Communication system with receivers employing generalized two-stage data estimation

A wireless transmit/receive unit (WTRU) configure to receive and sample wireless signals in a shared spectrum where the wireless signal comprise encoded symbols, the WTRU comprising:

• a channel estimation device configured to process received signal samples to produce an estimate of a channel response of the received signals corresponding to a matrix H;
• a two stage data estimator comprising a first stage channel equalizer and a second stage despreader;
• said channel equalizer configured to process received signal samples using the estimated channel response matrix H to produce a spread signal estimate of the received signals including:
• means for processing codes of the signals received in a shared spectrum using a block Fourier transform (FT) and producing a code block diagonal matrix;
• means for extending and modifying the channel response matrix H to produce a channel response block diagonal matrix;
• and
• means for combining the code block diagonal matrix and the channel response block diagonal matrix;
• and
• said despreader configured to process the spread signal estimate of the received signals produced by said channel equalizer to recover encoded symbols of the received signals.