Outage Probability of Interference Cancellation Based Two-Way Relaying Cognitive Radio Protocol with Primary MIMO Communication

In this paper, we propose a digital network coding protocol to enhance data rate for the secondary network in underlay cognitive radio environment. In the proposed protocol, transmit antenna selection and selection combining techniques are respectively used by a primary transmitter and a primary receiver to enhance performance for a primary network. In a secondary network, two secondary sources exchange their information via assistance of a common secondary relay that employs interference cancellation method to reduce one time slot, as compared with the conventional digital network coding protocol. We derive expressions of transmit power of the secondary nodes under a constraint of outage probability (OP) given by the primary network. Exact and asymptotic closed-form formulas of OP of the secondary network over Rayleigh fading channel are derived, and verified by Monte-Carlo simulations.