On the Optimality of Treating Inter-Cell Interference as Noise in Uplink Cellular Networks

TL;DR

This paper investigates the optimality of treating inter-cell interference as noise in uplink cellular networks modeled by the Gaussian IMAC, establishing conditions where TIN is capacity-achieving or near-optimal.

Contribution

It characterizes the GDoF region achievable by TIN in uplink cellular networks and identifies regimes where TIN is optimal or within a constant gap of capacity.

Findings

TIN achieves the entire GDoF region under certain conditions.

The paper identifies regimes where TIN is within a constant gap of capacity.

Convexity conditions for the GDoF region are established.

Abstract

In this paper, we explore the information-theoretic optimality of treating interference as noise (TIN) in cellular networks. We focus on uplink scenarios modeled by the Gaussian interfering multiple access channel (IMAC), comprising $K$ mutually interfering multiple access channels (MACs), each formed by an arbitrary number of transmitters communicating independent messages to one receiver. We define TIN for this setting as a scheme in which each MAC (or cell) performs a power-controlled version of its capacity-achieving strategy, with Gaussian codebooks and successive decoding, while treating interference from all other MACs (i.e. inter-cell interference) as noise. We characterize the generalized degrees-of-freedom (GDoF) region achieved through the proposed TIN scheme, and then identify conditions under which this achievable region is convex without the need for time-sharing. We then tighten these convexity conditions and identify a regime in which the proposed TIN scheme achieves the entire GDoF region of the IMAC and is within a constant gap of the entire capacity region.