Enhanced transmitter designs for indoor MIMO-VLC systems

Abstract

Multiple-input multiple-output (MIMO) technology, a fundamental element of 6G, has been widely implemented in visible light communication (VLC) systems. However, actual MIMO-VLC systems face significant challenges due to severe channel correlation. To tackle this issue, in this paper, we propose two enhanced transmitter designs for performance improvement of indoor MIMO-VLC systems, including single transmitter partial coverage (STPC) and enhanced STPC. For the STPC scheme, a single LED transmitter only needs to cover part of the receiving plane, instead of covering the whole receiving plane as in the conventional single transmitter full coverage (STFC) scheme. For the enhanced STPC scheme, each light-emitting diode (LED) is replaced with an LED subarray so as to further improve the system performance. Our simulation results reveal that the system performance is influenced by the LED array spacing, LED subarray spacing, and the LED semi-angle at half power. We identify the optimal combinations of these parameters to maximize the average achievable spectrum efficiency of the system. Notably, the STPC and Enhanced STPC schemes demonstrate increases in average achievable spectrum efficiency of 478.14% and 589.49%, respectively, compared to the benchmark STFC scheme.