Date Added: Apr 2011
Cooperative communication with rateless codes has attracted much attention recently because it can provide both spatial diversity and high bandwidth efficiency. However, relay selection for asynchronous relaying, which shows great potential for practical applications, has not been carefully studied yet. In this paper, based on rateless codes, the authors propose a simple probabilistic relay selection protocol for asynchronous multi-relay networks, where no symbol-level inter-node synchronization or multiuser detection is needed. In such asynchronous networks, a decoding relay can help the other relays which have not decoded the message yet. Moreover, the tradeoff between the first hop and the second hop can be controlled by setting the decoding relay threshold.