Low Correlation Zone Sequence Research Articles

Millimeter-Wave Phase-Coded CW MIMO Radar Using Zero- and Low-Correlation-Zone Sequence Sets

A phase-coded continuous-wave multiple-input multiple-output (MIMO) radar based on code division multiplexing is presented. Zero-correlation-zone (ZCZ) and low-correlation-zone (LCZ) sequence sets are used to separate signals from multiple transmitters at the receivers. In particular, we investigate three different sequence set types: an equidistantly shifted almost-perfect autocorrelation sequence set, sequence sets based on mutually orthogonal Golay complementary sets, and a binary LCZ sequence set. The required sequence lengths are discussed according to the physical propagation behavior in a radar sensor scenario. Furthermore, we summarize the theoretical limitations of LCZ/ZCZ sequence sets and provide examples with regard to the chosen scenario. We present measurements carried out with a software-defined radar platform, which is equipped with 16 MIMO channels operating at a frequency of 77 GHz. We investigated the behavior of the sequence sets on real hardware in the range, cross-range, and range-Doppler domains.

New constructions of quaternary low correlation zone sequence sets

Sequence sets with low correlation have very important applications in modern communication systems. As in quasi-synchronous code-division multiple access (QS-CDMA) system, sequence sets with low correlation zone (LCZ) perform better than other well-known sequence sets. Furthermore, binary or quaternary sequence sets are preferred because of their easy implementation. In this paper, based on the inverse Gray mapping and special binary sequence pairs, new quaternary LCZ sequence sets were constructed. In the LCZ, the maximum of the nontrivial autocorrelation and crosscorrelation values is 1 which show that the QS-CDMA system used the new sequences sets can control the interference in a very low level.

2-Adic complexity of binary sequences with interleaved structure

In this paper, 2-adic complexity of some binary sequences with interleaved structure is investigated. Firstly, 2-adic complexity of low correlation zone (LCZ) sequences constructed by Zhou et al. [23] is completely determined. We show that their 2-adic complexity could attain the maximum if suitable parameters are chosen. Secondly, we also determine 2-adic complexity of optimal autocorrelation sequences constructed by Tang and Ding [16]. Results show that they have the maximum 2-adic complexity.

Linear complexity of binary sequences with interleaved structure

In this study, the minimal polynomials and the linear complexity of interleaved binary sequences are investigated. Both the linear complexity and the minimal polynomials of low correlation zone sequences constructed by Zhou et al. are completely determined. Besides, an open problem proposed by Li and Tang is discussed. At last, a sufficient condition and a necessary condition are presented about when the linear complexity of the interleaved sequences constructed by Tang et al. attains the maximum.

A generic construction of low correlation zone sequences based on interleaved technique

Low correlation zone (LCZ) sequences are useful in quasi-synchronous code-division multiple access (QS-CDMA) communication systems. In this paper, a generic construction of LCZ sequences based on interleaved technique is investigated. Firstly, the shift sequence is shown to correspond to two-tuple balanced d -form function essentially, which results in new shift sequence. Secondly, an optimal design of p 2 -ary sequences over the integer residue class ring Z p 2 is proposed, which improves the previous construction when p is an odd prime.

A New Method for Constructing Quaternary Sequence Sets with Low Correlation Zone

A method of constructing multiple quaternary low correlation zone (LCZ) sequence sets with the same parameters is proposed. Two mappings which can map two binary variables to a quaternary one are presented. Based on different mappings, new quaternary LCZ sequence sets are constructed. Furthermore, based on the same mapping, the parameters of shift sequences are changed to extend the number of LCZ sequence sets and there is only one shift equivalent sequence from different sets. The parameters of the LCZ sequence sets can be flexibly chosen. Compared with previous methods, the proposed construction extends the number of quaternary LCZ sequence sets. As a result, more spreading sequences are provided for multi-cell quasi-synchronous code-division multiple-access systems.

New construction of perfect sequence set and low correlation zone sequence set

For a given binary ideal autocorrelation sequence, we construct a perfect sequence set by changing a few bits of the sequence. The set has a large size with respect to the period of its sequences. Based on the constructed perfect sequence set, a new class of low correlation zone sequence sets whose low correlation zone length can be chosen flexibly is obtained. Moreover, the new constructed low correlation zone sequence sets can attain Tang-Fan-Matsufuji’s bound with suitably chosen parameters.

Computational Design of Sequences With Good Correlation Properties

In this paper, we introduce a computational framework based on an iterative twisted approximation (ITROX) and a set of associated algorithms for various sequence design problems. The proposed computational framework can be used to obtain sequences (or complementary sets of sequences) possessing good periodic or aperiodic correlation properties and, in an extended form, to construct zero (or low) correlation zone sequences. Furthermore, as constrained (e.g., finite) alphabets are of interest in many applications, we introduce a modified version of our general framework that can be useful in these cases. Several applications of ITROX are studied and numerical examples (focusing on the construction of real-valued and binary sequences) are provided to illustrate the performance of ITROX for each application.

