Performance of Selective Decode - and - Forward Relay Networks with Partial Channel Information

Relay selection is an attractive method to improve the bandwidth efficiency of cooperative networks [1]-[3]. Specifically, Bletsas and others [1] proposed a distributed relay selection based on the channel information of both the first and second hops for each relay, showing that the diversitymultiplexing tradeoff of relay selection is identical with that of distributed space-time coding. Recently, amplify-and-forward (AF) with partial relay selection and no source-destination link was proposed by Krikidis and others [4]. The basic idea of relay selection with partial channel information is to select the relay with the best instantaneous signal-to-noise ratio (SNR) across a single hop (the source-relay link) rather than two hops. Since only the first-hop channel state information is used for selection, the network lifetime can be prolonged in resource-constrained wireless systems such as sensor networks. In [5], Suraweera and others analyzed the outage and error performance of semiblind AF with partial relay selection. Kim and others presented a comparison of tightly power-constrained performance for