Harnessing Bursty Interference in Multicarrier Systems with Feedback

TL;DR

This paper investigates how bursty interference in multicarrier systems can be managed using feedback, proposing a helping mechanism that improves capacity in various interference regimes and providing complete capacity characterizations for deterministic and Gaussian models.

Contribution

It introduces a novel helping mechanism for bursty interference in multicarrier channels and characterizes capacity regions for deterministic and Gaussian cases.

Findings

Complete capacity region for deterministic model.

Outer bounds and tight degrees of freedom for Gaussian model.

Helping mechanism improves recovery of interfered signals.

Abstract

We study parallel symmetric 2-user interference channels when the interference is bursty and feedback is available from the respective receivers. Presence of interference in each subcarrier is modeled as a memoryless Bernoulli random state. The states across subcarriers are drawn from an arbitrary joint distribution with the same marginal probability for each subcarrier and instantiated i.i.d. over time. For the linear deterministic setup, we give a complete characterization of the capacity region. For the setup with Gaussian noise, we give outer bounds and a tight generalized degrees of freedom characterization. We propose a novel helping mechanism which enables subcarriers in very strong interference regime to help in recovering interfered signals for subcarriers in strong and weak interference regimes. Depending on the interference and burstiness regime, the inner bounds either employ the proposed helping mechanism to code across subcarriers or treat the subcarriers separately. The outer bounds demonstrate a connection to a subset entropy inequality by Madiman and Tetali.