Joint Optimization of Slot Selection and Power Allocation in Integrated Visible Light Communication and Sensing Systems

The integrated sensing and communication has emerged as a key technology for future wireless systems. This article considers a multislot integrated visible light communication and sensing (IVLCS) system. In the IVLCS system, the primary purpose is sensing, while the second purpose is communication. We formulate a joint slot selection and power allocation problem by minimizing the total transmitted power under the echo-to-noise ratio constraint, communication sum rate constraint, sensing slot number constraint, and power constraint. Such a problem is shown to be nonconvex. After convex relaxation reformulation, the original problem is divided into a sensing subproblem and a communication subproblem. We propose a sensing priority and power minimization-based joint slot selection and power allocation (SPPM-JSSPA) algorithm to solve the two subproblems. To further reduce the complexity, a low-complexity fixed slot selection and power allocation (FSSPA) algorithm is also proposed. The convergence and complexity analysis indicates that both the proposed SPPM-JSSPA algorithm and the FSSPA algorithm are convergent and efficient. Numerical results show that the proposed SPPM-JSSPA algorithm can obtain the best performance compared to the existing algorithms, and the low-complexity FSSPA algorithm can achieve a comparable performance to the SPPM-JSSPA algorithm.