• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.834-845
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• 2011

Massive broadcasting contents such as UHD(Ultra High Definition) TV which requires multi-channel capacity for transmission has been introduced in recent years. A transmission scheme with channel bonding has been considered for transmission of massive broadcasting contents. In HFC(Hybrid Fiber Coaxial) networks, DOCSIS 3.0(Data Over Cable Service Interface Specification 3.0) has already applied channel bonding schemes for up/downstream of data service. A method unlike DOCSIS 3.0 is required to introduce a channel bonding scheme in the broadcasting service having unidirectional transmission with a downstream. Since a massive broadcasting content requires several channels for transmission, VBR(Variable Bit Rate) transmission has been emerging for the bandwidth efficiency. In addition, research on channel allocation and resource scheduling is required to guarantee QoS(Quality of Service) for the broadcasting service based on VBR. In this paper, we propose a transmission method for mass broadcasting service in HFC network and show the UHD transmission simulator developed to evaluate the performance. In order to evaluate the performance, we define various scenarios. Using the simulator, we assess the possibility of channel bonding and VBR transmission for UHD broadcasting system to provide mass broadcasting service efficiently. The developed simulator is expected to contribute to the efficient transmission system development of mass broadcasting service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2C
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• pp.150-159
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• 2002

This paper presents the convergence time, SER(Symbol Error Rate), MSE(Mean Square Error), hardware complexity and step-size(${\mu}$) about various LMS(Least Mean Square) algorithms in FS-DFE(Fractionally Spaced-Decision Feedback Equalize) for Cable Modem based on MCNS(Multimedia Cable Network System) DOCSIS(Data Over Cable Service Interface Specification) v1.0/v1.1 standards. We designed and simulated using ${SPW}^{TM}$ and synthesized using STD90 library through ${SYNOPSYS}^{TM}$. And also, we adopted the time-multiplexed multiplication and tap shared architecture in order to achieve the low hardware complexity. Simulation results show that DS-LMS algorithms[1][3] is the optimum solution about performace and hardware size. in high order QAM applications. Finally, we achieved area saving about 58% using DS-LMS algorithm compare with conventional equalizer architecture.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.1-11
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• 2005

S-CDMA is the advanced physical layer modulation techniques of DOCSIS 2.0 specification. S-DMT is another challenging modulation technique for cable modem upstream channel due to the intrinsic robustness for fading and impulse noise. The BER performance of S-DMT and S-CDMA over the mixed channel model of AWGN and impulse noise were evaluated in comparison with TDMA. The mathematical BER derivation and the comparison of those three types of technique were performed based on the ${\varepsilon}-mixture$ non-Gaussian impulse noise model. The results of simulation show good compliance with those of analytic BER derivation. By the results of comparisons, it was verified that the performance of S-CDMA and S-DMT is almost the same, but the performance of S-DMT is far superior to that of TDMA at typical BER range of the practical data communications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.638-642
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• 2007

본 논문에서는 방송/통신 융합을 위한 차세대 기가급 케이블 전송 시스템으로서 디지털방송의 화두가 되고 있는 DOCSIS 3.0 고속데이터전송 시스템의 기술 및 동향에 관하여 분석하고 상향변조 기가급 케이블 전송 시스템 구현을 위해 가변 부호율을 제공하는 RS 인코더를 설계하였다. 본 논문에서 구현한 RS 인코더는 VHDL을 이용하여 설계하였고 ModelSim Tool을 이용한 시뮬레이션 분석을 통하여 동작을 검증하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.320-321
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• 2011

본 논문은 디지털 케이블전송망인 HFC(Hybrid Fiber and Coaxial)망 기반하에서 6MHz 다수의 방송채널결합 기술을 이용하여, 대용량 3D 및 8K-UHD 콘텐츠 전송을 위한 방송망 채널결합형 200Mbps 급 1024-QAM 송수신시스템 개발에 대하여 기술한다. H.264 비디오 부호화기를 사용하여 8K-UHDTV 및 3D/UHD 융합형 서비스를 시청자에게 제공하기 위해서는 약 120~160Mbps 의 대용량 데이터 전송률이 확보되어야 한다. 이와같이 대용량 3D/8K-UHDTV 콘텐츠를 전송하기 위해서는 상대적으로 채널환경이 우수한 HFC 디지털 케이블망을 이용한 대용량 실감미디어 콘텐츠 전송기법에 대한 연구가 주목 받고 있다. 본 논문에서는 FPGA 를 이용하여 HFC 망 기반에서 기존 OpenCalbe/DOCSIS 3.0 256-QAM 대비 약 30% 전송효율이 개선된 3D/8K-UHDTV 대용량 실감미디어 콘텐츠 전송을 위한 방송망 채널결합형 1024-QAM 송수신기 구현 및 개발에 관한 내용을 기술한다.