协作IRS辅助的CoMP-NOMA网络传输方案

A Transmission Scheme for Cooperative-IRS-Aided CoMP-NOMA Networks

为解决多小区网络中上行传输功率最小化问题,本文提出了一种基于多智能反射面(Intelligent reflecting surface,IRS)的协作多点非正交多址接入(Coordinated multiple point-nonorthogonal multiple access,CoMP-NOMA)系统上行传输方案。具体来说,在小区中心与边缘分别部署IRS提升小区中心用户与边缘用户的传输质量,同时考虑中心和边缘IRS之间的信号反射。为了求解建立的总发射功率最小化问题,本文推导了发射功率与相位偏移之间的关系,并进一步将功率分配系数和相位偏移联合优化问题转化为纯相位优化问题,并进一步采用顺序旋转法将转换后的问题分解为多个一维搜索问题进行求解。仿真结果表明,在相同仿真环境下,本文提出的解决方案在发射功耗方面明显优于其他基准方案。

To address the uplink transmit power minimization problem for multi-cell scenarios,this paper proposes an uplink transmission scheme for the coordinated multiple point-nonorthogonal multiple access(CoMP-NOMA)system with the collaboration of multiple intelligent reflecting surfaces(IRSs).Specifically,a couple of IRSs are deployed at the cell-center and the cell-edge respectively,to improve the transmission quality for both the cell-center and the cell-edge users,in which the inter-IRS reflection between the cell-center and the cell-edge IRSs is considered.To solve the formulated power minimization problem,the relation between the power allocation coefficients and the phase shifts is developed.Further,the joint optimization problem of power allocation and phase shift is converted into a pure phase shift determination problem,which is transformed to a series of one-dimensional search problems by using the sequential rotation method.Simulation results demonstrate that the proposed solution significantly outperforms other benchmark schemes in terms of transmit power consumption under the same simulation setups.