CSI reporting method and apparatus
The present disclosure relates to channel state information (CSI) reporting methods and apparatus. When receiving first indication information used to trigger reporting of CSI, a terminal device determines a first time interval from a plurality of candidate first time intervals. The first time interval is used to determine whether the first indication information is valid. The terminal device reports the CSI based on the first time interval.
1. A channel state information (CSI) reporting method, comprising:
receiving downlink control information (DCI) on a physical downlink control channel (PDCCH), wherein the DCI comprises first indication information, and wherein the first indication information is used to trigger a terminal device to report CSI on a first uplink channel; and
determining, based on at least one of the DCI or higher layer signaling, a first time interval from a plurality of candidate first time intervals corresponding to a first subcarrier spacing, wherein the first time interval is used to determine whether the first indication information is valid, wherein the first subcarrier spacing is one of a 15 kilohertz (kHz) subcarrier spacing, a 30 kHz subcarrier spacing, a 60 kHz subcarrier spacing, and a 120 kHz subcarrier spacing, and wherein a correspondence between the first subcarrier spacing and the first time interval meets at least one of the following conditions: a first time interval corresponding to the 15 kHz subcarrier spacing is less than or equal to eight symbols, a first time interval corresponding to the 30 kHz subcarrier spacing is less than or equal to 12 symbols, a first time interval corresponding to the 60 kHz subcarrier spacing is less than or equal to 24 symbols, and a first time interval corresponding to the 120 kHz subcarrier spacing is less than or equal to 42 symbols.
2. The method according to claim 1 , wherein the method further comprises:
when a time interval between the last symbol of the PDCCH and the first symbol of the first uplink channel is greater than or equal to the first time interval, determining that the first indication information is valid; or
when a time interval between the last symbol of the PDCCH and the first symbol of the first uplink channel is less than the first time interval, determining that the first indication information is invalid.
3. The method according to claim 1 , wherein the first time interval meets the following condition:
the first time interval is less than or equal to a time interval between the last symbol of a physical downlink shared channel (PDSCH) indicated by the DCI and the first symbol of a second uplink channel, wherein the second uplink channel is used to carry hybrid automatic repeat request (HARQ) feedback information corresponding to the PDSCH indicated by the DCI.
4. The method according to claim 3 , wherein:
the first subcarrier spacing is a smallest value among a subcarrier spacing corresponding to a demodulation reference signal (DMRS) corresponding to the PDSCH indicated by the DCI, a subcarrier spacing corresponding to the PDCCH, and a subcarrier spacing corresponding to the first uplink channel; or
the first subcarrier spacing is a smallest value among a subcarrier spacing corresponding to a channel state information reference signal (CSI-RS), a subcarrier spacing corresponding to a DMRS corresponding to the PDSCH indicated by the DCI, a subcarrier spacing corresponding to the PDCCH, and a subcarrier spacing corresponding to the first uplink channel.
5. The method according to claim 3 , wherein determining, based on at least one of the DC or the higher layer signaling, the first time interval from the plurality of candidate first time intervals corresponding to the first subcarrier spacing comprises:
determining the first time interval when at least one of the following conditions is met:
a time interval between a slot in which the PDSCH indicated by the DCI is located and a slot in which the HARQ feedback information is located is less than or equal to a first threshold;
a time length of a time domain resource of the PDSCH indicated by the DCI is less than or equal to a second threshold; and
a time length of a time domain resource of the first uplink channel indicated by the DCI is less than or equal to a third threshold.
6. The method according to claim 1 , wherein determining, based on at least one of the DCI or the higher layer signaling, the first time interval from the plurality of candidate first time intervals corresponding to the first subcarrier spacing comprises:
determining the first time interval when a radio network temporary identifier (RNTI) used to scramble the DCI is a first RNTI, wherein modulation and coding scheme (MCS) information in the DC scrambled by using the first RNTI corresponds to a first MCS table, and wherein the first MCS table comprises MCS information whose spectral efficiency is 0.0586.
7. An apparatus comprising:
one or more processors; and
a non-transitory computer readable medium storing programming instructions for execution by the one or more processors, the programming instructions instructing the apparatus to perform operations comprising:
sending downlink control information (DCI) to a terminal device on a physical downlink control channel (PDCCH), wherein the DCI comprises first indication information, wherein the first indication information is used to trigger the terminal device to report channel state information (CSI) on a first uplink channel, wherein at least one of the DCI or higher layer signaling is used to determine a first time interval from a plurality of candidate first time intervals corresponding to a first subcarrier spacing, wherein the first time interval is used to determine whether the first indication information is valid, wherein the first subcarrier spacing is one of a 15 kilohertz (kHz) subcarrier spacing, a 30 kHz subcarrier spacing, a 60 kHz subcarrier spacing, and a 120 kHz subcarrier spacing, and wherein a correspondence between the first subcarrier spacing and the first time interval meets at least one of the following conditions: a first time interval corresponding to the 15 kHz subcarrier spacing is less than or equal to eight symbols, a first time interval corresponding to the 30 kHz subcarrier spacing is less than or equal to 12 symbols, a first time interval corresponding to the 60 kHz subcarrier spacing is less than or equal to 24 symbols, and a first time interval corresponding to the 120 kHz subcarrier spacing is less than or equal to 42 symbols; and
receiving the CSI from the terminal device on the first uplink channel.
