Robust Power Allocation for Amplify-and-Forward Relay Networks

Relay power allocation has been shown to provide substantial performance gain in wireless relay networks when perfect global Channel State Information (CSI) is available. In this paper, the authors consider a more realistic scenario, where such global CSI is subject to uncertainty, and they aim to design robust power allocation protocols for both the coherent and non-coherent amplify-and-forward relay networks. The problem formulation is such that the output signal-to-noise ratio is maximized under both the aggregate and individual relay power constraints.