Low complexity LED grouping based precoding‐aided spatial modulation for highly correlated large‐scale MIMO‐VLC channels

Abstract

In this study, the authors propose a new precoding-aided spatial modulation (SM) to improve the transmission performance over significantly high correlated indoor multi-input multi-output visible light communication (MIMO-VLC) channels. Especially, their precoder design relies on the fixed-sized light-emitting diode (LED) grouping and transmit beamforming, which plays an important role in enhancing the system performance. First, they propose an approximate discrete-input continuous-output memoryless channel capacity based precoder design, which offers better performance at the cost of high-computational complexity. As far as large-scale MIMO-VLC schemes are considered, the proposed precoder design presents to be impractical. Therefore, they develop a spatial correlation measure-based fast LED grouping algorithm to construct the precoder for large-scale MIMO-VLC systems. Their simulation results show that the proposed precoding-aided SM scheme can outperform the precoding-aided spatial multiplexing over significantly high correlated large-scale MIMO-VLC channels when the proposed fast LED grouping is performed, whereas the latter scheme can perform better than their proposed scheme for less correlated channels.