Coverage in mmWave Cellular Networks with Base station Cooperation

TL;DR

This paper investigates how base station cooperation in dense mmWave cellular networks can significantly reduce outage probability and enhance coverage, especially under conditions of high density and directional transmissions, using stochastic geometry models.

Contribution

It demonstrates that base station cooperation decreases outage probability in mmWave networks within a stochastic geometry framework, highlighting conditions where coverage is notably improved.

Findings

Cooperation reduces outage probability in dense mmWave networks.

Coverage is significantly improved with cooperation and less severe fading.

Less impact of cooperation in sparse, highly blocked mmWave environments.

Abstract

The presence of signal outage, due to shadowing and blockage, is expected to be the main bottleneck in millimeter wave (mmWave) networks. Moreover, with the anticipated vision that mmWave networks would have a dense deployment of base stations, interference from strong line-of-sight base stations increases too, thus further increasing the probability of outage. To address the issue of reducing outage, this paper explores the possibility of base station cooperation in the downlink of a mmWave heterogenous network. The main focus of this work is showing that, in a stochastic geometry framework, cooperation from randomly located base stations decreases outage probability. With the presumed vision that less severe fading will be experienced due to highly directional transmissions, one might expect that cooperation would increase the coverage probability; our numerical examples suggest that is in fact the case. Coverage probabilities are derived accounting for: different fading distributions, antenna directionality and blockage. Numerical results suggest that coverage with base station cooperation in dense mmWave systems and with no small scale fading considerably exceeds coverage with no cooperation. In contrast, an insignificant increase is reported when mmWave networks are less dense with a high probability of signal blockage and with Rayleigh fading.