In this paper, a joint design of instantaneous channel estimation, beam tracking, and adaptive beamformer construction for a massive multiple-input multiple-output (MIMO) system is proposed. This design focuses on efficiency in terms of performance and computational complexity under the adverse effects of time variation and mobility of sources, the presence of multiuser and multipath components, or simply multi-clusters, and the near-far effect. The design is also suitable for hybrid beamforming and frequency-selective channels. In the proposed system, channel parameters are estimated in time-domain duplex (TDD) uplink mode using a per-cluster approach rather than a joint approach, which significantly reduces the complexity. Per-cluster estimation is possible thanks to the proposed interference-aware statistical beamforming method, namely reduced dimensional Generalized Eigenbeamformer (RD-GEB), which undertakes the computational load of interference mitigation and enables a simpler design for the remaining stages. In addition, the overall design is based on the separation of channel parameters as fast-time and slow-time, leaving only the instantaneous channel estimation and channel matched filtering as fast-time operations, which are handled inside cluster-specific reduced dimensional subspaces. Beam tracking and beamformer construction are held in slow-time rarely, which reduces the time-averaged complexity. Furthermore, beam tracking is performed by leveraging a batch of instantaneous channel estimates, which removes the need for an additional training process. The proposed low-complexity design is shown to outperform the conventional methods.
翻译:在本文中,提出了即时频道估计、波束跟踪和适应性光谱构造联合设计,用于大规模多投入多输出产出(MIMO)系统,该设计侧重于在源的时间变化和流动的不利影响、多用户和多路组件的存在、或简单的多孔集束和近远效应下,在性能和计算复杂性方面的效率;该设计也适用于混合波束和频率选择渠道;在拟议系统中,频道参数是按时和慢时间将频道参数分离出来的,而采用每个集群方法而不是联合方法,大大降低复杂性;由于拟议的干扰-认知源变化和源的流动性、多用户和多路组件的存在、或简单的多孔组合和近远远远效应等不利效应的不利影响,因此有可能在性工作效率和计算复杂性方面的效率;由于拟议的干扰-常态-通用的Eigenbeamore组件(RD-GEB)的存在,因此,频道参数是按时间和慢速流(TDD)链接的上链接模式进行估算,仅留下瞬间频道估计和频道匹配的筛选过程,因此,在快速的系统内进行定期跟踪,因此,正在逐步减少一个正常的频率-平流流路段的系统进行。</s>