• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.3
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• pp.283-292
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• 2005

After USA removed the Selective Availability (SA), Global Positioning System (GPS) has monopolized the world market and other countries have been depended on GPS, absolutely. So the other countries, Russia, European Community (EC) and Japan, which apprehend to monopolize in technical and strategic parts, are developing the next generation GNSS including GLONASS Galileo and JRANS. And the countries are planning to provide the another GNSS. This research has focused on the next generation GNSS system based on GPS and Galileo system with developing a GNSS simulation software, named as GlMS2005, which generates and analyzes satellite constellation and measurements. Based on the software, a variety of simulation tests have been carried out to recognize limits of GPS-only system and potential benefits of integrated GPS/Galileo positioning in terms of satellite geometry strength and solution accuracy.

• Journal of Satellite, Information and Communications
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• v.5 no.2
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• pp.14-18
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• 2010

The future of communication systems is expected to combine with the terrestrial and satellite networks. A commonality between wireless interfaces is important consideration for cost of user equipment in the integrated satellite and the terrestrial system. Because IMT-Advanced system take into account LTE based on the terrestrial system for the next generation of communication, a study of the LTE-based satellite system is especially required. A frame of the existing terrestrial wireless networks is designed to use for a random access up to the maximum cell radius of 100 km. However, the random access scheme for the terrestrial system cannot be used in the satellite system, because the satellite systems generally have large coverage than the terrestrial system. Therefore, we propose that the efficient random access procedure to reduce latency and complexity for the satellite system maintaining commonality with the terrestrial system in this paper.

• Journal of Satellite, Information and Communications
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• v.8 no.1
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• pp.54-60
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• 2013

The need for high performance of on-board computer (OBC) is essential due to the growing requirements and diversified missions, and so OBC has been developed on the basis of the standard design and reconfigurable modularization in order to improve the utilization of OBC for different missions. The processor in OBC of next generation satellite which is currently developed by KARI is adopted the LEON2-FT/AT697F processor based SPARC v8 as main processor and controls various devices such as SpaceWire, MIL-STD-1553B and CAN through PCI on the standardized communication chips. This paper presents the architecture and design of system software for LEON2-FT processor based on PCI, and development of PCI software component. Also it describes the porting of VxWorks 6.5 for LEON2-FT and the test under the simulation environment for LEON2-FT and PCI with communication chips.

• Journal of Satellite, Information and Communications
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• v.10 no.1
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• pp.44-48
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• 2015

The smart grid is a next-generation power grid to create a new value-added information technology. Power providers and consumers exchange information in real-time bi-directional, and optimize energy efficiency with using the smart grid. This paper describes the concept of demand response of the communication system used in the protocol, implementation of demand response systems with demand response scenarios for power reduction through the air conditioning control.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.50-55
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• 2013

The smart grid is a next-generation power grid to create a new value-added information technology. Power providers and consumers exchange information in real-time bi-directional, and optimize energy efficiency with using the smart grid. This paper describes the concept of demand response of the communication system used in the protocol communication model of the smart grid.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.6
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• pp.616-620
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• 2008

High reliability is the important parameter on designing satellite system and it is also important to design hish speed data processing unit. To make high speed satellite processing unit, it is needed to utilize space processor, high speed data interface technology, mass memory control technology and data protection technology under space radiation environment.

• Journal of Satellite, Information and Communications
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• v.4 no.2
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• pp.34-38
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• 2009

This paper is related with optimum burst structure design for high efficient TDMA satellite return link transmission. In general, some typical burst structure for data transmission is composed of a pair of preamble and traffic data in the DVB-RCS (Digital Video Broadcasting. Return Channel via Satellite) and IPOS (IP over Satellite) standard. This structure has some difficulties to increase spectral efficiency that it requires a large of preamble length, high SNR environment, or receiver complexity. To cope with them, burst structure with distributed pilot symbol can be used to alleviate the residual frequency offset effect by calculating accurate frequency offset than conventional one. In particular, we investigate some relevant to proposed distributed pilot structure, previously and analyze their strong points/drawbacks in terms of synchronization to draw the most appropriate one.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.93-98
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• 2006

2008년 서비스 제공을 목표로 진행 중인 유럽의 Galileo 시스템은 최초의 순수 민간 목적으로 제작되는 광역위성항법시스템(GNSS: Global Navigation Satellite System)이다. 현재 GPS의 SA는 제거되었지만, 군사 목적뿐만 아니라 차량 및 항공 항법, 토목 건설 분야, 텔레메틱스를 통한 민간 활용의 증가로 인해 위성측위에 있어 미국의 의존도는 그 어느 때보다 높은 실정이다. 이에 따른 전략적, 기술적 의존은 절대적이며 잠재적인 위험 요소를 포함하고 있다 이에 본 논문에서는 자체 개발한 소프트웨어를 이용하여 향후 제공될 유럽의 Galileo 시스템을 국내 적용 시뮬레이션하였으며 그 결과를 바탕으로 GPS 단독 처리의 한계를 제시하며 이를 극복할 수 있는 대안으로 Galileo 시스템에 대하여 연구하였다. 이를 통하여 러시아의 GLONASS를 포함하여 다원화되어가는 광역위성항법시스템의 안정적인 측위 환경에 대한 연구가 그 목적이다.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.494-497
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• 2008

DIMPEC, Direct Interactive Motion Picture Electronic Commerce technique is not only that gain additional detail information on the entry properties and actor custom by seeing and hearing VOD and TV drama with internet but also source technology which can buy product using electronic commerce. Also, this is enable to construct in variety platform environment like internet, PDA, MOBILE, Settop box, and this is a technology where competition is very high due to application is possible to satellite DMB, and DMB for ground which is high technology IT. DIMPEC is expected that next generation business model will be formed by combining to user participation, consumption magnification of mobile contents, advancement and intelligence of internet service which is next generation internet business model which combines this technique.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.745-748
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• 2001

Digital-ship is the next-generation ship with an one-man bridge system which consists of INS(Intelligent Navigation System), AIS(Automatic Identification System), and IMIT(Integrated Maritime Information Technology). INS implements the functions is related of the ship's navigation, and supports in the digital GIS environments optimal route planning, stranding and a collision avoidance among the ship, an economic navigation, and an integrated control of ship's engine. AIS prevents the ship's collision by means of transmitting periodically the own ship's information to the other ship or the shore control center. IMIT systems supports the integrated fiat-form in ships, the communication between a ship and a control center of the land using the INMARSAT, OrbComm, Ocean Observation Satellite, and etc. The satellite communication in ships can monitor the ship at an earth control renter. This paper deals with the method for system implementation of digital-ship and the detailed sub-system.