Secure spectrum sharing via rate adaptation

This paper addresses the problem of secure communication in spectrum sharing networks. The achievable rates are determined such that the unlicensed user security is guaranteed, i.e., the unlicensed user massages are not decodable by the license holders. Considering slowly-fading channels, the results are obtained under the licensed user interference- and signal-to-interference-and-noise ratio (SINR)-limited conditions. The results indicate that there is considerable potential for the unlicensed user secure data transmission under different license holder´s quality-of-service requirements. Moreover, depending on the channel condition and the license holder´s SINR constraint, the unlicensed user´s achievable rates may increase with the license holder transmission power.