Blind channel estimation for long code MIMO CDMA using first-order statistics

In this paper, we consider the problem of blind channel estimation in a multiple-input-multiple-output (MIMO) code division multiple access (CDMA) system employing long spreading codes. The proposed method consists of a decorrelating matched filter with block diagonal structure as the front-end. Based on a clustering procedure, the MIMO channel parameters are estimated efficiently up to a sign factor by exploiting the first-order statistics of the matched filter output. Simulation results illustrate the effectiveness of the proposed method and the robustness to channel order overestimation.