New ZCZ sequence sets composed of two subsets
Hideyuki Torii, Makoto Nakamura · 2007
Abstract:- The present paper proposes new ZCZ sequence sets which consist of two subsets. The most important property of the proposed ZCZ sequence sets is that the cross-correlation function between two arbitrary sequences which belong to different subsets has quite a large zero-cross-correlation zone. Of course, each subset is a ZCZ sequence set of which the family size is half of the original one. When the proposed ZCZ sequence sets are applied to AS-CDMA systems, one subset is assigned to users near to a base station and another subset is assigned to users far from it. By this allotment, the proposed sets can hypothetically achieve larger zero-correlation zones than conventional ZCZ sequence sets. Key-Words:- ZCZ sequence sets, AS-CDMA, perfect sequences, unitary matrices, spreading sequences, spread