• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.406-407
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• 2022

자율운항선박, 무인선과 같이 전통적 선박 형태에 자율성이 부여되는 형태로의 발전과 함께 드론, 비행체 같은 비행 형태까지 포함하는 해상 모빌리티는 기존 통신 체계 대비 실시간성 향상 및 대용량 데이터 교환이 요구되는 새로운 해상 안전 운항 체계가 수반되어야 한다. 초고속해상무선통신망(LTE-Maritime) 송수신기를 장착한 국내 선박의 경우, LTE급의 통신 서비스를 연안 최대 100km까지 받을 수 있지만, 국제 항해를 하는 국적선과 외국적 선박을 포함하는 해상 모빌리티 안전 운항 체계 구축을 위해서는 VDES(VHF Data Exchange System)와 같은 국제협약에서 인정하고 해상이동서비스(Maritime Mobile Service)에 속하면서 기존보다 빠른 통신망의 보급이 필수적이다. 본 논문에서는 향후 해상 모빌리티 구현을 위해 필요한 해상무선통신망의 하나로 VDES의 필요성에 주목하여 그간의 개발 현황으로부터 향후 VDES 서비스 도입 및 활용방안에 관해 논한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.339-343
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• 2022

In this study, a method for simplifying the structure of the VDES RF receiver, and the gain control method of the receiver to comply with the international standard in this structure was described. The input level of the wanted signal and unwanted signal to the receiver was defined, and when the two signals were input, the saturation state at the ADC was checked at the receiver output. As a result of the simulation by the circuit simulator, it was satisfied that the output power of the receiver was in the SFDR region of ADC with respect to the adjacent channel interference ratio, intermodulation, and blocking level. Through this study, it was found that the structure of th proposed RF receiver conforms to the international standard.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2839-2846
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• 2014

New VHF band for use in VDE is determined by WRC-12 due to the overload of AIS VDL, and the system characteristics of the VDE is recommended as ITU-R M. 1842-1. CS-TDMA, a multiple access method of AIS class B, is recommended as that of the VDE. It is inefficient for CS-TDMA just applying the report interval used in AIS class B to transmit high speed data with higher payload in the aspect of efficiency. In this paper, a simulation is executed in order to determine adequate report interval according to the number of active ships that affects directly network traffic. To this end, the performance of CS-TDMA, which includes the number of received packets, reception success rate, channel utilization, and collision rate, is investigated via a simulation.