Impacts of Licensed Interference and Inaccurate Channel Information on Information Security in Spectrum Sharing Environment

Spectrum sharing environment creates cross-interference between licensed network and unlicensednetwork. Most existing works consider unlicensed interference (i.e., interference from unlicensed networkto licensed network) while ignoring licensed interference (i.e., interference from licensed networkto unlicensed network). Moreover, existing channel estimation algorithms cannot exactly estimate channelinformation. In this paper, impacts of licensed interference and inaccurate channel information oninformation security in the spectrum sharing environment is analyzed under peak transmit power bound,peak interference power bound, and Rayleigh fading. Toward this end, a secrecy outage probabilityformula is proposed in an exact form and validated by simulations. Various results illustrate that secrecyoutage probability is constant in a range of large peak interference powers or large peak transmit powers,and is severely affected by licensed interference and inaccurate channel information.