• Journal of Satellite, Information and Communications
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• v.11 no.1
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• pp.46-50
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• 2016

The adaptive power control of Code Division Multiple Access (CDMA) systems for communications between User Equipments (UEs) with a link-budget based Signal-to-Interference Ratio (SIR) estimate which has distance information is applied to three inner loop power control algorithms. The speed estimation performances of these algorithms with their consecutive Transmit-Power-Control (TPC) ratios are compared to each other, and it is concluded that the speed can be estimated using the TPC ratio information of Consecutive TPC Ratio Step-size Closed Loop Power Control (CS-CLPC) and Fixed Step-size Power Control (FSPC).

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.233-237
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• 2008

This paper presents proposal for an application (only for Windows-based Mobile) that can synchronize the Third Generation Windows-based mobile with the prescribed server. This application can be used by mobile users to send information directly to the WAS server wirelessly. In this paper a comparison between Third Generation technology and WLAN ( both are parallel technologies first one embodied by IMT-2000 standards and the second one by ITU Standards) has been made and also a comparison between Wi-Fi and Bluetooth has been made.

• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.9-14
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• 2013

In this paper, we first introduce a Koinonia technology. Then we present a wireless Digital Video Recorder (DVR) system based on the Koinonia technology. In addition we implement the wireless DVR system, which is composed of Wireless DVR-Slave (WDVR-S), Wireless DVR-Access Point (WDVR-AP), and Wireless DVR-Emergence Management System (WDVR-EMS). Also we present the acquired Korea Communication Commission (KCC) mark for the last products. The developed system will give a hint that the Koinonia technology can be adopted in wireless DVR systems to handle safety and security issues.

• Electronics and Telecommunications Trends
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• v.17 no.1 s.73
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• pp.32-47
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• 2002

본 고에서는 Beyond IMT-2000 시스템에서 Mobile Access의 무선 전송 기법으로 OFDM 방식의 적용 가능성에 대하여 살펴본다. 현재 사용되는 CDMA 방식은 고속 전송 시 chip rate가 크게 증가하기 때문에, Beyond IMT-2000 시스템의 Mobile Access에서 요구하는 2∼100Mbps의 고속 데이터 전송률을 만족시키기가 용이하지 않다. 반면, OFDM 방식은 주파수 효율이 높고, 주파수 선택적 페이딩 채널에 쉽게 대처할 수 있으며, FFT를 사용하여 고속으로 구현할 수 있기 때문에 고속 데이터 전송 시 적합하다. 본 고에서는 OFDM 방식을 사용한 기존의 통신 시스템의 특징을 살펴본 후, Beyond IMT-2000 시스템 Mobile Access의 전송방식으로 OFDM을 적용할 경우의 기술적인 고려사항과 모의실험 결과에 대하여 서술한다.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.350-353
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• 2006

We enhance the stability of SaeManGeum Drainage Sluice Gate Bridge. We prevent a destruction disaster of it. We extend the life cycle of it. So We have developed the safety control system to manage the facility of bridge to the continuance. In this study, sensitive sensor and measuring instrument has been taken to consider the characteristic of the box-girder type concrete bridge. And CDMA type has adapted for wireless communication. Control program has been developed on web base. In this program, the advanced systems have applied like this; the setup of control range for management from the statistical analysis, the evaluation system for force and deformation and the control system for a heavy vehicle permit.

• Journal of information and communication convergence engineering
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• v.2 no.4
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• pp.209-213
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• 2004

With the commercialization of CDMA 2000-1x late in 2000, a high-speed wireless Internet, based on a mobile communication networks, appeared in Korea. This will develop into the next-generation of mobile communications(4G) in the future and the new cell layout will be required the cellular configuration of 4G. We would need the legislation with respect to base-stations and to building the mobile communication networks, as well as the optimization of mobile communication systems. In this study, in order to provide 4G, I examined and analyzed that the current laws & regulations related to licensing and operating a mobile communication base-stations in KOREA.

• Journal of Communications and Networks
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• v.2 no.1
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• pp.18-34
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• 2000

The evolution of mobile communications is inducting several new issues belonging to the system engineering disciplines. this paper tires to underline some of the most important problems staring room the novel requirements and the application characteristics expected for Third Generation Mobile System. Based on these new service peculiarities. the radio resource control and the architectural solutions to be chosen for the Mobile core network are becoming key issues to be investigated for the forthcoming configurations. Particularly. the service acceptance control and the perspective of integration with the IP (internet Protocol) context are of great importance for the definition of the radio control functions and the specification of the switching and nobility control features respectively．The paper presents some basic considerations on the cellular planning issues arising in W-CDMA ( wideband -code division Multiple access) systems. by underlying the most significant innovative elements that are to be introduced in the planning process form the mobile operator viewpoint..

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.31-33
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• 2003

Power amplifier linearity plays a major role in the design of RF communication systems. In this paper, predistortion type linearizer was designed an independently controllable AM/AM and AM/PM predistortion linearizers. This linearizer allows independent adjustment of the AM/AM and AM/PM curves by using two adjustable voltages to compensate the power amplifier non-linearities. The predistortion linearizer was improved the ACPR by 6dB with cdma2000 multi carrier signals. Applying this linearizer to two-tone 880MHz power amplifier, an improvement of adjacent channel leakage power up to 5dBm has been achieved.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.261-262
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• 2008

TD-SCDMA is considered as an innovative Chinese 3G technology adopted by the ITU for the IMT-2000 family. TD-SCDMA combines TDMA and CDMA components to provide more efficient use of radio resources. However, the downlink scheduler of TD-SCDMA should transmit data packets with the initial configuration and cannot change the configuration dynamically. Therefore, in this paper, we propose an enhanced channel allocation, by which mobile terminals can share the downlink channelization codes dynamically.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.267-268
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• 2008

TD-SCDMA is considered as an innovative Chinese 3G technology adopted by the ITU for the IMT-2000 family. TD-SCDMA combines TDMA and CDMA components to provide more efficient use of radio resources. According to the traffic volume and activity level, the operation mode of a mobile terminal can change from one state to other states. This paper focuses on the problem of recovery delay from inactive states, and proposes a resource management algorithm, which holds some resources for rapid recovery of service after the service determines to release the dedicated resources.