Coverage and Rate Analysis for Millimeter-Wave Cellular Networks

TLDR

Millimeter‑wave frequencies promise high‑capacity 5G, but their sensitivity to blockage invalidates conventional UHF cellular models. This study introduces a stochastic‑geometry framework to evaluate coverage and rate in mmWave cellular networks. The framework models LOS and NLOS base stations as independent non‑homogeneous Poisson point processes with a distance‑dependent LOS probability, derives SINR and rate‑coverage expressions, and analyzes performance versus antenna geometry, base‑station density, and dense‑network LOS‑ball approximations. Results show that dense mmWave networks achieve comparable coverage and substantially higher data rates than UHF systems, and that the optimal cell size scales with the average LOS area.

Abstract

Millimeter wave (mmWave) holds promise as a carrier frequency for fifth generation cellular networks. Because mmWave signals are sensitive to blockage, prior models for cellular networks operated in the ultra high frequency (UHF) band do not apply to analyze mmWave cellular networks directly. Leveraging concepts from stochastic geometry, this paper proposes a general framework to evaluate the coverage and rate performance in mmWave cellular networks. Using a distance-dependent line-of-site (LOS) probability function, the locations of the LOS and non-LOS base stations are modeled as two independent non-homogeneous Poisson point processes, to which different path loss laws are applied. Based on the proposed framework, expressions for the signal-to-noise-and-interference ratio (SINR) and rate coverage probability are derived. The mmWave coverage and rate performance are examined as a function of the antenna geometry and base station density. The case of dense networks is further analyzed by applying a simplified system model, in which the LOS region of a user is approximated as a fixed LOS ball. The results show that dense mmWave networks can achieve comparable coverage and much higher data rates than conventional UHF cellular systems, despite the presence of blockages. The results suggest that the cell size to achieve the optimal SINR scales with the average size of the area that is LOS to a user.