Simple phase rotation for two-input multile-output spatial multiplexing in transmit correlated channels

In MIMO wireless communications, spatial multiplexing can be employed to achieve high data rate. However, its performance can be degraded in the presence of spatial correlation among transmit antennas. Hence, we propose a simple closed-form linear precoder to improve the performance when two transmit antennas are exploited at the transmitter. For the proposed scheme, we consider a maximum likelihood detector (MLD) at the receiver. Our proposed precoder rotates the constellation by a certain phase which is easily obtained by the correlation matrix of the channel. Simulation results show that the proposed algorithm can achieve near- optimal performance with remarkably reduced computational complexity helped by the closed-form solution.