Beamforming device for antenna arrays

A beamforming device for use in a wireless communication system comprising an initiator and a responder, said beamforming device comprising:

• circuitry configured to
• control the initiator having one or more initiator antenna arrays each comprising two or more initiator antenna elements and/or the responder having one or more responder antenna arrays each comprising two or more responder antenna elements, wherein the initiator has at least two initiator antenna arrays and/or the responder has at least two responder antenna arrays,
• select one or more initiator antenna beams per initiator antenna array and one or more responder antenna beams per responder antenna array for use by the initiator and the responder in communicating with each other,
• control, in a first training stage, the responder antenna elements, per pair of initiator antenna array and responder antenna array to receive a first training signal transmitted by the initiator antenna array by successively using different initiator antenna beams of different initiator antenna beam directions and to transmit a first training signal by successively using different responder antenna beams of different responder antenna beam directions,
• determine an antenna score per initiator antenna array and per responder antenna array based on a first initiator quality information and a first responder quality information of the antenna beam combinations used in the first training stage, said antenna scores including a score value per antenna beam used in the first training stage,
• use the determined antenna scores for selecting the sub-set of antenna beam combinations for use in the second training stage,
• select a sub-set of the antenna beam combinations that have been used in the first training stage or are derived from the antenna beam combination used in the first training stage, for use in a second training stage, wherein at least some of the antenna beam combinations of said sub-set are selected by use of the first responder quality information indicating the quality of reception of the first training signals by the respective responder antenna array for the different initiator antenna beams used by the respective initiator antenna array for transmitting the first training signal and the first initiator quality information indicating the quality of reception of the first training signals by the respective initiator antenna array for the different responder antenna beams used by the respective responder antenna array for transmitting the first training signal in the first training stage, wherein the first responder quality information and the first initiator quality information obtained for the different pairs of initiator antenna arrays and responder antenna arrays of the first training stage is used,
• control, in the second training stage, the responder antenna elements of the responder antenna arrays to receive a second training signal commonly transmitted by the initiator antenna elements of the one or more initiator antenna arrays by successively using different initiator antenna beams of different initiator antenna beam directions according to one or more of the selected antenna beam combinations and/or to commonly transmit a second training signal by successively using different initiator antenna beams of different initiator antenna beam directions according to one or more of the selected antenna beam combinations, and
• select a final antenna beam combination for use by the initiator and the responder in communicating with each other from second responder quality information indicating the quality of reception of the second training signals by the responder antenna arrays for the different initiator antenna beams used by the initiator antenna arrays for transmitting the second training signal and/or from second initiator quality information indicating the quality of reception of the second training signals by the initiator antenna arrays for the different responder antenna beams used by the responder antenna arrays for transmitting the second training signal in the second training stage.

A beamforming method for use in a wireless communication system comprising an initiator and a responder, the initiator having one or more initiator antenna arrays each comprising two or more initiator antenna elements and/or the responder having one or more responder antenna arrays each comprising two or more responder antenna elements, wherein the initiator has at least two initiator antenna arrays and/or the responder has at least two responder antenna arrays,

• said beamforming method being configured for selecting one or more initiator antenna beams per initiator antenna array and one or more responder antenna beams per responder antenna array for use by the initiator and the responder in communicating with each other,
• said beamforming method comprising:
• controlling, in a first training stage, the initiator antenna elements, per pair of initiator antenna array and responder antenna array, to transmit a first training signal by successively using different initiator antenna beams of different initiator antenna beam directions and to receive a first training signal transmitted by the responder antenna array by successively using different responder antenna beams of different responder antenna beam directions,
• determining an antenna score per initiator antenna array and per responder antenna array based on a first initiator quality information and a first responder quality information of the antenna beam combinations used in the first training stage, said antenna scores including a score value per antenna beam used in the first training stage,
• using the determined antenna scores for selecting the sub-set of antenna beam combinations for use in the second training stage,
• selecting a sub-set of the antenna beam combinations that have been used in the first training stage or are derived from the antenna beam combination used in the first training stage, for use in a second training stage, wherein at least some of the antenna beam combinations of said sub-set are selected by use of first responder quality information indicating the quality of reception of the first training signals by the respective responder antenna array for the different initiator antenna beams used by the respective initiator antenna array for transmitting the first training signal and first initiator quality information indicating the quality of reception of the first training signals by the respective initiator antenna array for the different responder antenna beams used by the respective responder antenna array for transmitting the first training signal in the first training stage, wherein the first responder quality information and the first initiator quality information obtained for the different pairs of initiator antenna arrays and responder antenna arrays of the first training stage is used,
• controlling, in the second training stage, the initiator antenna elements of the initiator antenna arrays to commonly transmit a second training signal by successively using different initiator antenna beams of different initiator antenna beam directions according to the selected antenna beam combinations, and/or to receive a second training signal commonly transmitted by the responder antenna elements of the one or more responder antenna arrays by successively using different responder antenna beams of different responder antenna beam directions according to the selected antenna beam combinations, and
• selecting a final antenna beam combination for use by the initiator and the responder in communicating with each other from second responder quality information indicating the quality of reception of the second training signals by the responder antenna arrays for the different initiator antenna beams used by the initiator antenna arrays for transmitting the second training signal and/or from second initiator quality information indicating the quality of reception of the second training signals by the initiator antenna arrays for the different responder antenna beams used by the responder antenna arrays for transmitting the second training signal in the second training stage.