• Title/Summary/Keyword: Circulant matrix

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A study on the structure of concordance matrices of Li type PBIB designs ($L_i$ 계획에서 조화행렬의 구조에 관한 연구)

  • 배종성
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.289-297
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    • 1994
  • A block design will be said to have Property C if the concordance matrix can be expressed as a linear combination of Kronecker product of permutation matrices. No matrix inversions are necessary for the intrablock analysis of the block designs which possesses the Property C(Paik, 1985). In this paper, in order to show the Li type PBIB designs possesses the Property C, we suggest the structure of the concordance matrices of Li type PBIB designs are multi-nested block circulant pattern.

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An F-LDPC Codes Based on Jacket Pattern (재킷 패턴 기반의 F-LDPC 부호)

  • Lee, Kwang-Jae;Kang, Seung-Son
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.2
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    • pp.317-325
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    • 2012
  • In this paper, we consider the encoding scheme of Low Density Parity Check codes. In particular, using the Jacket Pattern and circulant permutation matrices, we propose the simple encoding scheme of Richardson's lower triangular matrix. These encoding scheme can be extended to a flexible code rate. Based on the simple matrix process, also we can design low complex and simple encoders for the flexible code rates.

Efficient Design of Structured LDPC Codes (구조적 LDPC 부호의 효율적인 설계)

  • Chung Bi-Woong;Kim Joon-Sung;Song Hong-Yeop
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.1C
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    • pp.14-19
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    • 2006
  • The high encoding complexity of LDPC codes can be solved by designing structured parity-check matrix. If the parity-check matrix of LDPC codes is composed of same type of blocks, decoder implementation can be simple, this structure allow structured decoding and required memory for storing the parity-check matrix can be reduced largely. In this parer, we propose a construction algorithm for short block length structured LDPC codes based on girth condition, PEG algorithm and variable node connectivity. The code designed by this algorithm shows similar performance to other codes without structured constraint in low SNR and better performance in high SNR than those by simulation

A Double Helix DNA Structure Based on the Block Circulant Matrix (I) (블록순환 행렬에 의한 이중나선 DNA 구조 (I))

  • Lee, Sung-Kook;Park, Ju-Yong;Lee, Moon-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.3
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    • pp.203-211
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    • 2016
  • The genetic code is a key to bio-informatics and to a science of biological self-organizing on the whole. Modern science faces the necessity of understanding and systematically explaining mysterious features of ensembles of molecular structures of the genetic code. This paper is devoted to symmetrical analysis for genetic systems. Mathematical theories of noise-immunity coding and discrete signal processing are based on Jacket matrix methods of representation and analysis of information. Both of the RNA and Jacket Matrix property also have the Element(Block) - wise Inverse Matrices. These matrix methods, which are connected closely with relations of symmetry, are borrowed for a matrix analysis of ensembles of molecular elements of the genetic code. This method is presented for its simplicity and the clarity with which it decomposes a Jacket Matrix in terms of the genetic RNA Codon.

Quasi-Cyclic LDPC Codes using Superposition Matrices and Their Layered Decoders for Wibro Systems (Wibro 시스템에서 중첩 행렬을 이용한 준 순환 LDPC 부호의 설계 및 계층 복호기)

  • Shin, Beom-Kyu;Park, Ho-Sung;Kim, Sang-Hyo;No, Jong-Seon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.2B
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    • pp.325-333
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    • 2010
  • Most communication systems including Wibro use quasi-cyclic LDPC codes composed of circulants. However, it is very difficult to design quasi-cyclic(QC) LDPC codes with optimal degree distribution satisfying conditions on layered decoding and girth due to the restriction of the size of its base matrix. In this paper, we propose a good solution by introducing superposition matrices to QC LDPC codes. We derive the conditions on checking girth of QC LDPC codes with superposition matrices, and propose new decoder to support layered decoding both for original QC LDPC codes and their modifications with superposition matrices. Simulation results show considerable improvements to convergence speed and error-correcting performance of proposed scheme which adopts QC LDPC codes with superposition matrices.

A Study for Spectral Properties of Preconditioner of Symmetric Toeplitz Systems (대칭 토플리츠 시스템의 선행조건에 대한 특정성질 연구)

  • Baik, Ran
    • Journal of Digital Contents Society
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    • v.10 no.4
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    • pp.579-585
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    • 2009
  • In [9], Tyrtshnikov proposed a preconditioned approach to derive a general solution from a Toeplitz linear system. Furthermore, the process of selecting a preconditioner matrix from symmetric Toeplitz matrix, which has been used in previous studies, is introduced. This research introduces a new method for finding the preconditioner in a Toeplitz system. Also, through analyzing these preconditioners, it is derived that eigenvalues of a symmetric Toeplitz are very close to eigenvalues of a new preconditioner for T. It is shown that if the spectrum of the preconditioned system $C_0^{-1}T$ is clustered around 1, then the convergence rate of the preconditioned system is superlinear. From these results, it is determined to get the superliner at the convergence rate by our good preconditioner $C_0$. Moreover, an advantage is driven by increasing various applications i. e. image processing, signal processing, etc. in this study from the proposed preconditioners for Toeplitz matrices. Another characteristic, which this research holds, is that the preconditioner retains the properties of the Toeplitz matrix.

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Noise Reduction by Using Eigenfilter in Cyclic Prefix System Based on SNR (SNR에 기초한 순환적 전치 부호를 가지는 시스템에서 고유필터를 사용한 잡음 제거)

  • Kim, Jin-Goog
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.10
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    • pp.700-707
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    • 2014
  • In this paper, we propose the noise reduction method by using the eigenfilter in cyclic prefix system based on SNR. To obtain the signal eigenvectors for the eigenfiltering, we propose a method of obtaining the autocorrelation matrix by exploiting the circulant property of the received block which results from the cyclic extension of the OFDM symbol. Since the structures of the transmitter and the receiver are not changed, the proposed method is easy to apply to the conventional OFDM system. To verify the proposed method, we evaluate the persistency of excitation (POE) criterion for the input and demonstrate the effectiveness of the proposed method in the simulation results.