• Title, Summary, Keyword: phase error

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

  • 박용우;이형재
    • Proceedings of the Korean Institute of Communication Sciences Conference
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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.

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

  • Jung Jae Kap;Kim Han Jun;Kwon Sung Won;Kim Myung Soo
    • The Transactions of the Korean Institute of Electrical Engineers C
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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.

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

  • Choi, Won;Koo, Kyung-Heon
    • The Journal of Advanced Navigation Technology
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    • v.18 no.4
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    • pp.341-346
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    • 2014
  • This paper has presented the design and fabrication of phase correlator for wideband digital frequency discriminator (DFD) operating over the 6.0 to 18.0 GHz frequency range. Fabricated DFD phase correlator has been measured I or Q output signal, and analyzed frequency discrimination error. The operation of the proposed mixer type correlator has been analyzed by deriving some analytic equations. To design the phase correlator, this paper has modeled and simulated IQ mixer and 8-way power divider by using RF simulation tool. Designed phase correlator has fabricated and measured. The phase error and frequency discrimination error have been presented using by measured I and Q output signal. Over the 6.0~18.0 GHz range, the root mean square(RMS) phase error is $4.81^{\circ}$, RMS and frequency discrimination error is 1.49 MHz, RMS.

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.

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

  • 박용우;이형재
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.9 no.1
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    • pp.11-17
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    • 1984
  • A study is presented showing the effect of carrier phase error on the error-rate of a (Class I, II, IV)PR shaped SQAM digital communication system. A simple upper bound on the probabilty of error as a function of phase error is derived and compared to one another. The results show that the three system can be used appropriately if carrier phase error is less than 3$^{\circ}$. However, if phase error is larger than 3, the PR class I is the best choice.

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

  • 류현미;김석성;홍석경;연규황
    • Korean Journal of Optics and Photonics
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    • v.13 no.3
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    • pp.182-188
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    • 2002
  • We have analyzed the phase-calculation-error of a three-dimensional shape measurement system using the projection of phase shifted fringe patterns. In this study, we have dealt various errors; an error caused by the variation of quantization levels, an error caused by the defocus of fringe pattern projected images, an error caused by phase-shifting errors, an error caused by the intensity variation of the background and modulation amplitude of fringe pattern projected images during the projection of multiple patterns, an error caused by the distortion of sinusoidal shape of a fringe pattern. The results will contribute to the design of a three-dimensional shape measurment system and give an important meaning to the calculation and the analysis of the accuracy of a system.

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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