I/Q失衡影响下无人机多向全双工中继NOMA传输系统性能分析

Performances Analysis in UAV-Aided Multi-Way NOMA Full-Duplex Relay System with I/Q Imbalance

无人机(UAV)具备高灵活性、强适应性和高机动性等优势,能够为6G网络提供便捷有效的辅助通信方案。为提高UAV通信系统的频谱效率,让所有用户彼此间在更少的时隙内完成信息交互,该文提出一种全双工(FD)多向中继非正交多址接入(NOMA)(FD NOMA MWRN)传输方案,考虑收发端都存在同相/正交(I/Q)失衡的情况,对系统的传输率和能量效率进行分析。仿真结果表明:相比半双工(HD),全双工技术可以实现频谱利用率的翻倍;所提方案比正交多址接入(OMA)方案更具性能优势,且不受用户数量的影响,传输消耗的时隙数始终为1;I/Q失衡会限制系统传输率,UAV的工作高度也对其起到一定的约束作用。

The Unmanned Aerial Vehicle(UAV)can provide convenient and effective supplementary communication solutions for 6G networks since it gets the advantages of flexibility,adaptability and high mobility.To improve further the spectrum efficiency and reduce the transmission time required for full data exchange,a Full-Duplex(FD)Multi-Way Relay Network Non-Orthogonal Multiple Access(NOMA)transmission scheme(FD NOMA MWRN)is proposed.In addition,a more practical case is assumed that in-phase/quadrature imbalance of transceiver is taken into account.Based on this,the transmission rate and energy efficiency are analyzed.The simulation results indicate the following conclusions.Firstly,the full-duplex transmission can improve the spectral utilization compared to the Half-Duplex(HD)mode.Secondly,the proposed scheme,which consumes the number of time slots is always one regardless of the number of users,has better performance than the Orthogonal Multiple Access(OMA)scheme.Thirdly,the In-phase/Quadrature(I/Q)imbalance and the working height of the UAV both limit the transmission rate of the system.