Outage of Frequency Diverse Array-based Secure Transmission Over Rayleigh Fading Channels*

Different from conventional phased-array (PA) scheme that provides security in angle dimension only due to the angle-dependent property of PA antenna beampattern, frequency diverse array (FDA) antenna emerges as a new form of antenna array, which can produce both range- and angle-dependent beampattern, thus providing security in both range and angle dimensions. In this paper, we investigate the secrecy outage performance of FDA-based physical-layer security over Rayleigh fading channels. A single-antenna multiple-channel receive structure is adopted to handle the time-variant property of FDA. Artificial noise (AN) is considered to mask the information-bearing signal and improve the system security. Specifically, an approximate closed form expression for secrecy outage probability is derived.together with eavesdropper's wiretap characteristic analyzed. Simulation results verified the proposed analysis, showing that FDA antenna for secure communication can significantly enhance the security of data transmission in range dimension and outperform that of phased-array antenna.