• Title/Summary/Keyword: Iterative scheme

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AN EFFICIENT THIRD ORDER MANN-LIKE FIXED POINT SCHEME

  • Pravin, Singh;Virath, Singh;Shivani, Singh
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.4
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    • pp.785-795
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    • 2022
  • In this paper, we introduce a Mann-like three step iteration method and show that it can be used to approximate the fixed point of a weak contraction mapping. Furthermore, we prove that this scheme is equivalent to the Mann iterative scheme. A comparison is made with the other third order iterative methods. Results are presented in a table to support our conclusion.

Rayleigh-Quotient and Iterative-Threshold-Test-Based Blind TOA Estimation for IR-UWB Systems

  • Shen, Bin;Zhao, Chengshi;Cui, Taiping;Kwak, Kyung-Sup
    • ETRI Journal
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    • v.32 no.2
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    • pp.333-335
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    • 2010
  • This letter proposes a non-coherent blind time-of-arrival (TOA) estimation scheme for impulse radio ultra-wideband systems. The TOA estimation is performed in two consecutive phases: the Rayleigh-quotient theorem-based coarse-signal acquisition (CSA) and the iterative-threshold-test-based fine time estimation (FTE). The proposed scheme serves in a blind manner without demanding any a priori knowledge of the channel and the noise. Analysis and simulations demonstrate that the proposed scheme significantly increases the signal detection probability in CSA and ameliorates the TOA estimation accuracy in FTE.

Iterative learning control of robot manipulators (로봇 매니퓰레이터의 반복 학습 제어)

  • 문정호;도태용;정명진
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.470-473
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    • 1996
  • This paper presents an iterative learning control scheme for industrial manipulators. Based upon the frequency-domain analysis, the input update law of the learning controller is given together with a sufficient condition for the convergence of the iterative process in the frequency domain. The proposed learning control scheme is structurally simple and computationally efficient since it is independent joint control depending only on locally measured variables and it does not involve the computation of complicated nonlinear manipulator dynamics. Moreover, it is capable of canceling the unmodeled dynamics of the manipulator without even the parametric model. Several important aspects of the learning scheme inherent in the frequency-domain design are discussed and the control performance is demonstrated through computer simulations.

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A RANDOM GENERALIZED NONLINEAR IMPLICIT VARIATIONAL-LIKE INCLUSION WITH RANDOM FUZZY MAPPINGS

  • Khan, F.A.;Aljohani, A.S.;Alshehri, M.G.;Ali, J.
    • Nonlinear Functional Analysis and Applications
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    • v.26 no.4
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    • pp.717-731
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    • 2021
  • In this paper, we introduce and study a new class of random generalized nonlinear implicit variational-like inclusion with random fuzzy mappings in a real separable Hilbert space and give its fixed point formulation. Using the fixed point formulation and the proximal mapping technique for strongly maximal monotone mapping, we suggest and analyze a random iterative scheme for finding the approximate solution of this class of inclusion. Further, we prove the existence of solution and discuss the convergence analysis of iterative scheme of this class of inclusion. Our results in this paper improve and generalize several known results in the literature.

Low Complexity LSD Scheme for Joint Iterative MIMO Detection (반복 MIMO 검출을 위한 저 복잡도 LSD 기법)

  • Ahmed, Saleem;Kim, Sooyoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.11
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    • pp.1051-1059
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    • 2013
  • This paper proposes a complexity reduced list sphere decoding (LSD) scheme for joint iterative soft detection scheme for coded MIMO system. The conventional LSD scheme is based on searching the candidates with a fixed radius. However, once the candidate list is full, it is highly probable that the radius can be reduced. By reducing the radius, the complexity can be also reduced. We propose a simple and efficient radius update method for complexity reduction of list version sphere decoding and its application to iterative soft MIMO detection. We evaluate the performance of the proposed scheme with a joint soft-input-soft-ouput iterative MIMO detection in combination with turbo codes. Simulation results show that the proposed methods provide substantial complexity reduction while achieving similar bit error rate (BER) performance as the conventional LSD scheme.

