• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12A
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• pp.1105-1112
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• 2010

Link-16 is a up-to-date tactical data link used in the armed forces of U.S. and NATO. In order to guarantee the required capabilities of anti-jamming and low probability of detection, Link-16 uses the techniques of frequency hopping and spreading code etc. In this paper, under Nakagami fading channels, we ananlyze the symbol error rates (SERs) of JTIDS/Link-16-type waveform based on both the single- and double-pulse schemes by considering the partial band noise jamming and the pulse jamming models, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4C
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• pp.355-361
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• 2007

In this paper, the hop-timing estimator, which NED and ELF are adopted to, has been proposed. The estimation performance of the proposed scheme and the conventional scheme is compared through computer simulations. The simulation results show that the new system has less hop-timing error than the conventional system in partial band noise jamming channel. The lover Eb/Nj and ratio of jamming bandwidth(rho) we, the bigger performance enhancement of the proposed system is.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.5
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• pp.1-9
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• 1994

In this paper, we analyzed the performances for FH/CPFSK system with limiter-discriminator detection and integrate-and-dump post-detection filtering under thermal noise and partial-band jamming noise. And,we considered intersymbol interference-related SNR and differential phase parameters for all eight of the possible adjacent bit data patterns, FM noise clicks for evaluating FH/CPFSK and CPFSK Systems. In result, the optimum modulation index h was 0.7 and the optimum value of bandwidth-time product D was 1.0 Next, when we considered the thermal noise under the partial-band jamming, the thermal noise significantly influenced the error probability of system below 20dB approximately but could ignore above 20dB.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.6
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• pp.42-51
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• 1996

Performance analysis of FH/CPFSK system with liiter-discriminator detection and integrate-dump post-detection filtering under the thermal noise and the partial-band noise jamming on the rayleigh fading channel have been analyzed. The thermal noise and partial-band noise jamming, rayleigh fading, intersymbol interference for all eight of the possible adjacent bit data patterns, and FM noise click for evaluating systems have been considered. Also optimum parameters to improve performance of FH/CPFSK system have been obtained and validities for AMPS and CDMA system of land-mobile-communication system through computer simulation have been proved.

• Journal of Space Technology and Applications
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• v.3 no.2
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• pp.144-153
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• 2023

The existing military satellite communication system was based on geostationary satellites equipped with special communication payloads against enemy's jamming and signal reception. With the advent of new weapon systems such as unmanned systems, the need for low-orbit satellite-based communication system is increasing. This paper introduces various waveform technologies suitable for cube satellite-based communication system and the operational concept of a future military nanosatellite communication system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.499-504
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• 2002

In this paper, we analyzed the performance of FH/CPFSK system with differential detection in thermal noise, partial-band jamming noise and adjacent interference of all eight bit pattern. The parameters to analize performances of FH/CPFSK system have been used the bit rate, modulation index and performances of FH/CPFSK system with the differential detector have been presented with the optimum correlation function. And, we were compared with performance of FH/CPFSK and FH/BFSK system. In result, we could know that bit error probability of the approximation equation and exact equation nearly accorded in the high signal-to-noise ratio. And, we have been proved that FH/CPFSK system with differential detection according to jamming fraction ${\gamma}$ was worst to 3dB than FH/CPFSK system with limiter-discriminator. but was superior to 2dB than FH/BFSK.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.95-99
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• 2013

GPS service is generally being used in the navigation application such as the car navigation and the smart phone. Recently, GPS service continues to increase in the timing application such as the mobile telecommunication network, the smart grid, and the financial network. As GPS signals are sensitive to GPS jamming, it should be monitored and protected. In oder to prevent and minimize the damage caused by GPS jamming, many countries are developing and operating GPS jamming monitoring system. This paper presents the implementation and the test results of the GPS jamming equipment which provides the detection, the direction finding and the location of GPS jamming.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.8
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• pp.859-867
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• 2016

The Global Positioning System is a navigation system that has been developed by the United States for military use. Currently, many countries, including the Republic of Korea, use GPS for civilian and military uses. However, as useful as it is, GPS is vulnerable to its Jamming signal, as the strength of the signal from satellites is very weak. In this paper, a novel jamming signal detection and cancellation method is proposed when a narrow-band jamming signal is included in the GPS received signal. At the GPS receiver, the received signal is transformed to a frequency domain sample by Fast Fourier Transform. In order to suppress the Spectral Leakage, the Blackman-Harris window is used. The proposed jamming signal cancellation algorithm will find the frequency sample with maximum power and null the maximum sample in addition to some lateral samples. If the GPS receiver is designed with FFT of size 128 to 512, it is shown that 42 samples are optimal to cancel the narrow-band jamming signal.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.723-730
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• 2017

In this paper, we consider an online compensation algorithm considering the mutual coupling and suggest a new GPS antenna array to apply. To evaluate the anti-jamming performance for the proposed antenna array, ULA and URA, we divide direction finding of multiple jamming signals into environments. 1. there is no mutual coupling. 2. there is mutual coupling but no compensation. 3. mutual coupling is compensated. RMSE analysis showed that the online compensation algorithm works and that peak detection is possible for multiple jamming signals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.4
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• pp.721-728
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• 1994

In this paper, we analyzed the performances of system considering diversity for FH/CPFSK system with limiter-discrimicator detection and integrate-and-dump post-detection filtering. And, we considered thermal noise and partial-band jamming noise, intersymbol interference for all eight of the possible adjacent bit data patterns, FM noise clicks for evaluation systems. In result, the performance of FH/CPFSK system with diversity under the worst-case partial band jamming noise degraded about 5dB rather than that of without diversity when we considered the thermal noise but improved about 16dB rather than of without diversity when we ignored the thermal noise.