Zero Correlation Zone Sequence Research Articles

Zero-Correlation Zone Sequence Set Construction Using an Even-Perfect Sequence and an Odd-Perfect Sequence

The present paper introduces a new construction of a class of binary periodic sequence set having a zero-correlation zone sequence set. The cross-correlation function and the side-lobe of the auto-correlation function of the proposed sequence set is zero for the phase shifts within the zero-correlation zone. The present paper shows that such a construction generates a binary zcz sequence set by using an arbitrary pair of an even-perfect sequence and an odd-perfect sequence. The proposed zcz sequence set reaches the theoretical upper bound of the member size of the sequence set.

A large class of binary ZCZ sequence families constructed by period doubling

In an Approximately Synchronized Code Division Multiple Access (AS-CDMA) communication system, a family with large number of Zero Correlation Zone (ZCZ) sequences is desired, which can satisfy the rapid increase of users. This paper presents a method to generate a (2L, 2M, Z′cz)-ZCZ sequence family from an original (L, M, Zcz)-ZCZ sequence family, where Z′cz = Zcz if Zcz is even and Z′cz = Zcz − 1 if Zcz is odd. This method can also recursively act on a ZCZ sequence family to construct a series of ZCZ sequence families with large sequence number and zero correlation zone length identical to or one less than that of original ZCZ sequences.

Zero-Correlation Zone Sequence Set Constructed from a Perfect Sequence

The present paper introduces the construction of a class of sequence sets with zero-correlation zones called zero-correlation zone sequence sets. The proposed zero-correlation zone sequence set can be generated from an arbitrary perfect sequence, the length of which is longer than 4. The proposed sets of ternary sequences, which can be constructed from an arbitrary perfect sequence, can successfully provide CDMA communication without co-channel interference. In an ultrasonic synthetic aperture imaging system, the proposed sequence set can improve the signal-to-noise ratio of the acquired image.

Family of uncorrelated binary ZCZ sequence pairs with mismatched filtering

A family of uncorrelated binary sequence pairs of length N=4(p m +1) with zero correlation zone (ZCZ) (N/4) -1 and mismatched filtering is proposed. The sequence pairs are derived from almost- perfect binary and ternary sequences and possess energy efficiency close to 1 as N becomes large. They can be used in quasi-synchronous code division multiple access and radar systems to reduce interference.

Binary Zero-Correlation Zone Sequence Set Construction Using a Cyclic Hadamard Sequence

The present paper introduces a new construction of a class of binary periodic sequence set having a zero-correlation zone (hereinafter binary ZCA sequence set). The cross-correlation function and the side-lobe of the auto-correlation function of the proposed sequence set is zero for the phase shifts within the zero-correlation zone. The present paper shows that such a construction generates a binary ZCA sequence set by using a cyclic difference set and a collection of mutually orthogonal complementary sets.

Orthogonal Set of Huffman Sequences and Its Application to Suppressed-Interference Quasi-Synchronous CDMA System

A Huffman sequence has a zero-sidelobe aperiodic autocorrelation function except at both shift ends. This paper presents orthogonal sets of the zero correlation zone (ZCZ) Huffman sequences and the application to a quasi-synchronous CDMA system with interferences suppressed. The sequences with low or large peak values are constructed on the basis of sequence spectra corresponding to multiple convolution of elementary sequences, and include the ZCZ sequences. The CDMA system is constructed from the ZCZ sequences, and suppresses intersymbol and interchannel interferences.

