• Title/Summary/Keyword: feed-forward equalizer

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A Continuous-time Equalizer adopting a Clock Loss Tracking Technique for Digital Display Interface(DDI) (클록 손실 측정 기법을 이용한 DDI용 연속 시간 이퀄라이저)

  • Kim, Kyu-Young;Kim, Gil-Su;Shon, Kwan-Su;Kim, Soo-Won
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.2
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    • pp.28-33
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    • 2008
  • This paper presents a continuous-time equalizer adopting a clock loss tracking technique for digital display interface. This technique uses bottom hold circuit to detect the incoming clock loss. The generated loss signal is directly fed to equalizer filters, building adaptive feed-forward loops which contribute the stability of the system. The design was done in $0.18{\mu}m$ CMOS technology. Experimental results summarize that eye-width of minimum 0.7UI is achieved until -33dB channel loss at 1.65Gbps. The average power consumption of the equalizer is a maximum 10mW, a very low value in comparison to those of previous researches, and the effective area is $0.127mm^2$.

Decision Feedback Algorithms using Recursive Estimation of Error Distribution Distance (오차분포거리의 반복적 계산에 의한 결정궤환 알고리듬)

  • Kim, Namyong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.5
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    • pp.3434-3439
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    • 2015
  • As a criterion of information theoretic learning, the Euclidean distance (ED) of two error probability distribution functions (minimum ED of error, MEDE) has been adopted in nonlinear (decision feedback, DF) supervised equalizer algorithms and has shown significantly improved performance in severe channel distortion and impulsive noise environments. However, the MEDE-DF algorithm has the problem of heavy computational complexity. In this paper, the recursive ED for MEDE-DF algorithm is derived first, and then the feed-forward and feedback section gradients for weight update are estimated recursively. To prove the effectiveness of the recursive gradient estimation for the MEDE-DF algorithm, the number of multiplications are compared and MSE performance in impulsive noise and underwater communication environments is compared through computer simulation. The ratio of the number of multiplications between the proposed DF and the conventional MEDE-DF algorithm is revealed to be $2(9N+4):2(3N^2+3N)$ for the sample size N with the same MSE learning performance in the impulsive noise and underwater channel environment.

Forward Osmotic Pressure-Free (△𝜋≤0) Reverse Osmosis and Osmotic Pressure Approximation of Concentrated NaCl Solutions (정삼투-무삼투압차(△𝜋≤0) 법 역삼투 해수 담수화 및 고농도 NaCl 용액의 삼투압 근사식)

  • Chang, Ho Nam;Choi, Kyung-Rok;Jung, Kwonsu;Park, Gwon Woo;Kim, Yeu-Chun;Suh, Charles;Kim, Nakjong;Kim, Do Hyun;Kim, Beom Su;Kim, Han Min;Chang, Yoon-Seok;Kim, Nam Uk;Kim, In Ho;Kim, Kunwoo;Lee, Habit;Qiang, Fei
    • Membrane Journal
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    • v.32 no.4
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    • pp.235-252
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    • 2022
  • Forward osmotic pressure-free reverse osmosis (Δ𝜋=0 RO) was invented in 2013. The first patent (US 9,950,297 B2) was registered on April 18, 2018. The "Osmotic Pressure of Concentrated Solutions" in JACS (1908) by G.N. Lewis of MIT was used for the estimation. The Chang's RO system differs from conventional RO (C-RO) in that two-chamber system of osmotic pressure equalizer and a low-pressure RO system while C-RO is based on a single chamber. Chang claimed that all aqueous solutions, including salt water, regardless of its osmotic pressure can be separated into water and salt. The second patent (US 10.953.367B2, March 23, 2021) showed that a low-pressure reverse osmosis is possible for 3.0% input at Δ𝜋 of 10 to 12 bar. Singularity ZERO reverse osmosis from his third patent (Korea patent 10-22322755, US-PCT/KR202003595) for a 3.0% NaCl input, 50% more water recovery, use of 1/3 RO membrane area, and 1/5th of theoretical energy. These numbers come from Chang's laboratory experiments and theoretical analysis. Relative residence time (RRT) of feed and OE chambers makes Δ𝜋 to zero or negative by recycling enriched feed flow. The construction cost by S-ZERO was estimated to be around 50~60% of the current RO system.