• Title/Summary/Keyword: k-Hadamard

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Eigenvalues of Non-Sylvester Hadamard Matrices Constructed by Monomial Permutation Matrices (단항순열행렬에 의해 구성된 비실베스터 하다마드 행렬의 고유치)

  • Lee Seung-Rae;No Jong-Seon;Sung Koeng-Mo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.4C
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    • pp.434-440
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    • 2006
  • In this paper, the eigenvalues of various non-Sylvester Hadamard matrices constructed by monomial permutation matrices are derived, which shows the relation between the eigenvalues of the newly constructed matrix and Sylvester Hadamard matrix.

Generalized Complex Hadamard Codes

  • Jiang, Xue-Qin;Shin, Tae-Chol;Lee, Moon-Ho;Hwang, Gi-Yean
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.1053-1054
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    • 2006
  • In this paper we consider a family {$H_m$},m =1,2,..., of generalized Hadamard matrices of order $P^m$, where p is a prime number, and construct the corresponding family {$C^*_m$} of generalize p-ary Hadarmard codes which meet the Plotkin bound. Index terms: Cyclotomic fields, cocyclic matrices, Butson-Hadamard matrices, generalized Hadamard codes, decoding.

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Modified Hadamard Codes for Spectral-Amplitude-Coding Optical CDMA (Spectral-Amplitude-Coding Optical CDMA를 위한 Modified Hadamard Code)

  • Jhee, Yoon-Kyoo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.8
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    • pp.5-9
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    • 2011
  • Spectral-amplitude-coding optical CDMA systems using codes based upon Hadamard matrices have very restrictive code lengths of $2^n$ and high phase-induced intensity noise(PIIN). In this paper a new code family, namely modified Hadamard code, is proposed to relax the code length restriction and the number of simultaneous users. The improved performance of the proposed system is analysed with the consideration of noise.

CONVEXITY OF DISTANCE FUNCTION BETWEEN GEODESICS

  • Kim, In-Su;Kim, Yong-Il;Lee, Doo-Hann
    • Honam Mathematical Journal
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    • v.30 no.2
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    • pp.335-341
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    • 2008
  • In this paper, we use the convexity of distance function between geodesics in a singular Hadamard space to generalize Hadamard-Cartan theorem for 2-dimensional metric spaces. We also determine a neighborhood of a closed geodesic where no other closed geodesic exists in a complete space of nonpositive curvature.

On Fast M-Gold Hadamard Sequence Transform (고속 M-Gold-Hadamard 시퀀스 트랜스폼)

  • Lee, Mi-Sung;Lee, Moon-Ho;Park, Ju-Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.7
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    • pp.93-101
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    • 2010
  • In this paper we generate Gold-sequence by using M-sequence which is made by two primitive polynomial of GF(2). Generally M-sequence is generated by linear feedback shift register code generator. Here we show that this matrix of appropriate permutation has Hadamard matrix property. This matrix proves that Gold-sequence through two M-sequence and additive matrix of one column has one of major properties of Hadamard matrix, orthogonal. and this matrix show another property that multiplication with one matrix and transpose matrix of this matrix have the result of unit matrix. Also M-sequence which is made by linear feedback shift register gets Hadamard matrix property mentioned above by adding matrices of one column and one row. And high-speed conversion is possible through L-matrix and the S-matrix.

A META-SOFTWARE SYSTEM FOR ORTHOGONAL DESIGNS AND HADAMARD MATRICES

  • Kotsireas, Ilias S.;Koukouvinos, Christos;Simos, Dimitris E.
    • Journal of applied mathematics & informatics
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    • v.29 no.5_6
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    • pp.1571-1581
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    • 2011
  • In this paper, we construct inequivalent Hadamard matrices based on several new and old full orthogonal designs, using circulant and symmetric block matrices. Not all orthogonal designs produce inequivalent Hadamard matrices, because the corresponding systems of equations do not possess solutions. The systems of equations arising when we search for inequivalent Hadamard matrices from full orthogonal designs using circulant and symmetric block matrices, can be concisely described using the periodic autocorrelation function of the generators of the block matrices. We use Maple, Magma, C and Unix tools to find many new inequivalent Hadamard matrices.

Blind Channel Estimation based on Hadamard Matrix Interstream Transmission for Multi-Cell MIMO Networks (다중 셀 MIMO 네트워크를 위한 Hadamard 행렬 Interstream 전송 기반 Blind 채널 추정)

  • Yang, Jae-Seung;Hanif, Mohammad Abu;Park, Ju-Yong;Lee, Moon-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.119-125
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    • 2015
  • In this paper, we introduce a Hadamard matrix interstream transmission based blind channel estimation for multi-cells multiple-input and multiple-output (MIMO) networks. The proposed scheme is based on a network with mobile stations (MS) which are deployed with multi cells. We assume that the MS have the signals from both cells. The signal from near cell are considered as desired signal and the signals from the other cells are interference signal. Since the channel is blind, so that we transmit Hadamard matrix pattern pilot stream to estimate the channel; that gives easier and fast channel estimation for large scale MIMO channel. The computation of Hadamard based system takes only complex additions, and thus the complexity of which is much lower than the scheme with Fourier transform since complex multiplications are not needed. The numerical analysis will give perfection of proposed channel estimation.