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[Keyword] directional error(11hit)

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  • Data Association in Bistatic MIMO of T/R-R Mode: Basis Decision and Performance Analysis

    Xiang DUAN  Zishu HE  Hongming LIU  Jun LI  

     
    PAPER-Digital Signal Processing

      Vol:
    E99-A No:8
      Page(s):
    1567-1575

    Bistatic multi-input multi-output (MIMO) radar has the capability of measuring the transmit angle from the receiving array, which means the existence of information redundancy and benefits data association. In this paper, a data association decision for bistatic MIMO radar is proposed and the performance advantages of bistatic MIMO radar in data association is analyzed and evaluated. First, the parameters obtained by receiving array are sent to the association center via coordinate conversion. Second, referencing the nearest neighbor association (NN) algorithm, an improved association decision is proposed with the transmit angle and target range as association statistics. This method can evade the adverse effects of the angle system errors to data association. Finally, data association probability in the presence of array directional error is derived and the correctness of derivation result is testified via Monte Carlo simulation experiments. Besides that performance comparison with the conventional phased array radar verifies the excellent performance of bistatic MIMO Radar in data association.

  • Bidirectional Limited-Magnitude Error Correction Codes for Flash Memories

    Myeongwoon JEON  Jungwoo LEE  

     
    PAPER-Coding Theory

      Vol:
    E96-A No:7
      Page(s):
    1602-1608

    NAND multi-level cell (MLC) flash memories are widely used due to low cost and high capacity. However, the increased number of levels in MLC results in larger interference and errors. The errors in MLC flash memories tend to be directional and limited-magnitude. Many related works focus on asymmetric errors, but bidirectional errors also occur because of the bidirectional interference and the adjustment of the hard-decision reference voltages. To take advantage of the characteristics, we propose t bidirectional (lu,ld) limited-magnitude error correction codes, which can reduce errors more effectively. The proposed code is systematic, and can correct t bidirectional errors with upward and downward magnitude of lu and ld, respectively. The proposed method is advantageous in that the parity size is reduced, and it has lower bit error rate than conventional error correction codes with the same code rate.

  • A Class of Array Codes Correcting a Cluster of Unidirectional Errors for Two-Dimensional Matrix Symbols

    Haruhiko KANEKO  Eiji FUJIWARA  

     
    PAPER-Coding Theory

      Vol:
    E92-A No:6
      Page(s):
    1508-1519

    Two-dimensional (2D) matrix symbols have higher storage capacity than conventional bar-codes, and hence have been used in various applications, including parts management in factories and Internet site addressing in camera-equipped mobile phones. These symbols generally utilize strong error control codes to protect data from errors caused by blots and scratches, and therefore require a large number of check bits. Because 2D matrix symbols are expressed in black and white dot patterns, blots and scratches often induce clusters of unidirectional errors (i.e., errors that affect black but not white dots, or vice versa). This paper proposes a new class of unidirectional lm ln-clustered error correcting codes capable of correcting unidirectional errors confined to a rectangle with lm rows and ln columns. The proposed code employs 2D interleaved parity-checks, as well as vertical and horizontal arithmetic residue checks. Clustered error pattern is derived using the 2D interleaved parity-checks, while vertical and horizontal positions of the error are calculated using the vertical and horizontal arithmetic residue checks. This paper also derives an upper bound on the number of codewords based on Hamming bound. Evaluation shows that the proposed code provides high code rate close to the bound. For example, for correcting a cluster of unidirectional 40 40 errors in 150 150 codeword, the code rate of the proposed code is 0.9272, while the upper bound is 0.9284.

  • A Novel Prefilter-Type Beamformer Robust to Directional Error

    Sung-Soo HWANG  Yong-Hwan LEE  

     
    LETTER-Antennas and Propagation

      Vol:
    E87-B No:11
      Page(s):
    3389-3391

    Some conventional beamformers require the direction of the desired signal. The performance of such beamformers can substantially be degraded even in the presence of small error on the directional information. In this letter, we propose a prefilter-type beamforming scheme robust to directional error by employing a simple compensator. The performance of the proposed scheme is verified by computer simulation.

  • A Systematic Construction of Inner Codes in Generalized Concatenated Codes for Correcting Unidirectional Byte Errors

    Ching-Nung YANG  Chi-Sung LAIH  

     
    LETTER-Information Theory and Coding Theory

      Vol:
    E81-A No:2
      Page(s):
    351-354

    In [1] a generalized concatenated code was used to construct the t-fold unidirectional b-bit-byte error-correcting/d(dt)-fold unidirectional b-bit-byte error-detecting (t-UbEC/d(t)-UbED) codes. The concatenated code is to choose an inner code satisfying some disjoint sets and each set is a binary b-tuples unordered code. However, [1] gave five methods including trial and error to construct the optimal inner codes. Here, we present a systematic method for constructing the inner codes. It is shown that we can improve the coding efficiency for t-UbEC/d(t)-UbED) codes in some cases by using our inner codes.

