Covert Wireless Communications with Channel Inversion Power Control in Rayleigh Fading

Considering Rayleigh fading channels, in this work we adopt channel inversion power control to achieve covert communications, where a transmitter can possibly hide itself from a warden while transmitting information to a receiver. Specifically, we examine the performance of the achieved covert communications in two scenarios in terms of the effective covert rate (ECR), which quantifies the amount of information that the transmitter can reliably convey to the receiver subject to the warden’s detection error probability being no less than some specific value. In the first scenario, the noise uncertainty at the warden serves as the enabler of covert communications and our examination shows that increasing the noise uncertainty at the warden and the receiver simultaneously may not continuously improve the ECR. In the second scenario, covert communications are aided by a full-duplex receiver, which always transmits artificial noise (AN) with a random power. Our analysis indicates that the achieved ECR approaches to an upper bound as the transmit power of AN approaches to infinity. This work provides J. Hu, F. Shu, and J. Li are with the School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing, China. (Emails: {jinsong hu, shufeng, jun.li}@njust.edu.cn). J. Hu is also a visiting PhD student at the Research School of Engineering, Australian National University, Canberra, ACT, Australia. F. Shu is also with National Key Laboratory of Electromagnetic Environment, China Research Institute of Radiowave Propagation, China, and with National Mobile Communications Research Laboratory, Southeast University, Nanjing, China. S. Yan is with the School of Engineering, Macquarie University, Sydney, NSW, Australia (Email: [email protected]). X. Zhou is with the Research School of Engineering, Australian National University, Canberra, ACT, Australia (Email:[email protected]). This work was supported in part by the National Natural Science Foundation of China (Nos. 61472190, 61501238, 61727802, and 61771244), the Jiangsu Provincial Science Foundation Project (BK20150786), and the open research fund of National Mobile Communications Research Laboratory, Southeast University, China (No. 2017D04).