Iterative V-BLAST Decoding Algorithm in the AMC System with a STD Scheme

  • Lee, Keun-Hong;Ryoo, Sang-Jin;Kim, Seo-Gyun;Hwang, In-Tae
    • Journal of information and communication convergence engineering
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    • v.6 no.1
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    • pp.1-5
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    • 2008
  • In this paper, we propose and analyze the AMC (Adaptive Modulation and Coding) system with efficient turbo coded V-BLAST (Vertical-Bell-lab Layered Space-Time) technique. The proposed algorithm adopts extrinsic information from a MAP (Maximum A Posteriori) decoder with iterative decoding as a priori probability in two decoding procedures of V-BLAST scheme; the ordering and the slicing. Also, we consider the AMC system using the conventional turbo coded V-BLAST technique that simply combines the V-BLAST scheme with the turbo coding scheme. And we compare the proposed decoding algorithm to a conventional V-BLAST decoding algorithm and a ML (Maximum Likelihood) decoding algorithm. In addition, we apply a STD (Selection Transmit Diversity) scheme to the systems for better performance improvement. Results indicate that the proposed systems achieve better throughput performance than the conventional systems over the entire SNR range. In terms of transmission rate performance, the suggested system is close in proximity to the conventional system using the ML decoding algorithm.

Formulation of Joint Iterative Decoding for Raptor Codes

  • Zhang, Meixiang;Kim, Sooyoung;Kim, Won-Yong;Cho, Yong-Hoon
    • Journal of Korea Multimedia Society
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    • v.17 no.8
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    • pp.961-967
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    • 2014
  • Raptor codes are a class of rateless codes originally designed for binary erasure channels. This paper presents a compact set of mathematical expressions for iterative soft decoding of raptor codes. In addition, an early termination scheme is employed, and it is embedded in a single algorithm with the formula. In the proposed algorithm, the performance is enhanced by adopting iterative decoding, both in each inner and outer code and in the concatenated code itself between the inner and outer codes. At the same time, the complexity is reduced by applying an efficient early termination scheme. Simulation results show that our proposed method can achieve better performance with reduced decoding complexity compared to the conventional schemes.

FIXED POINT THEOREMS IN COMPLEX VALUED CONVEX METRIC SPACES

  • Okeke, G.A.;Khan, S.H.;Kim, J.K.
    • Nonlinear Functional Analysis and Applications
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    • v.26 no.1
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    • pp.117-135
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    • 2021
  • Our purpose in this paper is to introduce the concept of complex valued convex metric spaces and introduce an analogue of the Picard-Ishikawa hybrid iterative scheme, recently proposed by Okeke [24] in this new setting. We approximate (common) fixed points of certain contractive conditions through these two new concepts and obtain several corollaries. We prove that the Picard-Ishikawa hybrid iterative scheme [24] converges faster than all of Mann, Ishikawa and Noor [23] iterative schemes in complex valued convex metric spaces. Also, we give some numerical examples to validate our results.

Performance Experimentation and an Optimal Iterative Coding Algorithm for Underwater Acoustic Communication (수중음향통신에서 최적의 반복부호 알고리즘 및 성능 실험)

  • Park, Gun-Yeol;Lim, Byeong-Su;Jung, Ji-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2397-2404
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    • 2012
  • Underwater acoustic communication has multipath error because of reflection by sea-level and sea-bottom. The multipath of underwater channel causes signal distortion and error floor. In order to improve the performance, it is necessary to employ an iterative coding scheme. Among the iterative coding scheme, turbo codes and LDPC codes are dominant channel coding schemes in recent. This paper concluded that turbo coding scheme is optimal for underwater communications system in aspect to performance, coded word length, and equalizer combining. Also, decision directed phase recovery was used for correcting phase offset induced by multipath. Based on these algorithms, we confirmed the performance in the environment of oceanic experimentation.