• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.132-133
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• 2017

The International Maritime Organization (IMO) has defined e-Navigation for the purpose of providing safe and efficient maritime information and communication services. Currently, a maritime cloud is being developed as a communication infrastructure for e-Navigation services. In this paper, we design the structure of vessel ID importation system which can efficiently register the maritime ID in the maritime cloud environment.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.593-595
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• 2020

본 논문에서는 5G NR 시스템을 위한 동기 신호를 이용한 cell ID 검출 방법에 대한 성능을 비교하였다. 5G NR(fifth-generation new radio) 시스템의 송신기는 SS/PBCH (synchronization signal/physical broadcast channel) 블록을 송신하며, 수신기는 수신된 SS/PBCH 블록을 이용하여 주파수 및 타이밍 오프셋 (frequency and timing offset)을 추정 할 수 있으며, cell ID (cell identity)는 PSS (primary synchronization signal)와 SSS (secondary synchronization signal)를 통해 검출할 수 있다. 본 논문에서는 cell ID 를 검출할 수 있는 방법으로서 2-stage 디코딩 방법과 결합 최대우도 결정 규칙 (joint maximum-likelihood decision rule: joint ML) 디코딩 방법을 사용하였다. Joint ML 디코딩 방법은 2-stage 디코딩 방법에 비해 더 좋은 검출 성능을 보이지만, 복잡도 측면에서는 2-stage 디코딩 방법이 joint ML 디코딩 방법에 비해 더 낮은 복잡도를 갖는 것을 확인하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.634-636
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• 2020

본 논문에서는 딥러닝 (deep learning) 방식을 이용한 5G NR (fifth-generation new radio)의 cell ID (cell identity) 검출 기법을 구현하였다. 5G NR 시스템의 단말 (user equipment)은 초기 접속 (initial access)과정에서 PSS (primary synchronization signal)와 SSS (secondary synchronization signal)을 이용한 동기 획득 및 cell ID 검출이 필요하다. 본 논문에서는 분류 기법 기반의 딥러닝 기술을 이용하여 인공 신경망 모델에 PSS 및 SSS 와 cell ID 의 상관 관계를 학습시키고, 학습된 모델의 성능을 제시하였다.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.870-881
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• 2020

This paper presents cell ID (cell identity) detection schemes using PSS/SSS (primary synchronization signal/secondary synchronization signal) for 5G NR (new radio) system and evaluates the detection performance. In this paper, we consider two cell ID detection schemes, i.e. two-stage detection and joint detection schemes. The two-stage detection scheme consists of two stages which estimate a channel gain between a transmitter and receiver and detect the PSS and SSS sequences. The joint detection scheme jointly detects the PSS and SSS sequences. In addition, this paper presents coherent and non-coherent combining schemes. The coherent scheme calculates the correlation value for the total length of the given PSS and SSS sequences, and the non-coherent combining scheme calculates the correlation within each group by dividing the total length of the sequence into several groups and then combines them non-coherently. For the detection schemes considered in this paper, the detection error rates of PSS, SSS and overall cell ID are evaluated and compared through computer simulations. The simulation results show that the joint detection scheme outperforms the two-stage detection scheme for both coherent and non-coherent combining schemes, but the two-stage detection scheme can greatly reduce the computational complexity compared to the joint detection scheme. In addition, the non-coherent combining detection scheme shows better performance under the additive white Gaussian noise (AWGN), fixed, and mobile environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.90-94
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• 2003

For the structure of VMS is required to the maritime MDT for realtime acquisition the position reporting of navigating ships. The first study is the recording method a navigating data by GPS, the 2th is SSB modem for data trans-receiver by use ship. And then the communication protocol of automatic traffic for in continues transmission a ship's ID, time and position data of GPS. In this paper have studied the SSB modem for transmission the voice and data at same time. Which is adapted to the communication control unit, protocol of data traffic and acquisition, displayer of character data. This maritime GPS MDT is considered to low-cost type by using microprocessor.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.211-216
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• 2014

In this paper, high throughput method is studied to provide floating objects with broadband service as ship by using satellite. In recent, satellite broadcastings standard is based on DVB-S3 for communication service using wireless device on navigation communication by satellite. LDPC codes are iterative coding algorithm proposed in DVB-S3. In this paper, FTN technique is applied to LDPC codes with 8-PSK modulation and then present the method to alleviate performance degradation due to FTN through BICM-ID. BICM-ID is the method to improve performance by calculating a new LLR from hard-decision value of decoder output. DVB-S2 system with 8-PSK modulation and FTN technique based on iterative decoding had a better performance than DVB-S2 with 8-PSK modulation and FTN technique over Gaussian channels.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.201-205
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• 2007

This paper proposes a link model that can provide the spacial position along the surface of the earth as an information or data using ePosition ID through the Internet. Moreover, to support the information service of maritime position, it needs the ENC linked technique based on S-57 that is an IHO transfer standard for digital hydrographic data. Therefore, it designs the linked model for applying and utilizing the ePosition technology with ENC data, as well as supplementing the base technology in applying them to marine related fields. As a study method, this paper first analyses ENC data model and structure, and converses for processing of ENC file to ePosition data. Finally, it derives the interconnection method with ePosition database and shows the ePosition service application based on the linked ENC data and its validity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.256-260
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• 2005

For the structure of AVLS is required to the GPS-MDT for realtime acquisition the position reporting of vehicle and traffic management S/W. It is necessary that the MODEM using VHF transceiver base on GPS and monitoring program for display base on GIS the traffic status by vehicles position report in management system. The other wise, vehicles among management system that is required the automatic communications protocol for GPS information and mobile's ID. In this paper have studied the VHF modem for transmission the voice and data at same time and S/W for management system using GIS-tool.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.1
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• pp.134-137
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• 2020

Recently, there are emphasized to support the maintenance and management system of vessels using acquired data from engine part equipment. But, there are limitations for data exchange and management. To solve the problem, the ISO published ISO 19847 and 19848. In this paper, we analyze the ISO 19848 requirements related to identify data channel ID for ship equipment, and propose the examples for applying encoding techniques. In addition, we suggest the proposed technique for applying of managing the failure and maintenance type of the ship's engine part facilities by examples. If this method is applied, the vessel's equipment can exchange data through the sharing of the code table, and express what response is needed or acted, including where the failure occurred.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.55-61
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• 2017

In DVB-S3 standard of satellite broadcasting systems, FTN technique is applied to LDPC codes with (1+7) PSK modulation. In standard, BICM-ID and BCJR decoding method are considered to alleviate performance degradation due to FTN processing. BICM-ID method improves performance by calculating a new LLR from hard-decision value of decoder output. BCJR also improves performance by calculating forward and backward matrix each other. However these two methods require high computational complexity. Therefore this paper proposed modified decoding method in order to reduce computational complexity without performance degradation.