• Title/Summary/Keyword: Communication Jamming

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Frequency Jamming System using Helical Antenna (헬리컬 안테나를 이용한 주파수 재밍 시스템)

  • Park, Ju-Won;Park, Min-U;Ryu, Je-Hyeon;Jang, Sung-Jun;Park, Yong-Wook
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.5
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    • pp.911-916
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    • 2018
  • Among the various microwaves, the microwaves that we are using in our life are the things that combined with the information on what we need with various technologies. However, the signals that we do not want to get as an information is just noise. Therefore, we need to collect only the necessary information, and other information needs to be blocked. This technology is called Jamming. In this paper, the Partial-Band Jamming System through the Helical Antenna about target 95.1 and 97.3MHz in 88Mhz to 108MHz of the FM radio frequency band was studied.

Implementation of Improved Functional Router Using Embedded Linux System (Subspace projection과 SCORE algorithm을 이용한 두 가지 전파방해 대응기술의 성능비교)

  • Han, Sang-Yoon;Shin, Jung-Hwan;Heo, Jun
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.79-80
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    • 2006
  • In this paper, we compare two different anti-jamming schemes, Subspace projection and SCORE algorithm. For multipath cancelation, nulling technique is applied to both anti-jamming schemes. It is noted that SCORE algorithm is more robust to the multipath interference. It is also noted that Subspace projection scheme requires nulling technique for multipath mitigation.

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A Study on Performance Analysis of IEEE 802.15.4b Noncoherent Receivers at 915MHz under Pulse Jamming (Pulse Jamming 환경 하에서 IEEE 802.15.4b 915MHz 비동기식 수신기 성능 분석에 대한 연구)

  • Lee, Sung-Yong;Cheong, Cha-Keon
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.296-298
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    • 2009
  • In this paper, we are performance analysis of IEEE 802.15.4b LR-WAPN(Low-Rate Wireless Personal Area Network; Zigbee) system noncoherent receivers at 915MHz under Jamming. IEEE 802.15.4b concerns itself with devices at 915MHz, which employ a higher data rate of up to 250 kbps, and which use O-QPSK(Offset Quradrature Phase Shift Keying modulation with DSSS(Direct Sequence Spread Spectrum). Communication between devices can still be hampered by the presence of interferers outside the network, whether the interference be intentional or not. Hence the receivers can not have stable receiving condition due to worse BER. To solve this problem, we present a mere stabilized receiver system of using noncoherent detection. In this paper, we look instead at the effect of jamming, i.e. intentional interference, on the BER performance of IEEE 802.15.4 devices.

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A Successive Repeat-back Jamming Cancellation Scheme Using a Combined-PRN Signal to Mitigate Repeat-back Jamming for GNSS Receivers (GNSS 수신기의 C-PRN 신호 기반 재방송재밍 완화기법)

  • Yoo, Seungsoo;Yeom, Dong-Jin;Jee, Gyu-In;Kim, Sun Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.10
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    • pp.1073-1078
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    • 2014
  • In this paper, an effective repeat-back jamming (RBJ) mitigation scheme known assuccessive repeat-back jamming cancellation (SRC) is proposed for the utilization of the successive interference cancellation (SIC) algorithm which is used to mitigate the near-far effect and the multiple-access interference for code division multiple-access communication systems. The proposed scheme uses a combined pseudo-random noise (C-PRN) signal from the estimated major parameters of RBJ signals. To evaluate the performance of the proposed scheme, the root mean squared (RMS) code tracking errors are shown according to the standard deviation of the parameter estimation errors of an RBJ signal, and using the well-known major parameters estimation schemes with a C-PRN signal through Monte-Carlo simulation.

Anti-Jamming 기반 전술통신 기술

  • Lee, Du-Ho;Go, Byeong-Hun;Kim, Gwang-Sun
    • Information and Communications Magazine
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    • v.24 no.10
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    • pp.24-33
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    • 2007
  • 최근 들어 차세대 전술통신 체계인 전술 종합 정보 통신 (TICN: tactical information communication network) 구축 사업이 진행되고 있다. 전술통신 환경에서 고속의 데이터 통신을 위해서는 상용 통신 시스템과는 달리 고려해야 할 점이 많다. 본고에서는, 전술통신에서 반드시 고려해야 할 위협 요소인 재밍 (jamming)에 대해서 이제까지 알려진 몇 가지 재밍 신호 모형과 재밍 신호를 효과적으로 탐지해 내고 제거할 수 있는 항재밍 (anti-jamming) 기법들에 대해 알아본다.

A Nulling Anti-Jamming Scheme for the Polyphase Filter Bank-Based Satellite Repeat System (다상 필터 뱅크 기반의 위성 중계시스템을 위한 항재밍 기법의 연구)

  • Oh, Jin-O;Im, Sung-Bin;Ko, Hyun-Suk
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.7
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    • pp.39-47
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    • 2012
  • The combination of the broadband property and the wide area coverage of satellite communications enables high speed transmission. Every user in the region under the satellite beam coverage can tranceiver and one can simultaneously communicate with multiple users. For these reasons, it is one of commendable telecommunication networks for information transfer. Since the satellite communications use open channels, it is likely to cause jamming with unwanted interference signals. In the thesis, APSK (Amplitude Phase Shift Keying) is employed, which is recommended for DVB-S2 due to high-speed transmission and excellent bandwidth efficiency. For obtaining reliable communication under the jamming environments, the communication satellite transponder rests on the polyphase filter bank structure, which enables switching among the subchannels and gain control on each subchannel, resulting in effectively eliminating jamming. Furthermore, the nulling scheme, one of the various anti-jamming approaches, is investigated, in which unwanted jamming signals are eliminated in the frequency domain after passing through the analysis part of the polyphase filter bank. The performance of the nulling scheme is evaluated for tone jamming and partial band jamming in terms of BER and EVM. The simulation results indicate that the nulling scheme improve the BER and EVM performance over the case without any anti-jamming approach.

