• Title, Summary, Keyword: amplitude error

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Compensation of Position Error due to Amplitude Imbalance in Resolver Signals

  • Hwang, Seon-Hwan;Kwon, Young-Hwa;Kim, Jang-Mok;Oh, Jin-Seok
    • Journal of Power Electronics
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    • v.9 no.5
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    • pp.748-756
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    • 2009
  • This paper presents a compensation algorithm for position error due to an amplitude imbalance between resolver output signals. Resolvers are typically used to obtain absolute position information for motor drive systems in severe environments. Position error is caused by an amplitude imbalance of the resolver output signals. As a result, the d- and q-axis currents of synchronous reference frame have periodic ripples in the stator fundamental frequency in permanent magnet synchronous motor (PMSM) drive systems. Therefore, this paper proposes a compensation algorithm to reduce the position error generated by the amplitude imbalance. The proposed method does not require any additional hardware, and reduces computation time with a simple integral operation according to rotor position. In addition, the position error can be directly compensated for by the estimated position error. The effectiveness of the proposed compensation algorithm is verified through several simulations and experiments.

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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Amplitude Control of Phase Modulation for Dithered Closed-loop Fiber Optic Gyroscope

  • Chong, Kyoung-Ho;Chong, Kil-To;Kim, Young-Chul
    • Journal of the Optical Society of Korea
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    • v.16 no.4
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    • pp.401-408
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    • 2012
  • The amplitude error of phase modulator used in closed-loop fiber optic gyroscope has occurred by the temperature dependency of the electro-optic coefficient, and also can be due to the square-wave dither signal which is generally applied for eliminating the deadzone. This error can cause bias drift and scale factor error. This paper analyzes the temperature dependency of the modulation amplitude and the relationship with the scale factor of the gyroscope, and deals with an amplitude control method. The error calculation logic considering the dither signal is implemented on the signal processing module. The result of experiments from a prototype gyroscope shows the effect of the modulation amplitude control and a considerable improvement on performances.

Exact Bit Error Probability of Orthogonal Space-Time Block Codes with Quadrature Amplitude Modulation

  • Kim, Sang-Hyo;Yang, Jae-Dong;No, Jong-Seon
    • Journal of Communications and Networks
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    • v.10 no.3
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    • pp.253-257
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    • 2008
  • In this paper, the performance of generic orthogonal space-time block codes (OSTBCs) introduced by Alamouti [2], Tarokh [3], and Su and Xia [11] is analyzed. We first define one-dimensional component symbol error function (ODSEF) from the exact expression of the pairwise error probability of an OSTBC. Utilizing the ODSEF and the bit error probability (BEP) expression for quadrature amplitude modulation (QAM) introduced by Cho and Yoon [9], the exact closed-form expressions for the BEP of linear OSTBCs with QAM in quasi-static Rayleigh fading channel are derived. We also derive the exact closed-form of the BEP for some OSTBCs which have at least one message symbol transmitted with unequal power via all transmit antennas.

Constant-Amplitude Multicode-Biorthogonal Modulation using Product Code (격자부호를 이용한 정진폭 다중부호 이진직교 변조방식)

  • Hong, Dae-Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.3
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    • pp.522-527
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    • 2007
  • In this paper, we propose an error control coding scheme for constant-amplitude multicode-biorthogonal modulation. The product code is appropriate to the constant-amplitude multicode-biorthogonal modulation for the bit error rate performance improvement. In the constant-amplitude multicode-biorthogonal modulation, the vertical redundant bits are used for the constant amplitude coding. The proposed product code can be constructed by using the additional horizontal redundant bits. The hardware complexity of the encoder/decoder pair is very low. The simulation results show that the bit error rate performance of the proposed coding scheme is improve

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Constant-Amplitude Biorthogonal Multi-Code Modulation (정 진폭 다중 보호 이진 직교 변조)

  • Hong Dae ki;Kang Sung jin;Ju Min chul;Kim Young sung;Seo Kyeung hak;Cho Jin woong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.3C
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    • pp.69-76
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    • 2005
  • In this paper, we propose a biorthogonal modulation employing a constant-amplitude transmission of multi-code signals by introducing a simple constant-amplitude coding scheme with redundant bits. The proposed constant-amplitude biorthogonal multi-code (CABM) modulation can provide high spectral efficiency compared with a conventional direct sequence/spread spectrum (DS/SS) modulation. Nevertheless the proposed CABM modulation can keep up a constant-amplitude signal. Additionally, we propose various types of demodulation structures for the CABM modulation. Simulation results show that bit error rate (BER) performance and hardware complexity of the proposed CABM modulation are highly improved in comparison with those of a constant-amplitude orthogonal multi-code (CAOM) modulation.

