Analysis of Multi-Cell Downlink Cooperation with a Constrained Spatial Model

TL;DR

This paper develops a new analytical framework for multi-cell cooperation in cellular networks, considering realistic spatial models, diverse fading conditions, and resource policies to improve understanding of cell-edge performance.

Contribution

It introduces a novel expression for outage probability conditioned on network topology and shadowing, incorporating non-identical Nakagami fading parameters and a realistic spatial model.

Findings

New outage probability expression for cooperative downlink with diversity combining.

Performance characterization over diverse network topologies and resource policies.

Insights into defining the cell edge in cooperative cellular networks.

Abstract

Multi-cell cooperation (MCC) mitigates intercell interference and improves throughput at the cell edge. This paper considers a cooperative downlink, whereby cell-edge mobiles are served by multiple cooperative base stations. The cooperating base stations transmit identical signals over paths with non-identical path losses, and the receiving mobile performs diversity combining. The analysis in this paper is driven by a new expression for the conditional outage probability when signals arriving over different paths are combined in the presence of noise and interference, where the conditioning is with respect to the network topology and shadowing. The channel model accounts for path loss, shadowing, and Nakagami fading, and the Nakagami fading parameters do not need to be identical for all paths. To study performance over a wide class of network topologies, a random spatial model is adopted, and performance is found by statistically characterizing the rates provided on the downlinks. To model realistic networks, the model requires a minimum separation among base stations. Having adopted a realistic model and an accurate analysis, the paper proceeds to determine performance under several resource-allocation policies and provides insight regarding how the cell edge should be defined.