Abstract
In this paper, we investigate the effect of channel estimation error on the error rate performance of a multi-relay system with amplify-and-forward relaying. We consider orthogonal relaying and study both conventional cooperative systems (i.e., all relays participate in the relaying phase) and opportunistic cooperative systems (i.e., only the best relay participates in the relaying phase). Based on the derivation of effective signal-to-ratio at the receiver taking into account channel estimation error, we obtain closed-form expressions for bit error rate. Monte-Carlo simulations are further provided to confirm the analytical results.