Splitting source power for a multicarrier relay system with direct link

We present optimization algorithms for source and relay power allocations for a multicarrier three-node relay system with direct link. We show that there is a benefit to the system capacity by allowing the source power to be split in both phases in a two-phase relay scheme. While the source power allocation problem is convex, the relay power allocation problem is not. But in both cases, we present efficient algorithms that yield the exact optimal solutions.