Research On The Design Of Spreading Sequences With Zero Correlation Zone

Zero correlation zone(ZCZ)sequences,which have ideal correlation performance,can be widely used in a diversity of areas such as spread spectrum communication,radar,Channel estimation and so on.Gaussian integer ZCZ sequence sets and ZCZ complementary sequence sets were obtained by introducing the concept of ZCZ into Gaussian integer sequence sets or complementary sequence sets,which provide more spread spectrum sequences for communication systems.Therefore the research on the design of spreading sequences with zero correlation zone is very important.Firstly,the construction method of Gaussian integer ZCZ sequence sets based on cyclotomic classes was proposed.According to cyclotomic classes and shift sequence,a number of real part sequences and imaginary part sequences are presented based on mapping relation.Then a class of optimal or almost optimal Gaussian integer ZCZ sequences sets was presented by combining the real parts sequences and imaginary parts sequences.The parameter setting of this method is flexible and simple,which can get abundant result sequences and provide more spreading sequences for communication systems.Secondly,the construction methods of Gaussian integer ZCZ sequence sets based on filtering were proposed.In Construction 1,the method of zero padding is implemented on the ZCZ sequence set,and then the Gaussian integer ZCZ can be obtained by the filtering operation.Furthermore,the degree of the Gaussian integer ZCZ sequence set is calculated in this paper.In Construction 2,two constructions of Gaussian integer orthogonal sequence sets are proposed.In addition,the optimal Gaussian integer ZCZ sequence sets are constructed based on the orthogonal sequence sets.The Gaussian integer ZCZ sequence sets can be applied to many communication systems such as quasi-synchronous code division multiple access(QS-CDMA)、orthogonal frequency division multiplexing(OFDM)and multiple input multiple output(MIMO)system to suppress the interference and improve the spectrum efficiency.Finally,the construction methods of ZCZ aperiodic complementary sequence(ZACS)sets based on orthogonal matrices were proposed.Based on aperiodic complementary sequence(ACS)sets and orthogonal matrices,Construction 1 proposed ZACS sets by utilizing cascade operation.And the parameters of the resulting sets are optimal if the original ACS sets can achieve the theoretical bound.In Construction 2,according to different setting methods of ζ,two classes of ZACS sets are presented based on two orthogonal matrices,and the length of ZCZ can be chosen flexibly.Furthermore,a great number of orthogonal matrices are available.By using these orthogonal matrices,a large number of optimal Gaussian integer or poly-phase ZCZ aperiodic complementary sequence sets are obtained,which can provide more spread sequences for multi carrier CDMA(MC-CDMA)communication system.