A code division multiple access (CDMA) radio system uses an adaptive
filter in a receiver to mitigate multipath radio propagation and to
filter out interfering signals. Characteristics of an initial stage of
the filter preferably are determined by cross correlation of a generated
pilot signal and the input signal with the integration of the correlation
performed over a time period selected to be an integral number of symbol
periods. The integration causes the portions of the cross correlation
corresponding to the user subchannels to average substantially to zero,
so that the pilot channel signal correlation is the primary contribution
to the signal used to characterize the channel to establish the
coefficients of the adaptive filter for the receiver.