MSE-Based Precoder Designs for Receive Quadrature Spatial Modulation Systems

This paper addresses the mean-square-error (MSE) based precoder design problems for a new multiple- input-multiple-output (MIMO) system employing the new Receive Quadrature Spatial Modulation (RQSM). We investigate the precoder design problem under the average total power constraint (ATPC), average per-antennna power constraint (APAPC), peak per- antenna power constraint (PPAPC), and the strict per-antenna power constraint (SPAPC). We show that the ATPC precoder can be obtained in closed-form, while the APAPC, PPAPC, SPAPC precoders can be formulated into a unified SOCP framework. The performance of these precoder design have been studied via numerical simulations and compared with the conventional power-backoff assisted approaches.