Design, Implementation and Characterization of a Cooperative Communications System

Cooperative communications is a class of techniques which seek to improve reliability and throughput in wireless systems by pooling the resources of distributed nodes. While cooperation can occur at different network layers and time scales, physical layer cooperation at symbol time scales offers the largest benefit. However, symbol level cooperation poses significant implementation challenges, especially in the context of a network of distributed nodes. We first present the design and implementation of a complete cooperative physical layer transceiver, built from scratch on the Wireless Open-Access Research Platform (WARP). In our implementation fully distributed nodes employ physical layer cooperation at symbol time scales without requiring a central synchronization source. Our design supports per-packet selection of non-cooperative or cooperative communication, with cooperative links utilizing either amplify-and-forward or decode-and-forward relaying. A single design implements transmission, reception and relaying, allowing each node to assume the role of source, destination or relay per packet. We also present experimental methodologies for evaluating our design and extensive experimental results of our transceiver's performance under a variety of topologies and propagation conditions. Our methods are designed to test both overall performance and to isolate and understand the underlying causes of performance limitations. Our results clearly demonstrate significant performance gains (more than 50× improvement in PER in some topologies) provided by physical layer cooperation even when subject to the constraints of a real-time implementation. As with all our work on WARP, our transceiver design and experimental framework are available via the open-source WARP repository for use by other wireless researchers.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Engineering

Grantor

Rice University

Year dc:date.issued

2011

Author dc:creator

• Murphy, Patrick O.

Advisor dc:contributor.advisor

• Sabharwal, Ashutosh

• Applied sciences
• Cooperative communication
• FPGA
• OFDM
• Computer engineering
• Electrical engineering

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/70364

OAI identifier oai:identifier

oai:repository.rice.edu:1911/70364