Physical-Layer Security for Frequency Diverse Array Communication System Over Nakagami-m Fading Channels

In this paper, we propose frequency diverse array (FDA) antenna for artificial-noise (AN) aided secure communication over independent but not necessarily identical distributed Nakagami-m fading channels, where a multichannel receiver structure is adopted to address the time-variance property of FDA beampattern. Closed-form expressions for probability of nonzero secrecy capacity, secrecy outage probability, and system secrecy throughput are derived to characterize the performance of the considered system. All derivations are verified by simulation results, which show that the proposed security scheme achieves higher probability of nonzero secrecy capacity, lower secrecy outage probability, and delivers superior secrecy throughput comparing with the conventional phased-array communication scheme. This implies that FDA provides superiority for physical-layer security communication in the range dimension, whereas in the angle dimension, we show that the performance comparison between the two schemes significantly relates to the angle difference of the desired and eavesdropper direction.