• Title, Summary, Keyword: 에러 정정 부호

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Performance Analysis of Coded FH/SSMA Communication Network system (부호화한 주파수 도약 대역 확산 통신 네트워크의 성능 분석)

  • 김근묵;정영지;홍은기;황금찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.7
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    • pp.730-738
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    • 1992
  • This paper alms to analyse the performance of frequency hopping /spread spectrum multiple access system by employing the channel with mixture of AWGN, partial band Jamming, fading and user interference. The performance analysis of FH /SSMA system, taking account of frequency 'hit'(user Interference ) which occurs in the presence of multiple user, produces the following numerical results by computing error probability and throughput of each code in two cases whether the side Information about channel is used or not. The numerical results are as follows : When composite interferences coexist In channel, RS code Is significantly superior to convolutional code in terms of performance. Concatenated code provides the same performance as RS code. The above results show that RS code is pertinent as error-correction code.

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Parallel BCH Encoding/decoding Method and VLSI Design for Nonvolatile Memory (비휘발성 메모리를 위한 병렬 BCH 인코딩/디코딩 방법 및 VLSI 설계)

  • Lee, Sang-Hyuk;Baek, Kwang-Hyun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.5
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    • pp.41-47
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    • 2010
  • This paper has proposed parallel BCH, one of error correction coding methods which has been used to NAND flash memory for SSD(solid state disk). To alter error correction capability, the proposed design improved reliability on data block has higher error rate as used frequency increasingly. Decoding parallel process bit width is as two times as encoding parallel process bit width, that could reduce decoding processing time, accordingly resulting in one half reduction over conventional ECC.

Study of error effects on SNR scalable coded bitstreams in the error channle environment (에러 채널 환경에서 SNR 계층부호화된 비트스트림의 에러 영향력에 관한 연구)

  • 박성찬;정정균;이귀상
    • Proceedings of the Korean Information Science Society Conference
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    • pp.421-423
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    • 2001
  • H.263 부호화 기법에 비해 H.263+에서의 주용 특징중 하나는 에러 강인성으로, 그중에서 계층부호화 모드는 한 개의 송신 영상에 대해서도 복호기와 전송로에 따라 여러 가지 화질의 재생 영상을 얻을 수 있는 기능, 즉 에러 및 패킷 손실 발생 가능 채널에서 비디오 정보 전송시 디코더측에서 사용 가능한 다양한 비트율, 해상도, 디스플레이 율을 허용함으로써 비디오 정보에 대한 전송을 향상시키는 기법이다. FEC(Forward Error Correction)기법에 의한 부가적인 비트 삽입에 제한적인 저 대역폭 네트워크 및 무선 통신망과 같은 네트워크 환경에서는 ATM(Asynchronous Transfer Mode)망에서와 같인 계층부호화된 비트 스트림의 기본 계층에 대해 무손실 전송이 어려우므로, 고급계층과 동등한 채널을 통해 전송시 기본계층 및 고급계층 모두에 대해서는 에러가 발생 할 수 있다. 따라서, 본 연구에서는 저대역폭 비디오 전송을 위해 계층 부호화 모드중 SNR(Signal to Noise Ratio) 계층부호화로 부호화된 비트스트림을 에러 발생가능 채널로 전송시 각 계층에 대한 에러의 영향력을 실험한다.

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Estimation of Error Performance for Digital Satellite Communication (디지털 위성통신 시스템에서의 오류 성능 추정)

  • Yeo, Sung-Moon;Kim, Soo-Young
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.2
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    • pp.52-59
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    • 2008
  • Recommendation ITU-R S.1062 specifies the performance of digital satellite systems. The performance objectives were given in terms of bit error probability divided by the average number of errors per burst versus percentage of time. This performance objective is highly dependent on the forward error correction(FEC) coding schemes used in the system. This implies that we need an effective way of estimating the error performance of a system by the given FEC scheme. In this paper, we derive theoretical formula to estimate performance measure of digital satellite systems defined in Recommendation ITU-R S.1062. We demonstrate various estimation results, and verify them by comparing to the simulation results.

Trellis Encoding of 6/8 Balanced Code for Holographic Data Storage Systems (홀로그래픽 저장장치를 위한 2차원 6/8 균형부호의 트렐리스 인코딩)

  • Kim, Byungsun;Lee, Jaejin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.10
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    • pp.569-573
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    • 2014
  • Holographic data storage is a strong contender to become the next-generation data storage method. Its major weaknesses are two-dimensional intersymbol interference between neighboring pixels and interpage interference caused by storing multiple pages in a single volume of hologram. In this paper, we present a trellis encoding scheme of 6/8 balanced modulation code, to address the two weaknesses. The proposed modulation coding scheme captures on characteristics of the balanced code: the scheme relaxes IPI and enables error correction by exploiting the trellis structure. The proposed method showed improved SNR over the conventional 6/8 modulation code.

