• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.95-98
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• 2006

본 논문의 목표는 지상파 디지털 방송과 데이터 방송 그리고 아날로그 방송을 수신할 수 있는 DTV Set를 구현하고 일체형 디지털 방송 수신기에서 아날로그 방송과 영상을 입력받았을 때 화질저하의 원인이 되는 De-interlace 알고리즘과 3-D Noise를 적절하게 제거할 수 있는 알고리즘에 관한 연구가 목표이다. 또한, 디지털방송의 수신된 컨텐츠를 다른 저장매체로 불법적으로 복사, 재생을 막기 위한 디지털 컨텐츠복사를 방지할수 있는 알고리즘에 관한 연구이다. 현재, 우리나라에서는 기존의 아날로그 방송과 고품질 디지털 방송 서비스를 위한 디지털 방송이 시험적으로 실시되고 있는 상황이다. 이러한 환경하에서 디지털 방송 수신만을 위한 수신기는 아직 시기상조이며 아날로그 방송과 디지털 방송을 동시에 수신할 수 있는 일체형 수신기가 필요한다. 일체형 수신기에서 가장 문제가 되는 부분이 아날로그 방송을 수신하여 디지털 영상으로 인코딩한 후 화면에 뿌려 줄 때 Even Field와 Odd Field를 분리하여 뿌려주기 때문에 많은 영상의 열화가 발생하게 된다. 이러한 문제를 해결하기 위한 많은 방법들이 연구되고 있는 실정이다. 본 연구에서 사용된 시스템을 간략하게 소개하면 디지털 방송 수신을 위한 SoC 로는 Zoran의 G9 Ellete 채택하였고 아날로그 영상의 Decoder로는 AMI의 ADV7401을 선택하였다. 이에 대한 Operating System는 Real-Time OS인 Thread-X를 선택하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.564-566
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• 2012

In this paper, a design method for a compact broadband planar monopole antenna fed by coplanar waveguide (CPW) is studied. The proposed broadband monopole is optimized for terrestrial digital television (DTV) receiving. The monopole is fed by a CPW with 75-ohm characteristic impedance on an FR4 substrate and its size is $100mm{\times}200mm$. A pair of slit is appended for size reduction and an inductive stub is loaded for the impedance matching between the feedline and monopole. The optimized monopole antenna for DTV band (470-806 MHz) is fabricated on an FR4 substrate and tested experimentally to verify the results of this study.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.869-874
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• 2004

Digital TV broadcasting's resolution or tone quality is very excellent than analog broadcasting and has many advantages including various multimedia functions such as home shopping, home banking, internet search, telecommuting, VOD, etc. In this study, it is essential to analyze the regional electromagnetic environment before Digital TV broadcasting, and therefore we analyzed Busan area's limitation using ETRI propagation model. For maintaining high-quality Digital TV signals, we measure electric field intensity wide and far in Busan including mountains area and high-rise buildings. Generally, it has lower value by a standard ETRI propagation model than simulated value about standard model, but distribution pattern are similar with it. Compared theoretical values with the measured results, they have similar values for flat area but very different values for crowded city area and mountains area So we conclude that ETRI propagation model and theoretical model are not suitable for Busan in a free space.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9C
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• pp.922-927
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• 2009

Utilization problem of the limited spectrum is the one of the most important issues in wireless communication systems. Cognitive radio technique which is finding and utilizing frequency holes is also one of those techniques. Specially, the spectrum sensing technique to detect the primary user signal is a core technology in cognitive radio area. In this paper, we propose the spectrum sensing algorithm using Bussgang theorem. The proposed algorithm calculates the statistical difference between the Gaussian noise and the primary user signal by applying Bussgang theorem to the received signal. The algorithm is not affected by noise uncertainty and can detect the primary user signal in the very low SNR environment. We evaluate the algorithm through computer simulations with 12 ATSC A/74 DTV signal captures based on IEEE 802.22 WRAN and formulate the sensing threshold for the proposed scheme.

