• Title/Summary/Keyword: TDL

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Performance Evaluation of Adaptive Equalizer in Mobile Communication Fading Channel (이동 통신 페이딩 채널에서 적응 등화기의 성능 평가)

  • 금홍식
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1992.06a
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    • pp.76-80
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    • 1992
  • We consider the tapped-delay line (TDL) equalizer with the few calculation quantity and the simplity, the decision feedback equalizer (DFE) with the good property for interference, and lattice equalizer(LE) with high insensitivity to roundoff noise in mobile communication fading channel. The used adaptive algorithm is the LMS algorithm and RLS algorithm. In this paper, we have evaluated the performance of the TDL equalizer, the decision feedback equalizer, and lattice-structured equalizer, for the digital signal corrupted by the impulsive noise and the white gaussian noise under the fading channel environment. From the results of error performance analysis, it is confirmed that lattice-structured equalizer has better performance than DFE equalizer and TDL equalizer.

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Optimum BPF Bandwidth of Noncoherent Tau-Dither Loops for PN Code Tracking (PN부호의 동기추적을 위한 비코히어런트 TDL에서 최적의 BPF 대역폭)

  • 송문규;최흥택;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.8
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    • pp.1421-1432
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    • 1994
  • The optimum design and performance of noncoherent TDL considering the effect of distortions due to the IF bandpasss filters are described. NRZ data and ideal filter is presumed in the simulation. The optimum filter bandwidth is calculated in the sense of minimizing the loop's squaring loss, which is equivalent to minimizing the loop's tracking jitter for a given data rate and data signal-to-noise ratio. As a result, the optimum filter bandwidth depends on the signal-to-noise ratio, and is obtained in the range of about 1-2 times of the data rate.

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A Stereophonic Acoustic Echo Canceller Based on a Multi-channel Lattice Predictor (Multi-channel Lattice Predictor를 이용한 효율적인 스테레오 음향 반향 제거기)

  • Lee Ji Hoon;Park Youngcheol
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.261-264
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    • 2004
  • 본 논문에서 는 muti-channel lattice 예측기를 사용하여 AP(affine projection) 알고리듬을 근사적으로 구현하는 알고리즘을 제안한다. Lattice 예측기의 예측 오차를 사용하여 TDL 필터 계수를 적응적으로 조정함으로써 AP 알고리듬을 근사화한다. 또한 전처리단으로 사용된 lattice 예측기를 TDL 필터와 결합함으로써 기존의 방법보다 계산량을 더욱 줄일 수 있는 알고리듬을 제안한다. 제안된 알고리즘은 기존의 알고리즘보다 적은 계산량을 필요로 하지 만 AP 알고리즘을 보다 근사적으로 구현할 수 있다는 장점이 있다.

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Development of realized contest spinning experience system (실감 경연형 스피닝 체험 시스템 개발)

  • Joo, Jae-Hong;Yang, Yong-Dae;Jeong, Dae-Ryong;Kim, Yu-Sin
    • Proceedings of the Korea Contents Association Conference
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    • 2015.05a
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    • pp.443-444
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    • 2015
  • 본 연구에서는 GX 프로그램의 하나인 스피닝 운동을 모델로 사용자의 골격을 추적하여 강사 아바타와의 동작 일치율을 판단하고, 스피닝 운동 중 감성을 분석하여 사용자에게 맞춤형 운동을 추천한다. 또한 현장감과 몰입감 증대를 위해 바람, 조명, 진동 등 다양한 실감효과를 제공하는 스포테인먼트 스피닝 시스템을 개발하고, 가정에서 원격지의 사용자와의 경연 서비스를 제공할 수 있는 실감 체험형 시스템을 제안한다.

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A Novel Equivalent Wiener-Hopf Equation with TDL coefficient in Lattice Structure

  • Cho, Ju-Phil;Ahn, Bong-Man;Hwang, Jee-Won
    • Journal of information and communication convergence engineering
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    • v.9 no.5
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    • pp.500-504
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    • 2011
  • In this paper, we propose an equivalent Wiener-Hopf equation. The proposed algorithm can obtain the weight vector of a TDL(tapped-delay-line) filter and the error simultaneously if the inputs are orthogonal to each other. The equivalent Wiener-Hopf equation was analyzed theoretically based on the MMSE(minimum mean square error) method. The results present that the proposed algorithm is equivalent to original Wiener-Hopf equation. The new algorithm was applied into the identification of an unknown system for evaluating the performance of the proposed method. We compared the Wiener-Hopf solution with the equivalent Wiener-Hopf solution. The simulation results were similar to those obtained in the theoretical analysis. In conclusion, our method can find the coefficient of the TDL (tapped-delay-line) filter where a lattice filter is used, and also when the process of Gram-Schmidt orthogonalization is used. Furthermore, a new cost function is suggested which may facilitate research in the adaptive signal processing area.

