A Unified Asymptotic Analysis of Area Spectral Efficiency in Ultradense Cellular Networks

TL;DR

This paper provides a comprehensive asymptotic analysis of the area spectral efficiency in ultradense cellular networks, revealing conditions under which ASE saturates or collapses as base station density increases.

Contribution

It introduces a unified framework for analyzing ASE in ultradense networks under various assumptions and derives explicit asymptotic behaviors in different scenarios.

Findings

ASE saturates to a constant with full CSI and no SINR constraints.

ASE collapses to zero when minimum SINR is enforced or CSI is unavailable.

Results unify and extend previous models of ultradense network performance.

Abstract

This paper studies the asymptotic properties of average area spectral efficiency (ASE) of a downlink cellular network in the limit of very dense base station (BS) and user densities. This asymptotic analysis relies on three assumptions: (1) interference is treated as noise; (2) the BS locations are drawn from a Poisson point process; (3) the path loss function is bounded above satisfying mild regularity conditions. We consider three possible definitions of the average ASE, all of which give units of bits per second per unit bandwidth per unit area. When there is no constraint on the minimum operational signal-to-interference-plus-noise ratio (SINR) and instantaneous full channel state information (CSI) is available at the transmitter, the average ASE is proven to saturate to a constant, which we derive in a closed form. For the other two ASE definitions, wherein either a minimum SINR is enforced or CSI is not available, the average ASE is instead shown to collapse to zero at high BS density. We provide several familiar case studies for the class of considered path loss models, and demonstrate that our results cover most previous models and results on ultradense networks as special cases.