• Review of Korean Society for Internet Information
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• v.6 no.4
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• pp.45-51
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• 2005

• The Safety technology
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• no.105
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• pp.32-33
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• 2006

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.310-314
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• 2007

WiBro는 IEEE 802.16에 이동성을 추가한 것으로서 현재 IPv4만을 지원하는데, IPv6를 적용할 경우 발생할 수 있는 문제점들은 최근에 이르러서야 이슈가 되고 있다. WiBro MAC은 IP 프로토콜 설계시 기본이 되는 이더넷과 많은 차이점이 존재한다. 망 구성요소들의 점대다(point-to-multipoint) 연결 형태와 상향링크 멀티캐스트 불가능으로 인해 정상적인 IP 멀티캐스팅/브로드캐스팅 동작이 어렵기 때문이다. 또한 이더넷과 같이 48비트 MAC 주소를 사용하는 것이 아니라 16비트 CID를 사용하기 때문에 IPv6를 적용할 경우 IPv6 Address Auto-Configuration, Neighbor Discovery, Duplicate Address Detection, Multicast Listener Discovery 등에서 정상적인 동작이 불가능하다. 이에 본 논문은 WiBro의 IPv6에서 MLD 프로토콜 적용방안과 무선자원을 효과적으로 사용하는 방법을 제시한다.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.1
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• pp.47-53
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• 2012

In cellular geo-location systems, positioning performance is influenced by hearability of receivers. Hearability can be enhanced by using long integration at the receiver. When unknown residual frequency remains in baseband signals, however, the coherent integration loss increases as the residual frequency becomes larger. Consequently, length of coherent integration is determined by the residual frequency. By precise estimation and compensation of the residual frequency, integration length can be enlarged. This paper presents a residual frequency estimator for WiBro geo-location and analyzes its performance in multipath environment. By computer simulation, an optimal receiver structure to enhance the hearability of WiBro geo-location is proposed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1660-1668
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• 2008

The WiBro was adopted to the 3G international standard. By the change of specification from Wave 1 to Wave 2, MIMO technology is applied in order to increase the speed of downlink. By MIMO the RF part of WiBro base station is increased to 2 Tx paths. Therefore, the size of RF part is bigger and material cost is increased. For reducing these demerits, the RF part which is consisted of PA, LNA, and TDD switch is designed to one complex RF unit. Also, the experimental results of the RF unit have been discussed. Since the complex RF unit is more compact than the RF part of Wave 1 base station, it can be used as the RF part of Wave 2 base station with 2T/2R MIMO.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.643-644
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• 2006

In this paper, WiBro system which is one of the mobile wireless metropolitan area network systems is presented. WiBro is an OFDMA system which has a sub-channelization process unlike conventional OFDM systems. The sub-channelization is the time consuming processing, so a time-efficient hardware architecture is needed. WiBro RAS(Radio Access Station) demodulator is designed with Verilog HDL, and the gate count is 81k using the $0.18{\mu}m$ processing.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1A
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• pp.10-15
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• 2010

This paper proposes a practical method for AGC (Automatic Gain Control) in WiBro (Wireless Broadband) AT (Access Terminal) system. Downlink packets in this system consist of preamble symbols for AGC, AFC (Automatic Frequency Control) and other purposes and data symbols for traffic transmission. In this paper we compare theoretical BER (Bit Error Rate) performance with simulation results and produce optimum parameters for AGC in this system. And we propose an efficient AGC scheme before synchronization.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.384-388
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• 2008

Multiple antenna technology, such as multiple input multiple output (MIMO), beamforming is one of the most promising technology for broadband wireless communication. In OFDM environment, we found that as the number of paths is increased, smart antenna system cannot fully exploit beamforming gain. In this paper, we propose a beamforming scheme and analyze the performance of the proposed beamforming scheme in WiBro smart antenna system. WiBro is an OFDMA-based multiple access service for wireless broadband multimedia environment. The proposed beamforming technique for WiBro smart antenna system can effectively improve the performance of the systems in multipath fading environment.

• TTA Journal
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• s.103
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• pp.36-40
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• 2006

지난해 11월초 열린 제64차 IETF(Internet Engineering Task Force) 국제 표준화회의에서는 휴대인터넷(WiBro, 와이브로) 서비스에 필요한 IPv6 기술표준을 제정할 표준 실무그룹인 16NG(IPv6 ove IEEE 802.16(e)Networks) 회의가 한국의 주도하에 신설되었다. 2006년 상반기, 세계 최초의 상용 서비스를 목표로 하는 우리나라의 와이브로 서비스의 해외시장 확산에 기여하게 될 이번 쾌거에 따라 TTA저널 2006년 신년호 인터뷰는 한국주도의 최초 IETF 워킹그룹 탄생에 의미를 부여하며 16NG에서 다루게 될“와이브로+IPv6 컨버전스 표준화”에 대하여 본 워킹그룹의 의장으로 선임예정인 삼성전자의 박수홍 선임연구원으로부터 관련 기술의 과거, 현재, 미래에 대하여 들어본다.

• 정보화사회
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• s.189
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• pp.18-23
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• 2007

우리나라가 개발한 세계 최초의 휴대인터넷 기술인 '와이브로(WiBro)'가 3세대 이동통신 국제표준에 채택됐다. 국제전기통신연합(ITU)이 지난 달 18일 제네바 국제회의센터에서 개최된 전파총회 본회의에서 와이브로 기술을 3세대(3G) 국제표준으로 최종 승인한 것이다. 이로써 와이브로는 'IMT-2000'으로 불리는 3세대 이동통신의 6번째 국제표준으로 이름을 올리게 됐다.