Direct Link Aware Cooperative Relaying

Cooperative relaying strategies enable spatial diversity gains. Using a proper forwarding strategy, these techniques can achieve diversity order as high as the number of diverse paths. We derive a strategy named direct link-aware relaying (DLA), which uses the source-destination link status as a condition to forward or not the signal at the relay. DLA is shown to achieve full diversity and to save energy compared to decode- and-forward strategies. Compared to selective-forwarding, DLA overcomes the use of error detection codes. Extension to the multi-branch case is developed. Simulations corroborate our analytical claims.