A Stochastic Geometry Framework for Analyzing Pairwise-Cooperative Cellular Networks

TL;DR

This paper develops a stochastic geometry model to analyze pairwise cooperation in cellular networks, showing that cooperation can significantly enhance coverage probability without additional network resources.

Contribution

It introduces a stochastic geometry framework for analyzing cooperative cellular networks with limited channel information, providing exact coverage probability expressions.

Findings

Cooperation improves coverage probability compared to non-cooperative networks.

Limited channel state information suffices for significant performance gains.

The framework accommodates variable cooperation policies based on user location.

Abstract

Cooperation in cellular networks has been recently suggested as a promising scheme to improve system performance, especially for cell-edge users. In this work, we use stochastic geometry to analyze cooperation models where the positions of Base Stations (BSs) follow a Poisson point process distribution and where Voronoi cells define the planar areas associated with them. For the service of each user, either one or two BSs are involved. If two, these cooperate by exchange of user data and channel related information with conferencing over some backhaul link. Our framework generally allows variable levels of channel information at the transmitters. In this paper we investigate the case of limited channel state information for cooperation (channel phase, second neighbour interference), but not the fully adaptive case which would require considerable feedback. The total per-user transmission power is further split between the two transmitters and a common message is encoded. The decision for a user to choose service with or without cooperation is directed by a family of geometric policies depending on its relative position to its two closest base stations. An exact expression of the network coverage probability is derived. Numerical evaluation allows one to analyze significant coverage benefits compared to the non-cooperative case. As a conclusion, cooperation schemes can improve system performance without exploitation of extra network resources.