Design of 4-Bit TDL(True-Time Delay Line) for Elimination of Beam-Squint in Wide Band Phased-Array Antenna (광대역 위상 배열 안테나의 빔 편이(Beam-Squint) 현상 제거를 위한 4-Bit 시간 지연기 설계)

  • Kim, Sang-Keun;Chong, Min-Kil;Kim, Su-Bum;Na, Hyung-Gi;Kim, Se-Young;Sung, Jin-Bong;Baik, Seung-Hun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.10
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    • pp.1061-1070
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    • 2009
  • In this paper, we have designed TDL(True-time Delay Line) for eliminating beam-squint occurring in active phased array antenna with large electrical size operated in wide bandwidth, and have tested its electrical performance. The proposed TDL device is composed of 4-bit microstrip delay line structure and MMIC amplifier for compensation of the delay-line loss. The measured results of gain and phase versus delay state satisfy the electrical requirements, also P1dB output power and noise figure meet the requirement. To verify the performance of fabricated TDL, we have simulated the beam patterns of wide-band active phased array antenna using the measured results and have certified the beam pattern compensation performance. As a result of simulated beam pattern compensation with respect to the 675.8 mm size antenna which is operated in X-band, 800 MHz bandwidth, we have reduced the beam squint error of ${\pm}1^{\circ}$ with ${\pm}0.1^{\circ}$. So this TDL module is able to be applied to active phase array antenna system.

A study on measurement of oxygen in a reheating furnace using TDLAS (가열로에서 TDLAS를 이용한 각대산소농도측정에 관한 연구)

  • Kim, Young-Il;Kim, Ki-Hong;Lee, In-Bum
    • 한국연소학회:학술대회논문집
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    • 2006.10a
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    • pp.160-167
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    • 2006
  • In this project, we studied more accurate and reliable sensing method for oxygen in reheating furnace, made the empirical model for NOx concentration based on oxygen and evaluate the stability of the Tuneable Diode Laser (Absorption) Spectroscopy(TDL(A)S). The tested oxygen monitoring system is installed at work-field reheating furnace on hot roll at POSCO and compared with the Zr sensor system which shows too sensitive because it measures oxygen concentration on a spot unlike TDLS sensor which is successfully applied at 13m-width reheating furnace to measures the line average along the Optical Path Line(OPL).

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MMSE based Wiener-Hopf Equation

  • Cho, Juphil;Lee, Il Kyu;Cha, Jae Sang
    • International Journal of Internet, Broadcasting and Communication
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    • v.4 no.1
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    • pp.18-22
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    • 2012
  • In this paper, we propose an equivalent Wiener-Hopf equation. The proposed algorithm can obtain the weight vector of a TDL(tapped-delay-line) filter and the error simultaneously if the inputs are orthogonal to each other. The equivalent Wiener-Hopf equation was analyzed theoretically based on the MMSE(minimum mean square error) method. The results present that the proposed algorithm is equivalent to original Wiener-Hopf equation. In conclusion, our method can find the coefficient of the TDL (tapped-delay-line) filter where a lattice filter is used, and also when the process of Gram-Schmidt orthogonalization is used. Furthermore, a new cost function is suggested which may facilitate research in the adaptive signal processing area.

Adaptive Echo Canceller with Improved Convergence Speed (적응 반향 제거기의 수렴 속도 향상)

  • 김남선;임용훈;임종민;차일환;윤대희
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1991.10a
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    • pp.111-114
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    • 1991
  • This paper proposes an efficient adaptive echo canceller using pilot filter approach to achieve improved convergence speed. The pilot filter is an adaptive filter with only a few filter coefficients to filter the received signal for the purpose of whitening the signal. Thus the convergence speed of the main LMS-TDL filter combined with the pilot filter is improved. In the proposed echo canceller, an adaptive lattice predictor as the pilot filter is used and its inverse filter is used to equalize the distorted near end talker signal. Simulation results for colored signal show that the convergence speed of the proposed echo cancellation algorithm is faster than that of the conventional LMS-TDL echo cancellation algorithm.