Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1810.05949 · IEEE Wireless Communications Letters

Delay-Constrained Covert Communications With a Full-Duplex Receiver

Feng Shu, Tingzhen Xu, Jinsong Hu, Shihao Yan

Published Jan 23, 2019• 130 citations
arXivHTMLPDF

Abstract

In this letter, we consider delay-constrained covert communications with the aid of a full-duplex (FD) receiver. Without delay constraints, it has been shown that the transmit power of artificial noise (AN) at the FD receiver should be random in order to enhance covert communications. In this letter, we show that transmitting AN with a fixed power indeed improve covert communications with delay constraints, since in a limited time period the warden cannot exactly learn its received power. This explicitly shows one benefit of considering practical delay constraints in the context of covert communications. We analyze the optimal transmit power of AN for either fixed or globally optimized transmit power of covert information, based on which we also determine the specific condition under which transmitting AN by the FD receiver can aid covert communications and a larger transmit power of AN always leads to better covert communication performance.

DOI
10.1109/lwc.2019.2894617

Related papers

Covert Communication with A Full-Duplex Receiver Based on Channel Distribution Information

Tingzhen Xu, Ling Xu, Xiaoyu Liu +1 more

In this work, we consider a system of covert communication with the aid of a full-duplex (FD) receiver to enhance the performance in a more realistic scenario, i.e., only the channel distribution information (CDI) rather than channel state information (CSI) is known to a warden. Our work shows that transmitting random AN can improve the covert communication with the infinite blocklength. Specifically, we jointly design the optimal transmit power and AN power by minimizing the outage probability at Bob, and we find that the outage probability decreases and then increases as the maximum allowable AN power increases. Intuitively, once AN exceeds an optimal value, the performance will become worse because of the self-interference. The simulation results also show that the performance behaviors of CDI and CSI are different. When Willie only knows CDI, there is an optimal AN power that minimizes Bob's outage probability. However, when Willie knows CSI, the outage probability monotonically decreases with AN power.

arXiv:1810.05460•International Symposium on Antennas, Propagation and EM Theory (ISAPE)•Dec 1, 2018•10 citations

Hiding Messages into Secure Connection Transmissions with Full-Duplex Receiver

Hien Quang Ta, Lap Luat Nguyen, Tien Tung Nguyen +2 more

This letter considers hiding messages into overt transmissions with a Full-Duplex receiver, which emits Artificial Noise to secure its transmission connection while a transmitter opportunistically sends a covert message to a covert user. The warden’s uncertainties of decoding the overt message and Artificial Noise received power are exploited to hide messages. Then, the covert throughput accompanied with the warden’s average detection error probability are determined. The results show that increasing the transmit power of Artificial Noise will improve the covert performance. The results also show that the covert performance is improved when the self-interference cancellation is improved at the Full-Duplex receiver or the warden is located close to the Full-Duplex receiver, indicating the positive impact of the overt performance on the covert performance.

•Oct 20, 2021•0 citations

Hiding Messages into Secure Connection Transmissions with Full-Duplex Receiver

Hien Quang Ta, Lap Luat Nguyen, Tien Tung Nguyen +2 more

This letter considers hiding messages into overt transmissions with a Full-Duplex receiver, which emits Artificial Noise to secure its transmission connection while a transmitter opportunistically sends a covert message to a covert user. The warden’s uncertainties of decoding the overt message and Artificial Noise received power are exploited to hide messages. Then, the covert throughput accompanied with the warden’s average detection error probability are determined. The results show that increasing the transmit power of Artificial Noise will improve the covert performance. The results also show that the covert performance is improved when the self-interference cancellation is improved at the Full-Duplex receiver or the warden is located close to the Full-Duplex receiver, indicating the positive impact of the overt performance on the covert performance.

•Oct 21, 2021•0 citations

Delay-Intolerant Covert Communications With Either Fixed or Random Transmit Power

Shihao Yan, Biao He, Xiangyun Zhou +2 more

In this paper, we study delay-intolerant covert communications in additive white Gaussian noise (AWGN) channels with a finite block length, i.e., a finite number of channel uses. Considering the maximum allowable number of channel uses to be N, it is not immediately clear whether the actual number of channel uses, denoted by n, should be as large as N or smaller for covert communications. This is because a smaller n reduces a warden's chance to detect the communications due to fewer observations, but also reduces the chance to transmit information. We show that n = N is indeed optimal to maximize the amount of information bits that can be transmitted, subject to any covert communication constraint in terms of the warden's detection error probability. To better make use of the warden's uncertainty due to the finite block length, we also propose to use uniformly distributed random transmit power to enhance covert communications. Our examination shows that the amount of information that can be covertly transmitted logarithmically increases with the number of random power levels, which indicates that most of the benefit of using random transmit power is achieved with just a few different power levels.

