Massive multiple-input multipleoutput(MIMO) refers to the idea that equipping base station(BS) with a large number of antenna elements,and features the ability of three dimensional(3D) beamforming technique to enable ...Massive multiple-input multipleoutput(MIMO) refers to the idea that equipping base station(BS) with a large number of antenna elements,and features the ability of three dimensional(3D) beamforming technique to enable improvement in system performance.The prior works on massive MIMO generally rely on a common assumption of the whole channel characteristics are perfectly known at both user equipment(UE) and BS,however,this is quite difficult to realize in practical frequency division duplexing(FDD) system since the channel state information reference signal(CSIRS) overhead and CSI feedback overhead are proportional to the number of antenna elements.In this paper,two hybrid CSI-RS transmission mechanism-based 3D beamforming schemes are proposed in FDD massive MIMO system,in which non-beamformed CSI-RS configuration is utilized in conjunction with beamformed CSIRS configuration.In the proposed schemes,an angle quantization-based vertical codebook and a DFT-based horizontal codebook are designed,respectively,and an eigenvalue decompositionbased precoding matrix indicator(PMI)selection algorithm is also proposed for CSI acquisition.Simulation results show that the proposed 3D beamforming schemes achieve significant improvement in system capacity without incurring excessive CSI-RS overhead.展开更多
3GPP标准在5G中引入了波束扫描和空域的维度,信道状态信息(channel state information,CSI)是UE上报给eNodeB的信道状态信息,信道状态信息参考信号(channel state information-reference signal,CSI-RS)是UE用来获取信道状态信息的参考...3GPP标准在5G中引入了波束扫描和空域的维度,信道状态信息(channel state information,CSI)是UE上报给eNodeB的信道状态信息,信道状态信息参考信号(channel state information-reference signal,CSI-RS)是UE用来获取信道状态信息的参考信号。终端接入时基站采用SSB波束轮发探测终端的最优波束,在终端接入后获取参考信号的配置信息后对信道状态信息进行反馈,基站采用CSI-RS波束轮发的最优波束。5G天线灵活配置波束个数并且兼顾水平维度、垂直维度的覆盖。结合广播波束发展、现网水平7波束面临的挑战,分析比较了水平7波束与1+X波束两种方案,并对两种方案进行测试分析。测试结果表明,1+X波束具有较水平7波束覆盖相当、控制干扰、降低资源开销和设备能耗的优势,结合自动优化工具的应用达到提升工作效率的效果。展开更多
文摘Massive multiple-input multipleoutput(MIMO) refers to the idea that equipping base station(BS) with a large number of antenna elements,and features the ability of three dimensional(3D) beamforming technique to enable improvement in system performance.The prior works on massive MIMO generally rely on a common assumption of the whole channel characteristics are perfectly known at both user equipment(UE) and BS,however,this is quite difficult to realize in practical frequency division duplexing(FDD) system since the channel state information reference signal(CSIRS) overhead and CSI feedback overhead are proportional to the number of antenna elements.In this paper,two hybrid CSI-RS transmission mechanism-based 3D beamforming schemes are proposed in FDD massive MIMO system,in which non-beamformed CSI-RS configuration is utilized in conjunction with beamformed CSIRS configuration.In the proposed schemes,an angle quantization-based vertical codebook and a DFT-based horizontal codebook are designed,respectively,and an eigenvalue decompositionbased precoding matrix indicator(PMI)selection algorithm is also proposed for CSI acquisition.Simulation results show that the proposed 3D beamforming schemes achieve significant improvement in system capacity without incurring excessive CSI-RS overhead.
文摘3GPP标准在5G中引入了波束扫描和空域的维度,信道状态信息(channel state information,CSI)是UE上报给eNodeB的信道状态信息,信道状态信息参考信号(channel state information-reference signal,CSI-RS)是UE用来获取信道状态信息的参考信号。终端接入时基站采用SSB波束轮发探测终端的最优波束,在终端接入后获取参考信号的配置信息后对信道状态信息进行反馈,基站采用CSI-RS波束轮发的最优波束。5G天线灵活配置波束个数并且兼顾水平维度、垂直维度的覆盖。结合广播波束发展、现网水平7波束面临的挑战,分析比较了水平7波束与1+X波束两种方案,并对两种方案进行测试分析。测试结果表明,1+X波束具有较水平7波束覆盖相当、控制干扰、降低资源开销和设备能耗的优势,结合自动优化工具的应用达到提升工作效率的效果。
