End-to-end security-reliability analysis of multi-hop cognitive relaying protocol with TAS/SC-based primary communication, total interference constraint and asymmetric fading channels

In this paper, we analyze the tradeoff between outage probability (OP) and intercept probability (IP) for a multi-hop relaying scheme in cognitive radio (CR) networks. In the proposed protocol, a multi-antenna primary transmitter (PT) communicates with a multi-antenna primary receiver (PR), using transmit antenna selection (TAS) / selection combining (SC) technique, while a secondary source attempts to transmit its data to a secondary destination via a multi-hop approach in presence of a secondary eavesdropper. The secondary transmitters such as source and relays have to adjust their transmit power to satisfy total interference constraint given by PR. We consider an asymmetric fading channel model, where the secondary channels are Rician fading, while the remaining ones experience the Rayleigh fading. Moreover, an optimal interference allocation method is proposed to minimize OP of the primary network. For the secondary network, we derive exact expressions of end-to-end OP and IP which are verified by Monte Carlo simulations.