On the secrecy performance of generalized user selection for interference-limited multiuser wireless networks

We investigate the secrecy performance of a multiuser diversity scheme for an interference-limited wireless network with a base station (BS), $N$ legitimate users, and an eavesdropper in the presence of a single dominant interferer. Assuming interference dominates noise power at the eavesdropper and at each legitimate user's receiver, the BS transmits information to the legitimate user with the kth best (highest) signal-to-interference ratio. We derive a closed-form expression for the secrecy outage probability for an arbitrary N and an asymptotic expression for a fixed k and large N. Furthermore, we derive a closed form asymptotic expression for the ergodic secrecy capacity of the kth best user and shows that it scales like O(log (N)) for a fixed k and large N.