Two channel estimation methods for amplify-and-forward relay networks

In this paper, we investigate the performance of amplify-and-forward relaying with two different pilot-symbol-assisted channel estimation methods. In the first estimation method, the cascaded channel consisting of source-to-relay and relay-to-destination links is estimated at the destination terminal. In the second estimation method, the estimation of cascaded channel is disintegrated into separate estimations of source-to-relay and relay-to-destination links which are carried out at the relay and destination terminals, respectively. The latter method involves feed-forwarding a quantized version of the source-to-relay channel estimate to the destination terminal. Our simulation results demonstrate that cascaded channel estimator outperforms its competitor with small number of quantization bits. As the number of employed quantization bits increase, disintegrated channel estimator approaches to its competitor eventually outperforming it.