Priority-based Unequal Error Protection Scheme of Data partitioned H.264 video with Hierarchical QAM

  • Chen, Rui;Wu, Minghu;Yang, Jie;Rui, Xiongli
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.11
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    • pp.4189-4202
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    • 2014
  • In this paper, we propose a priority-based unequal error protection scheme of data partitioned H.264/AVC video with hierarchical quadrature amplitude modulation. In order to map data with higher priority onto the most significant bits of QAM constellation points, a priority sorting method categorizes different data partitions according to the unequal importance factor of encoded video data in one group of pictures by evaluated the average distortion. Then we propose a hierarchical quadrature amplitude modulation arrangement with adaptive constellation distances, which takes into account the unequal importance of encoded video data and the channel status. Simulation results show that the proposed scheme improves the received video quality by about 2 dB in PSNR comparing with the state-of-the-art unequal error protection scheme, and outperforms EEP scheme by up to 5 dB when the average channel SNR is low.

Performance of Amplitude Comparison Monopulse Radar (진폭비교 모노펄스 레이다의 성능)

  • An, Do-Jin;Lee, Joon-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.12
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    • pp.969-975
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    • 2018
  • The main function of the tracking radar is to automatically track the target. The amplitude-comparison monopulse radar utilizes a monopulse radar to estimate the angular components of a target. In this paper, the operating performance of the amplitude-comparison monopulse radar is quantitatively analyzed via the MSEs, with considerations on additive noise. The performance of the amplitude comparison monopulse radar can be predicted by comparing it with an approximated estimate.

BER Performance Analysis of Linear Orthogonal Space-Time Block Codes with Quadrature Amplitude Modulation in Quasi Static Rayleigh Fading Channel (QAM 변조방식을 갖는 선형 직교 시공간 블록 부호의 준정지 레일리 페이딩 채널에서의 비트 오율 성능 분석)

  • Kim Sang-Hyo;Yang Jae-Dong;No Jong-Seon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.6C
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    • pp.575-581
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    • 2006
  • In this paper, we first define one-dimensional component symbol error function (ODSEF) from the exact expression of the pairwise error probability of orthogonal space-time block codes (OSTBC). Using the ODSEF and the general bit error probability (BEP) expression for quadrature amplitude modulation (QAM) introduced by Cho and Yoon, the exact closed form expressions for the BEP of linear OSTBCs with QAM in slow-varying Rayleigh fading channel are derived.

A Comparison of the Error Rate Performances of Various Digitally Modulated Signals in the Environment of Tone/Multiple Interferer (톤간섭 및 다중간섭하에서 제반 디지탈 변조신호의 오율특성 비교)

  • 공병옥;조성준
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.15 no.10
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    • pp.797-810
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    • 1990
  • The error rate equations of digitally modulated signals transmitted through the Gaussian noise and tone multiple interference channel have been derived. Using the derived equations of error probabilities in the environments of Gaussian noise tone interferer and Gaussian noise multiple interferer, the error rate performances of various digitally modulated signals have been evaluated, and compared in graphs as a function of average carrier to tone interferer power ratio(CIR), average carrier to multiple interferer power ratio(CIT) and the average carrer-to-Gaussian noise powr ratio(CIR). In this paper, the modulation schemes such as amplitude shift keying (ASK), phase shift keying(PSK), frequency shift keying(FSK), minimum shift keying(MSK), quadrature amplitud modulation(QAM) and amplitude phase shift keying(APK) have been selected for the study of performance comparison. The results of comparison show us that, in low bits/sec/Hz, PSK is superior to the other schemes, but in high bits/sec/Hz, mixed multi ary type is better than single multi ary type. And in strong noise evironment, the multiple interferer has much influence than tone interferer, however, in low noise environment. the mojor error factor is tone interferer. But tone interference effect nearly disappears over specified CIR level about 20[dB]. And the modulation schemes using amplitude are heavily influenced by multiple interference.

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