Joint Distribution of Distance and Angles in Finite Wireless Networks

TL;DR

This paper derives the joint distribution of distance and angles in finite wireless networks, revealing correlations influenced by network shape and node placement, with applications in beamforming and routing.

Contribution

It introduces a novel mathematical framework for modeling the joint distribution of distance and angles in finite networks with arbitrary node placement, extending beyond traditional assumptions.

Findings

Distance and azimuth angles are correlated in finite networks.

Derived joint distributions for 2D and 3D scenarios.

Applications include beamforming, codebook design, and routing algorithms.

Abstract

Directional beamforming will play a paramount role in 5G and beyond networks in order to combat the higher path losses incurred at millimeter wave bands. Appropriate modeling and analysis of the angles and distances between transmitters and receivers in these networks are thus essential to understand performance and limiting factors. Most existing literature considers either infinite and uniform networks, where nodes are drawn according to a Poisson point process, or finite networks with the reference receiver placed at the origin of a disk. Under either of these assumptions, the distance and azimuth angle between transmitter and receiver are independent, and the angle follows a uniform distribution between $0$ and $2\pi$. Here, we consider a more realistic case of finite networks where the reference node is placed at any arbitrary location. We obtain the joint distribution between the distance and azimuth angle and demonstrate that these random variables do exhibit certain correlation, which depends on the shape of the region and the location of the reference node. To conduct the analysis, we present a general mathematical framework which is specialized to exemplify the case of a rectangular region. We then also derive the statistics for the 3D case where, considering antenna heights, the joint distribution of distance, azimuth and zenith angles is obtained. Finally, we describe some immediate applications of the present work, including the analysis of directional beamforming, the design of analog codebooks and wireless routing algorithms.