Uplink User-Assisted Relaying in Cellular Networks

TL;DR

This paper uses stochastic geometry to analyze user-assisted relaying in uplink cellular networks, demonstrating significant rate improvements especially near cell edges with higher idle user density.

Contribution

It introduces geometric cooperation policies and derives analytical expressions for cooperation probability and interference, providing a theoretical framework for performance evaluation.

Findings

User-assisted relaying improves transmission rates near cell edges.

Higher idle user density enhances relaying benefits.

Inter-cell interference can be modeled with Gamma distribution.

Abstract

We use stochastic geometry to analyze the performance of a partial decode-and-forward (PDF) relaying scheme applied in a user-assisted relaying setting, where an active user relays data through another idle user in uplink cellular communication. We present the geometric model of a network deploying user-assisted relaying and propose two geometric cooperation policies for fast and slow fading channels. We analytically derive the cooperation probability for both policies. This cooperation probability is further used in the analytical derivation of the moments of inter-cell interference power caused by system-wide deployment of this user-assisted PDF relaying. We then model the inter-cell interference power statistics using the Gamma distribution by matching the first two moments analytically derived. This cooperation and interference analysis provides the theoretical basis for quantitatively evaluating the performance impact of user-assisted relaying in cellular networks. We then numerically evaluate the average transmission rate performance and show that user-assisted relaying can significantly improve per-user transmission rate despite of increased inter-cell interference. This transmission rate gain is significant for active users near the cell edge and further increases with higher idle user density, supporting user-assisted relaying as a viable solution to crowded population areas.