New families of asymmetric zero-correlation zone sequence sets based on interleaved perfect sequence

A zero-correlation zone (ZCZ) sequence set consisting of multiple ZCZ sequence subsets is said to be an asymmetric ZCZ (A-ZCZ) sequence set if and only if the cross-correlation function (CCF) between two arbitrary sequence which belong to different subsets has quite a large zero-cross-correlation zone (ZCCZ). In such an A-ZCZ sequence set, each subset is a conventional ZCZ sequence set. Our proposed A-ZCZ sequence set can be generated by interleaving any perfect sequence of length P = Nqk with N > 1, q ≥ 1 and k > 1. It is optimal or quasi-optimal conventional ZCZ sequence set if q = 1. The proposed A-ZCZ sequence set are applied to quasi-synchronous code-division multiple-access (QS-CDMA) systems and it can hypothetically achieve larger ZCZ than conventional ZCZ sequence set, as well as eliminating both multiple access and multipath interference in the QS-CDMA system.