Asymptotic Capacity of Large Relay Networks with Conferencing Links

TL;DR

This paper analyzes the asymptotic capacity of large relay networks with conferencing links, showing that decode-and-forward scales logarithmically and amplify-and-forward can achieve capacity bounds as network size grows.

Contribution

It introduces and analyzes the asymptotic rates of relay schemes with conferencing links, demonstrating capacity scaling and optimality in large networks.

Findings

DF rate scales as O(log N)

AF scheme asymptotically achieves capacity upper bound

Conferencing links enable capacity scaling in large networks

Abstract

In this correspondence, we consider a half-duplex large relay network, which consists of one source-destination pair and $N$ relay nodes, each of which is connected with a subset of the other relays via signal-to-noise ratio (SNR)-limited out-of-band conferencing links. The asymptotic achievable rates of two basic relaying schemes with the "$p$-portion" conferencing strategy are studied: For the decode-and-forward (DF) scheme, we prove that the DF rate scales as $\mathcal{O} (\log (N))$; for the amplify-and-forward (AF) scheme, we prove that it asymptotically achieves the capacity upper bound in some interesting scenarios as $N$ goes to infinity.