Method and system for mixed analog/digital beamforming in wireless communication systems

A receiver device for use in a wireless communication system, the device comprising:

• a plurality of receive antennas;
• at least two analog front-ends;
• an estimator configured to determine information representative of communication channels formed between a receive antenna of the plurality of receive antennas and a transmit antenna of a plurality of transmit antennas of a transmitter device of the wireless communication system, the estimator being further configured to determine an estimate of the frequency responses of the communication channels;
• and
• a controller configured to calculate an optimized set of coefficients based on a beamforming cost function using the information obtained in the estimator and a set of initial coefficients representing the transmit and receive analog beamforming coefficients and taking into account the at least two analog front-ends, the controller being further configured to calculate for each communication channel transmit digital beamforming coefficients and receive digital beamforming coefficients and to send the transmit digital beamforming coefficients to the transmitter device.

A transmitter device for use in a wireless communication system, the device comprising:

• a plurality of transmit antennas;
• at least two analog front-ends;
• an estimator configured to determine information representative of communication channels formed between a transmit antenna of the plurality of transmit antennas and a receive antenna of a plurality of receive antennas of a receiver device of the wireless communication system, the estimator being further configured to determine an estimate of the frequency responses of the communication channels;
• and
• a controller configured to calculate an optimized set of coefficients based on a beamforming cost function using the information obtained in the estimator and a set of initial coefficients representing the transmit and receive analog beamforming coefficients and taking into account the at least two analog front-ends, the controller being configured to calculate for each communication channel transmit digital beamforming coefficients and receive digital beamforming coefficients and to send the receive digital beamforming coefficients to the receiver device.

A device for mixed analog/digital beamforming in a wireless communication system, the wireless system having a plurality of transmit antennas and receive antennas and a plurality of analog front-ends connected to the plurality of transmit and receive antennas, at least two of the analog front-ends being connected to either the transmit antennas or the receive antennas, the device comprising:

• means for determining information representative of communication channels formed between a transmit antenna and a receive antenna of the plurality of antennas;
• and
• means for computing an optimized set of coefficients by exploiting a beamforming cost function, the beamforming cost function determined using the information and a set of coefficients representing transmit analog beamforming coefficients and receive analog beamforming coefficients, the beamforming cost function taking into account the plurality of analog front-ends, the optimized set of coefficients comprising optimized transmit analog beamforming coefficients and optimized receive analog beamforming coefficients,
• wherein the means for determining information includes means for deriving an estimate of the frequency responses of the communication channels using the determined information representative of communication channels, and
• wherein the means for computing includes means for deriving, for each communication channel, the transmit digital beamforming coefficients and receive digital beamforming coefficients using the estimated frequency responses and the optimized transmit and receive analog beamforming coefficients.