IEEE Transactions on Information Forensics and Security•Jun 11, 2018•263 citations

Disguised Full-Duplex Covert Communications

Jihwan Moon

Covert communications have arisen as an effective communications security measure that overcomes some of the limitations of cryptography and physical layer security. The main objective is to completely conceal from external devices the very existence of the link for exchanging confidential messages. In this paper, we take a step further and consider a scenario in which a covert communications node disguises itself as another functional entity for even more covertness. To be specific, we study a system where a source node communicates with a seemingly receive-only destination node which, in fact, is full-duplex (FD) and covertly delivers critical messages to another hidden receiver while evading the surveillance. Our aim is to identify the achievable covert rate at the hidden receiver by optimizing the public data rate and the transmit power of the FD destination node subject to the worst-case detection error probability (DEP) of the warden. Closed-form solutions are provided, and we investigate the effects of various system parameters on the covert rate through numerical results, one of which reveals that applying more (less) destination transmit power achieves a higher covert rate when the source transmit power is low (high). Since our work provides a performance guideline from the information-theoretic point of view, we conclude this paper with a discussion on possible future research such as analyses with practical modulations and imperfect channel state information.

Sensors•Jul 19, 2023•4 citations

Covert Communication Achieved by a Full-Duplex Multi-Antenna Receiver in Wireless Networks

Ling Yang, Weiwei Yang, Jia Tu +3 more

In this paper, we consider a covert communication system with a multi-antenna full-duplex (FD) receiver to enhance covert performance. More precisely, the receiver Bob (i.e., multiple antennas) selects the best antenna to receive the covert message, and then it sends artificial noise (AN) to the warden Willie causing uncertainty by utilizing an antenna among the remaining antennas. In order to take full advantage of multi-antenna technology, we consider two cases: (1) Willie does not know which antenna Bob chooses to send AN, and Willie knows only part of the channel information. (2) Willie knows which antenna Bob chooses to send AN, and Willie knows all the channel information. Based on the analysis of the optimal detection threshold, we derive the minimum detection error probability of the two cases. Furthermore, given the pre-determined convert constraints, the closed-form expression of the maximum effective convert rate is derived. When the power of AN sent by Bob is greater than that of covert message sent by the sender Alice, surprised research results are shown: (1) the detection error rate of case 1 is higher than that of case 2. (2) the effective covert rate of case 1 is always lower than that of case 2. The simulation results show that the proposed scheme is more conducive to sending covert messages for Alice; in addition, the numerical results imply that the maximum effective covert rate of the system using the multi-antenna FD receiver is significantly higher than that of the traditional dual-antenna FD receiver system.

