Auto-Correlation and Coherence Time of Interference in Poisson Networks

TL;DR

This paper studies the temporal behavior of interference in Poisson networks, deriving a flexible framework for auto-correlation and introducing the concept of interference coherence time, which varies with network parameters and influences protocol design.

Contribution

It provides a novel analytical framework combining multiple correlation sources to characterize interference dynamics and introduces the interference coherence time concept.

Findings

Interference coherence time varies significantly across different scenarios.

The framework allows for flexible modeling of interference correlations.

Knowledge of coherence time can improve protocol performance.

Abstract

The dynamics of interference over space and time influences the performance of wireless communication systems, yet its features are still not fully understood. This article analyzes the temporal dynamics of the interference in Poisson networks accounting for three key correlation sources: the location of nodes, the wireless channel, and the network traffic. We derive expressions for the auto-correlation function of interference. These are presented as a framework that enables us to arbitrarily combine the three correlation sources to match a wide range of interference scenarios. We then introduce the interference coherence time - analogously to the well-known channel coherence time - and analyze its features for each correlation source. We find that the coherence time behaves very different for the different interference scenarios considered and depends on the network parameters. Having accurate knowledge of the coherence time can thus be an important design input for protocols, e.g., retransmission and medium access control.