南京邮电大学学报（自然科学版）2025，Vol.45Issue(3)：48-57,10.DOI:10.14132/j.cnki.1673-5439.2025.03.006
IRS辅助OFDMA系统中的宽带相移模型和系统优化
A wideband phase shift model and system optimization in IRS-assisted OFDMA systems
摘要
Abstract
Aiming at the correlation between the reflection phase shift of intelligent reflecting surface(IRS)and the signal frequency,a simple but accurate mathematical model is proposed to describe the re-lationship between the phase shifts of different subcarriers and the phase shift at center frequency.On this basis,the joint optimization problem of maximizing system sum rate is proposed,which incorporates IRS phase shift matrix at center frequency,orthogonal frequency division multiple access(OFDMA)sub-carrier and power allocation.This problem is decomposed into two subproblems,namely,IRS phase-shift optimization and subcarrier and power allocation optimization,and alternatively solving the sub-problems can solve the joint problem.The sub-problem of the IRS phase-shift is converted to a convex problem and then solved by using the successive convex approximation,and the sub-problem of the sub-carrier and power allocation is solved by using the greedy algorithm and the water-filling algorithm.Simu-lation results show that the system sum rate in the scheme with IRS with optimized phase shift matrix is significantly higher than that in the scheme without IRS or that with IRS but with random phase shift.Compared to the scheme that assumes the same phase shift for all subcarriers,the proposed scheme can achieve a higher sum rate under the actual IRS phase shift.关键词
智能反射面/正交频分多址接入/宽带相移模型Key words
intelligent reflecting surface(IRS)/orthogonal frequency division multiple access(OFDMA)/wideband phase shift model分类
电子信息工程引用本文复制引用
余宁,雷维嘉..IRS辅助OFDMA系统中的宽带相移模型和系统优化[J].南京邮电大学学报（自然科学版）,2025,45(3):48-57,10.基金项目
国家自然科学基金(61971080)资助项目 （61971080）
