• 제목, 요약, 키워드: phase error

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PR Shaped SQAM의 Performance에 Carrier Phase Error가 미치는 영향에 관한 연구 (A Study on the PR Shaped SQAM Performance with Carrier Phase Error)

  • 박용우;이형재
    • 한국통신학회:학술대회논문집
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    • pp.97-101
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    • 1983
  • A Study is presented showing the effect of carrier phase error on the error-rate of a PR shaped SQAM digital radio system. A simple upper bound on the probability of error as a function of phase error is derived and compared to one another. The result is that if carrier phase error is less than 3 there is no serious degradation.

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Analysis of Phase Error Effects Due to Grid Frequency Variation of SRF-PLL Based on APF

  • Seong, Ui-Seok;Hwang, Seon-Hwan
    • Journal of Power Electronics
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    • v.16 no.1
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    • pp.18-26
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    • 2016
  • This paper proposes a compensation algorithm for reducing a specific ripple component on synchronous reference frame phase locked loop (SRF-PLL) in grid-tied single-phase inverters. In general, SRF-PLL, which is based on all-pass filter to generate virtual voltage, is widely used to estimate the grid phase angle in a single-phase system. In reality, the estimated grid phase angle might be distorted because the phase difference between actual and virtual voltages is not 90 degrees. That is, the phase error is caused by the difference between cut-off frequency of all-pass filter and grid frequency under grid frequency variation. Therefore, the effects on phase angle and output current attributed to the phase error are mathematically analyzed in this paper. In addition, the proportional resonant (PR) controller is adapted to reduce the effects of phase error. The validity of the proposed algorithm is verified through several simulations and experiments.

전기용량 부담을 이용한 전압변성기 비교 측정 시스템의 비오차 및 위상각 오차의 직선성 평가기술 (Evaluation Technique of Linearity of Ratio Error and Phase Angle Error of Voltage Transformer Comparison Measurement System Using Capacitor Burden)

  • 정재갑;김한준;권성원;김명수
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • v.54 no.6
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    • pp.274-278
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    • 2005
  • Voltage transformer(VT) comparison measurement system is usually used for measurements of ratio error and phase angle error of VT made in industry. Both ratio error and phase angle error in VT are critically influenced by values of burden of VT used. External burden effects on both ratio error and phase angle error in VT are theoretically calculated. From the theoretical calculation, a method of evaluation for linearity of ratio error and phase angle error in VT measurement system have been developed using the standard capacitive burdens, with negligible dissipation factor less than 10$^{-4}$. These burden consists of five standard capacitors, with nominal capacitance of 1.1 $\mu$F, 1 $\mu$F, 0.1 $\mu$F, 0.01 $\mu$F, 0.001 $\mu$F. The developed method has been applied in VT measurement system of industry, showing in good consistency and linearity within 0.001 $\%$ between theoretical and measured values.

6.0~18.0 GHz 주파수용 광대역 DFD 위상 상관기 설계 및 제작 (Design and Fabrication of Wideband DFD Phase Correlator for 6.0~18.0 GHz Frequency)

  • 최원;구경헌
    • 한국항행학회논문지
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    • v.18 no.4
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    • pp.341-346
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    • 2014
  • 본 논문은 6.0~18.0 GHz 대역에서 동작하는 광대역 디지털 주파수 변별기(DFD, digital frequency discriminator)의 위상 상관기(phase correlator)를 설계하고 제작하였으며, 제작된 DFD 위상 상관기의 I와 Q 신호를 측정하고, 주파수 변별 오차를 분석하였다. 믹서형 위상 상관기의 동작 특성에 대한 해석적 관계식을 유도하였으며, 위상 상관기에 포함되는 IQ 믹서(mixer)와 8-way 전력분배기(power divider)는 RF 시뮬레이션 툴(tool)을 이용하여 모델링하였다. 설계된 위상 상관기는 제작되어 측정하였다. 제작된 위상 상관기의 I와 Q 출력신호를 측정하여 제시하였으며, 측정된 I와 Q 출력신호를 이용하여 위상오차(phase error)와 주파수 변별오차(frequency discrimination error)를 나타내었다. 위상 상관기의 평균 위상오차(phase error)는 $4.81^{\circ}$, RMS(root mean square)이고, 주파수 변별 오차는 1.49 MHz, RMS 이다.

