Adaptive Cancellation of Narrowband Signals in Overlaid CDMA Systems

| Narrowband interference cancellation techniques described in the literature often overlook the possibility of using prior information known to the receiver in a commercial radio environment to improve their performance. This paper examines an adaptive receiver which exploits knowledge about the narrowband interference which is readily available in commercial CDMA systems, namely its frequency and signal pulse shape, to remove it. The proposed algorithm uses only one adaptive weight per interferer, as opposed to a transversal lter interference canceller which would require many more. Attendant advantages include faster convergence, removal of the need for lter order selection and reduced distortion of the desired signal.