Work in progress: Adaptive power allocation and relay selection for two hop AF cognitive relay networks

The problem of optimal power allocation with best relay selection in a two-hop amplify and forward (AF) cognitive radio relay network over independent Rayleigh fading channels is considered. We take into consideration of the transmit power allocation between the secondary transmitter and the secondary relay for a given power budget and the primary user´s interference limitation. To improve the performance of the secondary link, based on the analysis of maximizing the achievable SINR, we re-formulate the power allocation and relay selection (PARS) problem and finally the optimal solution is achieved. To reduce the computation complexity, furthermore, a suboptimal scheme is proposed with negligible performance loss. Simulation results confirm the effectiveness of the proposed schemes.