采用广义正交序列的多载波DS-CDMA系统在瑞利衰落信道中的性能分析  

Performance Evaluation of Multicarrier DS-CDMA in Rayleigh Fading Channel with Generalized Orthogonal Spreading Sequences

作　　者：谢俊松[1] 范平志[1] 

机构地区：[1]西南交通大学移动通信研究所,四川成都610031

出　　处：《电路与系统学报》2002年第1期87-91,共5页Journal of Circuits and Systems

基　　金：国家自然科学基金资助项目(69931050和69825102)

摘　　要：在CDMA系统中,采用正交序列可以有效地减小多址干扰的影响。然而,当由于多径衰落的影响使码片间的相对移位增加时,系统中用户扩频序列间的相互正交性减弱,导致性能大大恶化。本文基于新近提出的广义正交序列,分析了采用该序列的多载波直接序列码分多址系统在瑞利衰落信道中的误比特性能。数值结果表明,当扩频序列间相互移位在零相关区之内时,扩频序列仍可保持正交,因而大大提高了系统误比特性能。The multiple access interference (MAI) in the CDMA systems can be effectively reduced by the orthogonal spreading sequences. However, as the relative shifts between the sequences chips increase due to multipath fading, the orthogonality among different users tends to diminish, hence the system performance decays dramatically. In this paper, the bit error rate (BER) performance of a multi-carrier (MC) direct sequence (DS) code division multiple access (CDMA) system with generalized orthogonal sequences recently proposed under Rayleigh fading channel is analyzed. Numerical results are presented, showing significant BER performance improvement when the relative shifts among spreading sequences lie within the zero correlation zone (ZCZ), where the orthogonality among spreading sequences is kept.

关 键 词：广义正交序列 多载波DS-CDMA系统 瑞利衰落信道 性能分析 

分 类 号：TN914.53[电子电信—通信与信息系统]