New receiver for multiuser detection of CDMA signals with antenna arrays

A new receiver for multiuser detection of DS-CDMA signals with antenna arrays at the receiver is introduced. The receiver is based on processing a new, defined vector called the spatial-temporal signature vector that is closely related to the ʹsufficientʹ statistic. The proposed receiver integrates processing in time and space. The higher dimensionality of the spatial-temporal signature vector compared to conventional signatures and array response vectors used by conventional receivers, allows for better interference mitigation and near-far resistance. A new method for direction of arrival (DOA) estimation of usersʹ signals is also introduced that can be applied even if the number of active users far exceeds the number of antenna elements. Both synchronous single-path and general asynchronous multipath fading cases are considered. The algorithm can be applied blindly, i.e. for DOA estimation and detection of each userʹs symbols the signature code and synchronisation of that user is needed.