Introducing erasures in MIMO with successive interference cancellation to reduce error propagation

Multiple-input multiple-output (MIMO) spatial multiplexing is gaining increasing attention in UWB systems based on OFDM to further increase data rates. This can be obtained by adopting low-complexity minimum mean-square error (MMSE) or Zero Forcing (ZF) filtering in conjunction with successive interference cancellation (SIC). However, interference cancellation techniques are affected by the error propagation phenomenon. In this paper we propose a simple modification of the slicer for each layer of a low-complexity MIMO receiver with SIC, to reduce the effect of error propagation. The proposed modification, which has a negligible cost, is shown to provide an improvement of up to 25% in terms of symbol error probability (SEP).