• Title/Summary/Keyword: Hamming distance

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Performance of Space-Time Trellis Codes with Minimum Hamming Distance Mapping on Fast Fading Channels (빠른 페이딩 채널에서 MHD 매핑을 응용한 STTC 부호의 성능평가)

  • Jin, Ik-Soo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.2
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    • pp.96-103
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    • 2010
  • This paper studies the performance of STTC with minimum Hamming distance (MHD) mapping in order to improve the bit error rate (BER) performance. Unfortunately, the MHD mapping used in trellis coded modulation (TCM) or multiple trellis coded modulation (MTCM) cannot be directly applied to STTC because the trellis structure of STTC is generally different from that of TCM or MTCM. Therefore, we need a simple modification to apply the MHD mapping concept in STTC. The core of the modification assigns information bits with a Hamming distance in proportion to the sum of the Euclidean distance to trellis branch of STTC. To the best knowledge, this combination has not been considered yet. The BER performance is examined with simulations and the performance of MHD mapping is compared to that of well known natural mapping and Gray mapping on both fast Rayleigh as well as fast Rician fading channels. It is shown that the performance of MHD mapping is much better than that of natural mapping or Gray mapping over fast Rician fading channels, especially.

Performance Enhancement of Trellis Coded Mary PSK using Minimum Hamming Distance (최소해밍거리를 이용한 트렐리스 부호화된 M- ray PSK의 성능 향상)

  • 은도현;조훈상;이순흠
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.3
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    • pp.417-424
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    • 2001
  • This paper proposes new symbol mapping method that can enhance the performance of trellis coded M-ary PSK compared with conventional symbol mapping methods in AWGN environment. Since the basic criteria of TCM design is Maximum Euclidean distance in AWGN, conventional symbol mapping method keep this basic criteria. In this paper, proposed new symbol mapping method uses both Euclidean distance and Hamming distance to design, while conventional methods make use of only optimal Euclidean distance. New symbol mapping method show the better BER performance than the other through computer simulation and error equations.

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Robust Test Generation for Stuck-Open Faults in CMOS Circuits (CMOS 회로의 Stuck-open 고장검출을 위한 로보스트 테스트 생성)

  • Jung, Jun-Mo;Lim, In-Chil
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.11
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    • pp.42-48
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    • 1990
  • In this paper robust test generation for stuck-open faults in CMOS circuits is proposed. By obtaining initialization patterns and test patterns using the relationship of bit position and Hamming weight among input vectors for CMOS circuit test generation time for stuck-open faults can be reduced, and the problem of input transition skew which make fault detection difficult is solved, and the number of test sequences are minimized. Also the number of test sequences is reduced by arranging test sequences using Hamming distance between initialization patterns and test patterns for circuit.

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Ternary Content Addressable Memory with Hamming Distance Search Functions

  • Uchiyama, Hiroki;Tanaka, Hiroaki;Fukuhara, Masaaki;Yoshida, Masahiro;Suzuki, Yasoji
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1535-1538
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    • 2002
  • The flexibility of content addressable mem-ory (CAM) can greatly be extended through the use of trits (ternary digits) Trits consist of binary logical values “0” and “1” with addition of “x” (“dont’t care”). The “dont’t care“is extremely useful for providing com- pact representation of sets of bit strings. In this paper, we propose a new ternary CAM with Hamming distance search functions. Each memory cell in the CAM consists of a pair of lambda diodes which can store trits, namely, a logical “0”, “1” and “x” (“dont’t care“). The CAM can compare stored data and an input data in parallel, and find stored data with Hamming distance within a certain range (“near match“). Also, the interrogation characteristics of the ternary CAM are analyzed in detail. Furthermore, the results obtained these analyses are fully confirmed by simulation using the circuit analysis program HSPICE.

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Machine-printed Numeral Recognition using Weighted Template Matching (가중 원형 정합을 이용한 인쇄체 숫자 인식)

  • Jung, Min-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.3
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    • pp.554-559
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    • 2009
  • This paper proposes a new method of weighted template matching fur machine-printed numeral recognition. The proposed weighted template matching, which emphasizes the feature of a pattern using adaptive Hamming distance on local feature areas, improves the recognition rate while template matching processes an input image as one global feature. The experiment compares confusion matrices of the template matching, error back propagation neural network classifier, and the proposed weighted template matching respectively. The result shows that the proposed method improves fairly the recognition rate of the machine-printed numerals.

