1. A parameter estimator of a multiuser detection receiver comprising: means for estimating a training sequence location index (&tgr; TS ) in each frame of a received baseband signal; means for calculating an estimate of an average noise power ({circumflex over (&sgr;)}(p) 2 ) in said received baseband signal in accordance with said training sequence location index (&tgr; TS ) input; means for estimating signature waveforms (s K (n,p)) unique to each user in said received baseband signal in accordance with said training sequence location index (&tgr; TS ) input and said transformation matrix ( T r ) input; means, coupled to an output of said estimate of an average noise power calculating means and to an output of said signature waveforms estimating means, for determining the number of active users; and means, coupled to said means for determining the number of active users and to prestored known training sequences for each user, for generating said transformation matrix ( T r ) to send to said signature waveform estimating means.