MSE and Outage Probability Based Training Power Allocations for Relay Networks

For a multi-relay amplify-and-forward (AF) network, we investigate the power allocation problem during the channel training process for the destination to estimate the global channel state information (CSI) of the whole network. We consider two objective functions: the total mean-square-error (MSE) of all channel estimates and the end-to-end outage probability (OP) of the network under channel estimation error. Closed-form solutions for the joint power allocation among different relay paths and between the source and the relay at different training stages for each relay path are derived. Our simulation results demonstrate that the proposed MSE-based and OP-based power allocation schemes are superior to even power allocation.