• Title, Summary, Keyword: phase error

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System Phase Noise for Mobile Satellite Communication Service (이동형 위성통신 서비스를 위한 시스템 위상 잡음)

  • Kim, Young-Wan;Jang, Myeong-Shin;Baek, Wha-Jong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.735-738
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    • 2005
  • The phase error in the digital transmission system are generated by random phase noise and tracking phase error due to doppler phenomenon. In the mobile satellite communication system that generates the doppler frequency, which is a system with a movement, the proper system phase noise spectrum should be designed based on analyses for phase noise and static phase error effects. Based on the analyses of the doppler frequency and the phase error for bilateral satellite communication system providing an asynchronous service, the phase noise spectrums for the mobile satellite communication are designed in this paper. Also, the available transmission services under the less doppler effect are proposed and the proper signal source units for a required transmission system can be designed under the proposed system phase noise spectrum.

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The estimation of first order derivative phase error using iterative algorithm in SAR imaging system (SAR(Synthetic Aperture Radar)Imaging 시스템에서 제안 알고리즘의 반복수행을 통한 위상오차의 기울기 추정기법 연구)

  • 김형주;최정희
    • Proceedings of the IEEK Conference
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    • pp.505-508
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    • 2000
  • The success of target reconstruction in SAR(Synthetic Aperture Radar) imaging system is greatly dependent on the coherent detection. Primary causes of incoherent detection are uncompensated target or sensor motion, random turbulence in propagation media, wrong path in radar platform, and etc. And these appear as multiplicative phase error to the echoed signal, which consequently, causes fatal degradations such as fading or dislocation of target image. In this paper, we present iterative phase error estimation scheme which uses echoed data in all temporal frequencies. We started with analyzing wave equation for one point target and extend to overall echoed data from the target scene - The two wave equations governing the SAR signal at two temporal frequencies of the radar signal are combined to derive a method to reconstruct the complex phase error function. Eventually, this operation attains phase error correction algorithm from the total received SAR signal. We verify the success of the proposed algorithm by applying it to the simulated spotlight-mode SAR data.

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A Study on Measurement Method of Optical Path Error in Arrayed Waveguide Grating Router (광도파로열 격자 라우터의 경로오차 측정 방법에 관한 연구)

  • Park, Jae-Sung;Chung, Young-Chul;Mun, Seong-Uk
    • Proceedings of the KIEE Conference
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    • pp.2431-2433
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    • 1999
  • Phase errors of arrayed waveguide degrade the performance of AWG router, especially for dense WDM system. So it is necessary to measure the phase error and to compensate. The analysis method of the interference signal from the low coherence interferometer to measure the path length difference phase error is studied. The interference signal generated assuming the intentional path length difference errors of 0.1$\sim$0.4${\mu}m$ are analyzed and the results show that the path length difference phase error of ${\Delta}L$ within ${\pm}14^{\circ}$ of sampling phase error can be accurately measured.

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Effect of Phase Error on the Lateral Resolution of Reconstruction Image in Incoherent Triangular Holography (인코히어런트 삼각 홀로그래피에서 위상오차가 횡축방향의 해상도에 미치는 영향에 관한 연구)

  • Kim, Soo-Gil
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.11
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    • pp.1-6
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    • 2013
  • It is introduced the phase error sources of a incoherent hologram in incoherent triangular holography and derived the reconstruction image of point-source including the phase error in the lateral direction. From the reconstruction image of point-source, we analyzed the effect of phase error on the lateral resolution. When the phase retardation errors and azimuth angle error of a wave plate and a polarizer range from 0 to $2{\pi}/15$, the normalized intensities of reconstructed images are down by about 0.1% and 2.3%, respectively.

