摘要
传统的正交信号用于码分多址 (CDMA)通信系统时 ,由于多址接入时延和信道多径时延影响 ,信号间的正交性将不可避免地因相对时移而受到不同程度的破坏 ,从而严重影响通信性能 ,降低系统容量。作者提出的广义正交新概念 ,使得信号之间可以在一个区域内正交 ,而不是传统的单点正交。基于这一概念 ,可以构造出适用于准同步CDMA(QS -CDMA)通信且性能优异的广义正交扩频码。本文阐述了这一广义正交新理论 ,给出了相应的广义正交信号设计和理论界 ,并讨论了在QS
In conventional CDMA communication systems, due to the delays caused by multiple access interference and multipath interference, the orthogonality between the orthogonal signals used will inevitably be destroyed to some extent, resulting degraded communication performance and reduced system capacity. The new concept of generalized orthogonality (GO) proposed by the author makes it possible for the signals to be mutually orthogonal within an orthogonal zone instead of a conventional orthogonal point. Based on this idea, a number of generalized orthogonal codes with excellent properties and suitable for the QS-CDMA communications can be constructed. In this paper, the generalized orthogonal theory is presented, the corresponding signal designs, theoretical bounds, and the related applications in QS-CDMA communications systems are discussed.
出处
《世界科技研究与发展》
CSCD
2002年第5期33-38,共6页
World Sci-Tech R&D
基金
国家自然科学基金课题(69825102
69931050)
国家863计划
中日国际合作研究(NSFC/MEXT/JSPS)
中英国际合作研究(NSFC/RS)等课题支持
关键词
正交信号
扩频码
广义正交码
码分多址通信
orthogonality, quasi-orthogonality, generalized orthogonality, spreading code, signal bounds, QS-CDMA
