User Identification and Multiuser Detection of L out of K Users in a Cdma System

Two multiuser detectors are proposed for an asynchronous code-division multiple-access system [?]. Both detectors determine which users are on the system without side channel information and perform multiuser detection with knowledge of the previous active users. One detector, the Two Pass Detector works with matched filter outputs and requires knowledge of all potential users’ signature sequences. The second detector, the Cyclic Detector uses the cyclostationary properties of received signal (sampled at the chip) to detect new users. This detector can estimate the delay and the signature sequence of a new user.