• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.301-304
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• 2001

이 논문에서는 미국과 유럽에서 디지털 CATV 전송 방식으로 각각 채택하고 있는 Opencable 시스템과 DVB-C 시스템의 전송성능을 비교하였다. 채널 환경의 신호손상요소는 랜덤잡음과 CTB (Composite Tripple Beats) 잡음을 고려하였다. 전송성능을 비교하기 위하여 각 전송시스템에 대한 모의실험장치를 S/W적으로 구현하여, 각 잡음 값에 따른 BER(Bit Error Rate) 값을 구하였다. 동일한 조건에서 모의실험을 실시한 결과, 64-QAM 모드에서는 Opencable 방식이 우수하고, 256-QAM 모드에서는 두 가지 전송방식의 성능이 비슷하다는 결과를 얻었다.

• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.297-304
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• 2004

TV-Anytime specification provides metadata standards for personalized broadcasting service. For personalized broadcasting service, the metadata is transmitted through the specific way to the employed broadcasting system. In an MPEG-2 environment. the metadata can be transmitted using Sections, objects within a DSM-CC Object Carousel or modules within a DSM-CC Data Carousel. In this paper, we introduce a TV-Anytime metadata delivery method within Object Carousel which is used in ATSC-ACAP and DVB-MHP, We describe an actual example of unidirectional personalized broadcasting which is implemented on an ATSC-ACAP data broadcasting receiver, where the metadata is delivered as objects within a DSM-CC Object Carousel.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.77-84
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• 2000

In this paper, we discuss a symbol clock extraction scheme based on maximizing the band-edge component of the transmitted signal frequency spectrum for applications to 51.84Mbps VDSL system which uses a 16-QAM. The major characteristics of the digital PLL are examined. In addition, we suggest an efficient design method of a sinusoidal look-up table which is used for NCO.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.863-870
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• 2012

The market trends of automatic meter reading associated with smart water meters were investigated. Also, recent developments and field applications of key technology for automatic meter reading associated with smart water meters were analyzed. Smart water meters have been manufactured mostly in United States and Europe and have been expanded their business to Asia. Integrated water management system combining with the additional functions such as real-time consumption metering, cost notification, water conservation, leak detection, water quality monitoring, and flow control have been operated in automatic meter reading. Both water quality and quantity data measured from smart water meters and sensors were transferred to data concentration units through neighborhood area network, and then were transferred to integrated server through wide area network. The data transfer methods were determined by comprehensively considering urban scale, density of smart water meters, power supply and network topologies. Common data collection methods such as fixed network to data concentation units, vehicles drive by, people walk by, and drone fly by have been applied. The automatic meter reading associated with smart water meters are spread throughout the world, and both water and energy savings result in saving the money and reducing the greenhouse gases emission.

• Information and Communications Magazine
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• v.15 no.7
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• pp.169-179
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• 1998

본 논문에서는 현재 연구 개발되고 있는 Fiber-to-the-curb / Very high-rate digital subscriber line(FTTC/VDSL) 시스템의 DAVIC 표준 가입자 전송 기술인 51.84 Mb/s 16-CAP (Carrierless AM/PM) 전송시스템 (downstream)과 1.62 Mb/s QPSK burst-mode TDMA 전송시스템 (upstream)및, 타이밍 복원회로 등의 동작 원리 및 구조를 간략하게 기술하였다. 본 논문은 FTTC/VDSL 전송시스템 개발을 위하여 전체시스템이 운영될 환경, 즉 채널에 대하여 기술한 후, 주어진 채널에 적합한 down-stream전송시스템 알고리즘 및 구조를 설명하였으며, 타이밍 복원 시스템을 기술하였다. FTTC/VDSL시스템은 네트워크의 한 개의 송수신부가 가입자 댁내의 여러 개의 set-top box와 데이터를 주고받는 점 대 다점 (point-to-multipoint) 구조로 이루어져 있으며, 따라서 역 방향 (upstream) 채널 데이터 전송을 위한 QPSK 전송시스템은 네트워크쪽의 QPSK 수신부가 가입자 댁내의 여러개의 QPSK 송신부를 서비스할 수 있게끔 시분할 다중접속 방식인 burst-mode TDMA전송방식으로 구현되었다. FTTC/VDSL 전송시스템은 DAVIC의 시스템 성능 요구조건을 만족하게 설계되었으며, 모든 기능은 디지털로 구현되었고 칩 구현을 위하여 각 기능의 VLSI 시스템 파라메타 들을 추출하고 성능 시험을 실시하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.971-982
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• 2008

