• ETRI Journal
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• v.34 no.4
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• pp.492-502
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• 2012

We consider an overlaid broadcast service, where a spread spectrum (SS)-based broadcast signal is overlaid onto the existing terrestrial Digital Multimedia Broadcasting (T-DMB) band. The system is similar to the augmented data transmission in the ATSC DTV, for which it was investigated mostly in terms of link level performance, such as bit error rate. Our focus in this paper is on the system-level performances. More specifically, utilizing both a large scale path loss and a small scale fading channel model, the primary objective is to explore the tradeoff between the coverage and the achievable rate of the overlaid service and, finally, to determine the achievable rate in the overlaid service for marginal coverage reduction in the existing broadcast service. The analytical and simulation results show that an SS-based add-on service of 10 kbps to 20 kbps can co-exist with the T-DMB service while resulting in only a marginal degradation in T-DMB coverage (for example, less than one percent reduction).

• Broadcasting and Media Magazine
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• v.20 no.4
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• pp.67-73
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• 2015

2016년 하반기까지 표준화 완료를 목표로 표준화 논의가 진행 중인 북미 차세대 지상파 방송시스템 규격인 ATSC3.0 지상파 방송시스템 표준은 UHD기반 실감형 방송, 모바일 HD 방송을 RF 6MHz대역 한 채널내에서 서비스제공이 가능하며, IP통신망과 연동하여 방송통신 융합형 실감방송시스템 제공이 가능한 지상파 방송기술 표준화를 지향하고 있다. 본고에서는 차세대 북미지상파 방송방식인 ATSC3.0에서 표준화가 진행되고 있는 실감형 초고화질 3DTV 서비스 규격인 ATSC3.0 고정/이동방송 융합형 UHD 표준화 동향에 대하여 기술하고자 한다.

• Journal of electromagnetic engineering and science
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• v.1 no.2
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• pp.131-138
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• 2001

The DTV (Digital TV) tuner for an 8-VSB (Vestigial Side-Band) modulation was developed to meet the requirements of the ATSC (Advanced Television Systems Committee). The double frequency conversion and the active tracking filter in the front-end were used to cancel interferences between adjacent channels and multi-channels by suppressing the IF beat and the Image frequency. However, It was impossible to get frequency mapping between the tracking filter and the first VCO (Voltage Controlled Oscillator) in the existing DTV tuner structure which differs from the NTSC (National Television Systems Committee) tuner. This paper, therefore, suggests an assailable structure and a new method for the automatic frequency selection by mapping the frequency characteristics over the tracking voltage and the combined HW which is composed of a Micro-controller, an EEPROM (Electrically Erasable Programmable Read Only Memory), a DAC (Digital-to-Analog Converter), an OP amplifier, and a switch driver.

• Electronics and Telecommunications Trends
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• v.21 no.4 s.100
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• pp.52-61
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• 2006

전자 통신 및 방송 기술의 눈부신 발전에 힘입어 디지털방송 시대가 도래하였다. 디지털방송은 보다 선명한 HD급의 화면을 수신자에게 제공할 수 있다는 장점뿐 아니라, 영상물들에 대한 보관, 편집, 배포 과정에 있어서도 아날로그 방송과는 비교가 되지 않을 정도의 편리성을 가지고 있다. 그러나, 이러한 디지털방송 기술의 발달과 더불어, 디지털 미디어에 대한 저장 기술의 발달과 컴퓨터 기술의 발달은 그에 따른 부작용을 야기시키고 있다. 암호화되지 않은 상태로 전송되는 디지털방송 콘텐츠는 PVR 또는 셋톱박스나 TV 수신카드가 탑재되어 있는 개인용 컴퓨터를 통해, 원본과 동일한 화질의 콘텐츠를 무제한적으로 복사 또는 배포하는 것이 가능하게 되었다. 본 원고에서는 디지털방송 콘텐츠 저작권 보호와 관련하여, 최근 이슈로 대두되고 있는 Broadcast Flag의 개념 및 관련 저작권 보호기술 요소, 그리고 이를 이용한 콘텐츠 재분배 제어 기술에 대해서 살펴본다. 마지막으로 Broadcast Flag가 실제 법제화 되었을 경우, 여러 이익단체 및 사용자에 미칠 영향과 앞으로의 전망에 대해서 살펴본다.

