• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.2 s.17
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• pp.48-56
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• 2004

This paper presents the GPS receiver's inherent interference effectiveness based on the receiver's internal processing gain. This research is to verify the weakness of the GPS satellite signals and evaluate the receiver's vulnerability in an interference situation. The experiment for the narrow band interference effectiveness for the L1 C/A code GPS receiver has been performed by using the Spirent GSS4765 jamming simulator. After analyzing the experimental result, it is compared with the calculated J/S value of the two different L1 C/A code GPS receivers. By the above result, the narrowband jamming effectiveness of the each jamming source and the jamming margin for the each receiver are to be analyzed in detail. Finally, we could utilize the result to analyze the jamming effectiveness on the GNSS receiver.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.361-363
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• 2005

최근의 컴퓨터 네트워킹 환경에서 무선 멀티미디어 응용 서비스에 대한 사용자의 요구는 날로 증가하고 있다. 그러므로 사용자에게 원활한 서비스를 제공위해서 QoS 보장을 위한 무선 네트워크 프로토콜의 설계는 중요하다. 본 논문에서는 무선 인터넷에서 QoS를 보장하기 위한 표준인 IEEE 802.11e[1]의 문제점들을 분석하고, Multi-Hop Ad Hoc Network에서 성능 향상을 위하여 Single-channel Jamming 신호를 기반으로 한 SJMAC(Sing1e-channel Jamming MAC) 프로토콜을 설계하고, NS2 모듈을 구현한 후에 성능 평가를 하였다. 기존 IEEE 802.11e과의 성능 비교를 위하여 NS2 (Network Simulator2)[2]에 SJMAC 모듈을 추가하여 제안된 프로토콜의 성능을 검증한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.280-282
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• 2005

급변하는 컴퓨터 네트워킹 환경에서 이동화에 따른 무선통신의 비중이 날로 더해지고 있다. 본 논문에서는 무선 인터넷 프로토콜 표준인 IEEE 802.11의 문제점들을 분석하고, Multi-Hop Ad Hoc Network에서 성능 향상을 위하여 Single-channel Jamming 신호를 기반으로 한 SJMAC(Single-channel Jamming MAC) 프로토콜을 설계하고, NS2 모듈을 구현한 후에 성능 평가를 하였다. 기존 IEEE 802.11과의 성능 비교를 위하여 NS2 (Network Simulator2)[1]에 SJMAC 모듈을 추가하여 제안된 프로토콜의 성능을 검증한다.

• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.33-46
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• 2020

The purpose of Electronic warfare is to disturbe, neutralize, attack, and destroy the opponent's electronic warfare weapon system or equipment. Suppression of Enemy Air Defense (SEAD) mission is aimed at incapacitating, destroying, or temporarily deteriorating air defense networks such as enemy surface-to-air missiles (SAMs), which is a representative mission supported by electronic warfare. This paper develops a simulator for analyzing the effectiveness of SEAD missions under electronic warfare support using C++ language based on the DEVS (Discrete Event Systems Specification) model, the usefulness of which has been proved through case analysis with examples. The SEAD mission of the friendly forces is carried out in parallel with SSJ (Self Screening Jamming) electronic warfare under the support of SOJ (Stand Off Jamming) electronic warfare. The mission is assumed to be done after penetrating into the enemy area and firing HARM (High Speed Anti Radiation Missile). SAM response is assumed to comply mission under the degraded performance due to the electronic interference of the friendly SSJ and SOJ. The developed simulator allows various combinations of electronic warfare equipment specifications (parameters) and operational tactics (parameters or algorithms) to be input for the purpose of analysis of the effect of these combinations on the mission effectiveness.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2131-2138
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• 2011

