Distributed space-time-coded protocols for exploiting cooperative diversity in wireless networks

TLDR

The paper addresses space‑time code design issues for distributed cooperative diversity protocols, focusing on codes that enable appealing distributed implementations. The study develops and analyzes space‑time coded cooperative diversity protocols to mitigate multipath fading across multiple protocol layers in wireless networks. The protocols exploit spatial diversity among distributed terminals that relay messages, with relays that fully decode using a space‑time code to cooperatively forward to the destination, allowing the destination to average fading even without knowing which terminals participate. The protocols achieve full spatial diversity proportional to the number of cooperating terminals and enable higher spectral efficiencies than repetition‑based schemes.

Abstract

We develop and analyze space-time coded cooperative diversity protocols for combating multipath fading across multiple protocol layers in a wireless network. The protocols exploit spatial diversity available among a collection of distributed terminals that relay messages for one another in such a manner that the destination terminal can average the fading, even though it is unknown a priori which terminals will be involved. In particular, a source initiates transmission to its destination, and many relays potentially receive the transmission. Those terminals that can fully decode the transmission utilize a space-time code to cooperatively relay to the destination. We demonstrate that these protocols achieve full spatial diversity in the number of cooperating terminals, not just the number of decoding relays, and can be used effectively for higher spectral efficiencies than repetition-based schemes. We discuss issues related to space-time code design for these protocols, emphasizing codes that readily allow for appealing distributed versions.