Massive-MIMO Meets HetNet: Interference Coordination Through Spatial Blanking

摘要: In this paper, we study the downlink performance of a heterogeneous cellular network (HetNet) where both macro and small cells share same spectrum hence interfere with each other. We assume that users are concentrated at certain areas in cell, i.e., they form hotspots . While some assumed to have cell their vicinity, others directly served by macrocell. Due relatively area hotspot, lying particular hotspot appear be almost co-located macrocells, which typically deployed elevation. large number antennas macrocell relative simultaneously served. “massive MIMO” regime, channel vectors become highly directional. exploit directionality obtain spatial blanking , concentrating transmission energy only directions while creating opportunities for other directions. addition inherent interference suppression, also develop three low-complexity coordination strategies: 1) turn off based on amount cross-tier receive or cause scheduled hotspots; 2) schedule such treating as noise is approximately optimal resulting Gaussian channel; 3) offload nearby improve throughput fairness across all hotspots. For these schemes, merits demerits uniform deployment vs. deploying more towards center edge.