Jung-Soo Chung

New Sets of Optimal p-ary Low Correlation Zone Sequences

In this paper, we propose the new construction methods of constructing optimal low correlation zone (LCZ) sequences. We construct the new p-ary LCZ sequence sets by adopting p-ary sequence of period p m - 1 with ideal autocorrelation for integers n and m such that m n as a column sequence. The new construction methods give us the optimal sets with respect to the bound by Tang, Fan, and Matsufuji

Low correlation zone sequences

It is well known that low correlation zone sequences have been adopted as spreading sequences in the quasi-synchronous code division multiple access (QS-CDMA) systems of wireless communication systems, where time delay among different users is allowed to be within a few chips. In this paper, numerical analysis shows that the QS-CDMA systems using low correlation zone (LCZ) sequences outperform the conventional code division multiple access (CDMA) systems. Also, several LCZ sequences are revisited and a new extension method for the construction of LCZ sequences is proposed.

New construction of p-ary sequence family with large linear span

In this paper, we propose a method to construct sequence family S_r = {tr₁ ^m ([tr_m ⁿ (alpha^t) + tr_m ⁿ (balpha^dt)]^r) | b isin F_p ⁿ, 0 les t < pⁿ - 1} with large linear span from a sequence family S₁, where gcd(r, p^m - 1) = 1. Let T = (pⁿ - 1)/(p^m - 1). If dT = T mod pⁿ - 1, the correlation distributions of families S_r are the same. Two examples of decimation factor d satisfying the condition dT = T mod pⁿ - 1 are given and the linear span of the ternary sequences in S_r with d = 2p^m - 1 is derived for some cases.

Quaternary low correlation zone sequence set with flexible parameters

In this paper, we proposed a new quaternary low correlation zone(LCZ) sequence set with parameters (2(2n - 1),M, L, 2). The new LCZ sequence set is constructed from the binary sequence with ideal autocorrelation of period 2n - 1. The proposed construction method corresponds to the generalization of the construction method of binary LCZ sequence set by using binary sequence with ideal autocorrelation proposed by Kim, Jang, No, and Chung [1].

Generalized extending method for construction of q-ary low correlation zone sequence sets

In this paper, a new extending method of q-ary low correlation zone(LCZ) sequence sets is proposed, which is a generalization of binary LCZ sequence set by Kim, Jang, No, and Chung. Using this method, q-ary LCZ sequence set with parameters (N,M,L, isin) is extended as a q-ary LCZ sequence set with parameters (pN, pM, plfloor(L + 1)/plfloor - 1, pisin), where p is prime and p|q.

A new M-ary sequence family constructed from Sidel'nikov sequences

In this paper, a new family of M-ary sequences of period pⁿ −1 is proposed, which has large family size and the good correlation property, that is, the maximum magnitude of their correlation values is upper bounded by 4√pⁿ +5.