Performance Comparison of LDPC codes with Different Soft-output Algorithm for High Density Optical Recording Channel (고밀도 광 기록 채널에서 LDPC 부호의 연판정 출력 알고리즘별 성능비교)

  • Lee, Bong-Il;Lee, Jae-Jin
    • Proceedings of the IEEK Conference
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    • pp.891-892
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    • 2008
  • 본 논문에서는 최근 주목받고 있는 에러 정정 기법 중 하나인 LDPC(Low Density Parity Check) 부호를 광 기록 채널(Optical Recording Channel)에 적용해 보았고 이때 사용되는 연판정 출력 알고리즘으로 MAP과 SOVA를 이용하여 성능을 비교하였다.

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The FPGA Implementation of The Viterbi Algorithm for Error Correcting (에러 정정을 위한 Viterbi 알고리즘의 FPGA 구현)

  • 조현숙;한승조;이상호
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.9 no.1
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    • pp.115-126
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    • 1999
  • As the processing speed of communication and computer system has been improved, high speed data processing is required to correct error of data. In this paper, decoding algorithm which is applicable to the wireless communication system is proposed and encoder and decoder are designed by using the proposed decoding algorithm. We design the encoder and decoder by using the VHDL(VHSIC Hardware Description Language) and simulate the designed encoder and decoder by using V-system. Designed algorithm is synthesized by using synopsys tools and is made to one chip by means of XILINX XC4010EPC84-4. When 20MHz was used as the input clock, data arrival time was 29.20ns and data require time was 48.70ns.

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An Efficient Algorithm for Soft-Decision Decoding of Linear Block Codes (선형 블록 부호의 연판정 복호를 위한 효율적인 알고리듬)

  • Shim, Yong-Geol
    • The KIPS Transactions:PartC
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    • v.10C no.1
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    • pp.27-32
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    • 2003
  • An efficient soft-decision decoding algorithm for binary block codes it proposed. The proposed soft-decision decoding algorithm is implemented by a series of hard-decision decoding process. By the hard-decision decoding result, the candidate codewords are efficiently searched for A new decoding method, which prevents the missing of the candidate codeword, is proposed. Also, the method fir reducing complexity is developed. This method removes the practical complexity increase caused by the improved algorithm. There facts are confirmed by the simulation results for binary (63, 36) BCH code.

A Low Density Parity Check Coding using the Weighted Bit-flipping Method (가중치가 부과된 Bit-flipping 기법을 이용한 LDPC 코딩)

  • Joh, Kyung-Hyun;Ra, Keuk-Hwan
    • 전자공학회논문지 IE
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    • v.43 no.4
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    • pp.115-121
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    • 2006
  • In this paper, we proposed about data error check and correction on channel transmission in the communication system. LDPC codes are used for minimizing channel errors by modeling AWGN Channel as a VDSL system. Because LDPC Codes use low density parity bit, mathematical complexity is low and relating processing time becomes shorten. Also the performance of LDPC code is better than that of turbo code in long code word on iterative decoding algorithm. This algorithm is better than conventional algorithms to correct errors, the proposed algorithm assigns weights for errors concerning parity bits. The proposed weighted Bit-flipping algorithm is better than the conventional Bit-flipping algorithm and we are recognized improve gain rate of 1 dB.

A Study on Frequency-Hopped Code Division Multiple Access for Mobile Radio (이동무선통신을 위한 주파수 도약부호 분할 다중접근에 관한 연구)

  • 한영렬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.14 no.3
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    • pp.227-234
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    • 1989
  • In this paper, a new receiver for a frequency-hopped multilevel FSK system for mobile Communications is presented. This new receiver provides an implementation advantage by eliminating unecessary energy detection of all the frequency channels. A performace analysis of the proposed system is carried out by using the union bound. We show that an optimim number of message bits that minimize the word error probability exists for a given number of simultaneous users. This scheme is a generalization of the MFSK system that allows the message bits to be uaried, making it possible for designers to increase the flexibility of implementation. Error probabilities are calculated in the case of fixed bandwidth and fixed tone repetition number. The effect of using error-correcting coding is considered.

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