Phase Error Reduction for Multi-frequency Fringe Projection Profilometry Using Adaptive Compensation

  • Cho, Choon Sik;Han, Junghee
    • Current Optics and Photonics
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    • v.2 no.4
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    • pp.332-339
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    • 2018
  • A new multi-frequency fringe projection method is proposed to reduce the nonlinear phase error in 3-D shape measurements using an adaptive compensation method. The phase error of the traditional fringe projection technique originates from various sources such as lens distortion, the nonlinear imaging system and a nonsinusoidal fringe pattern that can be very difficult to model. Inherent possibility of phase error appearing hinders one from accurate 3-D reconstruction. In this work, an adaptive compensation algorithm is introduced to reduce adaptively the phase error resulting from the fringe projection profilometry. Three different frequencies are used for generating the gratings of projector and conveyed to the four-step phase-shifting procedure to measure the objects of very discontinuous surfaces. The 3-D shape results show that this proposed technique succeeds in reconstructing the 3-D shape of any type of objects.

Motion Compensation Based on Signal Processing Method for Airborne SAR

  • Song, Won-Gyu;Shin, Hee-Sub;Lee, Ho-Jin;Lim, Jong-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1199-1201
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    • 2005
  • In the synthetic aperture radar (SAR) system, the motion error is the main phase error sources and the motion compensation is very important. The phase gradient autofocus (PGA) is a state of art technique for phase error correction of SAR. It exploits the redundancy of the phase-error information among range bins by selecting the strongest scatter for each range bin and synthesizes them. The motivation of this paper is based on the observation that the redundancy of phase error is also among the cross-range direction. Moreover, the proposed method applies the weighting function to better utilize the phase error information. The validity of the proposed scheme for PGA is tested with some numerical simulation.

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Improved DC Offset Error Compensation Algorithm in Phase Locked Loop System

  • Park, Chang-Seok;Jung, Tae-Uk
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1707-1713
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    • 2016
  • This paper proposes a dc error compensation algorithm using dq-synchronous coordinate transform digital phase-locked-loop in single-phase grid-connected converters. The dc errors are caused by analog to digital conversion and grid voltage during measurement. If the dc offset error is included in the phase-locked-loop system, it can cause distortion in the grid angle estimation with phase-locked-loop. Accordingly, recent study has dealt with the integral technique using the synchronous reference frame phase-locked-loop method. However, dynamic response is slow because it requires to monitor one period of grid voltage. In this paper, the dc offset error compensation algorithm of the improved response characteristic is proposed by using the synchronous reference frame phase-locked-loop. The simulation and the experimental results are presented to demonstrate the effectiveness of the proposed dc offset error compensation algorithm.

PR Shape된 SQAM의 오율에 반송파위상오차가 미치는 영향에 대한 연구 (A Study on the PR shaped SQAM error rate with carrier phase error)

  • 박용우;이형재
    • 한국통신학회논문지
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    • v.9 no.1
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    • pp.11-17
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    • 1984
  • 本論文에서는 帶域幅效率을 높이기 위해서 Partial Response Signaling(PRS)을 利用한 PR shaped된 SQAM(staggered quadrature amplitude modulation)에 대하여 硏究하였다. 硏究過程에 있어서 誤率의 上限値를 구하여 서로 比較하였으며 그 結果 誤差가 3$^{\circ}$보다 작으면(Class I, II, IV)PR 시스템을 使用目的에 따라 別差異없이 使用할 수 있지만 3以上이 되면 Class I을 使用해야 한다는 結論을 얻었다.

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위상이동 간섭무늬 투영을 이용한 3차원 형상측정 시스템의 위상계산오차 해석 (Phase calcuation error analysis of 3D shape measurement system using phase-shifted fringe projection method)

  • 류현미;김석성;홍석경;연규황
    • 한국광학회지
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    • v.13 no.3
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    • pp.182-188
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    • 2002
  • 위상이동 간섭무늬 투영 방법을 이용한 3차원 형상측정 시스템의 위상계산오차를 분석하였다. 본 연구에서 다룬 오차의 요소에는 물체 표면의 특성에 따라 검출기에 나타나는 양자화 크기의 변이 효과, 물체 표면에 맺히는 간섭무늬 패턴의 초점 어긋남 효과, 간섭무늬의 위상이동 오차에 의한 효과, 위상 이동된 간섭무늬 패턴이 투영된 여러 개의 물체 상을 받아들이는 도중에 시스템 및 주위 환경 변화에 의한 오차, 그리고 투영되는 격자 패턴의 왜곡에 의한 효과들을 계산하고 논의하였다.

Noncentral F-Distribution for an M-ary Phase Shift Keying Wedge-Shaped Region

  • Kim, Jung-Su;Chong, Jong-Wha
    • ETRI Journal
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    • v.31 no.3
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    • pp.345-347
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    • 2009
  • This letter presents an alternative analytical expression for computing the probability of an M-ary phase shift keying (MPSK) wedge-shaped region in an additive white Gaussian noise channel. The expression is represented by the cumulative distribution function of known noncentral F-distribution. Computer simulation results demonstrate the validity of our analytical expression for the exact computation of the symbol error probability of an MPSK system with phase error.

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