MIMO-NOMA系统下的URLLC与eMBB混合业务场景的共存调度研究

Coexistence scheduling of URLLC and eMBB mixed service scenarios in MIMO-NOMA system

增强移动带宽(enhancedmobilebroadband,eMBB)和超可靠低时延通信(ultra-reliableandlow-latency communications,URLLC)是5G移动通信网络中的两大主要服务。URLLC服务具有严格的时延和可靠性要求,eMBB服务具有巨大的吞吐量需求,2种业务差异化的服务质量(quality of service,QoS)需求,使两者在相同带宽资源上的共存成为一个极具挑战性的问题。基于下行链路的多输入多输出(multiple-input multiple-output,MIMO)非正交多址接入(non-orthogonal multiple access,NOMA)系统,在用户分簇的基础上,研究了URLLC和eMBB的共存策略,制定了一个URLLC和eMBB联合资源调度问题,在最大化eMBB业务频谱效率的同时满足URLLC业务的低时延需求。为求解该调度问题,提出了一个基于连续凸逼近(successive convex approximation,SCA)和凸函数差分规划(difference of convex functions,D.C.)的迭代算法。理论分析和数值结果证明了所提出的解决方案对于共存问题的适用性,在提升系统频谱效率的同时实现了多用户连接。

Enhanced mobile broadband(eMBB)and ultra-reliable and low-latency communications(URLLC)are the two main services in 5G mobile communication networks.URLLC has strict reliability and latency requirements,eMBB service has huge throughput requirements,and the two services have differentiated quality of service(QoS)requirements,which makes the coexistence of the two services in the same bandwidth resources a very challenging problem.A downlink-based multiple-input multiple-output(MIMO)with nonorthogonal multiple access(NOMA)system is established.On the basis of user clustering,the co-existence strategy of URLLC and eMBB is studied,and a joint resource scheduling problem of URLLC and eMBB is developed to maximize the spectral efficiency of eMBB services and meet the low latency requirements of URLLC efficiency.To solve this scheduling problem,an iterative algorithm based on the methods of successive convex approximation(SCA)and difference of convex functions(D.C.)programming is proposed.Theoretical analyses and numerical results demonstrate that the proposed solution is suitable for the coexistence problem,and can significantly improve the spectrum efficiency while realizing the multi-user connection.