• Title/Summary/Keyword: 가변스텝 LMS

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A Study On ECLMS Using Estimated Correlation (추정상관을 이용한 ECLMS에 관한 연구)

  • 오신범;권순용;이채욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7A
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    • pp.651-658
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    • 2002
  • Although least mean square(LMS) algorithm is known to one of the most popular algorithm in adaptive signal processing because of the simplicity and the small computation, the choice of the step size reflects a tradeoff between the misadjustment and the speed of adaptation. In this paper, we present a new variable step size LMS algorithm, so-called ECLMS(Estimated correlation LMS), using the correlation between reference input and error signal of adaptive filter. The proposed algorithm updates each weight of filter by different step size at same sample time. We applied this algorithm to adaptive multiple-notch filter. Simulation results are presented to compare the performance of the proposed algorithm with the usual LMS algorithm and another variable step algorithm.

A novel class of LMS Algorithms with exponential step size for Smart Antenna Applications (Exponential 스텝사이즈를 이용한 스마트안테나용 블라인드 LMS 알고리즘)

  • Tuan, Le-Minh;Park, Jaedon;Giwan Yoon;Kim, Jewoo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.10a
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    • pp.331-335
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    • 2001
  • In this paper, we propose two novel blind LMS algorithms, called exponential step sire LMS algorithms (ES-LMS), for adaptive array antennas whose convergence speed is increased, hence they are much more capable of tracking the desired signal than the conventional LMS algorithms. Both of the algorithms require neither spatial knowledge nor reference signals since they use the finite symbol property of digital signal. Computer simulations were carried cot in CDMA environment affected by multi-path Rayleigh fading to verify the performance of the two proposed algorithms.

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A Study on Modified IGC Algorithm for Realtime Noise Reduction (실시간 소음 제거에 적합한 변형 IGC 알고리즘에 관한 연구)

  • Lee, Chae-Wook
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.2
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    • pp.95-98
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    • 2013
  • The LMS(Least Mean Square) algorithm, one of the most famous, is generally used because of tenacity and high mating spots and simplicity of realization, But it has trade-off between nonuniform collection and EMSE(Excess mean square error). To overcome this weakness, a variable step size is used widely, but it needs a lot of calculation loads. In this paper, we suggest changed algorithm in case of environment changes of cars and reduce amount of calculation as it uses original signal and noise signal of IGC(Instantaneous Gain Control) algorithm. In this paper, logarithmic function is removed because of real-time processing IGC. The performance of proposed algorithm is tested to adaptive noise canceller in automobile.

A LMS algorithm with variable step size (가변 스텝 크기를 갖는 LMS 알고리즘)

  • 김관준;이철희;남현도
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.224-227
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    • 1993
  • In this paper, a new LMS algorithm with a variable step size (VVS LMS) is presented. The change of step size .mu. at each iteration, which increases or decreases according to the misadaptation degree, is computed by a proportional fuzzy logic controller. As a result the algorithm has very good convergence speed and low steady-state misadjustment. The norm of the cross correlation between the estimation error and input signal is used. As a measure of the misadaptation degree. Simulation results are presented to compare the performance of the VSS LMS algorithm with the normalized LMS algorithm.

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A LMS Algorithm with Fuzzy Variable Step Size (퍼지 가변 스텝 크기 LMS 알고리즘)

  • Lee, Chul-Heu;Kim, Koan-Jun
    • Journal of Industrial Technology
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    • v.13
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    • pp.33-41
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    • 1993
  • In this paper, a new LMS algorithm with a fuzzy variable step size (FVS LMS) is presented. The change of step size ${\mu}$, at each iteration which is increases or decreases according to the misadaptation degree, is computed by a proportional fuzzy logic controller. As a result the algorithm has very good convergence speed and low steady-state misadjustment. As a measure of the misadaptation degree, the norm of the cross correlation between the estimation error and input signal is used. Simulation results are presented to compare the performance of the FVSS LMS algorithm with the normalized LMS algorithm.