On the characteristics of the Hamming distances in medical diagnosis (의학진단에 이용되는 해밍 거리의 특성 탐색)

  • Ahn, Jeong-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.2
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    • pp.227-234
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    • 2012
  • Hamming distances in medical science are used for the diagnosis of diseases. The differences of the distances, however, are often very small, and is not in the general statistical form such as normal or chi-square distribution. In this study, we explore the characteristics and significance of the differences of Hamming distances generated in medical diagnosis.

Data Hiding in Halftone Images by XOR Block-Wise Operation with Difference Minimization

  • Yang, Ching-Nung;Ye, Guo-Cin;Kim, Cheon-Shik
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.2
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    • pp.457-476
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    • 2011
  • This paper presents an improved XOR-based Data Hiding Scheme (XDHS) to hide a halftone image in more than two halftone stego images. The hamming weight and hamming distance is a very important parameter affecting the quality of a halftone image. For this reason, we proposed a method that involves minimizing the hamming weights and hamming distances between the stego image and cover image in $2{\times}2$-pixel grids. Moreover, our XDHS adopts a block-wise operation to improve the quality of a halftone image and stego images. Furthermore, our scheme improves security by using a block-wise operation with A-patterns and B-patterns. Our XDHS method achieves a high quality with good security compared to the prior arts. An experiment verified the superiority of our XDHS compared with previous methods.

A Study on Fast Matching of Binary Feature Descriptors through Sequential Analysis of Partial Hamming Distances (부분 해밍 거리의 순차적 분석을 통한 이진 특징 기술자의 고속 정합에 관한 연구)

  • Park, Hanhoon;Moon, Kwang-Seok
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.4
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    • pp.217-221
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    • 2013
  • Recently, researches for methods of generating binary feature descriptors have been actively done. Since matching of binary feature descriptors uses Hamming distance which is based on bit operations, it is much more efficient than that of previous general feature descriptors which uses Euclidean distance based on real number operations. However, since increase in the number of features linearly drops matching speed, in applications such as object tracking where real-time applicability is a must, there has been an increasing demand for methods of further improving the matching speed of binary feature descriptors. In this regard, this paper proposes a method that improves the matching speed greatly while maintaining the matching accuracy by splitting high dimensional binary feature descriptors to several low dimensional ones and sequentially analyzing their partial Hamming distances. To evaluate the efficiency of the proposed method, experiments of comparison with previous matching methods are conducted. In addition, this paper discusses schemes of generating binary feature descriptors for maximizing the performance of the proposed method. Based on the analysis on the performance of several generation schemes, we try to find out the most effective scheme.

Analysis of CRC-p Code Performance and Determination of Optimal CRC Code for VHF Band Maritime Ad-hoc Wireless Communication (CRC-p 코드 성능분석 및 VHF 대역 해양 ad-hoc 무선 통신용 최적 CRC 코드의 결정)

  • Cha, You-Gang;Cheong, Cha-Keon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.6A
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    • pp.438-449
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    • 2012
  • This paper presents new CRC-p codes for VHF band maritime wireless communication system based on performance analysis of various CRC codes. For this purpose, we firstly describe the method of determination of undetected error probability and minimum Hamming distance according to variation of CRC codeword length. By using the fact that the dual code of cyclic Hamming code and primitive BCH code become maximum length codes, we present an algorithm for computation of undetected error probability and minimum Hamming distance where the concept of simple hardware that is consisted of linear feedback shift register is utilized to compute the weight distribution of CRC codes. We also present construction of transmit data frame of VHF band maritime wireless communication system and specification of major communication parameters. Finally, new optimal CRC-p codes are presented based on the simulation results of undetected error probability and minimum Hamming distance using the various generator polynomials of CRC codes, and their performances are evaluated with simulation results of bit error rate based on the Rician maritime channel model and ${\pi}$/4-DQPSK modulator.

A Weight on Boolean Algebras for Cryptography and Error Correcting Codes (암호학 및 오류 수정 코드를 위한 부울 대수 가중치 연구)

  • Yon, Yong-Ho;Kang, An-Na
    • Journal of Advanced Navigation Technology
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    • v.15 no.5
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    • pp.781-788
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    • 2011
  • A sphere-packing problem is to find an arrangement of the spheres to fill as large area of the given space as possible, and covering problems are optimization problems which are dual problems to the packing problems. We generalize the concepts of the weight and the Hamming distance for a binary code to those of Boolean algebra. In this paper, we define a weight and a distance on a Boolean algebra and research some properties of the weight and the distance. Also, we prove the notions of the sphere-packing bound and the Gilbert-Varshamov bound on Boolean algebra.