Wavelet-packet-based signatures for asynchronous CDMA systems

Abstract

A wavelet-packet-based family of user signatures for asynchronous CDMA systems is investigated. These signatures are of non-binary nature and are generated by the application of the inverse wavelet packet transform. Through numerical optimization, we obtain the wavelet filter which minimizes the crosscorrelation among signatures for different user configuration systems. The improvement in performance is especially notable in the oversaturated system scenario. Finally, we comment briefly on the topics of bandwidth efficiency, user privacy, and implementation.