Method, access point, and station for transmitting channel state information

1. A method for transmission of channel state information, comprising:

generating, by an access point, a trigger frame, wherein the trigger frame comprises a type field, a feedback segment retransmission bitmap field, and a resource scheduling message, wherein the type field indicates that the trigger frame is a beamforming report poll trigger frame, wherein the feedback segment retransmission bitmap field indicates a requested feedback segment, and wherein the resource scheduling message indicates a communication resource to be used by a target station (STA) for feeding back channel state information; and

sending, by the access point, the trigger frame.

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

receiving the channel state information sent by the target STA using the communication resource.

3. The method according to claim 1 , wherein before generating the trigger frame, the method further comprises:

sending a null data packet announcement (NDPA) frame, wherein the NDPA frame carries a feedback indication message which indicates the target STA that needs to feed back channel state information.

4. The method according to claim 3 , wherein before generating the trigger frame and after sending the NDPA frame, the method further comprises:

sending a null data packet (NDP), wherein the NDP carries a high-efficiency long training sequence to be used for determining the channel state information by the target STA.

5. The method according to claim 4 , wherein there is an inter frame space between the NDP and the trigger frame.

6. A method for transmission of channel state information, comprising:

receiving, by a target station (STA), a trigger frame, wherein the trigger frame comprises a type field, a feedback segment retransmission bitmap field, and a resource scheduling message, wherein the type field indicates that the trigger frame is a beamforming report poll trigger frame, wherein the feedback segment retransmission bitmap field indicates a requested feedback segment, and wherein the resource scheduling message indicates a communication resource to be used by the target STA for feeding back channel state information; and

in response to receiving the trigger frame, feeding back, by the target STA, the channel state information using the communication resource.

7. The method according to claim 6 , wherein before receiving the trigger frame, the method further comprises:

receiving a null data packet announcement (NDPA) frame, wherein the NDPA frame carries a feedback indication message which indicates that the target STA needs to feed back channel state information.

8. The method according to claim 7 , wherein before receiving the trigger frame and after receiving the NDPA frame, the method further comprises:

receiving a null data packet (NDP), wherein the NDP carries a high-efficiency long training sequence to be used by the target STA for determining the channel state information.

9. The method according to claim 8 , wherein after receiving the NDP, the method further comprises:

determining, by the target STA, the channel state information based on the high-efficiency long training sequence and based on the STA parsing the feedback indication message.

10. The method according to claim 8 , wherein there is an inter frame space between the NDP and the trigger frame.

11. An apparatus for transmission of channel state information, comprising:

at least one processor; and

a non-transitory computer-readable storage medium coupled to the at least one processor and storing programming instructions for execution by the at least one processor;

wherein the at least one processor is configured to execute the programming instructions to facilitate the following operations being performed by the apparatus:

generating a trigger frame, wherein the trigger frame comprises a type field, a feedback segment retransmission bitmap field, and a resource scheduling message, wherein the type field indicates that the trigger frame is a beamforming report poll trigger frame, wherein the feedback segment retransmission bitmap field indicates a requested feedback segment, and wherein the resource scheduling message indicates a communication resource to be used by a target station (STA) for feeding back channel state information; and

sending the trigger frame.

12. The apparatus according to claim 11 , wherein the at least one processor is further configured to execute the programming instructions to facilitate the following operations being performed by the apparatus:

receiving the channel state information sent by the target STA using the communication resource.

13. The apparatus according to claim 11 , wherein the at least one processor is further configured to execute the programming instructions to facilitate the following operations being performed by the apparatus:

before generating the trigger frame,

sending a null data packet announcement (NDPA) frame, wherein the NDPA frame carries a feedback indication message which indicates the target STA that needs to feed back channel state information.

14. The apparatus according to claim 13 , wherein the at least one processor is further configured to execute the programming instructions to facilitate the following operations being performed by the apparatus:

before generating the trigger frame and after sending the NDPA frame, sending a null data packet (NDP), wherein the NDP carries a high-efficiency long training sequence to be used by the target STA for determining the channel state information.

15. The apparatus according to claim 14 , wherein there is an inter frame space between the NDP and the trigger frame.

16. A target station (STA) for transmission of channel state information, comprising:

at least one processor; and

a non-transitory computer-readable storage medium coupled to the at least one processor and storing programming instructions for execution by the at least one processor;

wherein the at least one processor is configured to execute the programming instructions to facilitate the following operations being performed by the target STA:

receiving a trigger frame, wherein the trigger frame comprises a type field, a feedback segment retransmission bitmap field, and a resource scheduling message, wherein the type field indicates that the trigger frame is a beamforming report poll trigger frame, wherein the feedback segment retransmission bitmap field indicates a requested feedback segment, and wherein the resource scheduling message indicates a communication resource to be used by the target STA for feeding back channel state information; and

in response to receiving the trigger frame, feeding back the channel state information using the communication resource.

17. The target STA according to claim 16 , wherein the at least one processor is further configured to execute the programming instructions to facilitate the following operations being performed by the target STA:

before receiving the trigger frame,

receiving a null data packet announcement (NDPA) frame, wherein the NDPA frame carries a feedback indication message which indicates that the target STA needs to feed back channel state information.

18. The target STA according to claim 17 , wherein the at least one processor is further configured to execute the programming instructions to facilitate the following operations being performed by the target STA:

before receiving the trigger frame and after receiving the NDPA frame,

receiving a null data packet (NDP), wherein the NDP carries a high-efficiency long training sequence to be used by the target STA for determining the channel state information.

19. The target STA according to claim 18 , wherein the at least one processor is further configured to execute the programming instructions to facilitate the following operations being performed by the target STA:

after receiving the NDP, determining the channel state information based on the high-efficiency long training sequence and based on parsing the feedback indication message.

20. The target STA according to claim 18 , wherein there is an inter frame space between the NDP and the trigger frame.