Journal of Circuits Systems and Computers•May 12, 2021•3 citations
In this letter, we consider delay-constrained covert communications with the aid of a full-duplex (FD) receiver. Without delay constraints, it has been shown that the transmit power of artificial noise (AN) at the FD receiver should be random in order to enhance covert communications. In this letter, we show that transmitting AN with a fixed power indeed improve covert communications with delay constraints, since in a limited time period the warden cannot exactly learn its received power. This explicitly shows one benefit of considering practical delay constraints in the context of covert communications. We analyze the optimal transmit power of AN for either fixed or globally optimized transmit power of covert information, based on which we also determine the specific condition under which transmitting AN by the FD receiver can aid covert communications and a larger transmit power of AN always leads to better covert communication performance.
In this work, we consider a system of covert communication with the aid of a full-duplex (FD) receiver to enhance the performance in a more realistic scenario, i.e., only the channel distribution information (CDI) rather than channel state information (CSI) is known to a warden. Our work shows that transmitting random AN can improve the covert communication with the infinite blocklength. Specifically, we jointly design the optimal transmit power and AN power by minimizing the outage probability at Bob, and we find that the outage probability decreases and then increases as the maximum allowable AN power increases. Intuitively, once AN exceeds an optimal value, the performance will become worse because of the self-interference. The simulation results also show that the performance behaviors of CDI and CSI are different. When Willie only knows CDI, there is an optimal AN power that minimizes Bob's outage probability. However, when Willie knows CSI, the outage probability monotonically decreases with AN power.
This letter considers hiding messages into overt transmissions with a Full-Duplex receiver, which emits Artificial Noise to secure its transmission connection while a transmitter opportunistically sends a covert message to a covert user. The warden’s uncertainties of decoding the overt message and Artificial Noise received power are exploited to hide messages. Then, the covert throughput accompanied with the warden’s average detection error probability are determined. The results show that increasing the transmit power of Artificial Noise will improve the covert performance. The results also show that the covert performance is improved when the self-interference cancellation is improved at the Full-Duplex receiver or the warden is located close to the Full-Duplex receiver, indicating the positive impact of the overt performance on the covert performance.
This letter considers hiding messages into overt transmissions with a Full-Duplex receiver, which emits Artificial Noise to secure its transmission connection while a transmitter opportunistically sends a covert message to a covert user. The warden’s uncertainties of decoding the overt message and Artificial Noise received power are exploited to hide messages. Then, the covert throughput accompanied with the warden’s average detection error probability are determined. The results show that increasing the transmit power of Artificial Noise will improve the covert performance. The results also show that the covert performance is improved when the self-interference cancellation is improved at the Full-Duplex receiver or the warden is located close to the Full-Duplex receiver, indicating the positive impact of the overt performance on the covert performance.
In this paper, we study delay-intolerant covert communications in additive white Gaussian noise (AWGN) channels with a finite block length, i.e., a finite number of channel uses. Considering the maximum allowable number of channel uses to be N, it is not immediately clear whether the actual number of channel uses, denoted by n, should be as large as N or smaller for covert communications. This is because a smaller n reduces a warden's chance to detect the communications due to fewer observations, but also reduces the chance to transmit information. We show that n = N is indeed optimal to maximize the amount of information bits that can be transmitted, subject to any covert communication constraint in terms of the warden's detection error probability. To better make use of the warden's uncertainty due to the finite block length, we also propose to use uniformly distributed random transmit power to enhance covert communications. Our examination shows that the amount of information that can be covertly transmitted logarithmically increases with the number of random power levels, which indicates that most of the benefit of using random transmit power is achieved with just a few different power levels.
Covert communications have arisen as an effective communications security measure that overcomes some of the limitations of cryptography and physical layer security. The main objective is to completely conceal from external devices the very existence of the link for exchanging confidential messages. In this paper, we take a step further and consider a scenario in which a covert communications node disguises itself as another functional entity for even more covertness. To be specific, we study a system where a source node communicates with a seemingly receive-only destination node which, in fact, is full-duplex (FD) and covertly delivers critical messages to another hidden receiver while evading the surveillance. Our aim is to identify the achievable covert rate at the hidden receiver by optimizing the public data rate and the transmit power of the FD destination node subject to the worst-case detection error probability (DEP) of the warden. Closed-form solutions are provided, and we investigate the effects of various system parameters on the covert rate through numerical results, one of which reveals that applying more (less) destination transmit power achieves a higher covert rate when the source transmit power is low (high). Since our work provides a performance guideline from the information-theoretic point of view, we conclude this paper with a discussion on possible future research such as analyses with practical modulations and imperfect channel state information.
In this paper, we consider a covert communication system with a multi-antenna full-duplex (FD) receiver to enhance covert performance. More precisely, the receiver Bob (i.e., multiple antennas) selects the best antenna to receive the covert message, and then it sends artificial noise (AN) to the warden Willie causing uncertainty by utilizing an antenna among the remaining antennas. In order to take full advantage of multi-antenna technology, we consider two cases: (1) Willie does not know which antenna Bob chooses to send AN, and Willie knows only part of the channel information. (2) Willie knows which antenna Bob chooses to send AN, and Willie knows all the channel information. Based on the analysis of the optimal detection threshold, we derive the minimum detection error probability of the two cases. Furthermore, given the pre-determined convert constraints, the closed-form expression of the maximum effective convert rate is derived. When the power of AN sent by Bob is greater than that of covert message sent by the sender Alice, surprised research results are shown: (1) the detection error rate of case 1 is higher than that of case 2. (2) the effective covert rate of case 1 is always lower than that of case 2. The simulation results show that the proposed scheme is more conducive to sending covert messages for Alice; in addition, the numerical results imply that the maximum effective covert rate of the system using the multi-antenna FD receiver is significantly higher than that of the traditional dual-antenna FD receiver system.