A Nonlinear Precoding Design for Two-Group Alamouti System in MIMO Correlated Channel

In order to simplify the detection complexity of the receiver and improve the bit error rate (BER) performance of the two-group Alamouti system in correlated channel, we design a nonlinear precoding scheme for two-group Alamouti system in multiple input multiple output (MIMO) correlated channel in this paper. We apply the geometric mean decomposition (GMD) algorithm to the equivalent channel matrix and the dirty paper coding (DPC) technique to the transmitter of the system. Thus, interference between signals can be eliminated at the transmitter, meanwhile, sub-channel with equal gain are obtained. However, a high peak power ratio is caused by the dirty paper coding technique at the transmitter. To solve this problem, Tomlinson-Harashima Precoding (THP) with modulo operation is applied to the transmitter. From the simulation results, it is observed that the proposed system can significantly improve the BER performance as well as Peak-to-Average Power Ratio (PAPR) performance.