• Journal of the Korea Society for Simulation
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• v.29 no.2
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• pp.49-61
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• 2020

It is important to operate a limited number of interceptors effectively to counter ballistic missile threats. The existing interceptor operating method determines the number of interceptors according to the level of TBM (Theater Ballistic Missile) engagement effectiveness applied to a defended asset. It can cause either excessive interceptor waste compared to the intercept probability or the intercept probability decrease. Thus, interceptor operating method must be decided considering the number of ballistic missiles, intercept probability and cost. This study proposes a mathematical model to improve the existing interceptor operating method. In addition, the efficiency indicator is proposed for trade-off between intercept probability and cost. As a result of the simulations, the mathematical model-based interceptor operating method can achieve better results than the existing interceptor operating method.

• Journal of electromagnetic engineering and science
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• v.4 no.2
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• pp.63-67
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• 2004

DAM(Delay-And-Multiplier) intercept receiver usually detects the symbol rate of the transmitted DS spread spectrum signal for the feature extraction. It is important for secure communication to reduce the normalized output signal-to-noise ratio that is generated at the DAM intercept receiver as a measure of detectability. In this paper, several kinds of chip waveforms are novelly analyzed for LPI(Low-Probability of Intercept) communication against DAM intercept receiver. Consequently, it is shown that the rectangular chip waveform shows the best LPI performance in the bandwidth of 2/$T_c$TEX>, 4/$T_c$TEX>, and 6/$T_c$TEX>/. Except the rectangular waveform, kaiser chip waveform show better LPI performance than the other waveforms in the bandwidth of 4/$T_c$TEX> and 6/$T_c$TEX>.

• Journal of Information Processing Systems
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• v.16 no.6
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• pp.1261-1270
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• 2020

The physical security layer of industrial wireless sensor networks in the event of an eavesdropping attack has been investigated in this paper. An optimal sensor selection scheme based on the maximum channel capacity is proposed for transmission environments that experience Nakagami fading. Comparing the intercept probabilities of the traditional round robin (TRR) and optimal sensor selection schemes, the system secure performance is analyzed. Simulation results show that the change in the number of sensors and the eavesdropping ratio affect the convergence rate of the intercept probability. Additionally, the proposed optimal selection scheme has a faster convergence rate compared to the TRR scheduling scheme for the same eavesdropping ratio and number of sensors. This observation is also valid when the Nakagami channel is simplified to a Rayleigh channel.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.6
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• pp.815-823
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• 2019

A naval surface-to-air missile is an effective countermeasure against increasing threats of anti-ship missiles. Optimal operation is imperative for high survivability due to limited defense resources of a warship. This paper addresses a problem of optimal engagement to maximize the overall probability of intercept under Shoot-Look-Shoot tactics. The problem is formulated and analyzed with consideration of a realistic single-shoot probability model. The analysis shows that a global solution is achieved for some engagement scenarios. A numerical algorithm to optimize the overall probability of intercept is suggested. An illustrative example is provided to verify our results.

• ETRI Journal
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• v.38 no.1
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• pp.70-80
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• 2016

This paper addresses the problem of robust waveform design for distributed multiple-radar systems (DMRSs) based on low probability of intercept (LPI), where signal-to-interference-plus-noise ratio (SINR) and mutual information (MI) are utilized as the metrics for target detection and information extraction, respectively. Recognizing that a precise characterization of a target spectrum is impossible to capture in practice, we consider that a target spectrum lies in an uncertainty class bounded by known upper and lower bounds. Based on this model, robust waveform design approaches for the DMRS are developed based on LPI-SINR and LPI-MI criteria, where the total transmitting energy is minimized for a given system performance. Numerical results show the effectiveness of the proposed approaches.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.5
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• pp.519-526
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• 2021

In this paper, an array antenna for LOS datalink for mounting UAV(Unmanned Aerial Vehicle) of low-probability of intercept is presented. For low RCS, radome was designed by conformal form, and other components were inserted into the UAV. The antenna of the transmitter and receiver are each composed of 12×12 array antennas, and include a beam steering function by controlling the phase of the unit element for the Uni-directional pattern and the Bi-directional pattern. As a result of the measurement of the manufactured antenna, it was confirmed that all the required specifications were met, and the installing possibility of the UAV platform on low-probability of intercept in the future was confirmed.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.3
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• pp.200-209
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• 2017

In this paper, we investigate the tradeoff between security and reliability for a multi-hop protocol in cluster-based underlay cognitive radio networks. In the proposed protocol, a secondary source communicates with a secondary destination via the multi-hop relay method in the presence of a secondary eavesdropper. To enhance system performance under the joint impact of interference constraint required by multiple primary users and hardware impairments, the best relay node is selected at each hop to relay the source data to the destination. Moreover, the destination is equipped with multiple antennas and employs a selection combining (SC) technique to combine the received data. We derive closed-form expressions of the intercept probability (IP) for the eavesdropping links and the outage probability (OP) for the data links over a Rayleigh fading channel. Finally, the correction of our derivations is verified by Monte-Carlo simulations.

• The Journal of the Acoustical Society of Korea
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• v.31 no.7
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• pp.441-448
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• 2012

Spread spectrum provides the minimized inter-symbol interference, the low probability of intercept and the multiple access capability. This paper presents a direct sequence spread spectrum with carrier/timing recovery and equalizer which compensates the delay spread caused by multipath transmission. When the sea trials were performed in Korean East Sea, the bit error rates of QPSK and direct sequence spread spectrum are $1.46{\times}10^{-2}$ and $5.17{\times}10^{-4}$ at 3 km source-receiver range, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.999-1011
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• 2015

In modern electronic warfare, RADAR is under constant threat of ECM(Electronic Counter Measures) signals from nearby jammers. The conventional linear frequency modulated(Linear-FM) waveform is easy to be intercepted to estimate its signal parameters due to its periodical phase transition. Recently, APCN(Advanced Pulse Compression Noise) waveform using random amplitude and phase transition was proposed for LPI(Low probability of Intercept). But random phase code signals such as APCN waveform tend to be sensitive to Doppler frequency shift and result in performance degradation during moving target detection. In this paper, random phase and code rate transition based radar waveform(RPCR) is proposed for Doppler tolerance improvement. Time frequency analysis is carried out through ambiguity analysis to validate the improved Doppler tolerance of RPCR waveform. As a means to measure the vulnerability of the proposed RPCR waveform against LPI, WHT(Wigner-Hough Transform) is adopted to analyze and estimate signal parameters for ECCM(Electronic Counter Counter Measures) application.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.79-86
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• 2016

Physical layer security is cryptography technique to protect information by using physical nature of signals. Currently, many works on physical layer security have been actively researching while those researching models still have some problems to be solved. Eavesdropper does not share its channel state information with legitimate users to hide its presence. And when node transmits signal, hardware impairments are occurred, whereas many current researches assume that node model is ideal node and does not consider hardware impairments. The main features and contributions of this paper to solve these problems are as follows. First, our proposed system model deploys torch node around legitimate user to obtain channel state information of eavesdropper and considers hardware impairments by using channel state information of torch node. Second, we derive closed-form expression of intercept probability for the proposed system model. The results of the performance evaluation through various simulations to find out the effects on proposed system model in physical layer security show that imperfect channel state information does not effect on intercept probability while imperfect node model effects on intercept probability, Ergodic secrecy capacity and secrecy capacity.