Multiple chip-rate DS/CDMA system and its spreading code dependent performance analysis

The authors study a multiple chip-rate DS/CDMA system and its spreading code dependent performance. The multiple chip-rate technique is useful in some CDMA applications needing extra divisions among users in addition to code division to support variable data rate applications, such as multimedia systems. The study is applicable to both synchronous and asynchronous multiple chip-rate CDMA systems. A co-channel interference model based on correlation statistics for deriving bit error rate of a dual-chip-rate CDMA system is introduced considering various spreading codes, such as m-sequence, Gold, Gold-like, Kasami and Walsh codes. The results show that Gold code families are most suitable for the use in the dual-chip-rate CDMA system.