This paper evaluates outage probability (OP) of a path-selection protocol in multi-path multi-hop decode-and-forward (DF) relaying networks. In the considered protocol, relying on the end-to-end signal to interference-plus-noise ratio (SINR), the best path between the source and the destination is selected to enhance the outage performance under joint impact of co-channel interference and hardware imperfection. We derive exact and asymptotic closed-form expressions of the end-to-end OP for the considered protocol over Rayleigh fading channels. The simulation results are then presented to validate the theoretical results.

This paper investigates a cognitive radio network where a secondary sender assists a primarytransmitter in relaying primary information to a primary receiver and also transmits its own information toa secondary recipient. This sender is capable of jamming to protect secondary and/or primary informationagainst an eavesdropper and self-powering by harvesting radio frequency energy of primary signals.Security capability of both secondary and primary networks are analyzed in terms of secrecy outageprobability. Numerous results corroborate the proposed analysis which serves as a design guidelineto quickly assess and optimize security performance. More importantly, security capability trade-offbetween secondary and primary networks can be totally controlled with appropriate selection of systemparameters.