• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12C
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• pp.997-1005
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• 2008

In this paper, we proposed advanced T-DMB system which is based on Eureka-147 using UEP coding methods and hiererchical modulation for providing additional services while maintaining BER performance. We simulated the proposed advanced T-DMB system using unequal l6QAM modulation scheme combined with various bit split methods and coding methods such as double binary turbo code of DVB-RCS standard and LDPC code of DVB-S2 standard. In the simulation results, double binary turbo code and LDPC code of proposed advanced T-DMB system have coding gain of 2dB and 3.5dB compared to conventional T-DMB system respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.629-636
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• 2011

This paper presents the design of a novel integrated T-DMB/GPS/Mobile antenna for vehicular application. The T-DMB antenna is designed with a modified meander-type microstrip patch providing linearly a polarized broadside radiation pattern. The GPS antenna is designed with an inserted slot in the patch antenna providing circularly polarized broadside radiation pattern. The Mobile (GSM, AMPS, DCS, PCS, UMTS, etc.) antenna is designed as a modified G-type patch antenna providing multi-band operation. Experimental results indicate that the impedance bandwidth (VSWR 1:2.5) of the proposed T-DMB /GPS/Mobile antenna satisfactorily matches that of the simulation results. The 2D and 3D radiation patterns and gains according to the results of the experiment are also presented and discussed.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.146-150
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• 2017

In OFDM system, the out-of-band radiation of ensemble interferes with the adjacent ensemble and result in the reduction of receiving performance. So the reduction scheme of out-of-band radiation is very important. In this paper, a time-domain windowing method to reduce the out-of-band radiation is considered to DAB systems. We adopt the considered method to T-DMB(DAB mode-1) and AT-DMB Systems, and we get about 3-dB gains of out-of-band radiation. And also we show that the considered method doesn't reduce the BER performance.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.123-125
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• 2010

3D 영화의 상업적 성공으로 인하여, 기존 컨텐츠와 차별화된 고품질 컨텐츠에 대한 사용자의 요구가 증대되고 있다. 하지만, 방송의 특성상 기존 방송망을 유지하면서 새로운 컨텐츠를 제공하기 위해서는 각 매체별 채널 용량 증대에 대한 기술 개발이 선행되어야 한다. 최근에 지상파 DMB 방송과 동일한 주파수 영역 내에서 채널 용량을 증대시킬 수 있는 차세대 지상파 DMB (advanced t-dmb, AT-DMB)와 관련된 국내 표준화가 완료 되었다. 이에 본 논문은 T-DMB와의 역호환성을 유지하면서도 추가 서비스를 제공할 수 있는 AT-DMB 시스템을 간단히 소개하고, 수신기 개발 시 고려해야 할 T-DMB 전송프레임과 AT-DMB 전송 프레임의 차이점과 구조에 대해서 논한다. 특히 추가서비스를 제공 할 수 있는 수신 플랫폼의 설계 방법을 제안한다. 마지막으로, AT-DMB 송출 환경에서 제안된 수신 플랫폼 처리 방법에 따른 수신 테스트 및 성능을 검증하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.7
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• pp.664-672
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• 2009

In this paper we propose an on-glass antenna which consists of conducting dual center striplines and multi-loaded striplines. Multi-loaded striplines and dual center lines were employed for achieving a broad matching bandwidth and improving a vertical radiation gain, respectively. The detail design parameters were determined using the Pareto genetic algorithm with an full wave EM simulator. The optimized design was built and installed on a commercial vehicle, and the antenna performances such as the return loss and the radiation gain were measured in a semi-anechoic chamber. The measurement results showed the matching bandwidth($S_{11}$<-3 dB) of about 49 % in the T-DMB frequency band, the vertical gain of about -3 dBi along the bore-sight direction, and the average gain of about -10 dBi along the azimuth direction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.173-179
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• 2012

In this study, cavity filter performing BPF function in Korea T-DMB system was designed by using of HFSS simulation tool, and we compared measured results with the simulated data. By simulation of HFSS that is magnetic and electric 3D simulating tool, we can save time and money maximumly by checking performances before actual filter implementation. Optimum conditions for the cavity filter were delivered based on the cylindrical waveguide characteristics. Measured results by implementation were compared with the simulation data.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.75-77
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• 2009

