《计算机应用》唯一官方网站 ›› 2023, Vol. 43 ›› Issue (11): 3559-3567.DOI: 10.11772/j.issn.1001-9081.2022101559

• 网络与通信 • 上一篇    下一篇

RIS辅助索引调制协作系统的误码率性能分析

喻诚皓1,2, 仇润鹤1,2()   

  1. 1.东华大学 信息科学与技术学院,上海 201620
    2.数字化纺织服装技术教育部工程研究中心(东华大学),上海 201620
  • 收稿日期:2022-10-20 修回日期:2023-01-11 接受日期:2023-01-16 发布日期:2023-04-12 出版日期:2023-11-10
  • 通讯作者: 仇润鹤
  • 作者简介:喻诚皓(1999—),男,湖北应城人,硕士研究生,主要研究方向:空间调制、智能反射面
    仇润鹤(1961—),男,上海人,教授,博士,主要研究方向:无线通信系统、协作中继网络、认知无线电网络。qiurh@edu.cn
  • 基金资助:
    上海市自然科学基金资助项目(20ZR1400700)

Performance analysis of bit error rate on RIS assisted index modulation cooperative system

Chenghao YU1,2, Runhe QIU1,2()   

  1. 1.College of Information Sciences and Technology,Donghua University,Shanghai 201620,China
    2.Engineering Research Center of Digitalized Textile and Fashion Technology,Ministry of Education (Donghua University),Shanghai 201620,China
  • Received:2022-10-20 Revised:2023-01-11 Accepted:2023-01-16 Online:2023-04-12 Published:2023-11-10
  • Contact: Runhe QIU
  • About author:YU Chenghao, born in 1999, M. S. candidate. His research interests include spatial modulation, reconfigurable intelligent surface.
    QIU Runhe, born in 1961, Ph. D., professor. His research interests include wireless communication system, cooperative relay network, cognitive radio network.
  • Supported by:
    Natural Science Foundation of Shanghai(20ZR1400700)

摘要:

针对中继协作通信在发射机和接收机之间的直接路径信号较弱,且信噪比(SNR)低的场景,提出一种智能反射面(RIS)辅助解码转发(DF)中继的协作索引调制(IM)系统(RIS-DF-IM)。在该系统中,RIS作为智能接入点(AP)充当源节点和中继节点发射机的一部分,根据发射信息对反射信道进行相位补偿,最大化接收天线的SNR,并对中继和目的节点接收机的多天线进行索引调制,提高系统的频谱效率;同时,利用矩母函数(MGF)法求解所提出的双跳系统误码率(BER)的理论联合界。此外,还提出了一种预贪婪的最大似然简化(SPML)检测器,通过预贪婪减少遍历天线索引数量,以及简化最大似然译码准则式,降低计算复杂度。蒙特卡洛仿真结果表明,在RIS元件数取128且采用空间调制时,RIS-DF-IM与RIS在远端不接入发射机的协作空间调制系统相比,BER降低了约10;与传统的预编码空间调制系统相比,BER大幅降低,约20;SPML检测器相较于最大似然(ML)检测器,BER增加了约1.4,但是计算复杂度减少了一半,实现了BER与复杂度之间的有效平衡。

关键词: 智能反射面, 索引调制, 协作通信, 检测器, 信噪比, 误码率

Abstract:

For relayed collaborative communications have weak signal of direct paths between the transmitter and the receiver and low Signal-to-Noise Ratio (SNR), a Reconfigurable Intelligent Surface (RIS) assisted cooperative Index Modulation (IM) system of Decode-and-Forward (DF) relay (RIS-DF-IM) was proposed. In RIS-DF-IM, as smart Access Points (APs), RISs were adopted as part of the transmitter at the source and relay nodes to perform phase compensation for the reflected channel to maximize the receiving antenna SNR according to the transmission information, and perform IM on multiple antennas of receivers of the relay and destination nodes to improve the spectral efficiency of the system. At the same time, the theoretical union bounds about the Bit Error Rate (BER) of the proposed dual-hop system were solved by using the Moment Generating Function (MGF) method. Besides, a Simplified Pre-greedy Maximum Likelihood (SPML) detector was proposed to reduce the computational complexity by decreasing the number of traversal antenna indexes and simplifying the Maximum Likelihood (ML) decoding criterion formula. Monte Carlo simulation results show that, when the number of RIS elements is 128 and the spatial modulation is adopted, the BER of RIS-DF-IM is about 10 lower than that of the cooperative spatial modulation system where RIS is not connected to the transmitter at the far end; and the BER is dramatically decreased by about 20 compared with the traditional precoded spatial modulation system. Although SPML detector has the BER increased by about 1.4 compared to the Maximum Likelihood (ML) detector, the computational complexity is reduced by a half, achieving an effective balance between BER and complexity.

Key words: Reconfigurable Intelligent Surface (RIS), Index Modulation (IM), cooperative communication, detector, Signal-to-Noise Ratio (SNR), Bit Error Rate (BER)

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