Cooperative Spectrum Sharing with Two-Way DF Relaying

In this paper we proposed a cooperative spectrum sharing protocol with two-way decode-and-forward (DF) relaying. Specifically, two primary users A and B communicate with each other with the assistant of the secondary user S. The secondary user uses a fraction of power to forward the primary signals by acting as a DF relay. As a reward, the secondary user can gain spectrum access by using the remaining power to transmit its own signal. We study the optimization of power allocation such that the secondary transmission rate is maximized, while both of the primary users can achieve their target rates. Numerical simulation and comparisons are presented to illustrate the performance of the proposed spectrum sharing protocol, and both primary and secondary users can benefit from the proposed spectrum sharing protocol.