Optimal power allocation for multi-LED phase-shifted based indoor MISO VLC systems with linear receivers

Abstract

The paper develops a power allocation strategy for Multi-LED phase-shifted superposition technique that parallelly transmitted to increase the rate of visible light communication (VLC) systems. In this paper, we apply linear zero forcing (ZF) detection and present an optimal power allocation strategy for multi-LED phase-shifted pulse amplitude modulation based indoor VLC multi-input single-output (VLC-MISO) systems, while preserving a low-complexity. Meanwhile, a closed-form allocation solution to the optimization problem under optical power constraint is obtained and the optimal design criterion is the max-SEP minimization. We compare the proposed optimal power allocation scheme based on ZF detection with the uniform scheme of the ZF and maximum likelihood (ML) detection in a set of numerical simulations. The simulation results show that the proposed power allocation strategy outperforms the uniform scheme and is very close to ML detection in some special channel scenarios, while improving the condition number of the equivalent channel.