IRS辅助的多载波NOMA系统上行传输方案研究OA

Poor performance of cell-edge users has long been a major challenge for telecommunications operators.This work investigates the performance enhancement for multi-cell,multi-carrier systems assisted by Intelligent Reflecting Surfaces(IRS).Specifically,an uplink Non-Orthogonal Multiple Access(NOMA)transmission model consisting of two cells is established,where an IRS is deployed at the boundary between the two cells to improve the coverage quality in the cell-edge region.Coordinated Multi-Point(CoMP)technology is employed to jointly detect the signals of edge users,thereby enhancing their performance.Different from existing studies,the proposed approach considers the impact of frequency-selective phase shift errors of IRS reflecting elements in wideband communication systems,and formulates a joint optimization problem of transmit power and phase shift.Due to the strong coupling between optimization variables,the original problem is difficult to solve directly.To tackle this joint optimization model,an explicit relationship between transmit power and phase shift is derived,the original coupled problem is equivalently transformed into a pure phase design problem.A continuous phase rotation algorithm is developed to solve the reformulated problem.Simulation results show that,under the same quality-of-service constraints,the proposed scheme achieves a lower total transmit power than all benchmark methods.