A precoding scheme to reduce the effect of channel correlation for MIMO-PLC system

MIMO technique can provide higher information throughput and transmission reliability for the PLC system. However, the MIMO-PLC system based on three-conductor cable has a high correlation among its sub-channels. Spatial multiplexing technology will be affected by the spatial correlation between MIMO-PLC sub-channels. To reduce the system bit error rate caused by MIMO-PLC correlation among sub-channels, this paper proposed a phase rotation precoding scheme for the 2 × 2 closed-loop MIMO-PLC system. According to the channel transfer function of high correlation MIMO-PLC system, the phase rotation precoding matrix F is calculated, and the transmission signal matrix S is modulated with the F, the code distance at the receiving point with smallest code distance is increased by phase rotation. Simulation results show that the scheme can effectively reduce the bit error rate of the 2 × 2 MIMO-PLC system based on ML detection, and significantly improve the system performance.