• The Magazine of the IEIE
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• v.11 no.2
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• pp.1-11
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• 1984

본 지 2월호에서 구술한 선형부호에 이어 이번호에서는 순회부호에 대해 기술하고자 한다. 선형블럭부호중 중요한 부류에 속하는 순회부호(cyclic code)는 그 내용이 대수적 구조를 갖고 있어 부호화 회로는 물론 부호에 필요한 오증(syndrome)계산회로 등 귀환연결이 있는 치환레지스터(shift register)를 사용한 장치화(implementation)가 매우 용이하다는 이점이 있다. 이런 순회부호는 산발오진(random error)뿐 아니라 연집오진(burst error)도 정정할 수 있는 매우 효과적인 부호로서 다중오진정정능력(multiple error correcting capability)을 갖는 BCH부호도 순회부호의 일종이다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10C
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• pp.605-613
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• 2011

In most digital communication systems over the noisy channel, some form of forward error correction scheme is employed for reliable communications. If one wants to recover the transmitted message without any knowledge of the error correcting codes employed, it is of utmost importance to figure out and reconstruct the error correcting codes. In this paper, we propose two algorithms of reconstructing linear cyclic codes from the corrupted received bit sequence, one for general linear binary cyclic codes and the other for Reed-Solomon codes. For two algorithms, we ran computer simulations and the performances are shown to be superior to those with the conventional LWM method.

• The Magazine of the IEIE
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• v.11 no.1
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• pp.11-18
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• 1984

부호이론(coding theory)은 그 내용이 매우 광범위할 뿐 아니라 군론, 환론, 본론 등 축예대수학과 확율론 및 수리통계학을 배경으로 발전된 학문이기 때문에 일반 속자를 상대로 논술하기에는 적지 않은 난점이 있다. 그렇다고 단순히 용어나열에만 그칠 수도 없고, 이론에 치중한 논문식으로 쓸수도 없으므로 대학 4년생을 위한 강의수준으로 소개하겠으며 3회에 걸쳐 선형부호(linear code), 순회부호(cyclic code), 길쌈부호(convolutional code)의 순으로 연재하기로 하겠다.

• The Magazine of the IEIE
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• v.11 no.3
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• pp.47-58
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• 1984

본지 2, 3월호에서 구술한 블록부호(선형부호 및 순회부호)에 이어 이번 호에서는 대합부호, 즉 길쌈부호(convolutional code)에 대해 기술하고자 한다. 길쌈부호는 그 부호법 중 역차 및 최근부호에 있어 그 구조적 표현이 대수학적(algebraic)이라기 보다는 오히려 위상학적(topological)이라는 점에서 주목할만한 특징을 지니고 있다. 길쌈부호를 응용한 예로는 1977년 NASA에 실시한 Voyager 우주탐사계획을 들 수 있다. 화성(Mars), 목성(Jupiter) 및 토성(Saturn) 등에서 일연의 과학 data 수집을 목적으로 했던 이 계획은 NASA소관 California공대 JPL연구소에서 개발한, 기억소자가 6단인(3, 1) 길쌈부호의 CODEC을 사용하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.8
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• pp.1128-1135
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• 1993

In this paper, new binary cyclic codes (hereafter, refered to as GMW code) which are generated by using GMW sequence, g(t) = tr((trk(a))r), and its cyclic shifts are introduced. Code length of GMW codes is 2a-1, where k is composite integer, e·J. Dimension of the GMW codes is k(k/j)w-1, where w is a Hamming weight of r. Several properties of GMW codes such as designed distance, minimum distance, and weights of code words are obtained in terms of parameters of GMW sequences. And expansion of GMW sequences in terms of m-sequence and its decimation sequences are introduced and characteristic polynomials of GMW sequences are also derived.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10A
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• pp.1576-1581
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• 2000

We investigated into the minimum distance of a primitive binary cyclic code C with a generator polynomial g(x)=$m_1(x)m_{d}(x)$. It is known that the necessary and sufficient condition for C to have minimum distance five is the fact that \ulcorner is an APN power function. In this paper we derived the new proof of minimum distance for the primitive binary cyclic codes with minimum distance five.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.10a
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• pp.1093-1096
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• 1996

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.326-335
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• 2006

Design criteria far a block code which guarantees minimized PAPR of the OFDM signals are proposed in this paper. Encoding procedure of the minimum PAPR codes (MPC) is composed of searching a seed codeword, circular shifting the register elements, and determining codeword inversion. It is shown that the PEP is invariant to the circular shift of register elements and codeword inversion. Based on such properties, systematic encoding rule for MPC is proposed. In addition proposed encoding rule can reduced greatly the size of look up table for MPC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.2
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• pp.156-163
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• 2013

The use of an error-correcting code is essential in communication systems where the channel is noisy. When channel coding parameters are unknown at a receiver side, decoding becomes difficult. To perform decoding without the channel coding information, we should estimate the parameters. In this paper, we introduce a method to reconstruct the generator polynomial of BCH(Bose-Chaudhuri-Hocquenghem) codes based on the idea that the generator polynomial is compose of minimal polynomials and BCH code is cyclic code. We present a probability compensation method to improve the reconstruction performance. This is based on the concept that a random data pattern can also be divisible by a minimal polynomial of the generator polynomial. And we confirm the performance improvement through an intensive computer simulation.

• The Transactions of the Korea Information Processing Society
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• v.2 no.5
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• pp.677-690
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• 1995

In this paper, we propose the high efficiency data compression capable of error control using block-sorting, move to front(MTF) and arithmetic code with variable length in to fixed out. First, the substring with is parsed into length N is shifted one by one symbol. The cyclic shifted rows are sorted in lexicographical order. Second, the MTF technique is applied to get the reference of locality in the sorted substring. Then the preprocessed sequence is coded using VF(variable to fixed) arithmetic code which can be limited the error propagation in one codeword. The key point is how to split the fixed length codeword in proportion to symbol probabilities in VF arithmetic code. We develop the new VF arithmetic coding that split completely the codeword set for arbitrary source alphabet. In addition to, an extended representation for symbol probability is designed by using recursive Gray conversion. The performance of proposed method is compared with other well-known source coding methods with respect to entropy, compression ratio and coding times.