In this paper, a multicarrier DS-CDMA system which employs Z-Complementary Se- quences (ZCS) as spreading code is investigated. The new system can not only eliminate multipath interference and Multiple Access Interfer...In this paper, a multicarrier DS-CDMA system which employs Z-Complementary Se- quences (ZCS) as spreading code is investigated. The new system can not only eliminate multipath interference and Multiple Access Interference (MAI), but also support flexible number of users com- pared with system using Orthogonal Complementary (OC) codes. Multicarrier DS-CDMA using OC codes can be regarded as a special case of our proposed system. Zero Correlation Zone (ZCZ) of ZCS can be flexibly adjusted to meet the requirements on the user number and maximum multipath and in- ter-user delay, in this way, more users can be supported without losing interference-free property. The effectiveness of the proposed system is validated through theoretical analysis and simulation results.展开更多
设计出扩展的Large area Synchronization地址码(LS码)——Daoben Lab地址码(DBL码).DBL码由基本LS码与矩阵左、右直积生成,分别称为DBL左乘码和DBL右乘码,两类DBL码各有特点.DBL右乘码特点是把码字分组,码组间码字存在更大的零相关窗,...设计出扩展的Large area Synchronization地址码(LS码)——Daoben Lab地址码(DBL码).DBL码由基本LS码与矩阵左、右直积生成,分别称为DBL左乘码和DBL右乘码,两类DBL码各有特点.DBL右乘码特点是把码字分组,码组间码字存在更大的零相关窗,增加了可用码字数,码组内码字非周期相关性与扩展矩阵行向量的相关性相同;DBL左乘码也是把码字分组,码组间的零相关窗长度不变,没有增加可用码字数,但当以正交矩阵扩展时,码组内有和原LS码同样长度的零相关窗.计算机仿真验证了两类DBL地址码的性质.展开更多
A general construction of inter-group complementary (IGC) codes is proposed based on perfect complementary (PC) codes,interleaving operation,and the orthogonal matrix.The correlation properties of the newly constructe...A general construction of inter-group complementary (IGC) codes is proposed based on perfect complementary (PC) codes,interleaving operation,and the orthogonal matrix.The correlation properties of the newly constructed IGC codes can be described as follows:(1) the autocorrelation sidelobes of the codes are zeros in the zero correlation zone (ZCZ);(2) the cross-correlation functions (CCFs) between any two different codes of the same group are zeros in the ZCZ;(3) the CCFs between any two codes of different groups are zeros everywhere.The key point of this construction is that the ZCZ length of the generated IGC codes can be chosen flexibly.It is well known that there is a limitation between the ZCZ length and the number of mates;that is,the smaller is the length of ZCZ,the more are the IGC codes that can be generated.Therefore,if we can choose the ZCZ length of the IGC codes flexibly according to the requirement of the system,more users can be accommodated in the system.展开更多
基金Supported by the National Natural Science Foundation of China (No.60772087, No.90604035)111 Project (No.111- 2-14)
文摘In this paper, a multicarrier DS-CDMA system which employs Z-Complementary Se- quences (ZCS) as spreading code is investigated. The new system can not only eliminate multipath interference and Multiple Access Interference (MAI), but also support flexible number of users com- pared with system using Orthogonal Complementary (OC) codes. Multicarrier DS-CDMA using OC codes can be regarded as a special case of our proposed system. Zero Correlation Zone (ZCZ) of ZCS can be flexibly adjusted to meet the requirements on the user number and maximum multipath and in- ter-user delay, in this way, more users can be supported without losing interference-free property. The effectiveness of the proposed system is validated through theoretical analysis and simulation results.
文摘设计出扩展的Large area Synchronization地址码(LS码)——Daoben Lab地址码(DBL码).DBL码由基本LS码与矩阵左、右直积生成,分别称为DBL左乘码和DBL右乘码,两类DBL码各有特点.DBL右乘码特点是把码字分组,码组间码字存在更大的零相关窗,增加了可用码字数,码组内码字非周期相关性与扩展矩阵行向量的相关性相同;DBL左乘码也是把码字分组,码组间的零相关窗长度不变,没有增加可用码字数,但当以正交矩阵扩展时,码组内有和原LS码同样长度的零相关窗.计算机仿真验证了两类DBL地址码的性质.
基金Project supported by the National Natural Science Foundation of China (Nos. 61001110,60773074,and 60903004)the China Post-doctoral Science Foundation (No. 20100470204)+1 种基金the Beijing Municipal Natural Science Foundation (No. 4082020)the National High-Tech R & D Program of China (Nos. 2007AA01Z213 and 2009AA01Z209)
文摘A general construction of inter-group complementary (IGC) codes is proposed based on perfect complementary (PC) codes,interleaving operation,and the orthogonal matrix.The correlation properties of the newly constructed IGC codes can be described as follows:(1) the autocorrelation sidelobes of the codes are zeros in the zero correlation zone (ZCZ);(2) the cross-correlation functions (CCFs) between any two different codes of the same group are zeros in the ZCZ;(3) the CCFs between any two codes of different groups are zeros everywhere.The key point of this construction is that the ZCZ length of the generated IGC codes can be chosen flexibly.It is well known that there is a limitation between the ZCZ length and the number of mates;that is,the smaller is the length of ZCZ,the more are the IGC codes that can be generated.Therefore,if we can choose the ZCZ length of the IGC codes flexibly according to the requirement of the system,more users can be accommodated in the system.
