Feasibility of positive secrecy rate in wiretap interference channels

Interference usually is an adverse phenomenon in wireless networks. However, the interference can potentially be used to boost the secrecy rate in wireless interference channels. This work studies the secrecy rate in a two-user interference network where unintended user may overhear one of the users, namely user 1. User 1 tunes its transmission power in order to maximize its secrecy rate as well as to maintain the quality of service at the other user´s destination, user 2, while both user´s power limits are considered. It is demonstrated that achieving a positive secrecy rate for user 1 only depends on the channel conditions and user 2´s transmission power. Consequently, depending on the channel conditions, the exact threshold for user 2´s transmission power which leads to a positive secrecy rate for user 1 is derived.