Joint relay selection and power allocation for two-way decode-and-forward relay networks

In this paper we consider a joint algorithm which combines relay selection with power allocation for two-way Decode-and-Forward (DF) relay channels. The selected relay use network coding to assist transceivers exchanging information. Power allocation at each node under the total transmit power constraint are proposed for better BER performance. A closed-form expression of the end-to-end BER is derived. Simulation results verify the theoretical analysis and show a performance improvement, in terms of bit error rate, of the optimal power allocation comparing to the equal power allocation scheme. Especially while one of the hops suffers deep fading, the joint algorithm can provide significant gain comparing to traditional relay selection scheme.