density function of output signal-to-noise ratio (SNR) and using the close approximation of BEP performance with QAM in additive white Gaussian noise (AWGN), we obtain a simple expression for arbitrary number of transmitter antennas and receive antennas. Simulations show that our approximation is very close to the exact one.