In a stochastic geometry evaluation of cellular networks it is common to consider single-exponent power-law path-loss model. This is however far from reality, as the close-by base stations (BSs) are more likely to be in line-of-sight (LOS) mode, while farer BSs often exhibit non-LOS (NLOS) propagation effects with much larger path-loss exponent. We in this paper set goal to incorporate such realistic propagation model into the analysis of multiple-antenna (MIMO) multiplexing systems, which has not treated in the literature. Specifically, we consider zero- forcing beamforming (ZFBF) at the receiver while the transmitter has not access to channel state information, maximum signal-to- interference ratio (ZIR) cell association, and scenarios that the QoS implies the reception of the all transmitted data streams of a communication link to distinguish coverage. We derive a closed-form of the coverage probability. As it imposes dramatically huge computational complexity, we further propose an easy-to-compute upper-bound on it, which its accuracy is investigated against simulations. We notice that there is a density of BSs that results in the best coverage probability, which is accurately obtained by our analysis. While ultra-dense configurations have very poor coverage, it yields proportional growth of spectral efficiency with density. We finally highlight several important compromises between coverage and spectral efficiency versus multiplexing gain and density of BSs, one may take into consideration when it comes to the design of the network.
Impact of LOS/NLOS Propagation on the Coverage Performance of Multi-Stream MIMO-ZFBF Cellular Downlink
01.09.2017
198547 byte
Aufsatz (Konferenz)
Elektronische Ressource
Englisch