Design and Performance Analysis of RIS-Aided DCSK-WPC System With Energy Buffer

Abstract

In this paper, we propose a simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) and energy buffer aided multiple-input single-output (MISO) simultaneous wireless information and power transfer (SWIPT) nonorthogonal multiple access (NOMA) system, which consists of a STAR-RIS, an access point (AP), and reflection users and transmission users with energy buffers. In the proposed system, the multi-antenna AP can transmit information and energy to several single-antenna reflection and transmission users simultaneously in a NOMA fashion, where the power transfer and information transmission states of the users are modeled using Markov chains. The reflection and transmission users harvest and store the energy in energy buffers as additional power supplies. The power outage probability, information outage probability, sum throughput, and joint outage probability closed-form expressions of the proposed system are derived over Nakagami-m fading channels, which are validated via simulations. Results demonstrate that the proposed system achieves better performance in comparison to the STAR-RIS aided MISO SWIPT-NOMA buffer-less, conventional RIS and energy buffer aided MISO SWIPT-NOMA, and STAR-RIS and energy buffer aided MISO SWIPT-time-division multiple access (TDMA) systems. Furthermore, a particle swarm optimization based power allocation (PSO-PA) algorithm is designed to maximize the sum throughput with a constraint on the joint outage probability. Simulation results illustrate that the proposed PSO-PA algorithm can achieve an improved sum throughput performance of the proposed system. Index Terms-Simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS), energy buffer, simultaneous wireless information and power transfer (SWIPT), non-orthogonal multiple access (NOMA), Markov chains.

Closed-Form Expressions of Upper Bound for Polarization-MDCSK System

“…is the polarization of the l symbol. The d 2 l n ,l s is obtained from (11) when ∆ε = 0 [8]. The closed expression is then calculated for each of these three components.…”

“…The scheme utilizes the advantages of MDCSK, such as low cost, less complexity, little power, and excellent anti-interference capabilities over multi-path fading channels [ 9 , 10 ]. Moreover, it only requires a simple non-coherent demodulator without channel estimation and equalization [ 11 ].…”

Performance Analysis and Resource Allocation of STAR-RIS Aided Wireless-Powered NOMA System

“…In [15], a RIS aided wirelesspowered sensor network was studied, where the RIS is deployed to enhance the sum throughput by intelligently adjusting the phase shift of each reflecting element. In [16], an energy buffer and RIS aided WPC system was proposed to improve the error performance. In [17], it was revealed that the doubly near-far issue in MIMO WPCN can be solved effectively with a rigorous deployment of the RIS.…”