NOMA for Multiple Access Channel in Indoor Visible Light Communications

In this letter, we consider a scenario of indoor visible light communications (VLC) where multiple transmitters (Txs) are communicating to a single receiver and each Tx uses a single light emitting diode (LED). For the considered multiple access channel scenario, we propose a generalized scheme based on non-orthogonal multiple access (NOMA) that can be applied for any number of Txs and any desired spectral efficiency for each of the Txs. We evaluate the performance of the proposed scheme using successive interference cancellation (SIC) based decoding, joint maximum likelihood (JML) decoding, and a combination of SIC and JML decoding. The numerical results indicate superior performance of the proposed NOMA-VLC scheme as compared to the state-of-the-art orthogonal multiple access schemes for VLC.