Approaching Gaussian Relay Network Capacity in the High SNR Regime: End-to-End Lattice Codes

TL;DR

This paper introduces a low-complexity end-to-end lattice coding scheme with amplify-and-forward strategy that approaches the capacity of Gaussian relay networks in high SNR conditions, simplifying network design.

Contribution

It presents a novel lattice coding approach for relay networks that is simpler and does not require detailed network knowledge, achieving near-capacity performance.

Findings

Approaches network capacity in high SNR regime

Simplifies relay network coding without topology knowledge

Extends to non-layered networks modeled as ISI channels

Abstract

We present a natural and low-complexity technique for achieving the capacity of the Gaussian relay network in the high SNR regime. Specifically, we propose the use of end-to-end structured lattice codes with the amplify-and-forward strategy, where the source uses a nested lattice code to encode the messages and the destination decodes the messages by lattice decoding. All intermediate relays simply amplify and forward the received signals over the network to the destination. We show that the end-to-end lattice-coded amplify-and-forward scheme approaches the capacity of the layered Gaussian relay network in the high SNR regime. Next, we extend our scheme to non-layered Gaussian relay networks under the amplify-and-forward scheme, which can be viewed as a Gaussian intersymbol interference (ISI) channel. Compared with other schemes, our approach is significantly simpler and requires only the end-to-end design of the lattice precoding and decoding. It does not require any knowledge of the network topology or the individual channel gains.