GPS is vulnerable to jamming because of extremely low signal power. Many anti-jamming techniques are studied for complement this vulnerability. Anti-jamming techniques using array antenna are most effective technique and these techniques are required the DOA estimates. MUSIC algorithm and Root-MUSIC Algorithm are typical algorithms used in DOA estimation. Two algorithms have different characteristics, so the choice of an algorithm may depends on many factors such as the environment and the system requirements. The analysis and performance comparison of both algorithms is necessary to choose the best method to apply. This paper summarizes the theory of MUSIC and Root-MUSIC algorithms. And this paper extends both algorithm to estimate two-dimensional angles. The software simulator of both algorithms are implemented to evaluate the performance. Root-MUSIC algorithm has the computational advantage on ULA. MUSIC algorithm is applicable to any antenna array. MUSIC shows better estimation performance when number of array element is small while the computational load of MUSIC is much higher than Root-MUSIC.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.2
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• pp.127-134
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• 2022

In this paper, a low-cost, flexible GPS simulator based on USRP is designed as a general-purpose software wireless front-end. The simulator consists of a software GPS signal generator and a USRP-based RF transmitter. The simulator supports various scenarios including specified reception time, quantization bit level, I/Q data types, IF frequency, sampling frequency, SNR, ionospheric delay and user dynamics. The generated GPS RF signal is verified using the spectrum analyzer and off-the-shelf GNSS receivers such as U-blox M8T. The experimental results shows that the difference between generated and real live signal is ignorable. It is expected that designed GPS simulator can be used to GNSS signal design, receiver design and signal processing algorithms such as anti-jamming.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.2
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• pp.79-94
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• 2021

A GNSS receiver installed in autonomous vehicles is the most essential device for its navigation. However, if an intentional jamming signal is generated, there is a risk of exposure to an accident risk due to deterioration of the GNSS sensor's performance. Research is required to prevent this, and accordingly, a jamming generating device must be provided. However, according to the provisions of the law related to jamming, this is illegal. In this paper, we implement an in-vehicle jamming device that complies with the provisions of the law and does not affect the surrounding GNSS sensors. Driving simulation is used to evaluate the performance of the GNSS algorithm, and the malfunction of autonomous vehicles occurring in the interference environment and data errors output from the GNSS sensor are analyzed.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.5
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• pp.452-458
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• 2020

In this paper, the contents of the development of RESS(Radar Environmental Signals Simulator) for the test of active phased array multi-function radar are described. The developed RESS can simulate multiple target environments, such as target/jamming/missile response/cluster signals, by using received radar operational information and simulated scenario. It can also modulate frequency, phase, gain, timing on all waveforms operated by multi-function radar and simulated two targets and one jamming in the beam. The RESS can be used to perform functional and performance verification of the active phased array multi-function radar with sub-array receiving structures.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.339-346
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• 2017

We propose the design of an INS simulated equipment to evaluate the enhanced jamming resistance of an INS-aided GPS receiver with INS, when a jamming signal is injected into a simulated high dynamic platform. We propose the design of a relative cheap INS simulated equipment, instead of an expensive INS simulator connected to GPS simulators. Based on the design, we implement the equipment and setup high dynamic test environment using the equipment to evaluate an INS-aided GPS receiver. In the GPS L1 C/A and L2C simulations that inject jamming signals of the narrow and wide bandwidth into the GPS receiver with and without INS-aided algorithm, we obtain increased jamming resistance performance as +5 dB compared with the GPS receiver without INS-aided algorithm in all kinds of jamming bandwidth. Based on the simulations, we verified that the INS simulated equipment can be used to evaluate the enhanced jamming resistance of INS-aided GPS receivers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5A
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• pp.441-450
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• 2007

In this paper, it is proposed the link performance analysis results using SNRAT(Satellite Network Resource Allocation & Analysis Tool) and verified the anticipated results by satellite communication network simulator. A communication satellite cannot be corrected or fixed for the error in orbit operation after launching unlike the ground operation equipment and has a restricted operation life. So, it is important to make possible to use satellite communications in the proper time. It is expected the link BER(Bit Error Rate), throughput and AJ(Anti-Jamming) performance using SNRAT tool before launching. And it is verified the performance of the repeaters and ground equipment specification using the satellite network simulator and is extracted the optimum operational scenarios through the tests of various network operational plans.