• Journal of Broadcast Engineering
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• v.14 no.2
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• pp.154-163
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• 2009

Traditional broadcasting environment is merged with various interactive broadcasting services, and the users use these services through Set-Top-Boxes. But they have limited user interfaces, which are not suitable for TV environments by adopting internet formats. Therefore, this paper suggests a User Navigating Interface which helps the audiences to select and watch their favorite channels more effectively. Firstly, this paper analyzes EPG interface - the most basic service in interactive broadcasting. Secondly, it suggests a user interface and service structure suitable in the network-integrated TV environment.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.10
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• pp.21-29
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• 1999

This paper is concerning about the demapping method using the pilots inserted in transmitter in COFDM(Coded Orthogonal Frequency Division Multiplexing) demodulator which is the standard transmission method of terrestrial digital TV system in Europe(DVB-T). We have presented a simple and efficient method of CSI(Channel State Information) generation and demapping method using CSI. The CSI was derived from the pilot carriers inserted with comb-type among the received active carriers, which is defined as a SNR. From the simulation results for the 3 different constellations of the receiver, we could confirm that the system performance comparing with conventional soft decision method has been improved under DVB-T standard Rayleigh and Ricean fading channel.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.188-196
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• 2003

In this paper, a demultiplexer for MPEG-2 Transport Stream which can be applied to terrestrial digital broadcast is developed. The demultiplexer separates video, audio, and data from MPEG-2 multimedia stream and transports them to each decoders respectively. While most existing demultiplexers of MPEG-2 transport stream have been developed as hardware systems, but the fast increment of computer's performance enables a software demultiplexer to be worked in realtime. The developed demultiplexer is implemented as a software module called a filter using DirectShow of Microsoft which is based on COM(Component Object Model)and works on the Windows system. The operation of the demultiplexer is verified by using the GraphEdit tool and rendering a test file formatted as MPEG-2 transport stream.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.10
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• pp.794-801
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• 2017

In this paper, we proposed airborne target recognition using multi-channel combining method in DTV-based passive radar. By combining multi-channel signals, we obtained the HRRP with sufficient range resolution. HRRP was obtained by AR method or zero-padding. From the obtained HRRP, we extracted scattering centers by CLEAN algorithm using the gradient descent. We extracted feature vectors and performed target recognition after training neural network using the extracted feature vectors. To verify performance of proposed methods, we assumed frequency bands of three broadcasting transmitters operated in Korea(Mt. Gwan-ak, Mt. Yong-moon, Kyeon-wol-ak) and used full scale 3D CAD model of four targets. Also we compared the target recognition performance of the proposed method with that of using only single-channel of three broadcasting transmitters. As a result, proposed methods showed better performance than using only single-channel at three broadcasting transmitters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.583-585
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• 2012

In this paper, we introduce a design method for a broadband planar quasi-Yagi antenna (QYA) for terrestrial digital television (DTV) receiving. The coplanar strip line feeding the driver dipole is connected to a microstrip line and is terminated by short circuit. By appending a wide strip-type director at a location close to the driver dipole, a broadband impedance matching and a gain characteristics in a high frequency region are obtained. The gain characteristics in a low frequency region are improved by adding a reflector formed by a truncated ground plane. To reduce the antenna size, the strip-type dipole and reflector are modified to half bowtie (V)-shaped elements. The effects of various parameters on the antenna characteristics are examined. An antenna, as an design example for the proposed antenna, is designed for the operation in the frequency band of 470-806 MHz for terrestrial DTV. The optimized antenna is fabricated on an FR4 substrate and tested experimentally to verify the results of this study.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.14-17
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• 2010

Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies prepare for starting stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast attains due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting system with heterogeneous video coding systems is considered for terrestrial 3DTV broadcast where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of two bit streams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter computed from the proposed optimization scheme. Besides, we also consider a condition on quality difference between the left and right images in the optimization. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm in terms of minimizing the mean image distortion as well as the mean value and the variation of absolute image quality differences.