Blind uplink space-time channel estimation for space-time coded multicarrier code division multiple access systems

The uplink of a space-time coded multicarrier code division multiple access (MC-CDMA) system equipped with a uniform linear array (ULA) at the base station is investigated. Transmission takes place over frequency-selective fading channels and the goal is to blindly estimate the space-time channels and the directions of arrival (DOA) for all active users in one macrocell. An auxiliary matrix including both uplink space-time channels and DOAs is constructed, on which the eigen decomposition is performed to acquire the DOAs for multiple users. Then, the singular value decomposition (SVD) is applied on the eigenvectors corresponding to the DOA of individual user to obtain a closed-form solution of the uplink space-time vector channel. Computer simulations demonstrate the effectiveness of the proposed scheme.