• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.50-50
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• 2000

• Broadcasting and Media Magazine
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• v.18 no.1
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• pp.67-73
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• 2013

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.87-87
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• 2002

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5A
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• pp.397-401
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• 2005

A different alternative method for simulating bit error rate(BER) performance of Satellite Digital Multimedia Broadcasting(DMB) in tunnel environments is presented. The method based on a channel model obtained by ray-tracing is able to support BER estimation over the channel presents arbitrary statistics that are difficult to fit to an analytic expression. The BER performance for System E over the tunnel fading channel that obtained by ray-tracing is predicted by the monte-carlo method. It can be observed that the BER performance for a straight tunnel channel is better than that for a line-of-sight(LOS) area in curved tunnel. Also, the BER performance for LOS areas in a curved tunnel outperforms that for non-line-of-sight(NLOS) areas in a curved tunnel. The BER performances for straight, curved LOS and curved NLOS tunnel channels are better than that for a Rayleigh channel(K=0) and less than that for a Rician channel with K=3. Moreover, for BER=10-3, it can be seen that there is approximately a $1{\sim}1.5\;dB$ difference between those three types of tunnel channels and a Rayleigh channel.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.302-310
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• 2006

ITU-R B.O. 1130-4 Digital System E adopted for Korean satellite DMB service is a multimedia broadcasting system based on DS-CDM-QPSK technique which broadcasts audio and video contents via the satellite or terrestrial gap-filler. However, Digital System E can not provide full loading services because the multi-channel interference (MCI) is increased due to the loss of orthogonality between signature waveforms in multipath fading channels. In this paper a chip equalizer using tap selection algorithm that enhances the receiving performance is proposed and compared to the conventional rake receiver for the satellite DMB system.

• Journal of Broadcast Engineering
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• v.8 no.3
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• pp.217-227
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• 2003

This paper describes an implementation of the slide-show functionality, which is one of the services that can be provided by the Digital Multimedia Broadcasting (DMB). While the existing analog radio broadcasting services provide audio only, DMB slide-show is the functionality that can deliver still images associated with the audio. For example, it can deliver the photographs of the singer, album cover images, or the lyrics of the song that correspond to the audio. There are two modes for the transmission of the slide-show. Firstly. the program-associated data (PAD) field within the DMB audio frame can be utilized and secondly, the slide-show data can be transmitted, after being multiplexed, with other service data as individual data stream separated from the audio. This paper describes PC-based implementations of a transmitter-side module that inserts slide-show data into the PAD area within audio bitstream and a receiver-side application module that plays the slide-show through decoding the PAD within the received audio bitstream and demonstrates their validity through experiments.

• Journal of Broadcast Engineering
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• v.8 no.3
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• pp.238-249
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• 2003

Eureka 147 DAB system based on the orthogonal frequency division multiplexing (OFDM) was adopted as the transmission scheme for terrestrial digital multimedia broadcasting (DMB) system in Korea. The OFDM has several advantages comparing to the single carrier modulation. However, its high Peak-to-average power ratio (PAPR) increases the complexity of the D/A and A/D converters and reduces the efficiency of the high power amplifier To reduce the high PAPR of OFDM, various techniques such as clipping, peak windowing, companding, selected mapping (SLM), Partial transmit sequences (PTS), etc. have been proposed. In this paper, we propose modified configurations of SLM and PTS for effective implementation and evaluate the performance on the PAPR reduction of DMB system. The simulation results show that the modified SLM (MSLM) has merits in reducing the amount of computation and hardware complexity due to the reduction of the number of vector $P^{(U)}$, while satisfying the same performance and maintaining the same required bits (RB) for side information. With the same amount of computation and the same RB, the modified PTS (MPTS) is also shown to be better than PTS in the performance of PAPR reduction.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.5
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• pp.311-319
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• 2007

Today, the data broadcasting service provides various multimedia contents to users. This paper suggests a resource management system which controls multimedia resources in order to reduce the receiving time of the contents during the realtime data broadcasting of multimedia traffic information. To verify the efficiency of the resource management system, this paper has introduced the realtime traffic information integrating and authoring systems through MOT (Multimedia Object Transfer) protocol-based BWS (Broadcast Web Site) service in which multimedia data are transmitted by T-DMB (Terrestrial Digital Multimedia Broadcasting) and implemented a resource management system which controls the creation of multimedia resources in connection with the said systems. As the receiving time of the contents created with resources from the resource management system has decreased by 1/13, they are suitable for realtime data broadcasting.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5A
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• pp.509-516
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• 2006

Satellite-Digital Multimedia Broadcasting(S-DMB) systems are single frequency networks which consist of a satellite and gap fillers. Though gap fillers are required to extend the coverage to NLOS(Non Line-of-Sight) area, the receiver performance can be degraded with a limited number of fingers due to the increased number of multi-paths. The paper proposes to use frequency domain equalizer(FDE) instead of conventional Rake receiver, where the guard interval is not considered in order to minimize the impact on the current S-DMB systems. Through a campaign of simulations, it is found that the proposed FDE is less sensitive to the number of gap fillers compared to the conventional Rake receiver, and can achieve a greater channel capacity in most channel environments.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2005.11a
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• pp.127-130
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• 2005

우수한 이동수신 성능을 지닌 지상파 DMB(T-DMB: Terrestrial-Digital Multimedia Broadcasting)의 킬러앱(Killer App)이라 불리는 교통 및 여행정보(TTI: Traffic and Travel Information) 서비스는 주 5일 근무제 실시와 지속적인 자동차수 증가로 인해 그 중요성이 부각되고 있다. 지상파 DMB 기반의 TTI 서비스 전송을 위한 프로토콜로 국제 표준인 TPEG(Transport Protocol Expert Group)이 유력시 되고 있으나, 현재 국제 표준화가 완료된 서비스 규격으로는 속도 ${\cdot}$ 유고정보 및 대중교통수단 관련 정보 전송이 가능한 RTM(Raod Traffic Message)과 PTI(Public Transport Information) 뿐이다. 국내의 경우, 속도 정보 제공을 위한 새로운 서비스 규격으로 CTT(Congestion and Travel Time Information)에 대한 표준화 작업이 진행 중에 있다. 최근 이동통신 인프라 대신 지상파 DMB를 기반으로 한 새로운 위치기반서비스의 규격 제정의 필요성이 대두되었으며, 이에 따라 이를 위한 국내 표준화 활동이 본격적으로 추진될 예정이다. 본 논문에서는 기존 TPEG 규격과 완벽히 호환되는 위치기반서비스 전송을 위한 새로운 POI(Point Of Interest) 프로토콜을 제안하였다. 이의 검증을 위해 POI 데이터 서비스 저작 및 전송서버 및 POI 수신 플랫폼을 설계 ${\cdot}$ 구현하여 송수신 플랫폼을 구성하였으며, 구축된 플랫폼을 이용한 방송실험을 통해 제안된 POI 서비스 응용 프로토콜의 안정성 및 전송 효율성을 확인하였다.