• Information and Communications Magazine
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• v.22 no.4
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• pp.65-74
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• 2005

• Information and Communications Magazine
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• v.22 no.4
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• pp.37-48
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• 2005

• Information and Communications Magazine
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• v.22 no.4
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• pp.110-120
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• 2005

• Satellite Communications and Space Industry
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• v.14 no.1 s.29
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• pp.6-14
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• 2007

• Information and Communications Magazine
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• v.26 no.5
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• pp.3-9
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• 2009

본 고에서는 현재 IEEE 802.15.7 TG VLC에서 본격적으로 논의되고 있는 가시광 무선통신의 응용 서비스 모델 중에서 LED(Light Emitting Diode) 조명과 통신이 융합된 응용 서비스 모델을 중심으로 알아본다. LED를 이용한 통신 기술은 광 케이블을 이용한 유선 광통신에서 이미 시작된 기술이나 LD를 이용하여 더 우수한 성능을 보이면서 잊혀져가던 기술중하나이다. 이러한 광통신 기술은 LED의 성능이 급격하게 증가하면서 다시금 주목을 받게 되었고, 특히 LED를 이용한 조명기술이 발전하면서 무선통신으로 다시금 주목받고 있는 기술이다. 실내 환경에서 LED 조명 고유의 기능을 그대로 유지하면서 무선통신을 가능하게 하고, 항공기 혹은 병원내에서와 같이 기존의 RF무선통신에 제약을 받는 환경에서도 무선통신이 가능하게 하며, 실내 LED 조명을 이용함으로써 국부지역에 특정 서비스 제공이 가능해 졌다. 따라서 가시광 무선통신은 조명산업과의 융합을 통해 통신뿐만 아니라 기존의 조명과 디스플레이 분야에서 새로운 가치를 창출 할 수 있는 그린 IT융합 기술이다. 본 고에서는 LED조명의 등장배경, 위치 정보 제공 서비스, 국부 방송 서비스, 항공기내 무선통신 서비스 등 LED 조명 기술과 통신기술이 융합된 가시광 무선통신의 응용 서비스 모델에 대하여 설명한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.7-12
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• 2019

Ambient backscatter communication is limited to channel estimation technique through a pilot signal, which is a channel estimation method in current RF communication, due to transmission power efficiency. In a limited transmission power environment, the research of traditional ambient backscatter communication has been studied assuming that it is an ideal channel without signal distortions due to channel conditions. In this paper, we propose an expectation-maximization(EM) algorithm, one of the blind channel estimation techniques, as a channel estimation method in ambient backscatter communication system which is the state of channel following normal distribution. In the proposed system model, the simulations confirm that channel estimate through EM algorithm is approaching the lower bound of the mean square error compared with the Bayesian Cramer-Rao Boundary(BCRB) to check performance. It shows that the channel parameter can be estimated in the ambient backscatter communication system.

• Broadcasting and Media Magazine
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• v.11 no.4
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• pp.104-117
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• 2006

In this Paper, we analyze the application of Interactive Data Broadcasting in DMB(Digital Multimedia Broadcasting) in the accordance with convergence of service and technology. With the acceleration of digital convergence in the Ubiquitous period substantial development of digital media technology and convergence of broadcasting and telecommunication industry are being witnessed. Consequently these results gave rise to newly combined-products such as DMB(Digital Multimedia Broadcasting), WCDMA(Wide-band code division multiple access), Wibro(Wireless Broadband Internet), IP-TV (Internet protocol TV) and HSDPA(High speed downlink packet access). The preparatory stage for the implementation of Interactive Data Broadcasting Service will be reached by the end of December, 2006. DMB is the first result of a successful convergence service between Broadcasting and Telecommunication in new media era. Multimedia technology and services are the core elements of DMB. The Data Broadcasting will not only offer various services of interactive information such News, Weather, Broadcasting Program etc, but also be linked with characteristic function of mobile phone such as calling and SMS(Short Message Service) via Return Channel.

• Electronics and Telecommunications Trends
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• v.23 no.5
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• pp.40-48
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• 2008

최근 초고속 인터넷의 급속한 발달로 IP 기반의 융합 서비스가 빠르게 발전하고 있다. 특히 방송 및 영상 분배 기능이 대두되면서 보안 서비스에 대한 요구사항도 급격히 증가하고 있다. 과거 아날로그 방송에서는 영상을 변조(scramble)하여 보내고 대응 복조기를 이용하여 정당한 가입자만 시청할 수 있도록 하는 기술을 사용한 반면 최근 융합 서비스인 IPTV 방송 시스템에서는 과거의 변조 방식이 IP의 개방형이라는 특징때문에 사용에 한계점을 보이고 있다. 이는 인터넷의 다양한 공격(man-in-the-middleattack, TCP-hijacking) 기술이 IPTV에서도 가능하기 때문이다. 본 고에서는 IPTV 환경에서 연구되고 있는 보안 서비스 기술에 대해서 정리하고 IPTV 서비스를 위한 적용 기술 및 표준화 중심의 대표적인 연구 사례들을 소개한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.327-335
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• 2001

In the 21st century, broadcasting, communication, and computer have been integrated due to the development of digital technology. Accordingly, to overcome the limit of respective communication media and to maintain them, their independent area shall not be classified. This study is to examine the future environment of digital TV broadcasting, to analyze customizing type service and interactive type TV technology, and to make asymmetric interactive digital TV publication broadcasting system, which is TV broadcasting in the next generation to treat visual image, sound, and various data all together by harmonizing broadcasting and communication like ISDB(Integrate Service Digital Broadcasting). In addition, to develop service on publication broadcasting with high quality, this study is to propose to develop relative devices for TV/PC reception to realize a new communication type TV publication broadcasting, by analyzing technology for producing, sending, transmitting, receiving, and saving to apply to customizing type interactive system and by examining its application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.2B
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• pp.59-68
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• 2008

In order to activate the digital broadcasting in Korea, the analog broadcasting will have been closed down until 2012. Recently IPTV(Internet Protocol TV) thorough internet has been regarded as the fourth media following the terrestrial, satellite, and cable for the digital broad casting. And it has been the important medium for the communication and broadcasting system. However IP is not easy to replace the entire broadcasting system with the digital - type broadcasting system. For the digital broadcasting, we should replace all TV sets, install the settop-boxes to receive the various IP media, solve problems about time delaying when changing channels, and support communication and broadcasting consolidation service for such as PVR and Network CCTV. IPMG is the digital converter that is able to solve these problems. In this paper, I'll develop and analyze IPMG converter's performance which sends and receives both the analogue and digital broadcasting signals through various media gives the Network PVR service.