The decorrelating detector and the linear minimum mean-square error (M
MSE) detector are known to be effective strategies to counter the pres
ence of multiuser interference in code-division multiple-access channe
ls; in particular, those multiuser detectors provide optimum near-far
resistance. When training data sequences are available, the MMSE multi
user detector can be implemented adaptively without knowledge of signa
ture waveforms or received amplitudes. This paper introduces an adapti
ve multiuser detector which converges (for any initialization) to the
MMSE detector without requiring training sequences. This blind multius
er detector requires no more knowledge than does the conventional sing
le-user receiver: the desired user's signature waveform and its timing
. The proposed blind multiuser detector is made robust with respect to
imprecise knowledge of the received signature waveform of the user of
interest.