Robust Signaling for Bursty Interference

TL;DR

This paper investigates bursty interference channels with variable interference states, analyzing how different levels of channel-state information impact achievable communication rates in both quasi-static and ergodic scenarios.

Contribution

It introduces bounds for various CSI configurations and compares quasi-static and ergodic setups, highlighting when burstiness and CSI knowledge improve performance.

Findings

Global CSI generally outperforms local CSI.

Interference burstiness can be beneficial under certain conditions.

Different setups require tailored coding strategies.

Abstract

This paper studies a bursty interference channel, where the presence/absence of interference is modeled by a block-i.i.d.\ Bernoulli process that stays constant for a duration of $T$ symbols (referred to as coherence block) and then changes independently to a new state. We consider both a quasi-static setup, where the interference state remains constant during the whole transmission of the codeword, and an ergodic setup, where a codeword spans several coherence blocks. For the quasi-static setup, we study the largest rate of a coding strategy that provides reliable communication at a basic rate and allows an increased (opportunistic) rate when there is no interference. For the ergodic setup, we study the largest achievable rate. We study how non-causal knowledge of the interference state, referred to as channel-state information (CSI), affects the achievable rates. We derive converse and achievability bounds for (i) local CSI at the receiver-side only; (ii) local CSI at the transmitter- and receiver-side, and (iii) global CSI at all nodes. Our bounds allow us to identify when interference burstiness is beneficial and in which scenarios global CSI outperforms local CSI. The joint treatment of the quasi-static and ergodic setup further allows for a thorough comparison of these two setups.