Secrecy Outage Probability of a Distributed Multi-Antenna Cooperative Communication System

Abstract

A distributed multi-antenna cooperative communication system with amplify-and-forward mode for secure communication in the presence of an eavesdropper is considered. In the communication system, there is no direct communication link between the transmitter and the intended receiver, and all nodes except relay nodes are equipped with multi-antenna. The secrecy capacity of this multiple input multiple output multiple eavesdropper system is investigated. The communication security depends on whether the noise on wiretap channel is stronger than that on main channel or not. The secrecy outage behavior of the flat Rayleigh fading channel is discussed and a relation between the strength of the channel noise and the secrecy outage probability is obtained. It is demonstrated that the secrecy outage probability is closely related to the channel noise strength and the number of the relay nodes. The thresholds for the noises received by legitimate receiver and eavesdropper are suggested, which is useful to design the secure distributed multi-antenna cooperative communication system.