A Fast Anti-jamming Decision Method Based on the Rule-Reduced Genetic Algorithm

  • Hui, Jin;Xiaoqin, Song;Miao, Wang;Yingtao, Niu;Ke, Li
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.9
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    • pp.4549-4567
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    • 2016
  • To cope with the complex electromagnetic environment of wireless communication systems, anti-jamming decision methods are necessary to keep the reliability of communication. Basing on the rule-reduced genetic algorithm (RRGA), an anti-jamming decision method is proposed in this paper to adapt to the fast channel variations. Firstly, the reduced decision rules are obtained according to the rough set (RS) theory. Secondly, the randomly generated initial population of the genetic algorithm (GA) is screened and the individuals are preserved in accordance with the reduced decision rules. Finally, the initial population after screening is utilized in the genetic algorithm to optimize the communication parameters. In order to remove the dependency on the weights, this paper deploys an anti-jamming decision objective function, which aims at maximizing the normalized transmission rate under the constraints of minimizing the normalized transmitting power with the pre-defined bit error rate (BER). Simulations are carried out to verify the performance of both the traditional genetic algorithm and the adaptive genetic algorithm. Simulation results show that the convergence rates of the two algorithms increase significantly thanks to the initial population determined by the reduced-rules, without losing the accuracy of the decision-making. Meanwhile, the weight-independent objective function makes the algorithm more practical than the traditional methods.

FH DFT-Spreading OFDM System for the Effective Channel Estimation and PAPR Reduction in Jamming Channel (재밍 채널에서 효과적 채널 추정과 PAPR 저감을 위한 주파수 도약 DFT-Spreading OFDM 시스템)

  • Kim, Jang-Su;Ryu, Heung-Gyoon;Lee, Seung-Jun;Ko, Dong-Kuk
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.7
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    • pp.796-804
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    • 2010
  • It is important to use the comb type pilot allocation for the continuous channel and efficient processing. And DFT-spreading OFDM is used a lot to solve high PAPR problem of OFDM system. However, PAPR is increased again when comb type pilot is used to estimate channel characteristics. So, in this paper, we employ a new SLM method to DFT-spreading OFDM system to reduce increased high PAPR. And we suggest an effective method to transmit side information without additional bandwidth. Pilot and side information must be preserved from jamming or intentional interferences since those are very important in DFT spread OFDM system using SLM. So, in this paper, we like to analyze and simulate the performance of DFT spread OFDM system based on SLM against jamming signal. To remedy the vulnerable shortcomings of DFT spread OFDM about jamming or intentional interferences, we employ FH(Frequency Hopping) method and analyze system performance under the several jamming conditions such as MTJ(Multi Tone Jamming) and PBJ(Partial Band Jamming).

Analysis of the Monopulse Radar Tracking Errors using Orthogonally Deployed Antenna Sets for Cross-eye Jamming (십자형으로 배치된 크로스아이 재머 안테나를 이용한 모노펄스 레이다 재밍 오차 분석)

  • Lim, Joong-Soo;Chae, Gyoo-Soo
    • Journal of Convergence for Information Technology
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    • v.10 no.6
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    • pp.14-18
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    • 2020
  • In this paper, when two sets of cross-eye jammer antennas are installed vertically to jam a monopulse radar, the jamming effects according to the jammer's phase difference, amplitude ratio, and radar angle of engagement are analyzed. The phase difference and amplitude ratio of the cross-eye jammer can be adjusted in the jammer, but since the angle of engagement is relatively determined by the radar, it is very important to respond to changes in the angle of engagement. The orthogonally deployed jammer antennas can be considered as a good way to increase the jamming effect while minimizing the hardware configuration, and the jamming effect is analyzed while changing the angle of inclination from 0° to 360°. This jammer greatly improves the jamming effects at the angles of incidence 45°~135° and 225°~315°, compared to a single jammer. And it is expected to be useful in the design of cross-eye jammers for military aircraft and ships.

Wideband Jamming Signal Remove Using Adaptive Array Algorithm (적응배열 알고리즘을 이용한 광대역 재밍 신호 제거)

  • Lee, Kwan-Hyeong
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.4
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    • pp.419-424
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    • 2019
  • In this paper, we proposed an algorithm to estimate the desired target in wideband jamming signal environment. In order to suppress the jamming signal, we use the spatial time adaptive algorithm and QR decomposition to obtain the optimal weight. The spatial time adaptive algorithm of adaptive array antenna system multiplies the tap delay signal by a complex weight to obtain a weight. In order to minimize the power consumption because of the inverse matrix, optimal weight is obtained by using QR decomposition. Through simulation, we compare and analyze the performance of the proposed algorithm and the existing algorithm. In the target estimation of [-40o,0o,+40o], the proposed algorithm estimated all three targets, but the existing algorithm estimated only [0o] due to of the jamming signal. We prove that the proposed algorithm improves performance by removing the jamming signal and estimating the target accurately.