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.