A Study on Current Ripple Reduction Due to Offset Error in SRF-PLL for Single-phase Grid-connected Inverters (단상 계통연계형 인버터의 SRF-PLL 옵셋 오차로 인한 전류 맥동 저감에 관한 연구)

  • Hwang, Seon-Hwan;Hwang, Young-Gi;Kwon, Soon-Kurl
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.11
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    • pp.68-76
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    • 2014
  • This paper presents an offset error compensation algorithm for the accurate phase angle of the grid voltage in single-phase grid-connected inverters. The offset error generated from the grid voltage measurement process cause the fundamental harmonic component with grid frequency in the synchronous reference frame phase lock loop (PLL). As a result, the grid angle is distorted and the power quality in power systems is degraded. In addition, the dq-axis currents in the synchronous reference frame and phase current have the dc component, first and second order ripples compared with the grid frequency under the distorted grid angle. In this paper, the effects of the offset and scaling errors are analyzed based on the synchronous reference frame PLL. Particularly, the offset error can be estimated from the integrator output of the synchronous reference frame PLL and compensated by using proportional-integral controller. Moreover, the RMS (Root Mean Square) function is proposed to detect the offset error component. The effectiveness of the proposed algorithm is verified through simulation and experiment results.

Error analysis for time-in-flight laser range finder with multiple toe amplitude modulation

  • Matsumoto-Moriyama, Masao;Mima, Kazuhiko;Ishimatsu, Takakazu
    • 제어로봇시스템학회:학술대회논문집
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    • pp.554-557
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    • 1993
  • The error analysis for the Time-in-Flight Laser Range Finder with Multiple Tone Amplitude Modulation relevant to the phase detection error is made. The distance can be estimated to solve the formulate which express the relationship between the absolute distance from the range finder to the object and the wavenumbers and the phases of the modulated waves by the optimization technique. The main cause of the estimation error can be considered as the phase detection error induced from the amplitude modulator and the phase detector. To clarify the phase detection error and the optimal amplitude frequency set, the numerical analysis are made.

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Error Rate Performance Variation by the Reception Phase Error in a Frequency-Selective Rayleigh Fading Channel Environment (주파수 선택성 레일리 페이딩 채널환경에서 수신 오차위상에 의한 오율 특성 변화)

  • 김용로;금홍식;류흥균
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.9
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    • pp.6-13
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    • 1993
  • In is well-known that system performance in the high speed digital radio communication system is usually deteriorted due to the frequency selective fading distortion. In this paper, bit error rate(BER) performance by the reception phase error in cellular mobile communication systems is derived and analyzed. The system is modeled as a frequency selective fast Rayleigh fading channel corrupted by additive white gaussian noise(AWGN) and co-channel interference(CCI). Our numerical results show that for the 24KBaud(48Kb/s) $\pi$/4-DQPSK operated at carrier frequency 800 MHz and C/I<20 dB, the BER will be dominated by CCI if the vehicular speed is below 100 Km/h. The results show that performance, when reception phase error is below $\pi$/12, is deterioreted less than 3 dB, and that performance, when reception phase error is above $\pi$/12, is degraded over 3 dB.

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Error Analysis for Optical Security by means of 4-Step Phase-Shifting Digital Holography

  • Lee, Hyun-Jin;Gil, Sang-Keun
    • Journal of the Optical Society of Korea
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    • v.10 no.3
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    • pp.118-123
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    • 2006
  • We present an optical security method for binary data information by using 4-step phase-shifting digital holography and we analyze tolerance error for the decrypted data. 4-step phase-shifting digital holograms are acquired by moving the PZT mirror with equidistant phase steps of ${\pi}/2$ in the Mach-Zender type interferometer. The digital hologram in this method is a Fourier transform hologram and is quantized with 256 gray level. The decryption performance of the binary data information is analyzed. One of the most important errors is the quantization error in detecting the hologram intensity on CCD. The greater the number of quantization error pixels and the variation of gray level increase, the more the number of error bits increases for decryption. Computer experiments show the results for encryption and decryption with the proposed method and show the graph to analyze the tolerance of the quantization error in the system.

A Study on Usefulness Verification Technique of the Measurement System by the Difference Between Caculated and Experimental Values of Ratio Error/phase Annie Error in Current Transformer (전류변성기의 비오차와 위상각오차의 계산값과 실험값의 차에 의한 측정시스템 유용성 검증기술에 관한 연구)

  • 정재갑;권성원;이상화;박영태
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.4
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    • pp.213-217
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    • 2004
  • A current transformer(CT) used for the estabilishment of high current national standard, has generally very small ratio error and phase angle error. Both the errors of CT depend critically on the external burden used. When both the ratio and phase angle errors at two different burdens including zero burden are known, those at any other burdens are calculated theoretically. The theoretical values are well consistent with the experimental results within the $82{\times}10$-6, implying the measurement system of CT in KRISS is well maintained.