깊이 영상 기반 렌더링(DIBR) 방법은 제한된 대역폭을 가진 지상파 DMB(T-DMB)환경에서의 3 차원 서비스를 위한 방법으로 연구되고 있다. T-DMB 환경에서의 DIBR 기반의 3 차원 서비스는 기준 영상과 깊이 영상을 전송 받아 가상의 좌/우 시점 영상을 생성한다. 가상의 좌/우 시점 영상을 생성하기 위해서는 콘텐츠와 디스플레이 환경에 따른 파라미터 값이 주어져야 한다. 하지만 많은 연구에서 표준화된 파라미터 값을 제시하지 않음으로써 렌더링의 기준이 모호해지고, 임의로 정해진 파라미터 값에 의해 DIBR 결과가 크게 달라진다. 또한 콘텐츠에 따른 파라미터 값을 임의로 설정하게 되면 추가적인 정보를 전송해야 하는 문제점이 발생한다. 이에 본 논문에서는 다양한 콘텐츠에 적용 가능하면서도 T-DMB 환경에 적합하도록 계산량을 줄일 수 있는 표준화된 파라미터 설정 방법을 제안하고자 한다.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.565-573
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• 2008

This paper proposes noise reduction methods to improve the channel estimation performance in Equalization On-Channel Repeater (E-OCR) for Terrestrial-Digital Multimedia Broadcasting (T-DMB) system. In the E-OCR for T-DMB system, the channel estimation is performed by the pilot signal extraction and the channel coefficient estimation. Since the performance of the channel estimation highly depends on the estimated channel coefficients whose accuracy is associated with the received signal-to-noise ratio (SNR), it is important to reduce noise existing at the estimated channel coefficients. To reduce such noise components, various noise reduction methods of the estimated channel coefficients based on the M -point weighted moving average are proposed. Computer simulations show that the proposed methods improve the estimation performance by more than 2 to 3 dB in terms of the symbol error rate after equalization.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.4
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• pp.443-451
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• 2010

This paper describes a fully integrated CMOS low-IF mobile-TV RF tuner for Band-III T-DMB/DAB applications. All functional blocks such as low noise amplifier, mixers, variable gain amplifiers, channel filter, phase locked loop, voltage controlled oscillator and PLL loop filter are integrated. The gain of LNA can be controlled from -10 dB to +15 dB with 4-step resolutions. This provides a high signal-to-noise ratio and high linearity performance at a certain power level of RF input because LNA has a small gain variance. For further improving the linearity and noise performance we have proposed the RF VGA exploiting Schmoock's technique and the mixer with current bleeding, which injects directly the charges to the transconductance stage. The chip is fabricated in a 0.18 um mixed signal CMOS process. The measured gain range of the receiver is -25~+88 dB, the overall noise figure(NF) is 4.02~5.13 dB over the whole T-DMB band of 174~240 MHz, and the measured IIP3 is +2.3 dBm at low gain mode. The tuner rejects the image signal over maximum 63.4 dB. The power consumption is 54 mW at 1.8 V supply voltage. The chip area is $3.0{\times}2.5mm^2$.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.153-156
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• 2006

본 논문에서는 T-DMB 수신기의 채널추정 성능향상을 위한 잡음감소 기법을 제안한다. 일반적으로 T-DMB 수신기에서의 채널추정은 파일럿 신호 추출과 채널계수 추정에 의해 수행된다. 채널추정의 성능은 수신 SNR (Signal to Noise Ratio)과 연관되어 추정된 채널계수에 남아있는 잡음성분에 의해 결정되기 때문에, 잔존하는 잡음성분을 감소시키는 것은 매우 중요하다. 이러한 잡음성분을 감소시키기 위해, M-point 가중이동평균(weighted moving average)을 기반으로 한 잡음제거 기법을 제안한다. 전산 실험에 의하면, 제안된 방법은 등화 후 SER (Symbol Error Rate) 측면에서 기존의 방법에 비해 2-3 dB의 성능 향상을 보인다.