Iterative data-aided channel estimation and multiuser detection for coded CDMA systems

In this paper, we propose an iterative approach for multiuser detection with integrated channel estimation for the uplink of coded direct sequence code-division multiple-access (DS-CDMA) systems in unknown multipath channels. For the first iteration, the integrated channel estimator provides an estimate of the multipath channel blindly by exploiting the orthogonality between the signal and noise subspaces. For the next iterations the channel is estimated using the soft estimates of coded bits of each user provided by a bank of single-user channel decoders in conjunction with the output of a linear MMSE multiuser filter. Simulation results demonstrate that the receiver performance is improved through iteration