• Title/Summary/Keyword: Cross-correntropy

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Complex-Channel Blind Equalization Using Cross-Correntropy (상호 코렌트로피를 이용한 복소 채널 블라인드 등화)

  • Kim, Nam-Yong
    • Journal of Internet Computing and Services
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    • v.11 no.5
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    • pp.19-26
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    • 2010
  • The criterionmaximizing cross-correntropy (MCC) of two different random variables has yielded superior performance comparing to mean squared error criterion. In this paper we present a complex-valued blind equalizer algorithm for QAM and complex channel environments based on cross-correntropy criterion which uses, as two variables, equalizer output PDF and Parzen PDF estimate of a self-generated symbol set. Simulation results show significantly enhanced performance of symbol-point concentration with no phase rotation in complex-channel communication.

Blind Equalization based on Maximum Cross-Correntropy Criterion using a Set of Randomly Generated Symbol (랜덤 심볼을 사용한 최대 코렌트로피 기준의 블라인드 등화)

  • Kim, Nam-Yong;Kang, Sung-Jin;Hong, Dae-Ki
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.1C
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    • pp.33-39
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    • 2010
  • Correntropy is a generalized correlation function that contains higher order moments of the probability density function (PDF) than the conventional moment expansions. The criterion maximizing cross-correntropy (MCC) of two different random variables has yielded superior performance particularly in nonlinear, non-Gaussian signal processing comparing to mean squared error criterion. In this paper we propose a new blind equalization algorithm based on cross-correntropy criterion which uses, as two variables, equalizer output PDF and Parzen PDF estimate of a set of randomly generated symbols that complies with the transmitted symbol PDF. The performance of the proposed algorithm based on MCC is compared with the Euclidian distance minimization.

Step Size Normalization for Maximum Cross-Correntropy Algorithms (최대 상호코렌트로피 알고리듬을 위한 스텝사이즈 정규화)

  • Kim, Namyong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.9
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    • pp.995-1000
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    • 2016
  • The maximum cross-correntropy (MCC) algorithm with a set of random symbols keeps its optimum weights undisturbed from impulsive noise unlike MSE-based algorithms and its main factor has been known to be the input magnitude controller (IMC) that adjusts the input intensity according to error power. In this paper, a normalization of the step size of the MCC algorithm by the power of IMC output is proposed. The IMC output power is tracked recursively through a single-pole low-pass filter. In the simulation under impulsive noise with two different multipath channels, the steady state MSE and convergence speed of the proposed algorithm is found to be enhanced by about 1 dB and 500 samples, respectively, compared to the conventional MCC algorithm.

Practical Approach for Blind Algorithms Using Random-Order Symbol Sequence and Cross-Correntropy (랜덤오더 심볼열과 상호 코렌트로피를 이용한 블라인드 알고리듬의 현실적 접근)

  • Kim, Namyong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.3
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    • pp.149-154
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    • 2014
  • The cross-correntropy concept can be expressed with inner products of two different probability density functions constructed by Gaussian-kernel density estimation methods. Blind algorithms based on the maximization of the cross-correntropy (MCC) and a symbol set of randomly generated N samples yield superior learning performance, but have a huge computational complexity in the update process at the aim of weight adjustment based on the MCC. In this paper, a method of reducing the computational complexity of the MCC algorithm that calculates recursively the gradient of the cross-correntropy is proposed. The proposed method has only O(N) operations per iteration while the conventional MCC algorithms that calculate its gradients by a block processing method has $O(N^2)$. In the simulation results, the proposed method shows the same learning performance while reducing its heavy calculation burden significantly.

Performance Analysis of Correntropy-Based Blind Algorithms Robust to Impulsive Noise (충격성 잡음에 강인한 코렌트로피 기반 블라인드 알고리듬의 성능분석)

  • Kim, Namyong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.12
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    • pp.2324-2330
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    • 2015
  • In blind signal processing in impulsive noise environment the maximum cross-correntropy (MCC) algorithm shows superior performance compared to MSE-based algorithms. But optimum weight conditions of MCC algorithm and its properties related with robustness to impulsive noise have not been studied sufficiently. In this paper, through the analysis of the behavior of its optimum weight and the relationship with the MSE-based LMS algorithm, it is shown that the optimum weight of MCC and MSE-based LMS have an equal solution. Also the factor that keeps optimum weight of MCC undisturbed and stable under impulsive noise is proven to be the magnitude controlled input through simulation.

A Study on the Minimum Error Entropy - related Criteria for Blind Equalization (블라인드 등화를 위한 최소 에러 엔트로피 성능기준들에 관한 연구)

  • Kim, Namyong;Kwon, Kihyun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.3
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    • pp.87-95
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    • 2009
  • As information theoretic learning techniques, error entropy minimization criterion (MEE) and maximum cross correntropy criterion (MCC) have been studied in depth for supervised learning. MEE criterion leads to maximization of information potential and MCC criterion leads to maximization of cross correlation between output and input random processes. The weighted combination scheme of these two criteria, namely, minimization of Error Entropy with Fiducial points (MEEF) has been introduced and developed by many researchers. As an approach to unsupervised, blind channel equalization, we investigate the possibility of applying constant modulus error (CME) to MEE criterion and some problems of the method. Also we study on the application of CME to MEEF for blind equalization and find out that MEE-CME loses the information of the constant modulus. This leads MEE-CME and MEEF-CME not to converge or to converge slower than other algorithms dependent on the constant modulus.

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