Distributed Transmit Diversity in Relay Networks

TL;DR

This paper investigates relay networks with single-antenna nodes, introducing relaying schemes that achieve the optimal diversity-multiplexing tradeoff, and identifies delay diversity and phase-rolling as optimal strategies.

Contribution

It presents a family of relaying schemes that attain the entire optimal diversity-multiplexing tradeoff curve in relay networks.

Findings

Relaying schemes achieve the full DM-tradeoff curve.

Delay diversity and phase-rolling are optimal strategies.

Optimality depends on appropriate delay and modulation choices.

Abstract

We analyze fading relay networks, where a single-antenna source-destination terminal pair communicates through a set of half-duplex single-antenna relays using a two-hop protocol with linear processing at the relay level. A family of relaying schemes is presented which achieves the entire optimal diversity-multiplexing (DM) tradeoff curve. As a byproduct of our analysis, it follows that delay diversity and phase-rolling at the relay level are optimal with respect to the entire DM-tradeoff curve, provided the delays and the modulation frequencies, respectively, are chosen appropriately.