Pilot-based ML estimation in Amplify-and-Forward cooperative networks

Cooperative communication is a promising technique that achieves spatial diversity without requiring multi-antenna receivers. In this paper we consider the cooperative Amplify-and-Forward protocol and assume the channel realizations to be unknown. We study several pilot-based channel estimation strategies at the relay and the destination. The obtained maximum-likelihood estimators are evaluated for transmission over Rice-fading channels, in terms of channel estimation accuracy and error performance.