Blind iterative multiuser delay estimator for CDMA

A near-far resistant iterative algorithm for multiuser signature sequence delay estimation is presented. It is shown that the maximum-likelihood delay estimator can be replaced by the so-called blind ML delay estimator which depends on delays only, not on transmitted symbols and complex channel coefficients. A variable projection type algorithm is presented to compute the blind ML estimator in an iterative way. According to the simulation results, the delays for all users can be estimated reliably both in AWGN and fading channels by using the scheme being proposed.