Power Allocation and Performance Comparison of Full Duplex Dual Hop Relaying Protocols

This paper provides two optimal power allocation (OPA) strategies for full duplex (FD) relay networks with amplify and forward (AF) protocol. Two strategies are designed based on statistical channel state information (S-CSI) and instantaneous CSI (I-CSI) to minimize the system outage probability under total source and relay power constraint. For the S-CSI scheme, the OPA factor is found through an exhaustive search while, for the I-CSI scheme, the OPA factor is given in a closed-form expression. To evaluate quickly the system performance with two proposed schemes, we derive the tight closed-form lower and upper bounds on the system outage for S-CSI based OPA scheme and the asymptotic performance for I-CSI based OPA scheme. Furthermore, how much difference in performance between AF and decode and forward (DF) relaying with OPA is also verified through our numerical results.