On the performance of RSMA-Based Visible Light Communication Systems With Multicolor LED

Abstract

In this work, we analyze the performance of rate-splitting multiple access (RSMA) in visible light communication (VLC) systems using multicolor light-emitting diodes (LEDs). The system splits the data of users into a common stream decoded by all users and user-specific private streams, maps these streams onto the color channels of a multicolor LED, and uses successive interference cancellation (SIC) at the receiver side to exploit color diversity. Closed-form expressions are derived for the key performance metrics such as outage probability (OP), coverage probability, and ergodic sum rate under the Lambertian channel model. To concurrently mitigate multiuser interference, which arises from cross-color coupling, and optimize the power division between the common and private data streams, a joint precoding and power allocation strategy is implemented. More specifically, the resulting nonconvex optimization problem is efficiently solved by an equivalent convex reformulation to efficiently obtain the optimal power allocation coefficients. Numerical results demonstrate that in the low-to-moderate common rate regime, RSMA demonstrates superior performance over the conventional scheme regarding coverage probability and ergodic sum rate. This improvement further enhances the reliability and spectral efficiency for VLC systems that employ practical multicolor LED configurations.