Enhanced performance of spatial modulation with angular diversity receiver for indoor visible light communication

Multi-input-multi-output (MIMO) technique is adapted to achieve high speed transmission in visible light communication (VLC) system. In MIMO VLC system, spatial modulation (SM) is employed to avoid inter-channel interference (ICI). However, the performance of SM MIMO indoor VLC system is restricted by the high channel response correlation. In this paper, we propose an angular diversity receiver approach for SM MIMO VLC system. By varying the receivers' normal vectors, the correlation of the channel transfer matrix is effectively reduced, which leads to 7 ~ 8dB signal-to-noise ratio (SNR) gains at BER level of 10-3 compared to the conventional SM in MIMO VLC system. Additionally, the horizontal rotation and vertical shift invariance verified by the simulation results makes the proposed scheme more practical and easier to be implemented.