Channel Uncertainty Effects on Multihop Nonregenerative Amplify-and-Forward Wireless Relay Network

The main purpose of this paper is studying the nonregenerative amplify-and-forward (AF) scheme for wireless relay network under channel uncertainty. A system consisting of one-source-one-destination pair and N-multihop relay nodes is studied. The system under investigation is suitable for a network of nodes with low power or widely spread nodes, where transmitted signal can reach its first tier nodes only. While signal degrades and doesn´t reach second tier neighbors. Therefore, unlike previous work in the literature, this paper studies a system where no direct link between the source and the destination node. A new proposed detection scheme using the maximum ratio combiner (MRC) is designed for such a network with uncertain channel links. It is applied at the destination to optimally detect the originally transmitted message from the source. Using the new proposed MRC detection scheme, Monte-Carlo simulation results are presented to evaluate the bit error rate (BER) for this system under study.