  • Generating Functions for Asymmetric/Unidirectional Error Correcting and Detecting Codes

    Ching-Nung YANG  Chi-Sung LAIH  

     
    PAPER-Information Theory and Coding Theory

      Vol:
    E80-A No:6
      Page(s):
    1135-1142

    Constantin and Rao have given a method for constructing single asymmetric error correcting (SAEC) codes based on the theory of the Abelian group, This paper uses the method of generating function in combinatorics to solve the implementation problems of the SAEC group theoretic codes. The encoding and decoding algorithms of the coding scheme perform simple arithmetic operations recursively. The idea of generating function can also be applied to t symmetric errors and simultaneously detect all unidirectional errors (t-syEC/AUED) codes for 1t3.

  • Unidirectional Byte Error Locating Codes

    Shuxin JIANG  Eiji FUJIWARA  

     
    PAPER

      Vol:
    E77-A No:8
      Page(s):
    1253-1260

    This papter proposes a new type of unidirectional error control codes which indicates the location of unidirectional errors clustered in b-bit length, i.e., unidirectional byte error in b (b2) bits. Single unidirectional b-bit byte error locating codes, called SUbEL codes, are first clarified using necessary and sufficient conditions, and then code construction algorithm is demonstrated. The lower bound on check bit length of the SUbEL codes is derived. Based on this, the proposed codes are shown to be very efficient. Using the code design concept presented for the SUbEL codes, it is demonstrated that generalized unidirectional byte error locating codes are easily constructed.

  • A Decoding Algorithm and Some Properties of Böinck and Tilborg's t-EC/AUED Code

    Kenji YOSHIDA  Hajime JINUSHI  Kohichi SAKANIWA  

     
    LETTER-Information Theory and Coding Theory

      Vol:
    E76-A No:9
      Page(s):
    1535-1536

    We propose a decoding algorithm for the t-EC/AUED code proposed by Böinck and Tiborg. The proposed algorithm also reveals some remarkable properties of the code.

  • Semidistance Codes and t-Symmetric Error Correting/All Unidirectional Error Detectiong Codes

    Kenji NAEMURA  

     
    PAPER-Fault Tolerant Computing

      Vol:
    E75-D No:6
      Page(s):
    873-883

    The paper considers the design of two families of binary block codes developed for controlling large numbers of errors which may occur in LSI, optical disks and other devices. The semidistance codes are capable of assuring a required signal-to-noise ratio in information retrieval; the t-symmetric error correcting/all unidirectional error detecting" (t-SyEC/AUED) codes are capable of correcting t or fewer symmetric errors and also detecting any number of unidirectional errors caused by the asymmetric nature of transmission or storage madia. The paper establishes an equivalence between these families of codes, and proposes improved methods for constructing, for any values of t, a class of nonsystematic constant weight codes as well as a class of systematic codes. The constructed codes of both classes are shown to be optimal when t is O, and of asymptotically optimal order" in general cases. The number of redundant bits of the obtained nonsystematic code is of the order of (t+1/2)log2 K bits, where K is the amount of information encoded. The obtained systematic codes have redundancy of the order of (t+1)log2 K bits.

  • Runlength-Limited Short-Length Codes for Unidirectional-Byte-Error-Control

    Yuichi SAITOH  Hideki IMAI  

     
    PAPER

      Vol:
    E75-A No:9
      Page(s):
    1057-1062

    Runlength-limited block codes are investigated. These codes are useful for storing data in storage devices. Since most devices are not noiselss, the codes are often required to have some error-control capability. We consider runlength-limited codes that can correct or detect unidirectional byte errors. Some constructions of such codes are presented.

  • Construction of m-out-of-k-Systematic t-Symmetric Error Correcting/All Unidirectional Error Detecting Codes

    Kenji NAEMURA  

     
    LETTER

      Vol:
    E75-A No:9
      Page(s):
    1128-1133

    This letter considers a subclass of t-symmetric error correcting/all unidirectional error detecting (t-SyEC/AUED) codes in which the information is represented in an m-out-of-k coded form, which thus can be regarded as virtually systematic for practical purposes. For t3, previous researchers proposed methods for constructing codes of this subclass which are either optimal or of asymptotically optimal order. This letter proposes a new method for constructing, for any values of t, m and k, codes that are either optimal or of asymptotically optimal order. The redundancy of the obtained code is of the order tlog2k bits when mt.