在不完美信道状态信息(Channel State Information,CSI)和不完美串行干扰消除(Successive Interference Cancellation,SIC)的场景下,研究了可重构智能表面(Reconfigurable Intelligent Surface,RIS)辅助多用户非正交多址接入(Non-Orthogonal Multiple Access,NOMA)网络的鲁棒资源分配问题.在考虑两类用户(信息用户和能量用户)服务质量(Quality of Service,QoS)和信息用户SIC约束下,建立了基站发射功率最小化的优化问题.该问题是一个多变量耦合的非凸优化问题.为了求解该问题,本文使用松弛变量、线性近似、S-程序、符号定性法转化该问题的非凸约束.然后将优化问题分解为两个子问题,最后使用交替优化方法迭代求解两个子问题,直到发送功率收敛.仿真结果表明:该文算法具有较好的收敛性,实现了资源的鲁棒分配,同时有效地降低基站发射功率.
Abstract
In the scenario of imperfect channel state information(CSI)and imperfect successive interference cancella-tion(SIC),the problem of robust resource allocation in reconfigurable intelligent surface(RIS)assisted multi-user non-or-thogonal multiple access(NOMA)is studied.Considering the constraints of two types of users(information user and energy user)quality of service(QoS)and information user SIC,a transmit power minimization problem is formulated.This optimi-zation problem is a multi-variable coupled non-convex optimization problem.In this paper,the non-convex constraints of the problem are transformed by using relaxation variables,linear approximation,S-procedure,and sign-definiteness meth-ods.Then,the optimization problem is decomposed into two sub-problems,Finally,the alternate optimization method is used to iteratively solve the above sub-problems.The simulation results show that the proposed approach has a good conver-gence behavior,realizes the robust allocation of resources and can effectively reduce the transmit power of the base station.
关键词
可重构智能表面/非正交多址接入/不完美信道状态信息/不完美串行干扰消除/传输功率优化/功率最小化
Key words
reconfigurable intelligent surface/non-orthogonal multiple access/imperfect channel state information/imperfect successive interference cancellation/transmit power optimization/power minimization
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