The Design Of Unequal Period ZCZ Sequence Pair

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 extend the existence space for the best signals, based on the sequence pair theory, applying the concept of unequal period and combining the properties of ZCZ sequence, the paper defines a new self-correlation sequence pair (unequal period ZCZ sequence pair). 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, especially the ZCZ sequence pair, and their correlation properties are discussed. The applications of the sequence pair in the signal process and communication system are also introduced.(2)The paper presents the definition and some characters of the unequal period ZCZ sequence pair are discussed. The paper also discusses the necessary condition of the being of the unequal period ZCZ sequence pair. The Fourier spectrum characters of this sequence pairs are also studied.(3)The paper defines the concept of the unequal period ZCZ sequence set, presents and proves the several transform properties of the unequal period ZCZ sequence set.(4) The paper presents the definition of unequal period ZCZ complementary sequence pairs. A method based on unequal period ZCZ complementary sequence pairs for constructing unequal period ZCZ sequence pairs set is presented.The result indicates that the unequal period ZCZ sequence pair is aexpansive 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.