非正交多址系统性能分析

Performance Analysis of Non-Orthogonal Multiple Access System

与传统的正交多址接入相比,在非正交多址接入中,无线电通过功率域复用允许多用户在相同频率内同时发射和接收信号,从而提升系统频谱的利用率。因此,非正交多址接入技术被认为是下一代网络的核心技术之一。基于随机几何将系统建模为泊松点过程,在误差干扰传播模型下,近端用户采用非理想SIC抵消远端用户的干扰,即近端用户具有最大干扰残留误差。基于此模型,主要分析下行NOMA系统中远端用户和近端用户的覆盖率和平均可达速率。仿真验证中,主要研究功率分配因子和非理想SIC误差因子对用户覆盖率和平均可达速率的影响,验证了NOMA可在一定程度上通过功率域复用提升远端用户的平均可达速率。

Compared with the traditional orthogonal multiple access,in the non-orthogonal multiple access,the radio allows multiple users to simultaneously transmit and receive signals in the same frequency through power domain multiplexing,thereby improving the utilization of the system spectrum.Therefore,non-orthogonal multiple access technology is considered to be one of the core technologies of next generation networks.The system is modeled as a Poisson point process based on stochastic geometry.Under the error interference propagation model,the cell-center user uses the non-ideal SIC to cancel the interference of the cell-edge user,that is,the cell-center user has the largest interference residual error.Based on this model,the coverage and average reachability of cell-center users and cell-edge users in the downlink NOMA system are mainly analyzed.In the simulation verification,the effects of power allocation factor and nonideal SIC error factor on user coverage and average reachability are studied.It is verified that NOMA can improve the average reachability of cell-center users by power domain multiplexing to some extent.