Low complexity space-time multiuser detectors

A design framework for space-time multiuser detectors is introduced based on the notion of canonical space-time coordinates (CSTC). The CSTC system employs a fixed set of basis signals which eliminates the need for estimating direction of arrivals (DOAs) and delays of the channel, thereby allowing significant reduction in receiver complexity. The proposed framework is based on a hybrid structure for multiuser detection which combines the power of centralized processing and the flexibility of decentralized reception. In the first stage, a subset of users whose spreading codes are assumed known are suppressed in a centralized fashion. The remaining interference is suppressed via the second stage in an adaptive decentralized mode. The hybrid scheme offers a flexible design framework by offering lower complexity compared to fully centralized receivers and improved adaptive performance compared to fully decentralized schemes