A layer-wise distribution analysis of the WLMMSE-SIC MIMO receiver for rectilinear or quasi-rectilinear signals

Abstract In this brief, we investigate the widely linear minimum mean square error (WLMMSE) successive interference cancellation (SIC) detector in multiple-input-multiple-output systems with rectilinear or quasi-rectilinear transmit signals. To this end, layer-wise approximate probability density functions (PDFs) of the post-detection signal-to-interference-plus-noise ratio are first derived. It is next shown that the so-derived PDFs enable explicit and concise performance evaluations in terms of the symbol error rate and the outage probability. For rigor, both the cases with and without inter-layer error propagation are addressed, and closed-form solutions are provided. Validity of theoretical analysis is demonstrated via Monte Carlo simulations.