Multiple-antenna systems, also known as multiple input multiple-output (MIMO) radio, can improve the capacity and reliability of radio communication systems. In this paper, the concept of MIMO systems and the some simulation results for the performance of maximum ratio combining (MRC) are introduced for 16-quadrature amplitude modulation (16-QAM). Also, we introduce the antenna selection method to reduce the complexity of MlMO systems and present results for this method with MRC system when 16-QAM modulation is employed. We observed the differences in performance, cost, and complexity of the full complexity MlMO system and the system with antenna selection.Index Terms-Multiple-input multiple-output (MIMO) systems, maxinmm ratio combining (MRC), antenna selection, 16-quadrature amplitude modulation (QAM).