Coverage and Rate in MIMO Cellular Networks With Location-Aware Transmission Rank Selection

In this letter, we study the performance of a multiple-input multiple-output (MIMO) cellular network with location-aware transmission rank selection, where the number of transmit streams for every base-station (BS) and user equipment (UE) link is determined based on the average received power at the UE (hence, the link distance). We assume open-loop zero-forcing beam-forming (OL-ZFBF) at the receiver. We first develop a stochastic geometry based analytical framework for this setup by including the adaptive rank as a mark of each BS. Using this framework, we derive the coverage probability and spectral efficiency (SE) as a function of the rank selection threshold. Our analysis demonstrates that selecting transmission rank for each link on the basis of distance improves SE. We also investigate the tradeoff between coverage probability and SE.