Secrecy Performance Improvement of a NOMA VLC Cellular Network With Artificial Noise

In this paper, we investigate the physical layer secrecy of a non-orthogonal multip le access (NOMA) VLC cellular network, where all users are moving based on the random waypoint mobility model. To improve the secrecy performan ce of the proposed network, we consider the artificial light induced noise with the aim of disrupting the eavesdropper. More precisely, by considering the dynamic behavior of the network, we formulate the achievable secrecy rate of the legitimate users. To allocate power to legitimate users, we modify two well-known fixed power allocation and the gain ratio power allocation methods to improve the network sum secrecy rate. The num erical results indicate that the secrecy performance of the network is improved at least 2dBs by employing the modified power allocation methods plus the artificial noise compared with the case of using the conventional version of the power allocation methods, which this value scales for higher tran smit p owers. F urtherm ore, the effect of half-power angle of the optical transmitter is considered with simulation results showing an optimum value for the half-p ower angle, which can vary depending on the considered scenario.