Method and device for performing beamforming

1. A method implemented by a first device in a wireless communication network, comprising:

determining that a second device is performing discontinuous reception;

determining a beam set from a plurality of predefined beams, wherein the beam set includes candidate beams for data transmission to the second device, wherein the beam set includes a beam used in historical data transmission, and wherein a size of the beam set is determined based on at least one of beam width of each of the plurality of predefined beams and a moving speed of the second device;

determining a target beam from the beam set by selecting at least one candidate beam according to the size of the beam set; and

transmitting data over the target beam to the second device in an active duration of the discontinuous reception.

2. The method according to claim 1 , wherein the beam set includes a beam adjacent to the beam used in historical data transmission as a candidate beam.

3. The method according to claim 1 , wherein the determining the target beam further comprises:

determining, as the target beam, a combination of the candidate beams.

4. The method according to claim 1 , further comprising:

determining a repetition number for the target beam based on historical transmission quality, and

transmitting data over the target beam for the repetition number of times to the second device.

5. The method according to claim 4 , wherein the determining the repetition number comprises:

obtaining the historical transmission quality based on a report from the second device;

obtaining reference transmission quality corresponding to a reference beam width; and

determining the repetition number based on the historical transmission quality and the reference transmission quality.

6. A method implemented by a second device performing discontinuous reception in a wireless communication network, comprising:

receiving data transmitted from a first device over a target beam in an active duration of the discontinuous reception, the target beam being determined based on:

a beam set determined from a plurality of predefined beams, wherein the beam set includes candidate beams for data transmission to the second device, wherein the beam set includes a beam used in historical data transmission, and wherein a size of the beam set is determined based on at least one of beam width of each of the plurality of predefined beams and a moving speed of the second device; and

the target beam determined from the beam set by selecting at least one candidate beam according to the size of the beam set.

7. The method according to claim 6 , wherein the beam set includes a beam adjacent to the beam used in historical data transmission as a candidate beam.

8. The method according to claim 6 , wherein receiving the data comprises:

obtaining a repetition number for the target beam, the data being transmitted from the first device for the repetition number of times; and

receiving the data for the repetition number of times.

9. The method according to claim 6 , further comprising:

measuring signal strength based on the received data;

determining transmission quality of the target beam based on the measured signal strength; and

if the transmission quality exceeds a predetermined quality threshold, transmitting a report indicating at least one of the determined transmission quality and the measured signal strength to the first device.

10. The method according to claim 6 , further comprising:

measuring signal strength based on the received data;

determining current transmission quality of the target beam based on the measured signal strength; and

when a difference between the current transmission quality and a historical transmission quality exceeds a predetermined difference threshold, transmitting a report indicating the current transmission quality to the first device.

11. A first device in a wireless communication network, comprising:

a controller configured to determine that a second device is performing discontinuous reception, determine a beam set from a plurality of predefined beams, wherein the beam set includes candidate beams for data transmission to the second device, wherein the beam set includes a beam used in historical data transmission, and wherein a size of the beam set is determined based on at least one of beam width of each of the plurality of predefined beams and a moving speed of the second device and the controller to determine a target beam from the beam set by selecting at least one candidate beam according to the size of the beam set; and

a transceiver configured to transmit data over the target beam to the second device in an active duration of the discontinuous reception.

12. The first device according to claim 11 , wherein the beam set includes a beam adjacent to the beam used in historical data transmission as a candidate beam.

13. A second device for performing discontinuous reception in a wireless communication network, comprising:

a transceiver configured to receive data transmitted from a first device over a target beam in an active duration of the discontinuous reception, the target beam being determined based on:

a beam set determined from a plurality of predefined beams, wherein the beam set includes candidate beams for data transmission to the second device, wherein the beam set includes a beam used in historical data transmission, and wherein a size of the beam set is determined based on at least one of beam width of each of the plurality of predefined beams and a moving speed of the second device; and

the target beam determined from the beam set by selecting at least one candidate beam according to the size of the beam set.

14. The second device according to claim 13 , wherein the beam set includes a beam adjacent to the beam used in historical data transmission as a candidate beam.