Blind multiuser MMSE detector for CDMA signals in ISI channels

In this letter, a technique is introduced that allows the blind and direct estimation of an optimal, in the minimum mean-squared error sense, linear m ultiuser receiver for direct-sequence code-division multiple-access signals . We consider the case of an asynchronous multiple access channel in the pr esence of possibly large intersymbol-interference. Our approach does not re quire channel estimation and uses the knowledge of the code for the user of interest only. Unlike other comparable techniques, this method converges t o the true optimum receiver as the sample size increases, regardless of sig nal-to-noise ratio.