Rate Splitting Multiple Access for Simultaneous Lightwave Information and Power Transfer
Zhengqing Qiu, Yijie Mao
TL;DR
This work addresses multi-user visible-light communication with simultaneous information and power transfer (SLIPT) by introducing rate-splitting multiple access (RSMA) in a time-splitting (TS) receiver mode, parameterized by $\theta$. It develops a CCCP-based beamforming design that leverages bilinear transformations, semidefinite relaxation (SDR), and a rank-one penalty to solve the non-convex max-min rate problem under per-user energy harvesting constraints and lighting requirements, resulting in a sequence of convex subproblems. A closed-form lower bound for RSMA-based information decoding is derived, and the system is evaluated in realistic indoor VLC scenarios showing substantial performance gains over SDMA and NOMA baselines across energy thresholds and SNRs, limited primarily by the optical-power constraint at high SNR. The results indicate RSMA is a potent multiple-access approach for VLC systems that must support simultaneous illumination, communication, and energy harvesting, especially with solar-panel receivers.
Abstract
This paper initiate the application of rate splitting multiple access (RSMA) for simultaneous lightwave information and power transfer (SLIPT), where users require to decode information and harvest energy. We focus on a time-splitting (TS) mode where information decoding and energy harvesting are separated in two different phases. Based on the proposed system model, we design a constrained-concave-convex programming (CCCP) algorithm to solve the optimization problem of maximizing the worst-case rate among users subject to the harvested energy constraint at each user. Specifically, the proposed algorithm exploits transformation of the bilinear function, semidefinite relaxation (SDR), CCCP, and a penalty method to effectively deal with the non-convex constraints and objective function. Numerical results show that our proposed RSMA-aided SLIPT outperforms the existing baselines based on space-division multiple access (SDMA) and non-orthogonal multiple access (NOMA).