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Fast Wavelet Adaptive Algorithm Based on Variable Step Size for Adaptive Noise Canceler (Adaptive Noise Canceler에 적합한 가변 스텝 사이즈 고속 웨이블렛 적응알고리즘)

  • Lee Chae-Wook;Lee Jae-Kyun
    • Journal of Korea Multimedia Society
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    • v.8 no.8
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    • pp.1051-1056
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    • 2005
  • Least mean square(LMS) algorithm is one of the most popular algorithm in adaptive signal processing because of the simplicity and the small computation. But the convergence speed of time domain adaptive algorithm is slow when the spread width of eigen values is wide. Moreover we have to choose the step size well for convergency in this paper, we use adaptive algorithm of wavelet transform. And we propose a new wavelet based adaptive algorithm of wavelet transform. And we propose a new wavelet based adaptive algorithm with variable step size, which Is linear to absolute value of error signal. We applied this algorithm to adaptive noise canceler. Simulation results are presented to compare the performance of the proposed algorithm with the usual algorithms.

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Phase Offset Estimation Based on Turbo Decoding in Digital Broadcasting System (차세대 고속무선 DTV를 위한 터보복호기반의 위상 옵셋 추정 기법)

  • Park, Jae-Sung;Cha, Jae-Sang;Lee, Chong-Hoon;Kim, Heung-Mook;Choi, Sung-Woong;Cho, Ju-Phill;Park, Yong-Woon;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.2
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    • pp.111-116
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    • 2009
  • In this paper, we propose a phase offset estimation algorithm which is based on turbo coded digital broadcasting system. The phase estimator is an estimator outside turbo code decoder using LMS (Least Mean Square) algorithm to estimate the phase of next state. While the conventional LMS algorithm with a fixed step size is easy implemented, it has weak points that are difficult the channel estimation and tracking in the multipath environment. To resolve this problem, we propose new phase offset estimation method with a variable step size LMS (VS-LMS). Additionally, we propose a scheme which consists of a conventional LMS. The performance is verified by computer simulation according to a fixed phase offset and a increased phase offset, the proposed algorithm improve the bit error rate performance than the conventional algorithm.

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A Study on Variable Step Size LMS Algorithm using estimated correlation (추정상관값을 이용한 가변 스텝사이즈 LMS 알고리듬에 관한 연구)

  • 권순용;오신범;이채욱
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.115-118
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    • 2000
  • We present a new variable step size LMS algorithm using the correlation between reference input and error signal of adaptive filter. The proposed algorithm updates each weight of filter by different step size at same sample time. We applied this algorithm to adaptive multip]e-notch filter. Simulation results are presented to compare the performance of the proposed algorithm with the usual LMS algorithm and another variable step algorithm.

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Implementation of Adaptive Noise Canceller Using Instantaneous Gain Control Algorithm (순시 이득 조절 알고리즘을 이용한 적응 잡음 제거기의 구현)

  • Lee, Jae-Kyun;Kim, Chun-Sik;Lee, Chae-Wook
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.6
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    • pp.95-101
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    • 2009
  • Among the adaptive noise cancellers (ANC), the least mean square (LMS) algorithm has probably become the most popular algorithm because of its robustness, good tracking properties, and simplicity of implementation. However, it has non-uniform convergence and a trade-off between the rate of convergence and excess mean square error (EMSE). To overcome these shortcomings, a number of variable step size least mean square (VSSLMS) algorithms have been researched for years. These LMS algorithms use a complex variable step method approach for rapid convergence but need high computational complexity. A variable step approach can impair the simplicity and robustness of the LMS algorithm. The proposed instantaneous gain control (IGC) algorithm uses the instantaneous gain value of the original signal and the noise signal. As a result, the IGC algorithm can reduce computational complexity and maintain better performance.

Subband Affine Projection Algorithm Using Variable Step Size (가변 스텝사이즈를 이용한 부밴드 인접투사 알고리즘)

  • Choi, Hun;Bae, Hyeon-Deok
    • The Journal of the Acoustical Society of Korea
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    • v.26 no.2
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    • pp.69-74
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    • 2007
  • In signal processing applications with highly correlated input signals, subband affine projection algorithm and step size controlling is a good solution for improving the slow convergence rate and large computational complexity of LMS-type algorithms. This paper proposes a subband affine projection algorithm using a variable step size. The proposed method achieves fast convergence rate and small steady-state error with a small computational complexity by combining the SAP and step size controlling in a subband structure. Experimental results on highly correlated input signal show that the proposed method is superior to the conventional methods.