• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.35-40
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• 2012

Since the opening of Korean high-speed rail, KTX in 2004, the use of trains in Korea soared. Improved rail technology, as well as the speed of the train was developed. However, the development of the train speed raised new issues of Doppler effect and this effect compensation. Depending on the speed of communication target, Doppler effect generates frequency shifting and this effect leads to a distortion of the signal. For this reason, the Doppler effect adversely affect the communication performance. Therefore, the Doppler effect problem must be solved for the railway wireless communication. In this paper, we present technique of compensation for the Doppler effect that occurs in high-speed railway communication and simulation result.

• 전기의세계
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• v.43 no.6
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• pp.35-42
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• 1994

여기서는 주로 신호제어의 면에서 본 열차제어시스템의 기술적 요건과 과제를 개관하고, 구체적인 사례로서 고속열차의 운전제어, 수송력 증강을 위한 운전시격 단축, 무인운전 등 주로 열차속도 제어와 관련한 시스템에 촛점을 맞추어 최근 동향을 소개한다. 특히 경부고속철도에 적용될 프랑스의 TGV의 열차 제어시스템에 관하여 소개하고, 첨단의 컴퓨터 및 통신기술을 도입하여 열차제어 및 운영의 효율화, 다양화를 추구하고 있는 최신 열차제어시스템의 발전 방향을 알아보기로 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.357-359
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• 2021

Railway system as a mass transportation is under progress to smart railway system beyond high speed and automation era. Communication network technology including 5G-R(5th Generation - Railway) mobile communication technology and information convergence technology of Big Data, Deep Learnig, AI(Artificial Intelliegnce) and Block Chain have to be used for implementation and operation of this smart railway system. In this paper, a communication network structure is suggested for this smart railway system. This suggested smart railway commnuication network structure is composed with layered structure of plane unit for safety operation of high speed railway, railway system management and customer services, and also have some complexed function of each plane. Results of this study can be used for smart railway communication network implementation, operation and managements, development of railway communication standards.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1017-1022
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• 2020

LTE-R(Long Term Evolution-Railway) for high speed railway system operation as an essential technology is based on LTE. Recently, moving speed of high speed train is on going to 600[km/h] level over commercial speed 400[㎞/h]. LTE-R as communication technology for a high speed railway system can be able to provide seamless communication to support moving speed for high speed railway system. In this study, a handover method based on prediction is suggested and performance of the suggested method is evaluated. Computer simulation based on NS(Network Simulator)-3 is used for this study.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.305-310
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• 2008

Wireless telecommunication frequency band becomes wider with the development of modern telecommunication technology, and highly integrated semiconductors are applied more at high speed tain system. RFI susceptibilities of the integrated power semiconductors in high speed train system influence much on the system safety. RFI susceptibility standards and measurement methods in high speed train system at wireless telecommunication frequency band is surveyed in this research.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.587-594
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• 2022

This paper analyzed radio link throughput performance by applying radio link simulation and test equipment because there is limit in train filed test in 420 km/h high speed environment. According to the radio performance analysis, the throughput performance is slightly degraded in QPSK and 16QAM modulation schemes. But throughput performance is highly degraded in 64QAM modulation scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.8
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• pp.437-444
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• 2014

In this paper, we propose a path loss model with the multiple antennas and doppler shift for high speed railroad communication. Path loss model is very important in order to design consider diverse characteristic in high-speed train communication. Currently wireless communication systems use the multiple antennas in order to improve the channel capacity or diversity gain. However, until recently, many researches on path loss model only consider geographical environment between the transmitter and the receiver. There is no study about path loss model considering diversity effect and doppler shift. In order to make average residuals considering doppler shift we use tuned free space path loss model which is utilized for measurement results at high speed railroad. The environment of high speed rail is mostly at viaduct and flatland over than 50 percent. And in order to make average residuals considering multiple antenna we use theoretical estimation of diversity gain with MRC scheme. proposed model predict loss of received signal by estimating average residuals between diversity effect and doppler shift.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.248-256
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• 2008

The study aims at verifying no generation of electrical power induced noise voltage on telecommunications lineside cable by analyzing the practical findings of noise voltage produced at the telecommunication lines in the vicinity of electrified high-speed railways like KTX, while proposing to make the current standard measurement circuit along with its measuring conditions revised in compliance with international ITU-T recommendations by identifiably finding out the present problems in balance level measuring instruments as well as their errors in the measurement method now applicable by local telecommunications companies and the Radio Research Laboratory.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.319-320
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• 2006

본 기술개발의 목표는 기존의 Side Scan Sonar 시스템에서 적용된 초음파 수신 신호의 직접적인 모선으로의 전송과 달리 수중 견인체에서 초음파 수신 신호를 취득하여 전력선을 통한 고속 통신 전이중 방식을 통하여 모선의 신호처리 장치로 전송하는 고속 통신 모들의 성능 및 소형화이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.864-867
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• 2016

In high speed railway system, LTE(Long Term Evolution) based LTE-R(LTE-Railray) mobile technology is used to supply various control signal required for safty operation of train. In this paper, railway communication technology be used in railway communication system based on LTE-R is investigated in focused on application services. Standardization trends for LTE-R technology are also considered. Results of this study can be used as basic data for research and development of LTE-R and railway mobile communication.