8. The apparatus according to claim 7 , wherein:
when a time interval between the last symbol of the PDCCH and the first symbol of the first uplink channel is greater than or equal to the first time interval, the first indication information is valid; or
when a time interval between the last symbol of the PDCCH and the first symbol of the first uplink channel is less than the first time interval, the first indication information is invalid.
9. The apparatus according to claim 7 , wherein the operations further comprise sending the higher layer signaling.
10. The apparatus according to claim 7 , wherein the first time interval meets the following condition:
the first time interval is less than or equal to a time interval between the last symbol of a physical downlink shared channel (PDSCH) indicated by the DCI and the first symbol of a second uplink channel, wherein the second uplink channel is used to carry hybrid automatic repeat request (HARQ) feedback information corresponding to the PDSCH indicated by the DCI.
11. The apparatus according to claim 10 , wherein:
the first subcarrier spacing is a smallest value among a subcarrier spacing corresponding to a demodulation reference signal (DMRS) corresponding to the PDSCH indicated by the DCI, a subcarrier spacing corresponding to the PDCCH, and a subcarrier spacing corresponding to the first uplink channel; or
the first subcarrier spacing is a smallest value among a subcarrier spacing corresponding to a channel state information reference signal (CSI-RS), a subcarrier spacing corresponding to a DMRS corresponding to the PDSCH indicated by the DCI, a subcarrier spacing corresponding to the PDCCH, and a subcarrier spacing corresponding to the first uplink channel.
12. The apparatus according to claim 7 , wherein the operations further comprise scrambling the DCI by using a first radio network temporary identifier (RNTI), wherein the first RNTI corresponds to the first time interval, wherein modulation and coding scheme (MCS) information in the DCI scrambled by using the first RNTI corresponds to a first MCS table, and wherein the first MCS table comprises MCS information whose spectral efficiency is 0.0586.
13. An apparatus comprising:
one or more processors; and
a non-transitory computer readable medium storing programming instructions for execution by the one or more processors, the programming instructions instructing the apparatus to perform operations comprising:
receiving downlink control information (DCI) on a physical downlink control channel (PDCCH), wherein the DCI comprises first indication information, and wherein the first indication information is used to trigger a terminal device to report CSI on a first uplink channel; and
determining, based on at least one of the DC or higher layer signaling, a first time interval from a plurality of candidate first time intervals corresponding to a first subcarrier spacing, wherein the first time interval is used to determine whether the first indication information is valid, wherein the first subcarrier spacing is one of a 15 kilohertz (kHz) subcarrier spacing, a 30 kHz subcarrier spacing, a 60 kHz subcarrier spacing, and a 120 kHz subcarrier spacing, and wherein a correspondence between the first subcarrier spacing and the first time interval meets at least one of the following conditions: a first time interval corresponding to the 15 kHz subcarrier spacing is less than or equal to eight symbols, a first time interval corresponding to the 30 kHz subcarrier spacing is less than or equal to 12 symbols, a first time interval corresponding to the 60 kHz subcarrier spacing is less than or equal to 24 symbols, and a first time interval corresponding to the 120 kHz subcarrier spacing is less than or equal to 42 symbols.
14. The apparatus according to claim 13 , wherein the operations further comprise:
when a time interval between the last symbol of the PDCCH and the first symbol of the first uplink channel is greater than or equal to the first time interval, determining that the first indication information is valid; or
when a time interval between the last symbol of the PDCCH and the first symbol of the first uplink channel is less than the first time interval, determining that the first indication information is invalid.
15. The apparatus according to claim 13 , wherein the first time interval meets the following condition:
the first time interval is less than or equal to a time interval between the last symbol of a physical downlink shared channel (PDSCH) indicated by the DCI and the first symbol of a second uplink channel, wherein the second uplink channel is used to carry hybrid automatic repeat request (HARQ) feedback information corresponding to the PDSCH indicated by the DCI.
16. The apparatus according to claim 15 , wherein:
the first subcarrier spacing is a smallest value among a subcarrier spacing corresponding to a demodulation reference signal (DMRS) corresponding to the PDSCH indicated by the DCI, a subcarrier spacing corresponding to the PDCCH, and a subcarrier spacing corresponding to the first uplink channel; or
the first subcarrier spacing is a smallest value among a subcarrier spacing corresponding to a channel state information reference signal (CSI-RS), a subcarrier spacing corresponding to a DMRS corresponding to the PDSCH indicated by the DCI, a subcarrier spacing corresponding to the PDCCH, and a subcarrier spacing corresponding to the first uplink channel.
17. The apparatus according to claim 15 , wherein determining, based on at least one of the DCI or the higher layer signaling, the first time interval from the plurality of candidate first time intervals corresponding to the first subcarrier spacing comprises:
determining the first time interval when at least one of the following conditions is met:
a time interval between a slot in which the PDSCH indicated by the DCI is located and a slot in which the HARQ feedback information is located is less than or equal to a first threshold;
a time length of a time domain resource of the PDSCH indicated by the DCI is less than or equal to a second threshold; and
a time length of a time domain resource of the first uplink channel indicated by the DCI is less than or equal to a third threshold.
18. The apparatus according to claim 13 , wherein determining, based on at least one of the DCI or the higher layer signaling, the first time interval from the plurality of candidate first time intervals corresponding to the first subcarrier spacing comprises:
determining the first time interval when a radio network temporary identifier (RNTI) used to scramble the DCI is a first RNTI, wherein modulation and coding scheme (MCS) information in the DCI scrambled by using the first RNTI corresponds to a first MCS table, and wherein the first MCS table comprises MCS information whose spectral efficiency is 0.0586.