The Generalized Degrees-of-Freedom of the Asymmetric Interference Channel with Delayed CSIT

TL;DR

This paper characterizes the optimal sum-GDoF of an asymmetric interference channel with delayed CSIT, revealing improvements over previous bounds and providing tight bounds for the symmetric GDoF in a specific antenna setting.

Contribution

It provides a complete characterization of the sum-GDoF for the asymmetric interference channel with delayed CSIT, including improved bounds and tightness results.

Findings

Optimal sum-GDoF characterized with matched converse and achievability

Symmetric GDoF lower bound can be elevated in the given antenna setting

Symmetric GDoF upper bound is tight in the considered setting

Abstract

In this paper, we investigate the generalized degrees-of-freedom (GDoF) of the asymmetric interference channel with delayed channel state information at the transmitter (CSIT), where each transmitter has two antennas, each receiver has one antenna, and the strength for each interfering link can vary. The optimal sum-GDoF is characterized by matched converse and achievability proof. Through our results, we also reveal that in our antenna setting, the symmetric GDoF lower bound in [Mohanty et. al, TIT 2019] can be elevated, and the symmetric GDoF upper bound in [Mohanty et. al, TIT 2019] is tight in fact.