Research Of Zcz Sequence Pairs Set And Its Construction Methods

In the quasi-synchronous CDMA system, the request to adopt the spreading sequence is that the sequence should have perfect correlation properties in the synchronous error (near the zero time delay), the zero-correlation zone (ZCZ) sequence is just fit for the need. After summarizing and comparing the known design methods of ZCZ sequence, to alter the deficiency of the binary ZCZ sequence, applying the sequence pair theory and combining the properties of ZCZ sequence, the paper defines a multi-value self-correlation sequence pair (ZCZ sequence pair) which has zero correlation zone. Based on these matters, the paper makes a series of theory study for the ZCZ sequence pair set. The main work is just as following:(1)The basic concepts of sequence pair, the correlation properties of the sequence pair and the applications of the sequence pair in the signal process and communication system are introduced. The paper introduces the definition of the ZCZ sequence pair, and the definition of the ZCZ complementary sequence pair. The paper also discusses the necessary condition of the being of ZCZ sequence pair, peak value characteristic, construction methods and the transform properties of the self-correlation function. The paper deduces the theory bound of the ZCZ sequence set, and also combining the study actuality of zero correlation sequence makes some discussion about the bound.(2)The paper presents two construction methods of the ZCZ sequence pair. The ZCZ sequence sets which are constructed by the two methods can approach or get the upper bound. It discusses the concept of the orthogonal sequence pairs. And it gives the correlation properties. Based the theory of sequence pairs and the correlation properties of orthogonal sequence set, A method based on the best binary sequence pairs for constructing mutual orthogonal ZCZ sequence pairs set is presented, we also give some examples.The result indicates that the ZCZ sequence pair set is a peculiar binary zero correlation sequence. At the same time, its performance is perfect, it is befitting to use as the spread spectrum sequence in the quasi-synchronous CDMA system.