In this paper, we propose a new digital duplexing scheme, called SDD(Synchronous Digital Duplexing), which can increase data efficiency and flexibility of resource by transmitting uplink signal and downlink signal simultaneously. In order to transmit uplink data and downlink data simultaneously, the proposed SDD obtains mutual informations between AP(access point) and each SSs(subscriber station), SS and other SSs by mutual ranging procedure. These informations are used for selection of transmission time, decision of CS insertion, setting of CS length, and FFT duration resetting, etc. It is shown that the proposed SDD is appropriate for duplexing scheme in indoor environments over the conventional TDD(Time Division Duplexing) and FDD(Frequency Division Duplexing).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.4
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• pp.423-434
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• 1989

In this paper, a PRS transmission system using TMRCP as the unit pulse is proposed, which solves the problems occur when the PRS method will be applied to the digital transmultiplexer for each channel. And a design technique which uses this PRS method for the FFT polyphase filter transmultiplexer concept is given. TMRCP-PRS signal require a bandwidth about 2.5KHz(including some guard-band) for a 4-KHz bandlimited voice channel. Therefore, in he 24 channel transmission line, it gives the same advantages as he ordinary PRS system and sloves the inter-channel interference problems. And its good speed-tolerance reduces the time-errors by the environments and the power loss, so it makes the system to be stable. The total system, however, attaces the filters for PCM-PRS, PRS-PCM conversion before and after the transmultiplexer respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12B
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• pp.1013-1021
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• 2004

Recently, there have been the rapid increasing needs to integrate high-speed communications and digital TV in home network. To realize the integration of those services, the MIC formulated the broadband convergence network (BcN) plan as one of the new growth engines. The BcN will be implemented by FTTH solutions and these solutions are designed to support digital home network. To develop and promote the BcN, we need to find the bandwidth requirements for home network. This paper will examine the bandwidth requirements in detail to accommodate data traffics for high-speed communications and TV at building intra network and home intra network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1672-1678
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• 2007

The communication systems and characteristics of transmit are very importance a serious view of ubiquitores society. The high rate systems have to construct for data of voice, graphics and moving-video with the multimedia to transmit on the low frequency band. The rate of data are relation that there are the bandwidth of line and channels, the bit per second and communication-systems. This paper study for the error performance of 2, 4 8 level FSK to transmit amount of data in the communication systems and design to FDM system.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.177-178
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• 2008

지상파 방송(DMB: Digital Multimedia Broadcasting)은 음성, 영상, 데이터와 같은 다양한 멀티미디어 신호를 디지털 방식으로 변조하여 이동 중에 방송을 청취할 수 있는 차세대 디지털방송 서비스이다. 그러나 지상파 DMB 전송 고도화망에서는 계층 변조(Hierarchical Modulation)전송 기법을 통하여 추가의 전송대역폭을 확보할 수 있다. 또한 스케일러블 비디오 코딩(Scalable Video Coding)부호화 방식을 이용하여 고전송효율/고품질의 이동 멀티미디어 방송서비스를 제공할 수 있는 고품질 AT(Advanced Terrestrial)-DMB 시스템이 가능하다. 이러한 고품질 AT-DMB의 개발에 있어서 여러 방식들이 제시됨에 따라 시뮬레이터를 통한 다중화 시스템의 분석이 필요하다. 본 논문에서는 고품질 AT-DMB가 가능한 스케일러블 비디오 방식을 JSVM8.8을 사용하여 구현하였으며, 다중화 시스템의 실험을 하였다. 또한 시뮬레이터를 통하여 복호된 계층 간의 화질 차이와 엔지니어를 위해 비트스트림의 분석화면 및 PSNR을 제공 하였다.