Quadrature spatial modulation in correlated η-μ fading channels with imperfect channel state information

In this paper, the performance of quadrature spatial modulation (QSM) multiple-input multiple-output (MIMO) systems in the presence of imperfect channel state information (CSI) and under correlated η-μ fading channels is investigated. A simple and closed-form expression for the pairwise error probability (PEP) is provided. Based on the obtained PEP, a closed-form upper bound expression for the average bit error probability (BEP) is provided. Some representative numerical examples are presented to show the influence of the fading parameters, imperfect estimation, and correlation on the average BEP.