Generalized reference signaling scheme for multi-user, multiple input, multiple output (MU-MIMO) using arbitrarily precoded reference signals

A forward reference signaling method for a multiple input, multiple output (MIMO) space division multiple access (SDMA) system, comprising:

• feeding back to a transmitting device effective channel information from a receiving device;
• receiving over a feed forward channel a plurality of precoded reference signals from the transmitting device which are generated by using a plurality of transmit beamforming vectors which are generated based at least in part on the effective channel information;
• extracting at the receiving device the plurality of transmit beamforming vectors from the plurality of precoded reference signals;
• identifying which transmit beamforming vector is designed for said receiving device without requiring additional information to be fed forward that identifies the transmit beamforming vector or precoded reference signal that is designed for said receiving device;
• and
• using the transmit beamforming vectors to generate a receive beamforming vector at the receiving device.

A forward reference signaling method for a multiple input, multiple output (MIMO) space division multiple access (SDMA) system, comprising:

• receiving at a transmitting device effective channel information from a plurality of receiving devices;
• using a spatial separation algorithm to design a transmit beamforming matrix based on the effective channel information;
• generating one or more precoded reference signals by using all or part of the designed transmit beamforming matrix to encode said one or more reference signals;
• and
• feeding forward said one or more precoded reference signals to a plurality of receiving devices for use in generating receive beamforming vectors at each receiving device, where each receiving device extracts the transmit beamforming matrix from at least one of said one or more precoded reference signal and identifies a transmit beamforming vector that is designed for said receiving device without requiring additional information to be fed forward that identifies the transmit beamforming vector that is designed for said receiving device.

A forward reference signaling method for a multiple input, multiple output (MIMO) space division multiple access (SDMA) system, comprising:

• feeding back to a transmitting device effective channel information from a receiving device;
• receiving over a feed forward channel a precoded reference signal from the transmitting device, where the precoded reference signal is generated using all or part of a transmit beamforming matrix which is generated using a spatial separation algorithm based at least in part on the effective channel information;
• extracting at the receiving device the generated transmit beamforming matrix from at least the precoded reference signal;
• and
• using the transmit beamforming matrix to generate a receive beamforming vector at the receiving device without requiring additional information to be fed forward that identifies a transmit beamforming vector that is designed for said receiving device.

A forward reference signaling method for a multiple input, multiple output (MIMO) space division multiple access (SDMA) system, comprising:

• feeding back to a transmitting device a preferred precoding vector or information representative thereof from a receiving device;
• receiving over a feed forward channel one or more index bits representative of a transmit beamforming matrix which is generated using a spatial separation algorithm based at least in part on the preferred precoding vector or information representative thereof;
• using the index bits at the receiving device to retrieve the generated transmit beamforming matrix from a finite set of candidate transmit beamforming matrices;
• and
• using the transmit beamforming matrix to generate a receive beamforming vector at the receiving device without requiring additional information to be fed forward that identifies which transmit beamforming vector in the transmit beamforming matrix is designed for said receiving device.