Anti-interference cooperative spectrum sharing strategy with optimal bandwidth allocation

We propose a cooperative spectrum sharing strategy in which the secondary system can access to the licensed spectrum of the primary system if it can help the primary system achieve the target rate. Specifically, the secondary system acts as a decode-and-forward relay for the primary system by splitting a fraction of its transmission bandwidth to help forward primary signal. It uses the remaining bandwidth to transmit its own signal as a compensation for helping the primary system. The secondary system uses different bandwidth to transmit the primary and secondary signal, there will be no interference felt at primary and secondary systems. We study the optimization of bandwidth allocation to maximize the rate of the secondary system while guaranteeing the primary system achieve its target rate. Simulation results are given to verify our analysis and illustrate the advantages of the proposed scheme.