Reduced-rank space-time channel estimation for DS-CDMA in MIMO dispersive channels

A reduced-rank space-time channel estimation scheme is presented for uplink multiuser DS-CDMA (direct-sequence code-division multiple access) systems in dispersive MIMO (multiple input and multiple output) channels. The proposed method is based on the alternative power (AP) method with the aid of pilot symbols. It is shown that the mean squared error (MSE) of channel estimation can be improved via rank order selection where optimal performance can be achieved using the generalized likelihood ratio test (GLRT). Both analytical and simulated results are provided to demonstrate the performance of the proposed scheme with various measurement criteria.