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