Covert Wireless Communication With Noise Uncertainty in Space-Air-Ground Integrated Vehicular Networks
Abstract : In this paper, we propose a covert wireless uplink transmission strategy in space-air-ground integrated vehicular networks, where the source vehicle transmits its own message over the channel that being used by the host communication system, to avoid being detected by the warden. It is obvious that the data transmission efficiency of the covert communication system is limited due to the co-channel interference. To improve the data transmission efficiency, we consider that the covert communication system adopts improper Gaussian signaling (IGS). We formulate a joint transmit power and IGS factor optimization problem to minimize the outage probability of the covert communication system. The minimum error detection probability of the warden is first analyzed with noise uncertainty, which is used to measure the system covertness. Under the constraints of the quality of service (QoS) of host communication system and the covertness requirement, the optimal transmit power is first derived with proper Gaussian signaling (PGS) scheme. Then, with the approximate outage probability derived under IGS scheme, the optimization problem is solved by jointly designing the transmit power and IGS factor. Finally, we provide extensive numerical results to validate the proposed covert transmission strategy, and demonstrate that the IGS scheme is beneficial in improving the data transmission efficiency in terms of outage probability compared to PGS scheme.
? In contrast, the covert localization technique dedicates to operating the signal detection process of the adversary, such that attackers are unaware of the existence of the localization process.
? However, the main issue of the works mentioned above is that the attacker may know the existence of the transmission process and even intercept the signal of the anchor network.
? In some instances, protecting the content of the transmitted information is insufficient, whereas covert communication is required to prevent the existence of transmission from being detected by the adversary .
? We focus on the detection strategy for the warden to detect the existence of the localization signals transmitted from anchors.
? We first formulate the basic optimization problem from the perspective of the legitimate agent and anchors to achieve covert localization.
? We formulate the power allocation optimization problem of the anchors in the presence of the total power constraint, and propose an algorithm based on the semidefinite program (SDP) to solve the problem.
? The problem aims to solve the optimal transmit powers of anchors to minimize the localization accuracy bound while satisfying the covert requirement constraint.
? Moreover, the robust optimization problem is formulated in the presence of the warden’s position uncertainty.
• Many strategies and manners are proposed coping with different types of potential threats and attackers.
• Several attacktolerant localization algorithms were proposed to compute the agent’s position robustly, such as robust statistical methods, voting-based estimation, and extra hardware based scheme.
• Based on the analysis of ACPs with BUM and UUM, we have proposed the CSPEB to measure the localization accuracy of the agent when the warden suffers noise uncertainty.
• We formulate the power allocation optimization problem of the anchors in the presence of the total power constraint, and propose an algorithm based on the semidefinite program (SDP) to solve the problem.
? In, the detection performance at the warden was analyzed by a worst-case approach from the warden’s perspective, where the actual noise power is assumed to be at the worst-case scenario for the detection.
? However, this approach has an important limitation for evaluating the detection performance at the warden for covert communication, since any true level of covertness cannot be guaranteed by assuming a worst-case scenario from the warden’s perspective.
? In this work, we adopt two new approaches to measure the covertness with noise uncertainty. Instead of focusing on the worst-case scenario at Willie, we analyze the overall performance at Willie with the noise uncertainty.
|