Optimal training power allocation for amplify and forward relay networks

In this paper, we consider a three node relay channel with amplify-and-forward (AF) transmission mode. Instead of analyzing the cascaded source-relay-destination channel directly at the destination, we estimate the source-relay channel based on the received pilot signals and the pre-estimated channel of relay-destination link by inserted training at the relay. Given that the outage probability has been derived at high SNR region, under the total transmit power constraints, we explore the optimal power allocation between training and data symbols at the source by minimized the outage probability. Through simulation results, we examine the correctness of our proposed optimal power allocation method and discuss how the channel quality impacts the optimal power allocation.