• Journal of Satellite, Information and Communications
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• v.10 no.1
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• pp.12-16
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• 2015

In this paper, we introduce a wireless package system based on the amateur radio HR(HAM Radio) and satellite communication as a novel wireless disaster communication system and have configured a interference scenario receiving interference from adjacent base stations and D2D groups in the disaster network. In such interference scenarios, we propose a frequency re-allocation method to avoid interference and communicate with disaster networks by securing the channel capacity required between D2D terminals. As a result of computer simulation, we can find the proposed method has improved BED performance of a gain of 1.5dB and overall system throughput than conventional methods.

• Journal of Satellite, Information and Communications
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• v.12 no.1
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• pp.43-48
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• 2017

Recently, demands on civilian UAV (Unmanned Aerial Vehicle) has been increasing and appropriate communication system is required for the UAV. In this paper, the performance of the UAV communication system using commercial wireless mobile network is discussed. The main service area of the wireless mobile network is ground level however the flying range of the UAV is normally in high altitude. Because of this mismatch of service area the performance of the UAV communication system is degraded in high altitude. To compensate performance degradation of the UAV communications system in high altitude, adaptive array antenna is introduced which is able to overcome altitude limitation of the UAV communication system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2763-2771
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• 1997

To determine the satellite orbital positions considering interference caused by inter-satellite systems is one of the most improtant issues in terms of optimal usage of satellite network resources. In this paper, considering ITU filing situation, we present the satellite orbital positions determination method to minimize iter-satellite system interference effect in the fixed satellite communication using an optimization method. Through the computer simulatio, it was shown that the proposed method is suitable to determine the satellite orbital positions.

• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.95-101
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• 2015

The backup site operation of the Image Data Acquisition and Control System (IDACS) for Communication Ocean Meteorological Satellite (COMS) is discussed in terms of the ground station configuration, image data processing, and the characteristics of backup activities for both the meteorological image data and the ocean image data. The well-performed backup operation of the COMS IDACS is also confirmed with the first three years normal operation results from April, 2011 to March, 2014. The operation results are analyzed through statistical approach to provide the achieved operational performance of the image data reception, preprocessing, and broadcast.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2498-2507
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• 1994

This paper proposes the Doppler frequency tracking system by the optimum synchronization technique which compensates the frequency shifts caused by satellite movement in a coherent digital satellite communication system. A Doppler frequency shift caused by satellite movements and the design theories of the optimum synchronization system are mathematically described. Based on this theory, a Doppler frequency tracking system is implemented via digital signal processing techniques utilizing a DSP chip, RAMs, PROMs, and a 80286 microprocessor. The performance of the designed system was evaluated through the experiments with the INTELSATVA satellite.

• ETRI Journal
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• v.22 no.1
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• pp.1-11
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• 2000

The Satellite Operation System (SOS) has been developed for a low earth orbiting remote sensing satellite, Korea Multipurpose Satellite-I, to monitor and control the spacecraft as well as to perform the mission operation. SOS was designed to operate on UNIX in the HP workstations. In the design of SOS, flexibility, reliability, expandability and interoperability were the main objectives. In order to achieve these objectives, a CASE tool, a database management system, consultative committee for space data systems recommendation, and a real-time distributed processing middle-ware have been integrated into the system. A database driven structure was adopted as the baseline architecture for a generic machine-independent, mission specific database. Also a logical address based inter-process communication scheme was introduced for a distributed allocation of the network resources. Specifically, a hotstandby redundancy scheme was highlighted in the design seeking for higher system reliability and uninterrupted service required in a real-time fashion during the satellite passes. Through various tests, SOS had been verified its functional, performance, and inter-face requirements. Design, implementation, and testing of the SOS for KOMPSAT-I is presented in this paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.845-852
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• 2000

In the 21s1 century, it may be possible to offer comprehensive service by integrating all communication media under the development of digital technology without the classification of broadcasting and communication. In addition, it will be begun to perform HDTV broadcasting by focusing on the Metropolitan area in 2001yr and will permit over 100 channels for satellite communication, thus multi-channel TV broadcasting age has come in Korea. Therefore, this study is to identify the future environment of TV broadcasting and service area in ISDB age and to present new interactive type publication satellite TV transmission system, which provides customizing type digital screen book publication, by analyzing satellite broadcasting technology to create Korean cultural area around the Korean peninsula.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.128-128
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• 2000

An antenna tracking technique, referred to as "step track", is commonly used in communication applications. In this paper, an algorithm to improve the step-tracking technique for satellite tracking is proposed. We suggest a method by which the antenna scans the azimuth, detects the satellite signal without the position information, and points quickly to the direction receiving the signal of peak level. After reaching the peak level, the step-track system maintains enough signal levels to receive satellite broadcasting normally. Performance of the Tracking Algorithm proposed in this paper are verified with simulation.

• Korean Management Science Review
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• v.10 no.1
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• pp.23-39
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• 1993

In this study, potential Communication Satellite Application Services (CSASs) that are suitable for our communication environment have been identified through a detailed analysis of the CSASs offered in advanced countries. The existing demand forecast based on the defined CSAS category has been improved, and the transponder assignment policy has also been recommended. Managerial problems rather than technical ones for KOREASAT project have mainly been addressed and tackled in this study. For the successful implementation of the domestic communication satellite system, these two problems should be solved simultaneously. Therefore, future research that includes technical as well as managerial issues is expected to come out soon.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.2
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• pp.139-147
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• 2020

In this paper, design measure were proposed for the construction of terminal systems for airborne platforms, which are key element in the Joint Tactical Data Link System (JTDLS) complete system. The Korean perfect tactical data link (JTDLS) is a communication system to establish an independent tactical data link network and needs to develop a MIDS-LVT (Link-16) communication terminal for datalink. Once a Ground/Navy JTDLS terminal system is established around airborne platform, it will be possible to break away from reliance on NATO-based tactical data link joint operations and establish independent Korean surveillance reconnaissance real-time data sharing and tactical data link operations concepts. in this paper, the essential development elements of airborne platform mounting and operable JTDLS terminals are presented, and the concept of system design is proposed to embody them. Further, improved system performance was analyzed by applying the concepts of complex relative navigation system and Advanced TDMA protocol for the deployment of airborne tactical datalink networks.