Novel Index Modulation Aided Non-Orthogonal Multiple Access for Visible Light Communication

In this paper, a novel index modulation aided non-orthogonal multiple access (NOMA) scheme is proposed for visible light communication (VLC). Unlike the conventional NOMA schemes, the proposed scheme conveys information for different users through both the index-domain and constellation-domain symbols with the aid of index modulation, which is able to cancel the intra-cluster interference completely and avoid the use of successive interference cancellation to decrease computational complexity. The achievable multi-user sum rate of the proposed scheme is analyzed and a closed-form expression of the lower bound is derived. Then, an approximation is further obtained to realize accurate prediction of the achievable multi-user sum rate. Simulation results validate the accuracy of the approximation of the achievable sum rate and the superior performance of the proposed scheme.