• Broadcasting and Media Magazine
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• v.7 no.2
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• pp.4-11
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• 2002

지난 96년 7월 국내 최초로 위성 디지털 시험방송을 시작한 KBS는 2001년 12월에 한국디지털위성방송 컨소시움인 스카이라이프에 참여하여 서비스를 제공하고 있으며, 지상파방송에서도 1년여 기간동안의 시험방송을 끝으로 2001년 11월부터 디지털 본방송을 실시하고 있다. 이러한 디지털방송 시대를 준비하는 과정의 일환으로 KBS 기술연구소에서는 98년 디지털 위성방송의 송출 및 수신상태 및 스트림의 이상 유무를 모니터링 할 수 있는 위성방송용 모니터링시스템을 개발하였으며, 지난 2000년에는 지상파 디지털방송을 모니터링 할 수 있는 지상파 DTV 방송용 모니터링 시스템을 개발하였다. 이 두 가지 시스템은 앞으로 본격화될 디지털방송 시대에 크게 기여할 것이다. 본 고에서는 지상파 디지털방송 모니터링 시스템의 특징과 기능에 대해서 서술하였다.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.350-364
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• 2008

Single frequency network (SFN) design based on the Advanced Television Systems Committee (ATSC) specification, a terrestrial digital television (DTV) system, normally causes a interference problem, among signals from multiple transmitters or repeaters. To solve this, the ATSC recommended practice (RP) introduces a transmitter identification (TxID) signal embedded in a signal from each transmitter or repeater. A TxID signal analyzer is then used to detect the TxID signal, and following the analysis results, a SFN design can be adjusted. This paper discusses the generation and usages of Kasami sequence, is used the TxID signal. The configuration of the TxID signal analyzer to efficiently detect TxID signal is proposed and the results of theoretical performance analysis are provided. Moreover, computer simulation and laboratory test results are provided to evaluate the performance of TxID signal analyzer and the theoretical performance analysis.

• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.463-478
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• 2008

A Distributed Translator Network(DTxR) is a cost-effective and frequency-effective method which can use existing transmission utilities and can be constructed in a shorter time as compared with Multiple Frequency Network(MFN) or Single Frequency Network(SFN) using On Channel Repeater(OCR). In order to verify the feasibility of DTxR, this field test was done in 30 points of north-west area in Seoul using 3rd, 5th, and 6th generation DIV receivers. Electric field strength, noise margin and ease of reception were measured and subjective evaluation of video quality was done in these points during the field test. With the test result, an improvement of receiving quality was obtained and an ease of reception was increased in case of the 5th. and 6th. receiver. From the results, we conclude that DTxR is a feasible method in DIV networks.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.540-546
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• 2010

Since the stereoscopic 3-dimensional (3D) video that provides users with a realistic multimedia service requires twice as much data as 2-dimensional (2D) video, it is difficult to construct the fast system. In this paper, we propose a fast stereoscopic 3D broadcasting system based on the depth information. Before the transmission, we encode the input 2D+depth video using x264, an open source H.264/AVC fast encoder to reduce the size of the data. At the receiver, we decode the transmitted bitstream in real time using a compute unified device architecture (CUDA) video decoder API on NVIDIA graphics processing unit (GPU). Then, we apply a fast view synthesis method that generates the virtual view using GPU. The proposed system can display the output video in both 2DTV and 3DTV. From the experiment, we verified that the proposed system can service the stereoscopic 3D contents in 24 frames per second at most.

• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.128-135
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• 2017

In this paper, the changes of broadcasting loudness before and after are measured for the major broadcasting channels according to the amendment of broadcasting law and enforcement of digital television broadcasting loudness technology standards. Before the implementation of digital television broadcasting loudness technology standards. all the channels to be measured were broadcast at a higher volume level than the technical standards. However, after the implementation, most of the channels to be measured were maintained at a loudness level suitable for the technical standards. However, some programs are inadequate to meet technical standards, requiring corrective action, and the need for additional research to improve the measurement method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1522-1536
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• 2011

Due to the advance of broadband communication networks including the Internet, the release of diverse media, and the busy life cycle of modern people, it became difficult to watch TV programs strictly according to the program schedule. Instead, demand to download and watch the programs at any time on TV is increasing. In order to meet the demand, terrestrial DTV broadcasters developed a TV service which provides various on-demand contents by integrating terrestrial DTV network and the Internet without enforcing viewers to subscribe broadcasting services such as IPTV or CableTV, and standardized it as OHTV(Open Hybrid TV). In this paper, we explain the current status of OHTV standard and worldwide hybrid TV services and their technical standards. We also provide a strategy for the next version of OHTV standard in order to enhance the value of OHTV.