Cooperative Diversity in Wireless Networks: Low-Complexity Protocols and Outage Behavior
J. Nicholas Laneman, David N. C. Tse, Gregory W. Wornell · 2004
We develop and analyze low-complexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks. The underlying techniques exploit space diversity available through cooperating terminals' relaying signals for one another. We outline several strategies employed by the cooperating radios, including fixed relaying schemes such as amplify-and-forward and decode-andforward, selection relaying schemes that adapt based upon channel measurements between the cooperating terminals, and incremental relaying schemes that adapt based upon limited feedback from the destination terminal. We develop performance characterizations in terms of outage events and associated outage probabilities, which measure robustness of the transmissions to fading, focusing on the high signal-tonoise (SNR) ratio regime. Except for fixed decode-and-forward, all of our cooperative diversity protocols achieve full diversity (i.e., second-order diversity in the case of two terminals), and are close to optimum