基于不完美硬件系统的双智能反射面辅助波束赋形设计

Dual IRS Assisted Beamforming Design in Hardware Damage System

在发射端具有不完美硬件的多输入多输出(Multiple Input Multiple Output,MIMO)系统中,存在失真噪声和干扰噪声,这导致用户侧接收信号受损,系统频谱效率低下。为解决此问题,考虑使用双智能反射面(Intelligent Reflecting Surface,IRS)辅助,联合优化基站波束赋形矩阵和两个IRS的反射相移矩阵,最大化多用户和速率。目标函数是变量高度耦合、复杂的非凸优化问题,分别使用交替优化方法、半正定松弛(Semi-Definite Relaxation,SDR)算法和奇异值分解归一化的方法求解。仿真结果表明,在发射端具有不完美硬件的MIMO系统中,与单IRS辅助和无IRS方案相比,使用双IRS辅助通信能够获得更好的系统频谱效率。

In MIMO(Multiple Input Multiple Output)systems with hardware damage at the transmitter,there is distortion noise and interference noise,which leads to the damage of the user’s received signal and the low spectral efficiency of the system.To address these problems,this paper considers the use of a dual IRS(Intelligent Reflecting Surface)to assist,and jointly optimizing the beamforming matrix of the basestation and the reflection phase shift matrix of the dual IRS to maximize multiple users’sum-rate.The objective function is a highly coupled and complex non-convex optimization problem that can be solved by alternate optimization method,SDR(Semi-Definite Relaxation)algorithm and singular value decomposition normalization method,respectively.Simulation results indicate that compared with single IRS assisted scheme and no IRS scheme,the dual IRS assisted scheme can obtain better spectral efficiency performance in MIMO system with hardware damage.