Pre-coded diversity forward channel transmission system for wireless communications systems supporting multiple MIMO transmission modes

摘要

A wireless communications system supporting multiple MIMO transmission modes supporting both diversity and directional transmissions under a plurality of different transmission modes comprises a plurality of transmit and receive antenna elements where the transmit antenna elements are arranged to provide polarization diversity. The transmitting station derives actual knowledge of the forward channel by feeding back certain information such as a preferred beam index and a channel quality indicator figure of merit for that beam from the receiving station to the transmitting station along a reverse channel. The receiving station knows the beam weights used by the transmitting station. The transmitting station applies the fed back information to transmit user data intended for the receiving station in the optimal fashion, such as along the preferred beam and at a time when forward channel conditions are satisfactory. The system provides robust single or multiple stream diversity transmission, together with the option of single user or multi-user beamforming to allow on-the-fly trade-offs between coverage gain and capacity in a wireless telecommunications system.