Constellation Quantization in Constrained Backhaul Downlink Network MIMO

摘要: In this paper we consider a downlink multi-cell scenario where central processor is connected by finite-throughput backhaul to base stations (BSs) employing beamforming and QAM constellations. Both the serving BS auxiliary BSs transmit signal that combines at mobile terminal (MT) provide symbol while achieving diversity gain. order reduce occupation, receive from only quantized version of symbols be forwarded MTs. We formalize problem maximizing network spectral efficiency on air for all MTs within an area illuminated cooperative optimizing a) constellation size, b) quantization rate dictated c) power allocated each BS. Since resulting optimization mixed integer programming problem, investigate suboptimal solution same MT obtain simple iterative algorithm optimization. Numerical results show typical cellular scenarios approach yields close theoretical limit Slepian-Wolf encoding.