On the diversity performance of nonregenerative cooperative transmission systems

In this paper we analyze the diversity performance of a general cooperative transmission system equipped with nonregenerative fixed gain relays in flat fading channels. Through outage probability and diversity analysis, we derive the diversity order of a two-hop cooperative transmission system when the relay has an arbitrary fixed gain. It is found that the end-to-end diversity order in such two-hop system is different from that of a nonregenerative system with channel state information (CSI)-assisted relays. Simulation results are provided to verify our analytical results