• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.195-202
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• 2013

Many communications and broadcast media have emerged by the rapid development of wireless communication and broadcasting technologies, so the radio resources are insufficient for these services. DMB can use the regional integrated channel due to the SFN broadcasting network, so DMB uses the frequency efficiently. However, the domestic DMB uses the existing analog TV frequency band and uses a plurality of channels in some areas because of the interference with the analog TV. However, the broadcasting of the analog TV was terminated, so the channel reallocation of the terrestial DMB is necessary for the efficient use of frequencies. This paper proposes the channel reallocation method of the terrestial DMB and analyzes the change of transmission and reception environments by using simulations.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.269-275
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• 2014

The DAB system was designed to provide CD quality audio and data services for fixed, portable and mobile applications with the required BER below $10^{-4}$. However for the T-DMB system with the video service of MPEG-4 stream, BER should go down $10^{-8}$ by adding FEC blocks which consist of the Reed-Solomon (RS) encoder/decoder and convolutional interleaver/deinterleaver. In this paper we propose two types of turbo coded T-DMB system without altering the puncturing procedure and puncturing vectors defined in the standard T-DMB system for compatibility. One(Type 1) can replace the existing RS code, convolutional interleaver and RCPC code by a turbo code and the other one (Type 2) can substitute the existing RCPC code by a turbo code. Simulation results show that two new turbo coded systems are able to yield considerable performance gain after just 2 iterations. Type 2 system is better than type 1 but the amount of performance improvement is small.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.465-472
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• 2003

In this paper we propose the structure of MPEG-4 multimedia player platform for Terrestrial Digital Multimedia Broadcasting (DMB) Service. Korea will launch DMB service at next 2004 you based on Eureka-147 Digital Audio Broadcasting (DAB) Service System. This new mobile multimedia broadcasting services provide not only high quality digital audio broadcasting services, but also various multimedia data broadcasting services including high quality video. For the sake of MPEG-4 Systems technologies, it will provide an interactive service to users in the near future. Therefore it terminal shall have various functionalities as well as playing audio-visual contents. However there is no precedence standard for such mobile interactive multimedia broadcasting system. Therefore it is very import to provide the multimedia player platform of DMB service for accelerating the development process of commercial terminal and providing a direction of next DMB terminal structure.

• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.501-515
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• 2008

Recently, as users' requests for high quality mobile multimedia services are rapidly increasing and additional bandwidth can be provided by adopting the hierarchical modulation transmission technology, the research on the Advanced Terrestrial DMB (AT-DMB) service using the SVC (Scalable Video Coding) scheme is being actively studied. But, in order to realize a compatible video service and to accelerate the successful standardization and commercialization, it is necessary to simplify the compatible encoder structure. In this parer, we propose a fast mode decision method by constraining the redundant coding modes in the spatial scalable encoder that keeps the current T-DMB video in base layer. The proposed method is based on the statistical characteristics of each coding mode at both base and enhancement layers, inter-layer predictions, which are derived by investigating macroblock-layer coding modes of the spatial scalable encoder's functional structure. Through computer simulations, it is shown that a simplified encoder model that reduces the heavy computational burden can be found, while keeping the objective visual quality very high.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.86-88
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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 청취 할 수 있는 차세대 디지털방송 서비스이다. 하지만 한정된 대역폭으로 인한 비디오 전송율의 한계에 따라 최대 CIF(Common Interleaved Frame)급 화면해상도까지 서비스가 가능하다. 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 JM8.8을 사용하여 구현하였으며, 다중화 시스템의 실험을 하였다. 또한 시뮬레이터를 통하여 확보된 계층 간의 화질 차이와 엔지니어를 위해 비트스트림의 분석화면 및 PSNR을 제공 하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.142-144
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• 2012

T-DMB는 개인용, 휴대용, 이동형의 디지털방송매체로서의 특징을 가지고 있으며 최근들어 수신기 보급 증가로 새로운 재난방송 매체로 부상하고 있다. 그러나 현재의 T-DMB 기반 재난방송 기술은 T-DMB를 시청하고 있어야만 재난정보 수신이 가능하다는 한계를 갖고 있다. 이에 본 논문은 기존 T-DMB를 시청해야만 재난정보 수신이 가능한 기존 T-DMB 재난방송 서비스의 한계를 뛰어 넘어 재난발생시 수신기가 자동으로 재난방송신호를 인지하여 T-DMB를 시청하지 않더라도 재난정보를 제공하고 평상시 지역정보, 날씨 등 공공서비스 정보를 제공하는 T-DMB 재난방송 서비스 기술을 소개한다.

