• Title/Summary/Keyword: 8VSB (8-Vestigial sideband)

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지상파 DTV 방송을 위한 채널환경분석 성능향상 기법

  • Lee, Jae-Gwon;Kim, Jeong-Hyeon;Gyeong, Il-Su
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2012.11a
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    • pp.228-229
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    • 2012
  • ATSC 지상파 DTV 방송은 8-VSB(Vestigial Sideband Modulation) 기반 단일 반송파 전송방식을 사용하기 때문에, 다중 경로에 의한 간섭에 취약한 단점이 있다. 다중경로에 의한 간섭은 DTV 수신기의 수신 성능을 열화시키기 때문에, 이러한 간섭을 효율적으로 등화하거나 또는 최소화되도록 방송망을 설계하는 것이 중요하다. 본 논문에서는 ATSC 지상파 DTV 방송 시스템에서 다중경로에 의한 간섭을 효율적으로 측정하는 방법을 제안하고, 모의실험을 통해 제안된 방법의 성능을 검증하고자 한다.

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Blind Equalization of Digital Television Broadcasting Signals in Dynamic Multipath Channels (다이내믹 다중경로 채널에서의 디지털 텔레비전 방송 신호에 대한 블라인드 등화)

  • 오길남
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.269-274
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    • 2004
  • In this paper, proposed is the dual-mode algorithm of blind decision feedback equalizer (DFE) for digital terrestrial television signals. According to channel impairments, the proposed dual-mode algorithm for blind DFE operates in decision-directed mode or in blind mode of operation. The error signals being used in tap update of the equalizer are generated in the best mode of operations, so that the confidence of equalizer tap coefficient update is more accurate. As a result, it is possible to track the channel characteristics variations by automatic switching over between two modes of operations. For 8-level vestigial sideband modulated digital television signals, the mean square errors and symbol error rates of the proposed algorithm are compared with those of conventional methods. And the usability of the proposed scheme is assessed by computer simulations under various static and dynamic multipath channel environments.

Implementation and Evaluation of the 100 Watt High Power Amplifier for Broadband Digital TV Repeater (광대역 디지털TV 중계기용 100 Watt 고출력증폭기의 구현 및 특성 측정에 관한 연구)

  • Sung, Jeon-Joong
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.5
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    • pp.575-582
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    • 2007
  • In this paper, a 100 Watt high power amplifier has been implemented and performed evaluation, which is operating at UHF band ($470\;{\sim}\;806\;MHz$) for Digital TV repeater. To achieve increase of bandwidth and high power capability, 3-way power combiner and divider of Wilkinson type was adopted. In order to measure the fabricated 100 Watt power amplifier, the estimation technique function which makes equivalent mask was used. As a result of the measurement, the existence of pilot signal is confirmed and the signal transmitted at the rated output power 100 Watt is brought out the flat feature through 6 MHz bandwidth. and it resulted that its value was less than -47 dB at the edge of radiation channel and less than -110 dB at more than 6 MHz position from channel edge.

A Design of Adaptive Equalizer for Terrestrial Digital Television Receivers (지상파 디지털 TV 수신기의 적응등화기 설계)

  • 정진희;김정진;권용식;장용덕;정해주
    • Journal of Broadcast Engineering
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    • v.8 no.2
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    • pp.153-162
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    • 2003
  • This paper describes a structure of adaptive equalizer to improve reception performance of ATSC digital television (DTV) for 8-VSB receivers. There are many strong and dynamic echoes affecting reliable reception of DTV signal. Conventional DFE based least mean square (LMS) algorithm is readily implemented and has good Performance. There are still problems to be solved, however, in handling strong echoes and indoor reception. In this paper, structure of adaptive equalizer to mitigate these Problems in strong multipath interference conditions and indoor reception environment is first presented. Methods to reduce error propagation effects on DFE and initialization scheme of filter coefficients for fast convergence are then introduced. Computer simulation results prove that an adaptive equalizer with proposed design methods can combat with Brazil Ensemble and the Threshold of Visibility(TOV) is improved.

Improved Channel Profile Measurement Technique for ATSC Terrestrial DTV System (향상된 지상파 DTV 채널 프로파일 측정기술)

  • Lee, Jaekwon;Jeon, Sung-Ho;Kim, Jung-Hyun;Suh, Young-Woo;Kyung, Il-Soo
    • Journal of Broadcast Engineering
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    • v.18 no.3
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    • pp.435-444
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    • 2013
  • ATSC terrestrial DTV system can support high data rates for HDTV(High Definition Television) service, but it suffers from significant performance degradation caused by multipath fading. Thus, it is necessary to analyze multipath fading effects in order to enhance the DTV reception performance. Generally, DTV channel profile can be obtained by auto-correlation between reference pseudo random signal and received DTV signal. However, in the ATSC terrestrial DTV system, the estimation performance of DTV channel profile may be decreased due to the VSB modulation features. In this paper, improved DTV channel profile measurement technique is analyzed and proposed.

A study on the digital carrier recovery loop with adaptive loop bandwidth (적응 루프 대역폭을 가진 디지털 반송파 동기 루프에 관한 연구)

  • 한동석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.8
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    • pp.1774-1781
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    • 1997
  • In this paper, we propose a full digital frequency and phase locked loop for CATV and HDTV receivers adopting VSB modulation. The CATV and HDTV receivers proposed by the Grand-Alliance in USA are ultilizing analog signal processing technology for carrier recovery. By the way, it is not a good architecture for the development of single chip ASIC operating in digital domain. To solve this problem while improving the performance, we first down convert the received r.f. signal to a near baseband signal for a low-rate AD converter and then we use digital signal processing techniques. The proposed system has the frequency pull-in range of -200 KHz +2.50 KHz. Moreover, it has the ability of adaptive loop bandwidth control according to the amount of frequency offset to improve the acquisition time while reducing the phase noise.

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