多有源可重构智能表面辅助通信系统的和速率优化研究

Research on Sum Rate Optimization of Multiple Active Reconfigurable Intelligent Surface Assisted Communication System

近年来,可重构智能表面(Reconfigurable Intelligent Surface,RIS)因其能够智能控制无线信道的能力而被认为是未来6G发展中至关重要的新技术之一。为了克服“乘性衰落”的影响,有源可重构智能表面(Active Reconfigurable Intelligent Surface,ARIS)被提出。但在一些通信质量较差的通信场景中,单个ARIS所带来的增益还不够。对由多个ARIS辅助的通信系统的性能进行了分析。多个ARIS的引入在对入射信号进行放大的同时也对RIS相关噪声进行了放大,为了解决多用户的和速率最大化问题,采用分式规划理论中的拉格朗日对偶变换和二次变换以及交替优化算法在基站和ARIS的功率约束下对基站处预编码矩阵和ARIS反射系数矩阵进行了联合优化。仿真结果表明,由多ARIS辅助的通信系统能够比由多无源RIS辅助的通信系统和单ARIS辅助的通信系统得到更大的和速率。

In recent years,Reconfigurable Intelligent Surface(RIS)is considered as one of the most important new technologies in the future development of 6G due to its ability to intelligently control wireless channels.In order to overcome the influence of“multiplicative fading”,Active Reconfigurable Intelligent Surface(ARIS)is proposed.However,in some communication scenarios with poor communication quality,the gain brought by a single ARIS is not enough.Therefore,the performance of multiple ARIS-assisted communication systems is analyzed.The introduction of multiple ARIS not only amplifies the incident signal,but also amplifies the RIS related noise.In order to solve the problem of multi-user sum rate maximization,Lagrangian dual transformation,quadratic transformation and alternative optimization algorithm in fractional programming theory are used to jointly optimize the precoding matrix and ARIS reflection coefficient matrix at the base station under the power constraints of the base station and ARIS.The simulation results show that multiple ARIS assisted communication system can achieve higher sum rate than multiple passive RIS assisted communication system and single ARIS assisted communication system.