Performance Optimization and Power Allocation of Amplify-and-Forward System with Multi-source

In this paper, a performance optimization scheme based on the maximum signal-to-noise ratio (SNR) at destination of amplify-and-forward (AF) system with multi-source nodes and multi-relay nodes is proposed. For the underlying AF systems, the signal is transmitted from several identical source nodes to several parallel relay nodes via the wireless channel, and then transmitted by the relay nodes to the destination node. In order to recover the original signal, the SNR under limited system power constraint is modeled as a constrained optimization problem. Then, we transform the constrained optimization problem to a convex function with respect to the power allocation, and obtain the expression of maximum SNR at destination and corresponding power allocation. Simulation results show that the SNR at the destination of the proposed scheme significantly outperforms the one in which the limited power is equally allocated among all source nodes and all relay nodes.