CFAR acquisition of DS-SS codes for CDMA ranging

Presents an adaptive thresholding acquisition procedure for use by a CDMA ranging system. The system provides constant false alarm rate (CFAR) in acquiring direct sequence spread spectrum signals in a multi-user environment. A bank of matched filters is used to match the received signal against the various user codes. A user is declared present when the energy in the output any filter exceeds a threshold proportional to the energy in the received signal itself. This procedure provides CFAR acquisition in a white gaussian noise level of unknown level. Most importantly, the method also provides a bounded probability of false detection as well. The authors present performance results which illustrate this decrease in false detections due to the CFAR thresholding with matched filtering. The proposed system is a very simple method for multiuser acquisition of CDMA signals