Performance analysis of uplink massive MIMO networks with a finite user density

In this paper, we conduct performance analysis for uplink (UL) massive multiple input and multiple output (mMI-MO) networks using stochastic geometry. With the consideration of practical system assumptions, such as sophisticated path loss model incorporating both line-of-sight (LoS) and non-line-of-sight (NLoS) transmissions and a finite user equipment (UE) density, we derive the coverage probability and the area spectral efficiency (ASE) performance. In particular, we adopt a practical user association strategy (UAS) based on the smallest pathloss since we differentiate LoS and NLoS transmissions, and we consider the correlation among the positions of UEs and base stations (BSs) in realistic networks. From our simulation and analytical results, we find that the performance impacts of the probabilistic LoS/NLoS transmissions and a finite UE density on UL mMIMO networks are significant. More specifically, the coverage probability performance suffers from a moderate decrease or even a severe degradation when the UE density becomes large in sparse mMIMO networks. Moreover, our results indicate that there exists an optimal BS density to maximize the sum spectral efficiency per BS. However, the ASE performance keeps growing with network densification.