New sequence families with zero or low correlation zone via interleaving techniques

Abstract

Sequence families with zero or low correlation zone can be used in the quasi-synchronous codedivision 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 ). The conditions are derived under which the new construction is optimal. Some examples are also given to specify the new construction.Index Terms. Quasi-synchronous code-division multiple access (QS-CDMA), low correlation zone (LCZ) sequence, zero correlation zone (LCZ) sequence, interleaving technique.

Interleaved Sequences Over Finite Fields

“…, (q n − 1)p}. We note that P (3) Hu and Gong increase the number of shift sequences under some assumptions and the number of the second base sequences to obtain more sequences by interleaving techniques [39]. The family they give is (s, ω j , e i ),…”

“…Zhou, Tang and Gong [95] give a new construction of LCZ/ZCZ sequence sets with period 2N using two shift sequences of period N . Finally, Hu and Gong [39] generalize this LCZ/ZCZ sequence set of period 2N to any multiple of N using the interleaving technique and complex Hadamard matrices.…”

“…, M . Because more shift sequences are employed, the signal set [39] has a larger size and the cross correlation has been shown to be low. We expect that an increase on the number of shift sequences or an increase on the number of the second base sequences in Algorithm 6.5 may bring more sequences to the family while still keeping the low correlation.…”