Covert communication technique for intelligent reflecting surface-assisted …
US20260039410A1
Abstract
We disclose a novel methodology and wireless network for covert wireless RF communications between an agent device and a client device in the presence of an adversary device which attempts to detect the existence of the transmission of the RF communication between the agent and client. The methodology comprises: providing an intelligent reflecting surface (IRS) to reflect wireless radio frequency (RF) communication signals transmitted from the agent device to the client device, the IRS comprising a two-dimensional array of individually controllable RF reflecting elements; providing a jamming device which radiates jamming signals with random power to confuse the adversary device in detecting the existence of the communication between the agent device and the client device; and establishing a covert RF communication link between the agent device and the client device using the IRS that optimizes the transmission probability, transmit power at an agent, and the reflection matrix of an IRS for covert RF communications.
Description (excerpt)
GOVERNMENT INTEREST The invention described herein may be manufactured, used and licensed by or for the U.S. Government without the payment of royalties thereon. RELATED PUBLICATION Some aspects relating to this invention have been previously disclosed by the inventors in the following paper: J. Kong, F. T. Dagefu, J. Choi, R. Aggarwal and P. Spasojevic, “Covert Communication in Intelligent Reflecting Surface Assisted Networks With a Friendly Jammer,” in IEEE Transactions on Vehicular Technology, vol. 73, no. 1, pp. 1467-1472 January 2024 (published online 31 August 2023), herein incorporated by reference in its entirety for all purposes. BACKGROUND OF THE INVENTION Field Embodiments of the present invention are directed to a covert communication technique for intelligent reflecting surface-assisted wireless networks with a friendly jammer. Description of Related Art Due to the increasing presence of adversaries and the threat they pose to both civilian and military networks, it is important to develop sophisticated secure wireless communication techniques. For many wireless communications applications, it is important to establish a covert communication system that hides the existence of the communication between a transmitter (agent) and a receiver (receiver). Some conventional methods for covert communications considered optimizing the achievable rate at a client by adjusting the transmission probability at an agent. This type of optimization has shown limited success. Intelligent reflecting surface (IRS)-based transmission, which adaptively reconfigures wireless environments via software-controlled reflections, has gained a lot of attention as a promising technology to significantly improve the performance of wireless communication networks in an energy-efficient way as well as enhance covert communications. In U.S. Pat. No. 11,750,319 B1, titled “Covert communication technique for intelligent reflecting surface assisted wireless networks, which issued on Sep. 5, 2023, and is herein incorporated by reference in its entirety, we disclosed a communication system that maximizes the achievable rate at a client while ensuring the covertness requirement of the transmission for IRS-assisted networks when there is noise uncertainty at an adversary. In doing so, we assumed that there is uncertainty of noise variance at an adversary. Even though covert performance can be improved in this manner, the noise uncertainty cannot be controlled thus posing challenges to implementation and control. Furthermore, it may not be possible to obtain information about the noise uncertainty at the adversary in practical scenarios. In light of the foregoing, improvements in covert communications for intelligent reflecting surface-assisted wireless networks are desired. BRIEF SUMMARY OF THE INVENTION We disclose a novel covert wireless communication network and methodology which incorporate a friendly jammer for covert communications in intelligent reflecting surface (IRS)-assisted wireless networks. It optimizes the transmission probability and transmit power at an agent, the reflection matrix of an IRS, and random jamming power with the goal of optimizing the expected rate at a client while ensuring the covertness requirement of the transmission. The methodology achieves near optimal performance and has low computational complexity since it uses only one-dimensional line search methods. It satisfies a constraint on the covertness of the transmission while maximizing the achievable communication rate to the client. Also, the instantaneous information about both the channels to an adversary and the channel from the jammer to the client may not be available. Therefore, the agent, IRS and jammer should find their transmission strategy by using the statistic of the channels to the adversary and the channel from the jammer to the client. Lastly, to reduce the computational overhead, it is desirable to reduce the computational complexity of identifying the transmission strategy with only negligible performance loss. This novel strategy enables one to send a confidential message to the client with the aid of an IRS in the presence of a friendly jammer. In order to mitigate the probability that the friendly communication signal is detected by an adversary, the transmission probability, the agent transmit power, the reflection matrix of the IRS in addition to the random jamming power at the jammer are jointly adjusted. This strategy can provide near-optimal performance and has low computational complexity since it uses only one-dimensional line search methods. <div id="p-001
Filing details
- Inventors
- Justin S. Kong
- Assignee
- U.S. Government, As Represented By The Secretary Of The Army
- Filed
- Aug 5, 2024
- Granted
- Application pending
Bibliographic data and excerpted text sourced from Google Patents (public record) as part of IP TechMatch's current-filings monitor. This filing is not part of the 2019 historical archive. For the authoritative full text, drawings, and legal status, see the source links above or consult USPTO records directly.