Downlink monitoring and transmission methods and devices, communication system, terminal and base station

1. A downlink monitoring method, comprising:

receiving first semi-static configuration information transmitted by a base station, and determining a first monitoring opportunity strategy according to the first semi-static configuration information; or, receiving second semi-static configuration information transmitted by a base station, and determining a second monitoring opportunity strategy according to the second semi-static configuration information;

receiving, by a terminal, a switching trigger; and

switching, by the terminal according to the switching trigger, a monitoring opportunity strategy for downlink monitoring from the first monitoring opportunity strategy which is currently used to the second monitoring opportunity strategy.

2. The downlink monitoring method according to claim 1 , wherein the first semi-static configuration information comprises: first symbol indication used to indicate whether the downlink monitoring needs to be performed for each symbol in a slot corresponding to the first monitoring opportunity strategy in a channel occupancy term (COT), and/or first frequency band indication used to indicate whether the downlink monitoring needs to be performed for each candidate frequency band in the slot corresponding to the first monitoring opportunity strategy; or, the first semi-static configuration information comprises a control resource set (CORESET) parameter and a search space parameter; or,

the second semi-static configuration information comprises: second symbol indication used to indicate whether the downlink monitoring needs to be performed for each symbol in a slot corresponding to the second monitoring opportunity strategy in a COT, and/or second frequency band indication used to indicate whether the downlink monitoring needs to be performed for each candidate frequency band in the slot corresponding to the second monitoring opportunity strategy; or, the second semi-static configuration information comprises a control resource set, CORESET, parameter and a search space parameter.

3. The downlink monitoring method according to claim 2 , wherein the first symbol indication is a symbol bitmap corresponding to each symbol in the slot corresponding to the first monitoring opportunity strategy; and the first frequency band indication is a frequency band bitmap corresponding to each candidate frequency band; or,

the second symbol indication is a symbol bitmap corresponding to each symbol in the slot corresponding to the second monitoring opportunity strategy; and the second frequency band indication is a frequency band bitmap corresponding to each candidate frequency band.

4. The downlink monitoring method according to claim 1 , wherein the downlink monitoring comprises: physical downlink control channel (PDCCH) monitoring.

5. The downlink monitoring method according to claim 1 , further comprising:

when determining that a current slot is a target slot in a channel occupancy term, COT, performing downlink monitoring according to a target monitoring opportunity strategy corresponding to the target slot;

wherein a mode for determining that the current slot is the target slot in the COT comprises any one of:

a first mode: determining that a current moment is within the target slot in the COT according to a moment of receiving COT starting indication information and a predetermined relative position of the target slot in the COT;

a second mode: determining that a resource mapping type, which is indicated in a time-domain resource assignment indication within recently monitored downlink control information, corresponding to a physical downlink shared channel (PDSCH) is a second mapping type.

6. The downlink monitoring method according to claim 5 , wherein the COT starting indication information comprises at least one of: a preamble signal, a demodulation reference signal, a measurement reference signal, a synchronization signal and a predefined sequence signal.

7. A downlink transmission method, comprising:

sending, by a base station to a terminal, a switching trigger for triggering switching of a monitoring opportunity strategy for downlink monitoring from a first monitoring opportunity strategy to a second monitoring opportunity strategy;

determining, by the base station based on the second monitoring opportunity strategy, a transmission starting time-frequency position of the downlink information to be transmitted to the terminal; and

transmitting, by the base station, the downlink information to the terminal at the transmission starting time-frequency position.

8. The downlink transmission method according to claim 7 , further comprising:

determining first semi-static configuration information, determining the first monitoring opportunity strategy according to the first semi-static configuration information, and transmitting the first semi-static configuration information to the terminal;

or,

determining second semi-static configuration information, determining the second monitoring opportunity strategy according to the second semi-static configuration information, and transmitting the second semi-static configuration information to the terminal.

