Near theoretical upper bound new loosely synchronous complementary spreading sequences

Abstract

A new class of loosely synchronous (LS) spreading sequences with zero correlation window (ZCW) was presented. It was constructed by making Kronecker product of orthogonal matrix and ZCW complementary sequences. This new LS sequence increases the number of perfect complementary pairs and extends ZCW within the same group. Moreover, both auto-correlation and cross-correlation of ZCW in the same group remain identical. The minimum ZCW among different groups is the same as that of basic LS sequences. The method for constructing these new LS sequences is presented and ZCW properties are also verified. The number of these new LS sequences is only smaller than theoretical upper bound by one.