• Title/Summary/Keyword: Pulse Canceller

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Clutter Suppression Method for Altitude and Mainlobe Clutter In Moving Platform Radar (이동 플랫폼 레이더에서 고도 클러터와 주엽 클러터 억제 기법)

  • Jeon, Hyeonmu;Bae, Chang-sik;Yang, Hoon-gee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.10
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    • pp.1386-1391
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    • 2018
  • The radar in the moving platform is interfered by the mainlobe clutter as well as the altitude clutter that is received from sidelobe. The altitude clutter is relatively short range compared to mainlobe clutter and therefore enters the radar with a strong signal. As these clutters are major reason making the probability of false alarm high, it is required to suppress both altitude clutter and mainlobe clutter. In this paper, It is proposed the clutter suppression method consisted of two pulse canceller to suppress the clutters being two frequency area in moving platform. It is analyzed the correlation of output signals according to the use of pulse canceller and provided the structure of staggered pulse canceller considered the correlation. Finally, it shows that altitude clutter and mainlobe clutter are suppressed by proposed staggered pulse canceller using the simulation.

Performance Improvement of TH PPM UWB-IR System with CCI Canceller in Multi-User Interference Environment (다중 사용자 간섭 환경에서 CCI Canceller를 채용한 TH PPM UWB-IR 시스템의 성능 개선)

  • Lee Yang-Sun;Kang Heau-Jo
    • Journal of Digital Contents Society
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    • v.5 no.3
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    • pp.171-175
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    • 2004
  • In this paper, We applied CCI canceller to remove multi-user interference in co-channel environment and improved performance of TH PPM UWB-IR system. As a result, We could get reception performance that data transmission of high speed is available in small reception power applying CCI canceller. Also, We could get permission available channel capacity to maximum access number 40 in high speed transmission environment more than 100Mbps.

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Design of an Adaptive Noise Canceller for the Motion Artifact Removal of a Pulse Oximetry Signal (펄스 옥시미터의 동잡음 제거 필터 설계)

  • Kim, Do-Young;Kim, Ill-Hwan
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.89-93
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    • 2006
  • Pulse oximetry, which monitors non-invasively the oxygen saturation in blood, is influenced by patient's respiration, movement or a factor of an environment. Specially, it's difficult to measure a PPG (Photoplethsmography) signal from the moving patient because of the motion artifact. Accordingly, it is required to extract the pure PPG signal from the PPG signal to measure oxygen saturation. In this paper, we propose an adaptive noise canceller to improve the performance of motion artifact removal. Then we design a hardware system for real time monitoring of the oxygen saturation. The proposed algorithm estimates the slope of transition rate between two different wavelength signals.

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Echo canceller compensating a nonlinear distortion of D/A converter (D/A 젼환기의 비선형왜곡을 보상하는 Echo Canceller)

  • Jeong, Gi-Seog
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.3
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    • pp.10-17
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    • 1995
  • this thesis proposes a new echo canceller that can be used in a fulll-duplex digital subscriber loopmodem. The modem suffers from nonlinear distortion such as transmitted pulse asymmetry, saturation in transformers, and nonlinearity of data converters. The proposed nonlinear echo canceller can compensate the nolinear distortion by using a nonlinear digital filter based on canonical pieceewise-linear (CPWL) function. Numerical results based on computer simulation are given in this paper. It is shown that the convergence characteristics depend on the initial values of weights of linear filters with absoluters and that the nonlinearity in digital-to-analog(D/A) converter can be compensated by a relatively small number linear filters with absoluters. It is also shown that the proposed algorithm has a faster convergence rate in comparison with Voterra algorithm.

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Detection the Biomedical Information using the Piezo Film Sensor (Piezo Film Sensor를 이용한 생체 정보 검출)

  • Lee, H.W.;Seo, H.;Jeong, W.G.;Jang, D.B.;Lee, G.K.
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.3 no.3
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    • pp.14-21
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    • 2010
  • For the ubiquitous healthcare environment, real-time measurement of biomedical signals and accuracy of the measured biomedical information are very important. In addition, it is important to develop a healthcare device with low power In this paper, the synchronized pulse in a heartbeat was detected from the radial artery using the piezo film sensor, in order to eliminate inconvenience to wear a pulse detection finger probe. We can get a best output after applying the adaptive noise canceller using two piezo film sensor signals, pulse signal having motion artifacts and motion artifacts reference signal. To detect heartbeat, we use maximum point detection method from pulse removed motion artifacts.

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A Digital Readout IC with Digital Offset Canceller for Capacitive Sensors

  • Lim, Dong-Hyuk;Lee, Sang-Yoon;Choi, Woo-Seok;Park, Jun-Eun;Jeong, Deog-Kyoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.3
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    • pp.278-285
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    • 2012
  • A digital readout IC for capacitive sensors is presented. Digital capacitance readout circuits suffer from static capacitance of sensors, especially single-ended sensors, and require large passive elements to cancel such DC offset signal. For this reason, to maximize a dynamic range with a small die area, the proposed circuit features digital filters having a coarse and fine compensation steps. Moreover, by employing switched-capacitor circuit for the front-end, correlated double sampling (CDS) technique can be adopted to minimize low-frequency device noise. The proposed circuit targeted 8-kHz signal bandwidth and oversampling ratio (OSR) of 64, thus a $3^{rd}$-order ${\Delta}{\Sigma}$ modulator operating at 1 MH was used for pulse-density-modulated (PDM) output. The proposed IC was designed in a 0.18-${\mu}m$ CMOS mixed-mode process, and occupied $0.86{\times}1.33mm^2$. The measurement results shows suppressed DC power under about -30 dBFS with minimized device flicker noise.

Automatic On-Chip Glitch-Free Backup Clock Changing Method for MCU Clock Failure Protection in Unsafe I/O Pin Noisy Environment (안전하지 않은 I/O핀 노이즈 환경에서 MCU 클럭 보호를 위한 자동 온칩 글리치 프리 백업 클럭 변환 기법)

  • An, Joonghyun;Youn, Jiae;Cho, Jeonghun;Park, Daejin
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.12
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    • pp.99-108
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    • 2015
  • The embedded microcontroller which is operated by the logic gates synchronized on the clock pulse, is gradually used as main controller of mission-critical systems. Severe electrical situations such as high voltage/frequency surge may cause malfunctioning of the clock source. The tolerant system operation is required against the various external electric noise and means the robust design technique is becoming more important issue in system clock failure problems. In this paper, we propose on-chip backup clock change architecture for the automatic clock failure detection. For the this, we adopt the edge detector, noise canceller logic and glitch-free clock changer circuit. The implemented edge detector unit detects the abnormal low-frequency of the clock source and the delay chain circuit of the clock pulse by the noise canceller can cancel out the glitch clock. The externally invalid clock source by detecting the emergency status will be switched to back-up clock source by glitch-free clock changer circuit. The proposed circuits are evaluated by Verilog simulation and the fabricated IC is validated by using test equipment electrical field radiation noise