Power Allocation and Relay Selection for Cognitive Relay Networks with Primary QoS Constraint
Peng Lan, Fenggang Sun, Lizhen Chen, Peng Xue, Jialin Hou · IEEE Wireless Communications Letters · 2013
In this letter, an optimal power allocation scheme between the secondary transmitter (ST) and secondary relay (SR) with best relay selection is proposed for a two-hop decode and forward cognitive relay network. Based on the joint consideration of the interference from ST and SR to the primary user (PU), the closed-form solution for optimal power allocation and relay selection (PARS) is presented under the quality of service (QoS) constraint of the PU transmission. Furthermore, a low complexity sub-optimal scheme is proposed. Simulation results verify the performance improvement of the proposed schemes.