On the performance of the zero-forcing-space-time block coding multiple-input–multiple-output receiver with channel estimation error and error propagation

Multi-user multiple-input-multiple-output (MU-MIMO) systems are a promising technology for increasing spectral efficiency and diversity gain in the up-link channel. Space-time block coding (STBC) or the spatial-multiplexing (SM) scheme may selectively be used by each user. The simple techniques, zero-forcing (ZF), STBC and successive interference cancellation are jointly applied to separate and detect all streams at the ZF-STBC MIMO receiver. Unfortunately the channel estimation error (CEE) and error propagation (EP) are usually presented in practical multi-layers detection. In this study, the author investigates the effect of CEE and EP on the bit error rate (BER) performance of the ZF-STBC MIMO receiver over Rayleigh flat fading channels. They derive a nearly exact closed-form BER for general phase shift keying/quadrature-amplitude modulation with CEE and EP for arbitrary number of users. Finally, simulation results demonstrate the validity of the author´s analysis.