• ETRI Journal
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• v.31 no.6
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• pp.795-802
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• 2009

This paper presents the design of an advanced terrestrial digital multimedia broadcasting (AT-DMB) baseband receiver SoC. The AT-DMB baseband is incorporated into a hierarchical modulation scheme consisting of high priority (HP) and low priority (LP) stream decoders. The advantages of the hierarchical modulation scheme are backward compatibility and an enhanced data rate. The structure of the HP stream is the same as that of the conventional T-DMB system; therefore, a conventional T-DMB service is possible by decoding multimedia data in an HP stream. An enhanced data rate can be achieved by using both HP and LP streams. In this paper, we also discuss a time deinterleaver that can deinterleave data for a time duration of 384 ms or 768 ms. The interleaving time duration is chosen using the LP symbol mapping scheme. Furthermore, instead of a Viterbi decoder, a turbo decoder is adopted as an inner error correction system to mitigate the performance degradation due to a smaller symbol distance in a hierarchically modulated LP symbol. The AT-DMB baseband receiver SoC is fabricated using 0.13 ${\mu}m$ technology and shows successful operation with a 50 mW power dissipation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.19-26
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• 2010

Since T-DMB commercial services have been launched, various broadcasting services such as DMB2.0, which provides interactive data broadcasting services, have emerged. Due to activation of T-DMB services, the needs of the existing video contents as well as new data contents are increasing. Especially, video contents are frequently reused because of the production cost of digitalized contents. In order to solve the problem occurring in the contents reusing process, this paper proposes the method controlling transfer rate by defining a numerical formula and verifies it through simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.183-188
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• 2008

Satellite DMB(Digital Multimedia Broadcasting) uses the Cap Filler(GF) that provides a service to the wave shade area of the satellite signal that is a non-line of sight area. The GF is the repeater and the Satellite DMB Systems certainly must construct the GF Network toguarantee the movement reception of the terminal. As the coverage of the GF is formed the Cell or Sector, when the multiple GF is established to be contiguous, the problem of the interference will be able to occur. This paper describes the Satellite DMB system and the GF, and it investigate the design fundamentals plan of the GF Network that it will be able to reduce this problem. As a result, in case of the distance that GF and terminal unit is above 4.6Km, service is not provided because of quality degradation according to mutual interference.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.108-110
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• 2010

최근 3D 비디오 서비스에 대한 관심이 고조되고 있는 가운데, 지상파 DMB 및 위성 DMB에서도 스테레오스코픽 비디오 서비스를 제공하기 위한 노력이 진행되고 있다[1]-[3]. DMB-AF 파일 포맷[4]은 MPEG에서 제정한 DMB 파일 포맷 국제 표준이다. 이 표준 제정 당시에는 스테레오스코픽 비디오 콘텐트를 지원하는 기능이 들어 있지 않았다. 본 논문에서는 DMB-AF 한 파일 내에서 2D 비디오, BIFS에 의해 스테레오스코픽 이미지가 오버레이된 2D 비디오, 스테레오스코픽 비디오 등이 시간적으로 혼용될 수 있는 방법을 제안한다. 또한 이 방법은 기존 2D 비디오의 재생만 지원하는 기존 DMB-AF 플레이어와의 호환성을 보장한다. 따라서 기존 DMB-AF 플레이어가 BIFS에 의해 스테레오스코픽 이미지가 오버레이된 2D 비디오 또는 스테레오스코픽 비디오가 포함된 DMB-AF 파일을 재생할 때에는 2D 이미지 또는 2D 비디오로 재생할 수 있다. 제안한 방법은 한 프레임을 좌우로 반으로 나누어 좌안 및 우안 비디오를 좌우로 배치한 화면분할(side-by-side) 포맷에 의한 스테레오스코픽 비디오뿐만 아니라 좌안 또는 우안 비디오 중 하나는 2D 재생용의 기준 비디오로 다른 하나는 스테레오스코픽 비디오를 위한 부가 비디오로 사용하는 기본 포맷에 의한 스테레오스코픽 비디오도 지원한다. 후자의 경우, 부가 비디오는 가로 해상도가 기준 비디오의 1/2인 선택사항 포맷도 지원한다. 스테레오스코픽 비디오를 지원하기 위해, 기존 DMB-AF 표준의 확장을 최소화하는 방법을 제안한다.