• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.7 no.4
• /
• pp.81-90
• /
• 1997

키 수열 발생기는 함수 조합 형태에 따라 여러 가지로 분류될 수 있으며, 비도 기본 요소(랜덤 특성, 주기, 선형 복잡도, 상관 면역도, 키 수열의 수 등)는 비선형 함수에 따라 달라진다. 모든 기본 요소를 잘 만족하는 키 수열 발생기는 설계가 어렵지만, 각 요소별로 특성이 뛰어난 발생기를 잘 조합하면 고비도 시스템을 설계할 수 있다. 본 논문에서는 선형 복잡도와 상관 면역도 측면에서 강한 개선된 합산 수열 발생기와 키 수열 수사 많은 일반화된 메모리 다수열 발생기를 조합하여 혼합형 수열 발생기를 제안하고, 비도 수준을 분석하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.5C
• /
• pp.313-319
• /
• 2005

In this paper, we propose a class of polyphase signature sequences, whose general odd correlation properties are useful for 4-phase signaling systems. The performance of the direct sequence code division multiple access (DS/CDMA) systems using the proposed sequences is compared with that using binary pseudo-noise sequences. The performance of the system using the proposed sequence is shown to be better than that using other conventional sequences both from the worst-case analysis and bit error rate simulations.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.1C
• /
• pp.6-11
• /
• 2008

From a periodic sequence, we can obtain new sequences with a longer period by r-symbol insertion to each period. In this paper we review previous results on the linear complexity of periodic sequences obtained by r-symbol insertion. We derive the distribution of the linear complexity of 1-symbol insertion sequences obtained from m-sequences over GF(p), and prove some relationship between their linear complexity and the insertion position. Then, we analyze the k-error linear complexity of the 1-symbol insertion sequences from binary m-sequences.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.11C
• /
• pp.1059-1065
• /
• 2007

In this paper, we propose a class of polyphase signature sequences, whose general odd correlation properties are useful for M-ary phase signaling systems. The maximum magnitude of the general odd correlation functions of the proposed sequences are investigated and compared with those of FZC (Frank-Zadoff-Chu) sequences and those of EOE (equivalent odd and even correlation) sequences. The performance of the asynchronous M-ary phase signaling systems using the proposed sequences is simulated and compared with that using FZC sequences in direct sequence code division multiple access (DS/CDMA) systems. The performance of the system using the proposed sequence is shown to be better than that using FZC sequences when the multipath fading is in existence.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.2C
• /
• pp.169-174
• /
• 2009

In this paper, we propose a new construction method of binary low correlation zone (LCZ) sequence set. New construction method applies Gray mapping to conventional quaternary LCZ sequence set that has specific property. The period of new binary sequence set is twice as that of used sequence set in construction, and maximum magnitude of correlation value within the LCZ and cardinality of new set is also twice as those of used quaternary sequence set. But the LCZ size is the same with that of used sequence set. If the used Quaternary sequence set is optimal, the constructed binary sequence set is optimal with high probability.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.4
• /
• pp.730-736
• /
• 2012

PN(Pseudo Noise) sequences play an important role in wireless communications, such as in a CDMA(code division multiple access) communication system. If there is a crash when multiple users simultaneously connected to a system, then PN sequences with low correlation help to minimize multiple access interference in such communication system. In this paper we propose a family of non-linear extended binary sequences with low cross-correlations and the family include $m$-sequence, GMW sequence, Kasami sequence and No sequence with optimal cross-correlation in terms of Welch bound. And we analyze cross-correlation of these sequences.

• The Korean Journal of Applied Statistics
• /
• v.22 no.5
• /
• pp.1103-1113
• /
• 2009

We know that the first digits sequence of fibonacci numbers obey Benford's law. For the sequence in which the first two numbers are the arbitrary integers and the recurrence relation $a_{n+2}=a_{n+1}+a_n$ is satisfied, we can find that the first digits sequence of this sequence obey Benford's law. Also, we can find the stucture of the first digits sequence of this sequence with the exploratory data analysis tools.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.1
• /
• pp.97-104
• /
• 2011

Pseudo-random sequences with high linear complexity and low correlation function values are widely used in communication and cryptology. In this paper, we study the properties of interleaved sequences generated by shrinking generator. And we give a method for obtaining the shrunken sequence from a partial description of the shrunken sequence by using the phase shifting of PN sequences generated by shrinking generator.

• Communications of Mathematical Education
• /
• v.26 no.2
• /
• pp.205-220
• /
• 2012

In this article convergent sequences with natural number terms are investigated and the behaviors of tails and limits of these natural number sequences are explored. Firstly this study showed how the pre-service teachers response to the intuitive limit definition using "getting closer" for constant sequences. As a case of convergent natural sequences, the sequences in which the latter term is determined by the sum of digit squares of the former term are considered. To exploring these sequences the computational and charting capabilities of spreadsheets are utilized and some mathematical findings are obtained. Spreadsheet can be instrumentalized by teachers or students to provide a laboratory-like environment to explore a mathematical problem.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.228-231
• /
• 2012

In this paper we propose a new family of nonlinear binary sequences generated by $m$-sequences for decimations $d=2^{k-1}(2^{s+1}-2^k+2^{k(i+1)}-2^{ki}-1)/(2^s-1)$ where $n=2k$, $i$ is odd and $s$ is such that $2s$ divides $k$. And we analyze the cross-correlation function between two $m$-sequences for new decimations $d$. Proposed sequences is extension of Rosendahl's sequnces and Dobbertin's sequences.