9. The downlink transmission method according to claim 8 , wherein the first semi-static configuration information comprises: first symbol indication used to indicate whether the downlink monitoring needs to be performed for each symbol in a slot corresponding to the first monitoring opportunity strategy in a channel occupancy term (COT), and/or first frequency band indication used to indicate whether the downlink monitoring needs to be performed for each candidate frequency band in the slot corresponding to the first monitoring opportunity strategy; or, the first semi-static configuration information comprises a control resource set (CORESET) parameter and a search space parameter; or,

the second semi-static configuration information comprises: second symbol indication used to indicate whether the downlink monitoring needs to be performed for each symbol in a slot corresponding to the second monitoring opportunity strategy in a COT, and/or second frequency band indication used to indicate whether the downlink monitoring needs to be performed for each candidate frequency band in the slot corresponding to the second monitoring opportunity strategy; or, the second semi-static configuration information comprises a control resource set, CORESET, parameter and a search space parameter.

10. The downlink transmission method according to claim 7 , wherein transmitting the downlink information to the terminal at the transmission starting time-frequency position comprises: transmitting the downlink information to the terminal through a physical downlink control channel (PDCCH) at the transmission starting time-frequency position.

11. The downlink transmission method according to claim 7 , further comprising:

transmitting COT starting indication information to the terminal at a starting moment of the COT, wherein the COT starting indication information is used in determination of a target slot at the terminal;

or,

transmitting downlink control information to the terminal, wherein a resource mapping type, which is indicated in a time-domain resource assignment indication within the downlink control information, corresponding to a physical downlink shared channel (PDSCH) is a second mapping type.

12. A downlink monitoring device, comprising a memory storing instructions and a processor in communication with the memory, wherein the processor is configured to execute the instruction to:

receive first semi-static configuration information transmitted by a base station, and determine a first monitoring opportunity strategy according to the first semi-static configuration information; or, receive second semi-static configuration information transmitted by a base station, and determine a second monitoring opportunity strategy according to the second semi-static configuration information;

receive a switching trigger; and

switch, according to the switching trigger, a monitoring opportunity strategy for downlink monitoring from the first monitoring opportunity strategy which is currently used to the second monitoring opportunity strategy.

13. A downlink transmission device, comprising a memory storing instructions and a processor in communication with the memory, wherein the processor is configured to execute the instruction to perform the method according to claim 7 .

14. The downlink monitoring method according to claim 1 , wherein switching, by the terminal according to the switching trigger, the monitoring opportunity strategy for downlink monitoring from the first monitoring opportunity strategy which is currently used to the second monitoring opportunity strategy comprises:

stopping using the first monitoring opportunity strategy for downlink monitoring, and using the second monitoring opportunity strategy for the downlink monitoring.

15. The downlink monitoring method according to claim 1 , wherein the switching trigger is indicated by a 1 bit flag in downlink control information, DCI, transmitted to the terminal, wherein the 1 bit flag is used to indicate to switch the monitoring opportunity strategy for the downlink monitoring.

16. The downlink monitoring method according to claim 1 , wherein the first monitoring opportunity strategy is a common monitoring opportunity strategy and the second monitoring opportunity strategy is a target monitoring opportunity strategy; or,

the first monitoring opportunity strategy is a target monitoring opportunity strategy and the second monitoring opportunity strategy is a common monitoring opportunity strategy;

wherein a monitoring granularity of the target monitoring opportunity strategy is smaller than a monitoring granularity of the common monitoring opportunity strategy.

17. The downlink transmission method according to claim 7 , wherein the switching trigger is used for:

triggering the terminal to stop using the first monitoring opportunity strategy for downlink monitoring, and use the second monitoring opportunity strategy for downlink monitoring.

18. The downlink transmission method according to claim 7 , wherein the switching trigger is indicated by a 1 bit flag in downlink control information, DCI, transmitted to the terminal, wherein the 1 bit flag is used to indicate to switch the monitoring opportunity strategy for the downlink monitoring.

19. The downlink transmission method according to claim 7 , wherein

the first monitoring opportunity strategy is a common monitoring opportunity strategy and the second monitoring opportunity strategy is a target monitoring opportunity strategy; or,

the first monitoring opportunity strategy is a target monitoring opportunity strategy and the second monitoring opportunity strategy is a common monitoring opportunity strategy;

wherein a monitoring granularity of the target monitoring opportunity strategy is smaller than a monitoring granularity of the common monitoring opportunity strategy.