Approximately universal optimality over several dynamic and non-dynamic cooperative diversity schemes for wireless networks

TL;DR

This paper introduces the first optimal cooperative diversity schemes for wireless relay networks, achieving the best tradeoff between data rate and reliability across various configurations without requiring channel knowledge or delay.

Contribution

It presents novel, optimal schemes based on perfect space-time codes that are universally optimal for multiple users and diverse fading conditions, regardless of channel knowledge or delay.

Findings

Schemes are optimal for any number of users.

No channel knowledge or delay needed for optimality.

Multiple strategies achieve the same optimal D-MG performance.

Abstract

In this work we explicitly provide the first ever optimal, with respect to the Zheng-Tse diversity multiplexing gain (D-MG) tradeoff, cooperative diversity schemes for wireless relay networks. The schemes are based on variants of perfect space-time codes and are optimal for any number of users and all statistically symmetric (and in some cases, asymmetric) fading distributions. We deduce that, with respect to the D-MG tradeoff, channel knowledge at the intermediate relays and infinite delay are unnecessary. We also show that the non-dynamic selection decode and forward strategy, the non-dynamic amplify and forward, the non-dynamic receive and forward, the dynamic amplify and forward and the dynamic receive and forward cooperative diversity strategies allow for exactly the same D-MG optimal performance.