基于SWIPT NOMA的星地系统性能分析

Performance analysis of SWIPT NOMA based satellite-terrestrial system

为了提高星地系统的资源利用率和用户公平性,提出一种无线携能(simultaneous wireless information and power transfer,SWIPT)非正交多址接入(non-orthogonal multiple access,NOMA)技术辅助星地系统的传输方案.首先,在非理想信道状态信息(channel state information,CSI)条件下研究了系统的中断性能,并推导了中断概率表达式.其次,通过分析渐近中断概率,发现由于存在非理想CSI导致中断概率在高信噪比区域出现了错误平层.此外,还研究了不同程度的信道估计误差和阴影衰落对系统吞吐量和能量效率的影响.最后,通过数值仿真结果验证了理论推导的正确性和SWIPT NOMA技术引入星地系统所获得的性能增益.

In order to improve the resource utilization and user fairness of satellite-terrestrial system,a simultaneous wireless information and power transfer(SWIPT)non-orthogonal multiple access(NOMA)technology assisted satellite-terrestrial system transmission scheme is proposed.Firstly,the outage performance of the system is investigated in the presence of imperfect channel state information(CSI),and the outage probability expression is derived.Secondly,by analyzing the asymptotic outage probability,it is observed that there is an error floor in the high SNR region due to the existence of imperfect CSI.In addition,the effects of channel estimation errors and shadow fading on system throughput and energy efficiency are studied.Finally,the numerical simulation results are provided to validate theoretical derivation and the performance gains obtained by introducing SWIPT NOMA technology into the satellite-terrestrial system.