基于无线供电的非正交多址接入网络的鲁棒资源分配研究

Robust Resource Allocation for Wireless Powered Non-orthogonal Multiple Access Net-works

无线能量传输是解决无线网络中节点设备能量短缺问题的新技术,非正交多址接入是缓解无线网络频谱紧缺难题和满足大规模节点接入需求的新型多址接入技术.将两者相结合不仅可以缓解节点设备电池能量不足、需要频繁更换电池的问题,还可以提高系统的频谱效率,满足大规模节点接入的需求.本文考虑基于无线供电的非正交多址接入网络,其中包含一个多天线的能量基站、多个单天线用户和一个单天线信息接收机.在该网络中,下行链路和上行链路分别表示从能量基站到用户和从用户到信息接收机的物理信道.在下行链路中,能量基站通过无线能量传输给多个用户提供可靠的能量;在上行链路中,用户使用收集到的能量并基于非正交多址接入技术发送信息给信息接收机.在系统的下行链路信道状态信息不完美的实际情况下,设计鲁棒资源分配策略,联合设计能量基站的波束赋形向量、用户的发射功率和上下行链路间的时间分配,最大化系统的吞吐量.仿真结果表明,所提鲁棒设计算法的吞吐量性能明显优于不具有鲁棒性的资源分配算法.

The wireless power transfer （WPT） is a controllable and promising way to solve the energy scarcityproblem of the devices in wireless networks. The non-orthogonal multiple access （NOMA） scheme is a newmultiple access technique, which has been proposed to provide higher spectral efficiency （SE） and support massiveuser accesses. A wireless powered NOMA network consisting of one multiple-antenna power station, multiplesingle-antenna users and one single-antenna information receiver is considered. In the downlink, the power stationtransfers wireless energy to the users, while in the uplink, the users transmit their information to the informationreceiver in the NOMA manner. A practical scenario where the power station knows imperfect channel stateinformation （CSI） of the downlink channel is viewed, and a robust resource allocation algorithm is proposed tojointly optimize the beamforming of the power station, the transmit powers of the users, and the time lengths of thedownlink and uplink in order to maximize the throughput of the system. Simulation results show that the proposedrobust design algorithm achieves significantly higher throughput than the non-robust benchmark scheme.