A Cross-Layer Approach for Cooperative Networks

This paper deals with a cross-layer approach for cooperative diversity networks, which use a combination of amplify-and-forward (AF) and decode-and-forward (DF) as a relaying strategy. Based on a well-selected ad hoc configuration, the proposed approach combines the cooperative diversity concept with a simultaneous optimization of physical, network, and multiple access control layers. The considered optimization problem requires an appropriate distribution of three roles among the network nodes, which are the diversity relays (AF concept), the intermediate router (DF and routing), and the destination (scheduling). The proposed role assignment is based on the instantaneous channel conditions between the links and jointly supports performance optimization and a long-term fairness concept. To minimize the required complexity, a partial and quantized channel feedback is also proposed. The proposed cross-layer solution is compared with conventional approaches by computer simulations and theoretical studies, and we show that it achieves an efficient performance-complexity tradeoff.