• 인터넷정보학회논문지
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• 제23권1호
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• pp.113-124
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• 2022

전시 상황에서 군용 항공기의 통신 시스템은 재밍(Jamming)에 노출되어 있으며, 아군의 무선통신에 대한 재밍 시도가 있는 환경에서도 원활한 항공작전을 수행하기 위해서는 항재밍 성능이 높은 통신장비를 탑재하는 것이 필요하다. 본 논문에서는 무선통신에 적용될 수 있는 재밍과 항재밍(Anti-Jamming) 기술에 대해 세부적으로 확인하고, 주파수 도약 방식 차세대 항재밍 무전기의 제원 차이와 이러한 변화에 따른 항재밍 성능 개선에 대해 공개된 자료 범위 내에서 간략하게 분석하였다. 또한 국산 신형 항공기 설계 시 고려해야 할 점과 현재 운영중인 항공기에 차세대 항재밍 통신장비 탑재 가능성을 확인하였으며 차세대 항재밍 통신장비의 항재밍 능력 향상이 갖는 전술적 유용성에 대해 확인하였다.

• Journal of Information Processing Systems
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• 제18권1호
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• pp.89-96
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• 2022

A novel multistage pulse jamming suppression algorithm was proposed to solve the anti-pulse jamming problem encountered in navigation receivers. Based on the characteristics of the short duration of pulse jamming and distribution characteristics of satellite signals, the pulse jamming detection threshold was derived. From the experiments, it was found that the randomness of pulse jamming affects jamming suppression. On this basis, the principle of the multistage anti-pulse jamming algorithm was established. The effectiveness of the anti-jamming algorithm was verified through experiments. The characteristics of the algorithm include simple determination of jamming detection threshold, easy programming, and complete suppression of pulse jamming.

• Journal of Positioning, Navigation, and Timing
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• 제4권1호
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• pp.17-23
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• 2015

With the increase in the risk of GPS jamming, the development and application of anti-jamming GPS techniques have been actively performed. As the objective performance verification of developed techniques is important, equipment development for verification and discussion on anti-jamming performance test method and procedure have also been conducted. However, most tests are related to the specification of equipment and therefore detailed procedure of the performance verification of an anti-jamming system needs to be developed. In this study, requirements for anti-jamming performance verification were described, and test configurations and performance evaluation items depending on three kinds of test methods (lab test, basic outdoor test, and chamber test) were suggested for anti-jamming performance verification.

• Journal of Positioning, Navigation, and Timing
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• 제3권2호
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• pp.63-69
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• 2014

In this study, due to the necessity of the equipment for inspecting an anti-jamming function depending on the expansion of the development of anti-jamming systems, an array antenna hood that can inspect the anti-jamming function of an anti-jamming system while being installed at the system was designed and manufactured. The manufactured array antenna hood plays a role in radiating GNSS signals and jamming signals. Based on an experiment, it was demonstrated that using a near-field radiation method, the manufactured array antenna hood could be used for examining the normal operation of an anti-jamming system function in outdoor or indoor environments rather than an anechoic chamber.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3333-3350
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• 2019

The smart jammer launches jamming attacks which degrade the transmission reliability. In this paper, smart jamming attacks based on the communication probability over different channels is considered, and an anti-jamming Q learning algorithm (AQLA) is developed to obtain anti-jamming knowledge for the local region. To accelerate the learning process across multiple regions, a multi-regional intelligent anti-jamming learning algorithm (MIALA) which utilizes transferred knowledge from neighboring regions is proposed. The MIALA algorithm is evaluated through simulations, and the results show that the it is capable of learning the jamming rules and effectively speed up the learning rate of the whole communication region when the jamming rules are similar in the neighboring regions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권10호
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• pp.2883-2902
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• 2023

Since the existing anti-jamming methods, including intelligent methods, have difficulty against high-speed reactive jamming, we studied a new methodology for jamming utilization instead of avoiding jamming. Different from the existing jamming utilization techniques that harvest energy from the jamming signal as a power supply, our proposed method can take the jamming signal as a favorable factor for frequency detection. Specifically, we design an intelligent differential frequency hopping communication framework (IDFH), which contains two stages of training and communication. We first adopt supervised learning to get the jamming rule during the training stage when the synchronizing sequence is sent. And then, we utilize the jamming rule to improve the frequency detection during the communication stage when the real payload is sent. Simulation results show that the proposed method successfully combated high-speed reactive jamming with different parameters. And the communication performance increases as the power of the jamming signal increase, hence the jamming signal can help users communicate in a low signal-to-noise ratio (SNR) environment.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.341-345
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• 2006

The GPS is widely used in various parts, therefore it is required higher integrity and continuity. These integrity and continuity are threatened by outer jamming signals which are intended or not. And various anti-jamming ways have been studied to remove these jamming signals. In this paper, we are going to test the efficiency of the anti-jamming algorithm in space and time-space domain, and analyze

• Journal of Positioning, Navigation, and Timing
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• 제12권3호
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• pp.229-236
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• 2023

As the importance and dependency of the positioning, navigation, and timing (PNT) information provided by the radio navigation satellite service (RNSS) increases, the vulnerability of RNSS to jamming can lead to significant risks. The signal design under the consideration of anti-jamming performance helps to provide service which is robust to jamming environment. Therefore, it is necessary to evaluate the jamming robustness performance during the design of new signals. In this paper, we introduce figures-of-merit (FoMs) that can be used for an anti-jamming performance analysis of designed signals of interest. We then calculate the FoMs, such as the quality factor (Q factor), tolerable jamming-to-signal ratio (tolerable J/S), and range to jammer (d) for legacy RNSS signals and analyze the results. Finally, based on the results of the analysis, we derive waveform design conditions to obtain good anti-jamming performance. As a result, this paper shows that the waveforms with wide bandwidth leading to good spectral efficiency provide strong anti-jamming performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3444-3457
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• 2021

In the field of anti-jamming based on dynamic spectrum, most methods try to improve the ability to avoid jamming and seldom consider whether the jammer would perceive the user's signal. Although these existing methods work in some anti-jamming scenarios, their long-term performance may be depressed when intelligent jammers can learn user's waveform or decision information from user's historical activities. Hence, we proposed a hidden anti-jamming method to address this problem by reducing the jammer's sense probability. In the proposed method, the action correlation between the user and the jammer is used to evaluate the hiding effect of the user's actions. And a deep reinforcement learning framework, including specific action correlation calculation and iteration learning algorithm, is designed to maximize the hiding and communication performance of the user synchronously. The simulation result shows that the algorithm proposed reduces the jammer's sense probability significantly and improves the user's anti-jamming performance slightly compared to the existing algorithms based on jamming avoidance.