Lower Bound of BER in M-QAM MIMO System with Ordered ZF-SIC Receiver

With the advent of multimedia services featured 4th generation (4G) mobile communications, multiple input multiple output (MIMO) combined with multi-level quadrature amplitude modulation (M-QAM) technique gains great popularity for its capability of supporting high data rate. In this paper, the statistical distribution of post signal to noise plus interference ratio (SINR) in each iterative step of optimal ordered zero forcing perfect successive interference cancellation (ZF-OOPSIC) detection is deduced based on order statistics theory. Resultantly, the bit error rate (BER) of M-QAM MIMO system with ZF-OOPSIC detector is analyzed under flat Rayleigh fading channel. This precise analytical BER result could be taken as the lower bound of various zero-forcing ordered successive interference cancellation (ZF-OSIC) receivers. Monte Carlo simulations validate the analytical results and prove the conclusions.