Beamforming to a subset of receive antennas in a wireless MIMO communication system

A wireless transmitter for transmitting an information signal to a plurality of receiver antennas associated with one or more receivers, the wireless transmitter comprising:

• a signal modulator configured to modulate the information signal to produce a modulated signal;
• a multiplicity of transmission antennas;
• a beamforming network coupled between the signal modulator and the multiplicity of transmission antennas;
• and
• a controller coupled to the beamforming network to control the beamforming network using a steering matrix so as to produce a transmit gain pattern having one or more high gain lobes when the modulated signal is transmitted via the multiplicity of transmission antennas;
• wherein a steering matrix calculation unit determines the steering matrix using a subset of receiver antennas, the subset of receiver antennas including less than all of the plurality of receiver antennas.

A wireless communication system, comprising:

• a transmitter having a plurality of transmission antennas;
• one or more receivers;
• a multiplicity of receiver antennas associated with the one or more receivers;
• a signal modulator disposed within the transmitter, the signal modulator configured to modulate an information signal to produce a modulated signal;
• a beamforming network coupled between the signal modulator and the plurality of transmission antennas;
• a controller coupled to the beamforming network to control the beamforming network using a steering matrix so as to produce a transmit gain pattern based on the steering matrix when the modulated signal is transmitted via the plurality of transmission antennas;
• and
• a steering matrix calculation unit configured to determine the steering matrix using a subset of receiver antennas, the subset of receiver antennas including less than all of the multiplicity of receiver antennas.

A beamforming system for use in a wireless communication system having a transmitter with multiple transmission antennas and one or more receivers having a plurality of receiver antennas, the beamforming system comprising:

• a computer readable memory;
• and
• a routine stored on the computer readable memory, the routine and adapted to be executed on a processor to
• determine a steering matrix using a subset of receiver antennas, the subset of receiver antennas including less than all of the plurality of receiver antennas, and
• apply the steering matrix to a signal to be transmitted via the multiple transmission antennas, wherein the steering matrix is used to produce a beam pattern having one or more high gain lobes.