Multiple access interference resistant channel acquisition for wideband CDMA signals

The problem of acquiring the channel parameters of a new user on the reverse link is considered for a wideband CDMA signal received in a frequency selective fading environment with multi-access interference. Following a minimum mean squared error (MMSE) strategy for suppressing the multi-access interference, the parameter estimation problem is posed in a maximum-likelihood framework. To reduce complexity, the solution is implemented in two stages: first the estimated tap delays are restricted to be at chip spacings, and then the number of taps is reduced by allowing for arbitrary spacing between them. The performance of the proposed techniques is studied through numerical simulations