• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.674-680
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• 2008

An SDR (Software Defined Radio) system based on general purpose computing platform has benefits of ease of software development process, high degree of software compatibility, and cost-effectiveness of general purpose processors. This paper discusses design and implementation of a dual-mode SDR system that supports both cordless phone and walkie-talky system running on Linux-based general purpose computing platform. For this purpose, we designed modulation and demodulation software on open source-based GNU radio middleware. We also designed a customized RF front-end hardware which performs frequency conversion between RF and IF. The proposed SDR system successfully exhibited its ability to operate both cordless phone and walkie-talky communication on Intel processor-based general purpose computing platform. But experience with the prototype SDR system shows that further research is required for run-time software reconfiguration and efficient integration with conventional TCP/IP protocol stacks.

• The Journal of the Korea Contents Association
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• v.7 no.3
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• pp.60-67
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• 2007

This research studies and analyzes the current trends and the frequency allocation bands for digital cordless phone(DCP) in other country. From these results, we propose 1.7GHz & 2.4GHz as a effective candidate frequency band for domestic DCP. A proposed 1.7GHz is expected to introduce DECT system of Europe. Therefore it is necessary to make an analysis of interference between 1.7GHz band and an adjacent IMT-2000 band. In this paper, we proposed the allocation of channel for 1.7GHz on the basis of the analysis of frequency interference between 1.7GHz band and an adjacent IMT-2000 band.

• Journal of Korean Electronics
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• v.4 no.11
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• pp.51-52
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• 1984

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.52-57
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• 2006

This research studies and analyzes the current trends and the frequency allocation bands for digital cordless phone(DCP) in other county. From these results, we propose 1.7GHz & 2.4GHz as a effective candidate frequency band for domestic DCP. A proposed 1.7GHz is expected to introduce DECT system of Europe. Therefore it is necessary to make an analysis of interference between 1.7GHz band and an adjacent IMT-2000 band. In this paper, we proposed the allocation of channel for 1.7GHz on the basis of the analysis of frequency interference between 1.7GHz band and an adjacent IMT-2000 band.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.699-705
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• 1998

This paper is about design of optimal structure of microstrip dielectric ceramic antenna with rectangular electrode patches in accordance with the cavity model and fabrication of its prototype sample operating at the frequency of 900 MHz. Results of this work can be employed as a useful too to develop and diversify ceramic antenna having superior performance and omni-directivity to that of current helical antenna.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.137-140
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• 2002

2.4Ghz ISM 대역에서 동작하는 Bluetooth는 동일한 대역에서 동작하는 WLAN(802.11.b), Cordless phone, microwave oven등의 신호가 interference로 작용하여, 성능이 크게 저하된다. 특히 Bluetooth과 WLAN은 상호간 interference로 작용하여 상호 성능 저하를 초래한다. 따라서, 두 장치간의 coexistence를 위한 방안으로 adaptive hopping frequency(AFH)이 제안되었다. 이 논문에서는 3 channel status를 이용한 AFH 방식을 제안하고, 그 성능을 검증하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.60-67
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• 2002

In this paper, the dual band VCO of mobile communication terminal using oscillation part switching circuit is proposed. In order to model the VCO accurately, the resonator is converted the equivalent circuit which is analyzed to use numerical method and designed optimal the dual band VCO operating GSM and DCS band. In order to demonstrate the objective theory of the proposed VCO, the dual band VCO is designed and experimented. The results of experiment, it is conformed that the VCO can be used mobile communication hand phone and components of three generation mobile communication systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.1
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• pp.50-58
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• 2003

In this paper, a new cm (Caller ID) transceiver is introduced for SMS(Short Message Service) and e-mail services by the wire and digital cordless phones in 900MHz like as mobile phones. For this wireless digital cm phone, improved radio transceiver modules is proposed and implementedusing the analysis of data processing errors. As a result, many wireless cm services can be popular without the kind of switching systems.

• Proceedings of the Korean Association for Survey Research Conference
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• 2001.04a
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• pp.87-108
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• 2001

Recently, the user of mobile and cordless internet is growing rapidly. So the advertising methodologies are appeared on stage through the internet and mobile service. But the current advertisement(AD) service into mobile phones supplies a short-sentence AD using letter-message, and gives mobile phone users an inconvenience by making them first listen to and then check the AD. Until now the AD service using mobile has been on the beginning level. In this study, we suggest the new advertising methodologies and propose both target marketing strategies and demand forecast through the data mining techniques.

• Survey Research
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• v.2 no.1
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• pp.87-108
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• 2001

Recently, the user of mobile and cordless internet is growing rapidly. So the advertising methodologies are appeared on stage through the internet and mobile service. But the current advertisement(AD) service into mobile phones supplies a short-sentence AD using letter-message, and gives mobile phone users an inconvenience by making them first listen to and then check the AD. Until now the AD service using mobile has been on the beginning level. In this study, we suggest the new advertising methodologies and propose both target marketing strategies and demand forecast through the data mining techniques.