Communication devices and methods with beamforming training
A communication device, e.g. an access point, for RF-based communication with another communication device, e.g. a station, comprises antenna circuitry configured to transmit and receive RF signals and beamforming circuitry configured to perform beamforming. The beamforming circuitry controls the antenna circuitry to transmit data, in a beacon transmission phase prior to the beamforming training phase, using a set of third directive transmit beams in subsequent time slots and to listen, in the beamforming training phase, using a set of first directive receive beams in subsequent time slots that is different from the set of third directive transmit beams.
1 . A communication device for radio frequency radiation (RF) based communication with another communication device, said communication device comprising:
antenna circuitry configured to transmit and receive RF signals, and
beamforming circuitry configured to perform beamforming and to control the antenna circuitry to transmit data using at least one first directive transmit beam while the other communication device is listening subsequently using different first directive receive beams,
wherein the data is only transmitted in one or more selected time slots, in which the other communication device is listening with a selected first directive receive beam,
wherein the one or more time slots are selected based on information received from the other communication device or derived from third directive transmit beams used by the other communication device to transmit one or more beacon frames in a beacon transmission phase prior to a beamforming training phase, and
wherein a set of one or more first directive receive beams used by beamforming circuitry for the listening by the other communication device in the beamforming training phase differs from the third directive transmit beams used by the other communication device for transmitting in the beacon transmission phase prior to the beamforming training phase in terms of number, width, and/or angular sector.
2 . The communication device as claimed in claim 1 ,
wherein the beamforming circuitry is configured to control the antenna circuitry to carry out, in the beacon transmission phase, the operations of
listening using different third directive receive beams in at least part of a time slot while the other communication device transmits the one or more beacon frames using a third directive transmit beam, wherein the other communication device transmits the one or more beacon frames using different third directive transmit beams in subsequent time slots, and
selecting one or more third directive receive beams for use in determining the at least one first directive transmit beam to be used in the subsequent beamforming training phase.
3 . The communication device as claimed in claim 1 ,
wherein the beamforming circuitry is configured to control the antenna circuitry to carry out, in the beacon transmission phase, the steps-operations of
listening using a quasi-omnidirectional receive beam in at least part of a time slot while the other communication device transmits the one or more beacon frames using a third directive transmit beam, wherein the other communication device transmits the one or more beacon frames using different third directive transmit beams in subsequent time slots, and
selecting one or more third directive transmit beams for use in determining in which one or more time slots to transmit the one or more beacon frames in the subsequent beamforming training phase, said selecting including determining when the other communication device listens with the different first directive receive beams corresponding to or covering the selected one or more third directive transmit beams.
4 . The communication device as claimed in claim 1 ,
wherein the beamforming circuitry is configured to control the antenna circuitry to select the one or more time slots in which it transmits the data in the beamforming training phase based on scheduling information received from the other communication device in a beacon transmission phase prior to the beamforming training phase, and
wherein said scheduling information indicates in which time slot which first directive receive beam of the different first directive receive beams will be used by the other communication device for listening in the beamforming training phase and/or indicates if the other communication device is transmitting in a certain time slot and/or if the communication device is allowed to transmit in a certain time slot.
5 . The communication device as claimed in claim 4 , wherein the beamforming circuitry is configured to derive the scheduling information from a sector sweep (SSW) field or a beamforming control field or an information field of a beacon frame transmitted by the other communication device in the beacon transmission phase.
6 . The communication device as claimed in claim 1 ,
wherein the beamforming circuitry is configured to control the antenna circuitry to select the one or more time slots in which it transmits the data in the beamforming training phase based on correspondence information received from the other communication device in a beacon transmission phase prior to the beamforming training phase, and
wherein said correspondence information indicates the correspondence between a third transmit beam used by the other communication device in the beacon transmission phase for transmitting the one or more beacon frames in a particular time slot and a first receive beam to be used by the other communication device in the beamforming training phase for listening in a particular time slot.
7 . The communication device as claimed in claim 1 ,
wherein the beamforming circuitry is configured to control the antenna circuitry to select the one or more time slots in which it transmits the data in the beamforming training phase based on a sequence in which the other communication device transmits the one or more beacon frames with the third directive transmit beams in the beacon transmission phase prior to the beamforming training phase, and
wherein two or more of the third directive transmit beams covered by a single first directive receive beam of the different first directive receive beams that will be used by the other communication device in the beamforming training phase are followed or preceded by another third directive transmit beam of the third directive transmit beams corresponding to said single first directive receive beam.
8 . The communication device as claimed in claim 1 ,
wherein the beamforming circuitry is configured to control the antenna circuitry to select the one or more time slots in which it transmits the data in the beamforming training phase based on a sequence in which the other communication device transmits the one or more beacon frames with the third directive transmit beams in the beacon transmission phase, and
wherein a predetermined number of subsequently used third directive transmit beams will be covered by a first directive receive beam of the different first directive receive beams and/or wherein a sequence of first directive receive beams corresponds to the sequence of third directive transmit beams.
