Channel quality indicator feedback method, user equipment, and network device

1. A channel quality indicator (CQI) feedback method, wherein the method is applied to a co-cell communications system, a cell in the co-cell communications system comprises at least two single sectors and at least one joint sector, each of the at least two single sectors for providing a single-sector communications service for user equipment in the cell, and each of the at least one joint sector for providing a joint-sector communications service for the user equipment, the method comprising:

receiving, by the user equipment, a secondary pilot receive signal of each single sector and that is obtained after a secondary pilot transmit signal of each single sector transmitted by a network device is transmitted by using a radio channel;

estimating, by the user equipment, a CQI of each single sector according to the secondary pilot receive signal of each single sector, a pre-known secondary pilot transmit signal of each single sector, and a first precoding matrix;

estimating, by the user equipment, a CQI of each joint sector according to the secondary pilot receive signal of each single sector, a pre-known secondary pilot transmit signal of each single sector, and a second precoding matrix; and

feeding back, by the user equipment, each CQI to the network device.

2. The method according to claim 1 , wherein when the user equipment feeds back each CQI to the network device, the method further comprises:

feeding back, by the user equipment to the network device, a precoding matrix indicating a sector corresponding to each CQI.

3. The method according to claim 1 , wherein feeding back, by the user equipment, each CQI to the network device comprises:

when a feedback period corresponding to each single sector arrives, feeding back, by the user equipment to the network device, the CQI corresponding to each single sector; or

when a feedback period corresponding to each joint sector arrives, feeding back, by the user equipment to the network device, the CQI corresponding to each joint sector.

4. The method according to claim 1 , wherein feeding back, by the user equipment, each CQI to the network device comprises:

when a single-sector joint feedback period arrives, feeding back, by the user equipment to the network device, the CQI of each single sector that is coded according to a predefined joint coding rule; or

when a joint-sector joint feedback period arrives, feeding back, by the user equipment to the network device, the CQI that is of each joint sector and that is coded according to the predefined joint coding rule.

5. The method according to claim 1 , wherein feeding back, by the user equipment, each CQI to the network device comprises:

when a single-sector joint feedback period arrives, feeding back, by the user equipment to the network device, the CQI of each single sector and a precoding matrix indicating a single sector corresponding to the CQI of each single sector; or

when a joint-sector joint feedback period arrives, feeding back, by the user equipment to the network device, the CQI of each joint sector and a precoding matrix indicating a joint sector corresponding to the CQI of each joint sector.

6. User equipment for use in a co-cell communications system, a cell in the co-cell communications system comprises at least two single sectors and at least one joint sector, each of the at least two single sectors for providing a single-sector communications service for user equipment in the cell, and each of the at least one joint sector for providing a joint-sector communications service for the user equipment, the user equipment comprising:

a receiver, configured to receive a secondary pilot receive signal of each single sector and that is obtained after a secondary pilot transmit signal of each single sector transmitted by a network device is transmitted by using a radio channel;

a processor, configured to:

estimate a channel quality indicator (CQI) of each single sector according to the secondary pilot receive signal of each single sector, a pre-known secondary pilot transmit signal of each single sector, and a first precoding matrix, and

estimate a CQI of each joint sector according to the secondary pilot receive signal of each single sector, a pre-known secondary pilot transmit signal of each single sector, and a second precoding matrix; and

a transmitter, configured to feedback, to the network device, each CQI estimated by the processor.

7. The user equipment according to claim 6 , wherein the transmitter is further configured to feedback, to the network device, a precoding matrix indicating a sector corresponding to each CQI.

8. The user equipment according to claim 6 , wherein the transmitter is configured to:

when a feedback period corresponding to each single sector arrives, feedback, to the network device, the CQI corresponding to each single sector; or

when a feedback period corresponding to each joint sector arrives, feedback, to the network device, the CQI corresponding to each joint sector.

9. The user equipment according to claim 6 , wherein the transmitter is configured to:

when a single-sector joint feedback period arrives, feedback, to the network device, the CQI of each single sector that is coded according to a predefined joint coding rule; or

when a joint-sector joint feedback period arrives, feedback, to the network device, the CQI of each joint sector that is coded according to the predefined joint coding rule.

10. The user equipment according to claim 6 , wherein the transmitter is configured to:

when a single-sector joint feedback period arrives, feedback, to the network device, the CQI of each single sector and a precoding matrix indicating a single sector corresponding to the CQI of each single sector; or

when a joint-sector joint feedback period arrives, feedback, to the network device, the CQI of each joint sector and a precoding matrix indicating a joint sector corresponding to the CQI of each joint sector.

11. A network device for use in a co-cell communications system, a cell in the co-cell communications system comprises at least two single sectors and at least one joint sector, each of the at least two single sectors for providing a single-sector communications service for user equipment in the cell, and each of the at least one joint sector for providing a joint-sector communications service for the user equipment, the network device comprising:

a transmitter, configured to transmit a secondary pilot transmit signal of each single sector to the user equipment; and

a receiver, configured to receive each channel quality indicator (CQI) fed back by the user equipment, wherein each received CQI is used by the network device to determine a target sector providing a communications service for the user equipment.

12. The network device according to claim 11 , wherein the receiver is further configured to receive a precoding matrix fed back by the user equipment that indicates a sector corresponding to each CQI.

13. The network device according to claim 11 , wherein the receiver is configured to:

when a feedback period corresponding to each single sector arrives, receive a CQI corresponding to each single sector that is fed back by the user equipment; or

when a feedback period corresponding to each joint sector arrives, receive a CQI corresponding to each joint sector that is fed back by the user equipment.

14. The network device according to claim 11 , wherein the receiver is configured to:

when a single-sector joint feedback period arrives, receive a CQI of each single sector that is coded according to a predefined joint coding rule and fed back by the user equipment; or

when a joint-sector joint feedback period arrives, receive a CQI of each joint sector that is coded according to the predefined joint coding rule and fed back by the user equipment.

15. The network device according to claim 11 , wherein the receiver is configured to:

when a single-sector joint feedback period arrives, receive a CQI of each single sector that is fed back by the user equipment and a precoding matrix indicating a single sector corresponding to the CQI of each single sector; or

when a joint-sector joint feedback period arrives, receive a CQI of each joint sector that is fed back by the user equipment and a precoding matrix indicating a joint sector corresponding to the CQI of each joint sector.