2014/03/27 by Gilwon Lee, Lee, Gilwon, Youngchul Sung +1 · 1 citation
Computer Science · Engineering · #Advanced MIMO Systems Optimization #Advanced Wireless Network Optimization #Cooperative Communication and Network Coding #E.4 #FOS: Computer and information sciences #Information Theory (cs.IT)
paper · pdf · doi:10.48550/arxiv.1403.6931
openalex publication_date 2014/03/27 · openalex created_date 2022/08/22 · openalex updated_date 2026/07/28
In this paper, a new user-scheduling-and-beamforming method is proposed for\nmulti-user massive multiple-input multiple-output (massive MIMO) broadcast\nchannels in the context of two-stage beamforming. The key ideas of the proposed\nscheduling method are 1) to use a set of orthogonal reference beams and\nconstruct a double cone around each reference beam to select `nearly-optimal'\nsemi-orthogonal users based only on channel quality indicator (CQI) feedback\nand 2) to apply post-user-selection beam refinement with zero-forcing\nbeamforming (ZFBF) based on channel state information (CSI) feedback only from\nthe selected users. It is proved that the proposed scheduling-and-beamforming\nmethod is asymptotically optimal as the number of users increases. Furthermore,\nthe proposed scheduling-and-beamforming method almost achieves the performance\nof the existing semi-orthogonal user selection with ZFBF (SUS-ZFBF) that\nrequires full CSI feedback from all users, with significantly reduced feedback\noverhead which is even less than that required by random beamforming.\n