针对传统模拟/数字混合波束赋形需要进行信道估计和高维奇异值分解(Singular Value Decomposition,SVD)的问题,设计了一种低复杂度的混合波束赋形方案。在模拟域,采用离散傅立叶变换(Discrete Fourier Transform,DFT)设计出码本波束,并...针对传统模拟/数字混合波束赋形需要进行信道估计和高维奇异值分解(Singular Value Decomposition,SVD)的问题,设计了一种低复杂度的混合波束赋形方案。在模拟域,采用离散傅立叶变换(Discrete Fourier Transform,DFT)设计出码本波束,并提出一种基于期望信号的波束扫描方法,搜索出最接近期望用户方向的模拟波束。在数字域,结合自适应算法将波束微调对准期望用户方向,并在干扰方向形成较深的“零陷”。通过理论分析和仿真,对误差收敛、信干噪比以及频谱效率等性能进行了研究。结果表明,所设计的混合波束赋形方案在不涉及信道估计、SVD分解的情况下,信干噪比和频谱效率等性能仍可以接近于纯数字波束赋形方案。展开更多
Massive Multiple-Input Multiple-Output(MIMO)is considered as a key technology for 4G and 5G wireless communication systems to improve spectrum efficiency by supporting large number of concurrent users.In addition,for ...Massive Multiple-Input Multiple-Output(MIMO)is considered as a key technology for 4G and 5G wireless communication systems to improve spectrum efficiency by supporting large number of concurrent users.In addition,for the target frequency band of 5G system,mmWave band,massive MIMO is pivotal in compensating the high pathloss.In this paper,we investigate the channel state information(CSI)acquisition problem for mmWave massive MIMO.With hybrid analog-digital antenna architecture,how to derive the analog beamforming and digital beamforming is studied.An iterative analog beam acquisition approach is proposed to save system overhead and reduce beam searching complexity.Regarding the digital beamforming,a grouping based codebook is proposed to facilitate CSI feedback.The codebook is then extended to incorporate also analog beam acquisition.Furthermore,channel reciprocity is exploited to save CSI reporting overhead and a two-stage approach is proposed to fully utilize the channel reciprocity at both mobile station and base station side and accelerate the CSI acquisition procedure.展开更多
文摘针对传统模拟/数字混合波束赋形需要进行信道估计和高维奇异值分解(Singular Value Decomposition,SVD)的问题,设计了一种低复杂度的混合波束赋形方案。在模拟域,采用离散傅立叶变换(Discrete Fourier Transform,DFT)设计出码本波束,并提出一种基于期望信号的波束扫描方法,搜索出最接近期望用户方向的模拟波束。在数字域,结合自适应算法将波束微调对准期望用户方向,并在干扰方向形成较深的“零陷”。通过理论分析和仿真,对误差收敛、信干噪比以及频谱效率等性能进行了研究。结果表明,所设计的混合波束赋形方案在不涉及信道估计、SVD分解的情况下,信干噪比和频谱效率等性能仍可以接近于纯数字波束赋形方案。
基金supported in parts by the National Natural Science Foundation of China for Distinguished Young Scholar under Grant 61425012the National Science and Technology Major Projects for the New Generation of Broadband Wireless Communication Network under Grant 2017ZX03001014
文摘Massive Multiple-Input Multiple-Output(MIMO)is considered as a key technology for 4G and 5G wireless communication systems to improve spectrum efficiency by supporting large number of concurrent users.In addition,for the target frequency band of 5G system,mmWave band,massive MIMO is pivotal in compensating the high pathloss.In this paper,we investigate the channel state information(CSI)acquisition problem for mmWave massive MIMO.With hybrid analog-digital antenna architecture,how to derive the analog beamforming and digital beamforming is studied.An iterative analog beam acquisition approach is proposed to save system overhead and reduce beam searching complexity.Regarding the digital beamforming,a grouping based codebook is proposed to facilitate CSI feedback.The codebook is then extended to incorporate also analog beam acquisition.Furthermore,channel reciprocity is exploited to save CSI reporting overhead and a two-stage approach is proposed to fully utilize the channel reciprocity at both mobile station and base station side and accelerate the CSI acquisition procedure.