9 . The communication device as claimed in claim 1 , wherein the beamforming circuitry is configured to control the antenna circuitry to listen, after the one or more time slots of transmitting the data, or in specially allocated feedback intervals, using a second receive beam for a response from the other communication device, which is configured to transmit, if the data transmitted by the communication device have been received, a response using a second directive transmit beam.
10 . The communication device as claimed in claim 9 , wherein the beamforming circuitry is configured to control the antenna circuitry to include a second transmit beam information in the data transmitted using said at least one first directive transmit beam for use by the other communication device for transmitting the response by the second directive transmit beam indicated by the second transmit beam information.
11 . The communication device as claimed in claim 1 , wherein the set of the one or more first directive receive beams used by the beamforming circuitry for listening in the beamforming training phase differs from the third directive transmit beams used by the other communication device for transmitting in the beacon transmission phase prior to the beamforming training phase in terms of two or more of the number, the width, and/or the angular sector.
12 . The communication device as claimed in claim 1 , wherein the different first directive receive beams used by the other communication device to listen for the beamforming are different from the at least one first directive transmit beam for the beamforming.
13 . A communication method for radio frequency radiation (RF) based communication with another communication device, said communication method comprising:
controlling an antenna circuitry to perform beamforming and in a beamforming training phase to transmit data using at least one first directive transmit beam while the other communication device is listening subsequently using different first directive receive beams,
wherein the data is only transmitted in one or more selected time slots, in which the other communication device is listening with a selected first directive receive beam,
wherein the one or more time slots are selected based on information received from the other communication device or derived from third directive transmit beams used by the other communication device to transmit the one or more beacon frames in a beacon transmission phase prior to a beamforming training phase, and
wherein a set of one or more first directive receive beams used by the beamforming circuitry for the listening by the other communication device in the beamforming training phase differs from the third directive transmit beams used by the other communication device for transmitting in the beacon transmission phase prior to the beamforming training phase in terms of number, width, and/or angular sector.
14 . The method as claimed in claim 13 , wherein the beacon transmission phase includes:
listening using different third directive receive beams in at least part of a time slot while the other communication device transmits the one or more beacon frames using a third directive transmit beam, wherein the other communication device transmits the one or more beacon frames using different third directive transmit beams in subsequent time slots, and
selecting one or more third directive receive beams for use in determining the at least one first directive transmit beam to be used in the subsequent beamforming training phase.
15 . The method as claimed in claim 13 , wherein the beacon transmission phase includes:
listening using a quasi-omnidirectional receive beam in at least part of a time slot while the other communication device transmits the one or more beacon frames using a third directive transmit beam, wherein the other communication device transmits the one or more beacon frames using different third directive transmit beams in subsequent time slots, and
selecting one or more third directive transmit beams for use in determining in which one or more time slots to transmit the data in the subsequent beamforming training phase, said selecting including determining when the other communication device listens with the different first directive receive beams corresponding to or covering the selected one or more third directive transmit beams.
16 . The method as claimed in claim 13 , further comprising selecting the one or more time slots in which to transmits the data in the beamforming training phase based on scheduling information received from the other communication device in a beacon transmission phase prior to the beamforming training phase,
wherein said scheduling information indicates in which time slot which first directive receive beam of the different first directive receive beams will be used by the other communication device for listening in the beamforming training phase and/or indicates if the other communication device is transmitting in a certain time slot and/or if the communication device is allowed to transmit in a certain time slot.
17 . The method as claimed in claim 13 , further comprising selecting the one or more time slots in which it transmits the data in the beamforming training phase based on correspondence information received from the other communication device in a beacon transmission phase prior to the beamforming training phase,
wherein said correspondence information indicates the correspondence between a third transmit beam used by the other communication device in the beacon transmission phase for transmitting the one or more beacon frames in a particular time slot and a first receive beam to be used by the other communication device in the beamforming training phase for listening in a particular time slot.
18 . The method as claimed in claim 13 , further comprising selecting the one or more time slots in which it transmits the data in the beamforming training phase based on a sequence in which the other communication device transmits the one or more beacon frames with the third directive transmit beams in the beacon transmission phase prior to the beamforming training phase,
wherein two or more of the third directive transmit beams covered by a single first directive receive beam of the different first directive receive beams that will be used by the other communication device in the beamforming training phase are followed or preceded by another third directive transmit beam of the third directive transmit beams corresponding to said single first directive receive beam.
19 . The method as claimed in claim 13 , further comprising selecting the one or more time slots in which it transmits the data in the beamforming training phase based on a sequence in which the other communication device transmits the one or more beacon frames with the third directive transmit beams in the beacon transmission phase,
wherein a predetermined number of subsequently used third directive transmit beams will be covered by a first directive receive beam of the different first directive receive beams and/or wherein a sequence of first directive receive beams corresponds to the sequence of third directive transmit beams.
20 . The method as claimed in claim 13 , further comprising:
listening, after the one or more time slots of transmitting the data, or in specially allocated feedback intervals, using a second receive beam for a response from the other communication device,
wherein a second transmit beam information is included in the data transmitted using said at least one first directive transmit beam for use by the other communication device for transmitting the response by the second directive transmit beam indicated by the second transmit beam information.