• ETRI Journal
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• v.36 no.4
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• pp.519-527
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• 2014

An integrated multi-beam satellite and multi-cell terrestrial system is an attractive means for highly efficient communication due to the fact that the two components (satellite and terrestrial) make the most of each other's resources. In this paper, a terrestrial component reuses a satellite's resources under the control of the satellite's network management system. This allows the resource allocation for the satellite and terrestrial components to be coordinated to optimize spectral efficiency and increase overall system capacity. In such a system, the satellite resources reused in the terrestrial component may bring about severe interference, which is one of the main factors affecting system capacity. Under this consideration, the objective of this paper is to achieve an optimized resource allocation in both components in such a way as to minimize any resulting inter-component interference. The objective of the proposed scheme is to mitigate this inter-component interference by optimizing the total transmission power - the result of which can lead to an increase in capacity. The simulation results in this paper illustrate that the proposed scheme affords a more energy-efficient system to be implemented, compared to a conventional power management scheme, by allocating the bandwidth uniformly regardless of the amount of interference or traffic demand.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.339-350
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• 2006

The bifurcation point where a satellite component buds from another component is characterized by the existence of the common tangent line between the two osculating components appearing in the degree-n bifurcation set. We investigate the existence, location and number of bifurcation points for satellite components budding from the main component in the degree-n bifurcation set as well as a parametric boundary equation of the main component of the degree-n bifurcation set. Cusp points are also located on the boundary of the main component. Typical degree-n bifurcation sets and their components are illustrated with some computational results.

• ETRI Journal
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• v.24 no.6
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• pp.415-428
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• 2002

This paper presents a new satellite radio interface, satellite code division multiple access (SAT-CDMA), for the satellite component of IMT-2000. The SAT-CDMA was proposed by Korea and was based on wideband CDMA (WCDMA) for a high degree of commonality with the terrestrial component of IMT-2000. Because a satellite link has a longer round trip delay and a higher Doppler shift than a terrestrial link, we developed new technologies that would make the satellite component especially efficient. We present the main features of the SAT-CDMA radio interface by focusing on satellite-specific schemes. We also demonstrate with extensive comparison results the performance of the main technologies in the SAT-CDMA radio interface.

• Journal of Satellite, Information and Communications
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• v.2 no.1
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• pp.27-34
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• 2007

A mobile satellite broadcasting service including an ancillary terrestrial component (ATC) takes advantage of the satellite's inherent capability to provide broadcast service over global coverage. We consider the downlink transmission concept using ATC with space=time code (STC) for the mobile satellite communication. We do not regard ATC as simply a repeater but consider it as an antenna for STC. First transmission scenarios for an application of STC are represented. Next, we apply STC in the mobile satellite system including ATC and compare the system performance in the proposed architecture of ATC to that in the conventional structure. The simulation results are compared to the conventional downlink transmission concept for the mobile satellite broadcasting service.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.65-69
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• 2014

The Communication, Ocean and Meteorological Satellite(COMS) data processing system(CMDPS) has developed to support the meteorological observation and weather prediction by NMSC(National Meteorological Satellite Center) and it is generating the 16 kind of meteorological data(Level 2 product). Unfortunately, currently CMDPS has some problems in terms of the system maintenance and the integrated software efficiency, and the extension to support the next generation meteorological satellite data processing. To solve this problems, in this paper, we suggest the extensible component-based system architecture for COMS meteorological data processing with consideration of identified issues. Proposed system is adapted the component-based frameworks with extensible architecture. We expects that this system will be provide easy ways to develop new satellite data processing algorithms and to maintain the system.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.45-48
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• 2002

Satellite image processing software should be able to support interoperability that is to enable consumers, citizens, large and small businesses and governments to make the fullest possible use of the world's spatial data and spatial processing resources. The goal of interoperability is to perform hands-on research, development, testing, fielding, and validation of potential and existing interoperable geoprocessing technologies. In this paper, component based architecture for fast interoperability is designed to maximize interoperability among the OpenGIS components specified in the OpenGIS abstract specifications and implementation specifications and to mix up the OpenGIS components and the fast access mechanism for high performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.957-961
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• 2005

A satellite component must withstand vibration caused when launch vehicle acoustics and engine rumble transfer to it through its structural mount. Components shall be subjected to environmental tests after manufacturing process thus the environmental test conditions are needed for component level test including vibration and shock. This paper deals with derivation of component-level environmental test specifications, especially for solar panels of STSAT-2(Science & Technology SATellite-2). Sine sweep random vibration, and shock test conditions were generated for solar panels by assuming the satellite as single-degree-of-freedom system with a base excitation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.9
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• pp.837-842
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• 2009

The efficient dynamic modeling of a satellite with flexible solar arrays is established by using the component mode synthesis technique. A flexible satellite model can be defined as the assembly of two sub-structures, central body and solar array. The reduced models of each substructure, which are expressed in each local frame, are coupled with respect to the satellite reference frame. The dynamic modeling method is applied to the numerical example of a satellite with a single solar array, and is verified by investigating the transfer function results with considering the solar array rotation.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.49-52
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• 2002

High-resolution satellite image processing software should be able to ensure accurate, fast, compact data processing in offline or online environment. In this paper, component software for high-resolution satellite image processing is developed using OpenGIS components and real-time data processing architecture. The developed component software is composed of three major packages, which are data provide package, user interface package, and fast data processing package. The data provider package encodes and decodes diverse image/vector data formats and give identical data access methods to developers. The user interface package supports menus, toolbars, dialogs, and events to use easier. The fast data processing package follows the OpenGIS's data processing standards, which can deal with several processors as components with standard procedural functionalities.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.40-45
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• 2002

A radiation analysis is performed for the Ka and Ku-band transponder of the Communications and Broadcasting Satellite (CBS) that is planned for launch into the geo-synchronous orbit. A particular attention is given to calculation of Total Ionizing Dose (TID) for the mission life time of 15 + 3 years. A numerical modeling of the charged particles at the geo-synchronous orbit is undertaken. The charged particles from the modeling are then transported through the mechanical structure and component housings of the transponder. A set of locations are selected for the detailed calculation of TID. The results from the present calculation show that three-dimensional modeling of the component housings as well as the mechanical structure of the spacecraft is requisite in order to acquire a reliable calculation of TID.