基于统计CSI的空中智能反射面辅助大规模MIMO系统传输优化方案  

Transmission optimization scheme of aerial intelligent reflecting surface-aided massive MIMO systems based on statistical CSI

作　　者：马露洁 梁彦[1] 李飞[1] MA Lujie;LIANG Yan;LI Fei(School of Communications and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China)

机构地区：[1]南京邮电大学通信与信息工程学院,江苏南京210003

出　　处：《物联网学报》2024年第1期17-28,共12页Chinese Journal on Internet of Things

基　　金：国家自然科学基金项目(No.61871238)。

摘　　要：智能反射面(IRS,intelligent reflecting surface)被认为是下一代移动通信的核心技术,其在增强网络覆盖、频谱效率、能源效率和部署成本方面具有显著优势。空中智能反射面(AIRS,aerial intelligent reflecting surface)结合了空中平台的高移动性和智能反射面提供的优质链路特性,可以有效解决复杂通信场景中基站与用户之间易受障碍物阻挡的问题,从而增强网络覆盖。针对AIRS辅助的多用户大规模多输入多输出(MIMO,multiple input multiple output)系统,研究了基站波束成形、AIRS部署位置与相移设计的联合优化问题。在已知统计信道状态信息(CSI,channel state information)的条件下,提出了一种基于块坐标下降(BCD,block coordinate descent)的系统遍历和速率优化方案。首先,建立了一个联合优化基站端波束成形、AIRS的部署位置与AIRS相移的复杂优化模型。其次,通过BCD算法,将非凸优化问题解耦成3个易于处理的子问题。最后,分别采用拉格朗日乘子法、松弛变量法和RMSProp梯度下降算法求解子问题。仿真结果表明,所提出的优化方案有效地提高了系统的遍历和速率,并且具有较好的收敛性。The intelligent reflecting surface(IRS)is considered a core technology of next-generation mobile communication.It has significant advantages in enhancing network coverage,spectrum efficiency,energy efficiency and deployment cost.The aerial intelligent reflecting surface(AIRS),which combines the high mobility of the air platform and the high-quality link characteristics provided by the intelligent reflecting surface,can effectively assist the transmission from the base station to the users in complex communication scenarios and enhance the network coverage.A joint optimization problem of the base station beamforming,AIRS deployment location and phase shift design for the AIRS was studied for AIRS assisted multi-user massive multiple input multiple output(MIMO)systems.Under the condition of the statistical channel state information(CSI)being known,an optimization scheme of system ergodic sum rate based on block coordinate descent(BCD)was proposed.Firstly,an optimization model was established by jointly optimizing the transmit beamforming at base station,the placement and the phase shift for AIRS.Secondly,the nonconvex optimization problem was decoupled into three subproblems that were easy to deal with by BCD algorithm.Finally,lagrange multiplier method,relaxation variable method and RMSProp gradient descent algorithm were used to solve the subproblems respectively.The simulation results show that the proposed optimization scheme can effectively improve the ergodic sum rate of the system with good convergence properties.

关 键 词：大规模多输入多输出 空中智能反射面 统计信道状态信息 位置优化 波束成形 

分 类 号：TN929.5[电子电信—通信与信息系统]