Two dimensional spreading codes for the downlink in a multiuser system with multiple antennas

We present a novel space-time spreading scheme for the down-link in a multiuser system. The primary goals of this work are to increase bandwidth efficiency, and to provide joint multiuser detection and space-time decoding, in each mobile station. Each receiver just needs to know its own spreading code and no information about the channel is required in the transmitter. In the proposed architecture, to achieve high bandwidth efficiency, the number of user-channels, is maximized by taking advantage of the large potential capacity of a multiple antenna system.