非正交多址接入的同步透射反射智能超表面信号增强算法  

A Signal Enhancement Algorithm for Simultaneous-Transmittingand-Reflecting Reconfigurable Intelligent Surface Based on Non-Orthogonal Multiple Access Networks

作　　者：侯天为 李洁[1] 王俊[1] 宋政育[1] 孙昕[1] HOU Tianwei;LI Jie;WANG Jun;SONG Zhengyu;SUN Xin(School of Electronic and Information Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学电子信息工程学院,北京100044

出　　处：《北京邮电大学学报》2024年第1期7-12,共6页Journal of Beijing University of Posts and Telecommunications

基　　金：国家自然科学基金项目(62201028);中国科协“青年人才托举”项目(2022QNRC001);欧盟“玛丽居里学者”项目(101106428)。

摘　　要：针对传统智能超表面无法透射信号的问题,利用同步透射反射智能超表面,提出了一种基于非正交多址接入的信号增强算法。同步透射反射智能超表面具有全向性的特点,可同时服务两侧的非正交多址接入用户。所提算法将同步透射反射智能超表面的信号与通信信号相干叠加,利用黎曼共轭梯度算法求解优化问题,理论上可大幅增强用户的信号功率,降低中断概率,提高频谱效率性能。由仿真结果可知,与不使用同步透射反射智能超表面相比,随机相位的同步透射反射智能超表面可以提高约3.6 bit/(s·Hz)的系统频谱效率。利用黎曼共轭梯度算法优化后,可进一步提高约2.3 bit/(s·Hz)的系统频谱效率,该结果验证了所提算法的优越性。In order to overcome the non-transition issue of the conventional reconfigurable intelligent surface,a signal enhancement algorithm based on non-orthogonal multiple access networks is proposed,aided by simultaneous-transmitting-and-reflecting reconfigurable intelligent surfaces.By utilizing the omni property of the simultaneous-transmitting-and-reflecting reconfigurable intlligent surface,it is possible to serve multiple users on both sides simultaneously.Since the direct signal and the reflected signals through simultaneous-transmitting-and-reflecting reconfigurable intelligent surface can be coherent,and by utilizing the Riemannian conjugate gradient algorithm,the signal power level of non-orthogonal multiple access users can be significantly boosted by the proposed signal enhancement based algorithm.As a result,the outage probability is decreased and the transmission rate performance is enhanced.Simulation results show that an improvement of 3.6 bit/(s·Hz)spectral efficiency is observed in the random phase shift scenario,compared to the scenario without simultaneous-transmitting-and-reflecting reconfigurable intelligent surface.Furthermore,an extra 2.3 bit/(s·Hz)gain on the spectral efficiency can be obtained when the proposed Riemannian conjugate gradient algorithm is employed,which validates the superiority of the proposed algorithm.

关 键 词：同步透射反射智能超表面 非正交多址接入 信号增强算法 中断概率 通信速率 

分 类 号：TN929.5[电子电信—通信与信息系统]