Covert wireless communication with random frequency diverse array
IEEE Transactions on Vehicular Technology
School of Science / Security Research Institute
National Natural Science Foundation of China / Strategic Priority Research Program of the Chinese Academy of Sciences
In this work, we consider a covert communication system with a random frequency diverse array (RFDA) at the transmitter Alice, while the warden Willie's location follows a binomial point process (BPP) around Alice. Specifically, we consider two scenarios, where Alice's location is known or unknown to Willie, for which Willie's detection performance is thoroughly anzlyzed in terms of deriving his optimal detection threshold and the minimum detection error rate. Our analysis explicitly reveals that a higher covert rate can be achieved when Willie does not know Alice's location and the performance gap decreases as the BPP radius increases. In addition, the conducted analysis also shows that the achievable covert rate increases with the number of antenna elements at Alice and the BPP radius for Willie, which is supported by the characterized best detection performance at Willie. Furthermore, we clearly show that a certain covert rate is still achievable from Alice to the receiver Bob even when Bob is further away from Alice relative to Willie's potential location, which shows one obvious benefit of using RFDA in covert communications.