Implicit MIMO Channel Estimation Without DC-Offset Based on ZCZ Training Sequences

In this letter, an implicit direct current (dc) free multiple-input multiple-output (MIMO) channel estimation scheme is proposed by employing a set of zero correlation zone (ZCZ) training sequences. The new implicit MIMO channel estimation scheme includes, as a special case, the conventional implicit single-input single-output (SISO) channel estimation scheme, which is also considered and analyzed. For implicit SISO channel estimation, by choosing properly a set of ZCZ sequences with balanced property, the harmful dc-offset can be completely removed, thus exhibiting significantly better estimation performance and resulting in simpler implementation when compared with the conventional implicit training schemes without dc-offset elimination and with dc-offset elimination based on perfect sequences, respectively

A New Framework for Constructing Mutually Orthogonal Complementary Sets and ZCZ Sequences

In this correspondence, new characterizations for the construction of zero correlation zone (ZCZ) sequences from mutually orthogonal Golay complementary sets (MOGCS) is presented. It is shown that the recursive construction of MOGCS is inherent in these characterizations. Previously known constructions of ZCZ sequences and MOGCS are shown to be special cases of this characterization. The notion of mutually orthogonal ZCZ sequence sets is also introduced

Binary Zero-Correlation Zone Sequence Set Constructed from an M-Sequence

The present paper introduces an improved construction of a class of binary sequences having a zero-correlation zone (hereafter binary ZCZ sequence set). The cross-correlation function and the side-lobe of the auto-correlation function of the proposed sequence set is zero for the phase shifts within the zero-correlation zone. The present paper shows that such a construction generates a binary ZCZ sequence set from an arbitrary M-sequence. The previously reported sequence construction of binary ZCZ sequence sets from an M-sequence can generate a single series of binary ZCZ sequence sets from an M-sequence. The present paper proposes an improved sequence construction that can generate more than one series of binary ZCZ sequence sets from an M-sequence.

Multilevel Hadamard matrices and zero correlation zone sequences

Constructions of multilevel Hadamard matrices are presented. Based on the multilevel Hadamard matrices, multilevel zero correlation zone sequences which are useful in quasi-synchronous CDMA systems and other applications are derived.

A New Class of Polyphase Sequence Sets with Optimal Zero-Correlation Zones

This paper proposes a new class of polyphase ZCZ (zero-correlation zone) sequence sets which satisfy a mathematical upper bound. The proposed ZCZ sequence sets are obtained from DFT matrices and unitary matrices. In addition, this paper discusses the cross-correlation property between different ZCZ sequence sets which belong to the proposed class.

Binary Zero-Correlation Zone Sequence Set Construction Using a Primitive Linear Recursion

The present paper introduces a new construction of a class of binary sequence set having a zero-correlation zone (hereafter binary ZCZ sequence set). The cross-correlation function and the side-lobe of the auto-correlation function of the proposed sequence set is zero for the phase shifts within the zero-correlation zone. The present paper shows that such a construction generates a binary ZCZ sequence set by using a primitive linear recursion over GF(2), the finite field of integers modulo 2.

On Optimal Training Sequence Design for Multiple-Antenna Systems Over Dispersive Fading Channels and Its Extensions

In this correspondence, previous work on (P,V,M) code sequences, which are sequences with a zero-correlation zone (ZCZ) that can be used to accurately and efficiently perform channel estimation in multiple-antenna communication systems, are noted. In addition, extensions of ZCZ sequence sets based on perfect sequences, almost-perfect sequences, and perfect arrays are presented. It is shown that those ZCZ sets based on perfect sequences/arrays are optimal with respect to theoretical bounds.

A New Class of Zero-Correlation Zone Sequences

In this correspondence, two new methods for constructing sets of zero-correlation zone (ZCZ) sequences are proposed. These methods are based on perfect sequences and unitary matrices. Compared with previous methods, the proposed methods can generate sets of nonbinary ZCZ sequences having a longer zero-correlation zone. The sequences obtained by these methods are suitable for approximately synchronized code-division multiple-access (AS-CDMA) systems.

Mutually orthogonal sets of ZCZ sequences

In the construction of zero correlation zone (ZCZ) sequences, as the length of the interference free window (IFW) increases, fewer sequences are available and hence their utility in multiuser systems diminishes. To address this issue, it is shown that, for a given IFW, it is possible to design multiple sets of ZCZ sequences which are mutually orthogonal.