A Unified Framework for the Tractable Analysis of Multi-Antenna Wireless Networks

TL;DR

This paper introduces a unified stochastic geometry framework for analyzing multi-antenna wireless networks, simplifying complex performance metrics and providing new insights into coverage probability behavior with multiple antennas.

Contribution

It develops two innovative, tractable representations of coverage probability, unifying analysis for single- and multi-antenna networks and enabling key performance insights.

Findings

Coverage probability decreases with transmitter density in ad hoc networks.

Coverage probability improves with more transmit antennas, showing a peak in ad hoc networks.

In cellular networks, coverage probability is independent of transmitter density and improves exponentially with antennas.

Abstract

Densifying networks and deploying more antennas at each access point are two principal ways to boost the capacity of wireless networks. However, the complicated distributions of the signal power and the accumulated interference power, largely induced by various space-time processing techniques, make it highly challenging to quantitatively characterize the performance of multi-antenna networks. In this paper, using tools from stochastic geometry, a unified framework is developed for the analysis of such networks. The major results are two innovative representations of the coverage probability, which make the analysis of multi-antenna networks almost as tractable as the single-antenna case. One is expressed as an $\ell_1$-induced norm of a Toeplitz matrix, and the other is given in a finite sum form. With a compact representation, the former incorporates many existing analytical results on single- and multi-antenna networks as special cases, and leads to tractable expressions for evaluating the coverage probability in both ad hoc and cellular networks. While the latter is more complicated for numerical evaluation, it helps analytically gain key design insights. In particular, it helps prove that the coverage probability of ad hoc networks is a monotonically decreasing convex function of the transmitter density and that there exists a peak value of the coverage improvement when increasing the number of transmit antennas. On the other hand, in multi-antenna cellular networks, it is shown that the coverage probability is independent of the transmitter density and that the outage probability decreases exponentially as the number of transmit antennas increases.