Method and device for performing precoding

1. A method for performing precoding in a base station, wherein the antenna array of the base station is divided into a plurality of panels, each of the plurality of panels corresponding to a plurality of ports to serve multiple users, the method comprising:

transmitting, using the base station, a channel status information CSI reference signal to a UE to request the UE to report status-related information of respective panels of the plurality of panels;

acquiring, using the base station, based on first feedback information from the UE, the status-related information of the respective panels whose status-related information has been measured by the UE and a serving panel among the plurality of panels selected by the UE; and

performing, using the base station, based on the status-related information of the respective panels and the serving panel selected by the UE, two-stage beamforming separately to the respective panels, so as to first perform decoupling to suppress inter-panel interference and then perform per-panel precoding.

2. The method according to claim 1 , wherein the performing includes:

calculating, based on channels from the UE to the respective panels, decoupling matrices and beamforming matrices corresponding to the respective panels, and

performing precoding to the respective panels.

3. The method according to claim 1 , wherein

the base station applies specific indicators to identify the respective panels, and the method further comprises steps of:

transmitting CSI configuration information to the UE so as to configure, in the UE, the indicators corresponding to the respective panels.

4. The method according to claim 1 , wherein the method further comprises:

in response to the base station needing to update the status-related information of one or more specific panels to perform two-stage beamforming,

transmitting an aperiodic CSI reporting request to the UE so as to request the UE to report the status-related information of the one or more specific panels,

updating the requested status-related information of the respective panels based on second feedback information from the UE, and

performing two-stage beamforming to the respective panels based on the updated status-related information of the respective panels.

5. The method according to claim 1 , wherein the method further comprises:

in response to the base station requiring the status-related information of the one or more specific panels to perform precoding

transmitting an aperiodic CSI reporting request to the UE so as to request the UE to report beamformed status-related information of the one or more specific panels,

updating the requested status-related information of the respective panels based on second feedback information from the UE, and

performing precoding to the respective panels based on the updated status-related information of the respective panels.

6. A method for assisting in performing precoding in a UE, comprising:

measuring status-related information of one or more panels upon receiving a CSI reference signal transmitted from a base station;

selecting, by performing a channel status estimation operation, one panel as a serving panel from respective panels whose status-related information has been measured;

generating corresponding first feedback information, wherein the first feedback information includes the indicator of the selected panel and the status-related information of the respective panels;

feeding back the first feedback information to the base station;

receiving an aperiodic CSI reporting request requesting reporting the status-related information of the respective panels; and

sending, to the base station, second feedback information reporting the status related information of the respective panels in response to the received aperiodic CSI reporting request.

7. The method according to claim 6 , wherein the base station applies specific indicators to identify the respective panels, the method comprising steps of:

receiving CSI configuration information from the base station so as to configure, in the UE, the indicators corresponding to the respective panels.

8. A precoding apparatus for performing precoding in a base station, wherein an antenna array of the base station is divided into a plurality of panels, each panel corresponding to a plurality of ports to serve multiple users, the precoding apparatus comprising:

at least one processor; and

at least one memory comprising computer program code, the at least one memory and computer program code configured, with the at least one processor, to cause the precoding apparatus at least to

transmit a channel status information CSI reference signal to a UE to request the UE to report status-related information of respective panels,

acquire, based on first feedback information from the UE, the status-related information of the respective panels measured by the UE and a serving panel selected by the UE, and

perform, based on the status-related information of the respective panels and the serving panel selected by the UE, two-stage beamforming separately to the respective panels, so as to first perform decoupling to suppress inter-panel interference and then perform per-panel precoding.

9. The precoding apparatus according to claim 8 , wherein the at least one memory and computer program code are configured, with the at least one processor, to cause the precoding apparatus at least to

calculate, based on channels from the UE to the respective panels, decoupling matrices and beamforming matrices corresponding to the respective panels, and

perform precoding to the respective panels.

10. The precoding apparatus according to claim 8 , wherein

the base station applies specific indicators to identify the respective panels, and

the at least one memory and computer program code are configured, with the at least one processor, to cause the precoding apparatus at least to

transmit CSI configuration information to the UE so as to configure, in the UE, the indicators corresponding to the respective panels.

11. The precoding apparatus according to claim 8 , wherein the at least one memory and computer program code are configured, with the at least one processor, to cause the precoding apparatus at least to

in response to the base station needing to update the status-related information of one or more specific panels to perform two-stage beamforming

transmit an aperiodic CSI reporting request to the UE to request the UE to report the status-related information of the one or more specific panels;

update the requested status-related information of the respective panels based on second feedback information from the UE; and

perform two-stage beamforming to the respective panels based on the updated status-related information of the respective panels.

12. The precoding apparatus according to claim 8 , wherein the at least one memory and computer program code configured, with the at least one processor, to cause the precoding apparatus at least to

in response to the base station requiring the status-related information of one or more specific panels to perform precoding

transmit an aperiodic CSI reporting request to the UE to request the UE to report beamformed status-related information of the specific one or more panels,

update the requested status-related information of the respective panels based on the second feedback information from the UE, and

perform precoding to the respective panels based on the updated status-related information of the respective panels.

13. An assisting apparatus for assisting in performing precoding in a UE, comprising:

at least one processor; and

at least one memory comprising computer program code, the at least one memory and computer program code configured, with the at least one processor, to cause the assisting apparatus at least to

measure status-related information of one or more panels upon receiving a CSI reference signal transmitted from a base station,

select, by performing a channel status estimation operation, one panel as a serving panel from the respective panels whose status-related information has been measured,

generate corresponding first feedback information, wherein the first feedback information includes the indicator of the selected panel and the status-related information of the respective panels,

feedback the first feedback information to the base station;

receive an aperiodic CSI reporting request requesting reporting the status-related information of the respective panels; and

send second feedback information reporting the status related information of the respective panels in response to the received aperiodic CSI reporting request.

14. The assisting apparatus according to claim 13 , wherein the base station applies specific indicators to identify the respective panels, and

the at least one memory and computer program code configured, with the at least one processor, to cause the assisting apparatus at least to:

receive CSI configuration information from the base station so as to configure, in the UE, the indicators corresponding to the respective panels.