Power allocation for outage rate maximization in OFDM relay links

The power allocation problem in a two-hop OFDM amplify-and-forward (AF) relay link is studied when the available channel state information (CSI) is an outdated, but correlated version of the actual instantaneous CSI. We propose a power loading scheme to maximize the outage rate. The outage rate achieved by the proposed approach is compared with uniform power allocation and instantaneous rate maximization to study the effectiveness of adaptive power loading when the available CSI is outdated. Results confirm that the proposed method achieves higher outage rate than the other two methods.