• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.45-50
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• 2002

A conceptual design on the link budget of TC&R RF subsystem which transfers command and telemetry data as RF signal between the ground system and the 2005SAT spacecraft is presented in this paper. In order to perform the analysis of the link budget, we divided the analysis process into two processes, i.e., uplink and downlink process. For the uplink the power flux density at the spacecraft and the margin of the command receiver are calculated. In the case of the downlink the downlink EIRP and the margin of C/ No and Eb / No at the ground station are calculated. Through the uplink performance analysis, the power at the command receiver has well efficient margin, and the margin of C/ No and Eb / No is also fully proper for the downlink case.

• Transactions on Semiconductor Engineering
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• v.2 no.1
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• pp.9-16
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• 2024

This paper discusses the design of bio-implanted ultra-low-power MICS RF transceivers for wireless sensor networks. The 400 MHz MICS standard was considered for the implementation of the WBAN wireless sensor system, indirectly minimizing radio propagation losses in the human body and the inference with surrounding networks. This paper includes link budget, various transmission and reception architectures for a system design and ultra-low power transceiver circuit techniques for the implementation of RF transceivers that meet MICS standards.

• Journal of Korea Technology Innovation Society
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• v.12 no.4
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• pp.819-839
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• 2009

Proposed increases to the government's R&D budget should be discussed based on merits of meeting efficiency and effectiveness criteria. The evaluation of the national R&D budget and related programs are performed in two areas: a system of R&D budget coordination and allocation, and a system of R&D program performance. This paper mainly focuses on the operational areas of R&D budget evaluation system with a focus on their impact to efficiency and effectiveness. The core view point for a R&D budget evaluation system involves two directions: Firstly, to detail the relationships between the later stage (ex. post) activities such as, program survey, analysis, and program performance evaluation, with the budget evaluation. Secondly, to critically oversee all R&D coordination procedures with a different perspective. Budgeting is generally known as a serial process of policy making, planning and executing. It is highly desirable for the budget to be allocated to, and spent by, specific programs as planned, and that each plan be aligned with a specific policy. As such, a strong relevance between the program structure and budget code system is integral to successful execution. It should be performed using a decision making system which closely examines the link between policy and budget. It is also recommended that systematic relationships be maintained among budget coordination and allocation, performance evaluations of policy and program levels, and program survey and analysis system, and that their operational schedule should be reviewed comprehensively as a one integrated system. The National Science and Technology Council is expected to play a major and practical role as the center of policy planning and should be supported by the objective and unbiased system which covers overall process from policy making to program evaluation. Finally, increased utilization of contents, timely program survey and analysis, and accurate of activity scheduling of budget coordination and allocation, and diligent program performance evaluation all contribute towards a more efficient and effective overall evaluation system.

• Journal of Astronomy and Space Sciences
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• v.27 no.1
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• pp.11-20
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• 2010

This paper designs a data link between a Lunar Orbiter (LO) and an Earth Station (ES), and analyzes the downlink performance of a space communications system for lunar exploration, conforming to the recommendations by the Consultative Committee for Space Data Systems (CCSDS). The results provided in the paper can be useful references for the design of reliable communication link for the Korean lunar exploration in the near future.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.1
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• pp.65-74
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• 2002

A three dimension(3D) link analysis is peformed considering multipath effects caused by a reflected signal and the difference angle between the antenna bore-sight and Line-Of-Sight(LOS). In addition, a direction of a receive antenna is determined for a receiver to get maximum signal strength in a telemetry situation. For a fixed receive antenna, the angle is determined to maximize the average Carrier to Noise Ratio(CNR) over the interested part of a trajectory. For a tracking antenna, the angle at every position is selected to give maximum CNR or to direct the boresight to the flying projectile.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.3
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• pp.117-124
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• 2002

A high speed data link capability is one of the critical factors in determining the performance of the spaceborne SAR system with high resolution because of the strict requirement for the real-time data transmission of the massive SAR data in a limited time of mission. In this paper, based on the data link model characterized by the spaceborne small SAR system, the high rate multi-channel data link module is designed including link storage, link processor, transmitter, and wide-angle antenna. The design results are presented with the performance analysis on the data link budget as well as the multi-mode data rate in association with the SAR imaging mode of operation from high resolution to the wide swath. The designed data link module can be effectively used for the spaceborne and airborne applications which requires to expand the high speed data link capability.

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.167-178
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• 2003

The design on the Telemetry Ground System for launch of KSLV(Korea Space Launch Vehicle) in the korean Space center has been conducted in this study. For the optimized system design, first of all, the system deployment plan reflecting the topographic and geographic environments of the space center and launch vehicle characteristics has been developed. The RF link budget analysis for the maximum tracking range, requirement for receiving subsystem including antenna subsystem, requirement for data processing subsystem are also analyzed based on the On-Board Telemetry characteristics and launch vehicle parameters. Based on those analysis, telemetry ground system containing tracking/receiving subsystem, recording subsystem and data processing subsystem, timing subsystem, calibration subsystem and monitoring and control subsystem are designed. Futhermore, the analysis for the maximum permissible data latency and communication protocol between each telemetry station and control center are conducted and the entire system is designed so that the major telemetry parameters selected to the best quality are provided in real time to the control center(RCC, RSC) for the launch mission operation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.642-650
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• 2010

In this paper, we study a TT&C link to obtain a required specifications of TT&C(Telemetry Tracking and Command system) antenna for an LEO(Low Earth Orbit) satellite. The premised mission orbit is the sun-synchronized and circular orbit and it performs earth-space observations. We design minimum TT&C link-budget to obtain required antenna beamwidth and gain. The proposed turnstile antenna provides wide beamwidth and circular polarization. We suggested the attaching position that shows the most effective results by confirming the variation of antenna performance when the proposed antenna is adapted to satellite's various positions. Also we proved the proposed antenna's ability while it is performing the mission through the orbit simulation based on the electrical performance of the proposed turnstile antenna.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.75-80
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• 2013

In this paper, the Ka-band maritime satellite communication systems for mobile terminals are proposed. The design includes the link budget analysis, determination of modulation and coding schemes and the overall structure of a transmitter. To avoid the harmful effects on the existing DVB-S2 services, the proposed maritime satellite system using the same spectrum with DVB-S2 at the same time employs the very wideband spreading transmission. Additionally, omni-directional low-gain antennas should be equipped in a mobile terminal to reduce the system cost. These two considerations limit the maximum transmission rate of the proposed system. Due to the limitations, the proposed system includes 36 dB or 39 dB spreading gain depending on the modulation scheme and a link-adaptive repetition method depending on the level of rain attenuation. To support short packets with minimal performance loss, the turbo code used in 3GPP instead of LDPC(low density parity check code) is adopted. By combining them, the overall structure of low-rate maritime satellite communication system is designed.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.45-52
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• 2016

In this paper, the method of interference analysis and its simulation have been suggested for the frequency sharing between aeronautical radio navigation systems and Link-16 platforms. In order to get the criteria for interoperability, the algorithm of interference analysis and protection ratio are derived to assure frequency sharing. Also the receiving power of wireless system has been illustrated with the help of radio propagation model of ITU-R Rec. P.1546 in VHF-UHF band. Finally the required receiving power or separation distance between DME/TACAN beacons and Link-16 ground station terminals has been considered based on system link budget in terms of evaluating interoperability as well as actual applications. As a result, if the suggested interference analysis and test set-up are applied to the field trial, it will lead to easy means to make a decision on interoperability over the existing incumbent systems.