Construction of Optimal Low Correlation Zone Sequence Sets Based on DFT Matrices

Construction of Optimal Low Correlation Zone Sequence Sets Based on DFT Matrices

A General Construction of Low Correlation Zone Sequence Sets Based on Finite Fields and Balanced Function

A General Construction of Low Correlation Zone Sequence Sets Based on Finite Fields and Balanced Function

Construction of asymptotic optimal LCZ sequence pairs set

Best binary sequence pair exists in a lager scope than perfect binary sequence,for the sake of enlarging the address code selection of Quasi-Synchronization Code Division Multiple Access(QS-CDMA).Two methods of constructing sequence pairs set of asymptotic optimal Low Correlation Zone(LCZ) were proposed.A kind of asymptotic optimal LCZ sequence pairs set was constructed based on perfect binary sequence pair with modified Walsh sequences set(or m-sequence's cyclic shift sequences set) and a set generated by the cyclic shift sequences of a binary sequence pair with two-level periodic autocorrelation.The asymptotic optimal LCZ sequence pairs set constructed have more various parameters combinations.It can provide more choices for engineering application.

A new class of quaternary LCZ sequence sets

In this article, we present a construction of low correlation zone (LCZ) sequence sets. This construction gives a new class of quaternary LCZ sequence sets. Furthermore, we observe a generalization of the LCZ sequence sets in Kim et al. (IEEE Trans Inform Theory 52(10):4607---4616, 2006) by using an orthogonal transformation. The obtained LCZ sequence sets are optimal with respect to the Tang, Fan and Matsufuji bound.

A Construction of Quaternary Low Correlation Zone Sequence Sets from Binary Low Correlation Zone Sequence Sets Improving Optimality

In this letter, we propose a new construction of quaternary low correlation zone (LCZ) sequence set using binary LCZ sequence sets and an inverse Gray mapping. The new construction method provides optimal quaternary LCZ sequence sets even if the employed binary LCZ sequence set is suboptimal. The optimality is improved at the price of alphabet extension.

New Method to Extend the Number of Quaternary Low Correlation Zone Sequence Sets

In this correspondence, a new method to extend the number of quaternary low correlation zone (LCZ) sequence sets is presented. Based on the inverse Gray mapping and a binary sequence with ideal two-level auto-correlation function, numbers of quaternary LCZ sequence sets can be generated by choosing different parameters. There is at most one sequence cyclically equivalent in different LCZ sequence sets. The parameters of LCZ sequence sets are flexible.

On the Noncyclic Property of Sylvester Hadamard Matrices

In this paper, we are concerned with Hadamard matrices with a certain noncyclic property. First we show that when the first column of a Sylvester Hadamard matrix of order 2m, m ≥ 2, a positive integer, is removed, the number of shift distinct row vectors in the matrix is given by 2m-m. Then, for m ≥ 4, we construct an infinite family of Hadamard matrices with a property that when the first column of the Hadamard matrix is removed, all the row vectors of the matrix are shift distinct. These Hadamard matrices are useful in constructing low correlation zone sequences.

New construction of quaternary low correlation zone sequence sets from binary low correlation zone sequence sets

In this paper, using binary (N, M, L, є) low correlation zone (LCZ) sequence sets, we construct new quaternary LCZ sequence sets with parameters (2N, 2M, L, 2є). Binary LCZ sequences for the construction should have period N ≡ 3 mod 4, L|N, and the balance property. The proposed method corresponds to a quaternary extension of the extended construction of binary LCZ sequence sets proposed by Kim, Jang, No, and Chung [1].

New Sets of Zero or Low Correlation Zone Sequences via Interleaving Techniques

Sequence families with zero or low correlation zone can be used in the quasi-synchronous code-division multiple-access (QS-CDMA) communication systems. Interleaving techniques are very useful for sequence design. In this paper, we present a general construction of sequence families with zero or low correlation zone using interleaving techniques and complex Hadamard matrices. The component sequences are perfect or ideal two-level. In two cases, we construct the shift sequences: 1) P|L; 2) P is even, and L ¿ P/2 ( mod P), which results in sequence families with zero or low correlation zone of parameters (NP, MP, L, P¿), where N is the period of component sequences, M is the number of inequivalent shift sequences, and ¿ = 0 or 1. The conditions are derived under which the new construction is optimal. Some examples are also given to specify the new construction.

Low Correlation Zone Sequences from Interleaved Construction

Recently there has been a surge of interest in construction of low correlation zone sequences. The purpose of this paper is to survey the known results in the area and to present an interleaved construction of binary low correlation zone sequences. The interleaved construction unifies many constructions currently available in the literature. These sequences are useful in quasi-synchronous code-division multiple access (QS-CDMA) communication systems.

New Extension Method of Quaternary Low Correlation Zone Sequence Sets

We propose an extension method of quaternary low correlation zone (LCZ) sequence set with odd period. From a quaternary LCZ sequence set with parameters (N , M, L, 1), the proposed method constructs a new quaternary LCZ sequence set with parameters (2N, 2M, L, 2), where N is odd. If the employed LCZ sequence set in the construction is optimal, the extended LCZ sequence set becomes also optimal where N = kL, L > 4, and k >2.

New Families of Binary Low Correlation Zone Sequences Based on Interleaved Quadratic Form Sequences

In this letter, new families of binary low correlation zone (LCZ) sequences based on the interleaving technique and quadratic form sequences are constructed, which include the binary LCZ sequence set derived from Gordon-Mills-Welch (GMW) sequences. The constructed sequences have the property that, in a specified zone, the out-of-phase autocorrelation and cross-correlation values are all equal to -1. Due to this property, such sequences are suitable for quasi-synchronous code-division multiple access (QS-CDMA) systems.