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 ´sufficient´ 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 users´ 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 user´s symbols the signature code and synchronisation of that user is needed.