Power and Rate Optimization for Visible Light Communication System With Lighting Constraints

Visible-light communication (VLC) will be deployed in various indoor environments, including those requiring different lighting colors, which imposes the needs for transmission optimization under certain lighting constraints. This work establishes a framework for the transmission power and rate optimization, for light emitting diode (LED)-based VLC systems under lighting constraints. We describe the system model of LED-based color-division VLC system, which incorporates the transmission power spectral density, the receiving optical filters, the human eye perception, and the lighting constraints. Then, we formulate the corresponding power and rate optimization problems, for both point-to-point communication system and broadcast communication system. More specifically, for a point-to-point communication system, it maximizes the transmission rate subject to the transmission power constraint and the lighting constraint; and for a broadcast system, it minimizes the total transmission power subject to some quality of service (QoS) constraint across all receivers. Various convex optimization problems have been formulated and solved analytically or using standard convex optimization solutions. It is obsesrved that the optimal symbol modulation power allocation scheme significantly outperforms the equal power allocation scheme.