Method and apparatus for control channel reception in wireless communication systems
The disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure discloses a signaling method and apparatus for properly increasing a control channel detection complexity of a terminal in order to efficiently detect a control channel for performing coordinated transmission such as non-coherent joint transmission (NC-JT).
1. A method performed by a terminal in a communication system, the method comprising:
identifying a number of cells associated with a capability to monitor physical downlink control channel (PDCCH) candidates based on a number of cells in a first set and a product of a number of cells in a second set and a coefficient;
determining a maximum number of PDCCH candidates for each cell based on the number of cells associated with the capability to monitor PDCCH candidates;
identifying search spaces to monitor based on the maximum number of PDCCH candidates; and
monitoring a PDCCH on the identified search space.
2. The method of claim 1 , wherein the maximum number of PDCCH candidates is determined based on whether the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than a number of configured cells which is determined based on a control resource set (CORESET) group identifier configured to each cell or not.
3. The method of claim 2 , wherein in case that the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than the number of configured cells, the maximum number of PDCCH candidates for a cell is determined as a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell or a multiple of the preconfigured number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell based on the CORESET group identifier configured to the cell.
4. The method of claim 2 , wherein in case that the number of cells is not equal to or less than the number of configured cells, the maximum number of PDCCH candidates for a cell is determined based on a number M total,μ corresponding to following equation:
M total,μ =└N cap ×M μ ×N μ /N total ┘,
where N cap is the number of cells associated with the capability to monitor PDCCH candidates, M μ is a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell μ, N μ is a number of at least one configured cells corresponding to the subcarrier spacing of the cell μ determined based on the CORESET group identifier configured to the cell, and N total is the number of configured cells.
5. The method of claim 1 , wherein the coefficient is associated with a CORESET group identifier configured to each of the cell in the second set.
6. The method of claim 5 , wherein the identifying the search spaces comprises:
selecting a search space to monitor which corresponds to CORESETs of a first CORESET group identifier (ID) in case that it is needed to select the search space to monitor in a primary cell.
7. A method performed by a base station in a communication system, the method comprising:
identifying a number of cells associated with a capability to monitor physical downlink control channel (PDCCH) candidates of a terminal based on a number of cells in a first set and a product of a number of cells in a second set and a coefficient;
determining a maximum number of PDCCH candidates for each cell based on the number of cells associated with the capability to monitor PDCCH candidates;
identifying search spaces to be monitored by the terminal based on the maximum number of PDCCH candidates; and
transmitting downlink control information on the identified search space of a PDCCH.
8. The method of claim 7 , wherein the maximum number of PDCCH candidates is determined based on whether the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than a second number of configured cells which is determined based on a control resource set (CORESET) group identifier configured to each cell or not.
9. The method of claim 8 , wherein in case that the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than the second number of configured cells, the maximum number of PDCCH candidates for a cell is determined as a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell or a multiple of the preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell based on the CORESET group identifier configured to the cell.
10. The method of claim 8 , wherein in case that the number of cells associated with the capability to monitor PDCCH candidates is not equal to or less than the number of configured cells, the maximum number of PDCCH candidates for a cell is determined based on a number M total,μ corresponding to following equation:
M total,μ =└N cap ×M μ ×N μ /N total ┘,
where N cap is the number of cells associated with the capability to monitor PDCCH candidates, M μ is a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell μ, N μ is a number of at least one configured cells corresponding to the subcarrier spacing of the cell μ determined based on the CORESET group identifier configured to the cell, and N total is the second number of configured cells.
11. The method of claim 7 , wherein the coefficient is associated with a CORESET group identifier configured to each of the cell in the second set.
12. The method of claim 11 , wherein the identifying the search spaces comprises:
selecting a search space to be monitored which corresponds to CORESETs of a first CORESET group identifier (ID) in case that it is needed to select the search space to monitor in a primary cell.
13. A terminal in a communication system, the terminal comprising:
a transceiver; and
a controller coupled with the transceiver and configured to:
identify a number of cells associated with a capability to monitor physical downlink control channel (PDCCH) candidates based on a number of cells in a first set and a product of a number of cells in a second set and a coefficient,
determine a maximum number of PDCCH candidates for each cell based on the number of cells associated with the capability to monitor PDCCH candidates,
identify search spaces to monitor based on the maximum number of PDCCH candidates, and
perform monitoring a PDCCH on the identified search space.
14. The terminal of claim 13 , wherein the maximum number of PDCCH candidates is determined based on whether the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than a number of configured cells which is determined based on a control resource set (CORESET) group identifier configured to each cell or not.
15. The terminal of claim 14 , wherein in case that the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than the number of configured cells, the maximum number of PDCCH candidates for a cell is determined as a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell or a multiple of the preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell based on the CORESET group identifier configured to the cell.
16. The terminal of claim 14 , wherein in case that the number of cells associated with the capability to monitor PDCCH candidates is not equal to or less than the number of configured cells, the maximum number of PDCCH candidates for a cell is determined based on a number M total,μ corresponding to following equation:
M total,μ =└N cap ×M μ ×N μ /N total ┘,
where N cap is the number of cells associated with the capability to monitor PDCCH candidates, M μ is a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell μ, N μ is a number of at least one configured cells corresponding to the subcarrier spacing of the cell μ determined based on the CORESET group identifier configured to the cell, and N total is the number of configured cells.
17. The terminal of claim 13 , wherein the coefficient is associated with a CORESET group identifier configured to each of the cell in the second set.
18. The terminal of claim 17 , wherein to identify the search spaces, the controller is further configured to select a search space to monitor which corresponds to CORESETs of a first CORESET group identifier (ID) in case that it is needed to select the search space to monitor in a primary cell.
19. A base station in a communication system, the base station comprising:
a transceiver; and
a controller coupled with the transceiver and configured to:
identify a number of cells associated with a capability to monitor physical downlink control channel (PDCCH) candidates of a terminal based on a number of cells in a first set and a product of cells in a second set and a coefficient,
determine a maximum number of PDCCH candidates for each cell based on the number of cells associated with the capability to monitor PDCCH candidates,
identify search spaces to be monitored by the terminal based on the maximum number of PDCCH candidates, and
transmit downlink control information on the identified search space of a PDCCH.
20. The base station of claim 19 , wherein the maximum number of PDCCH candidates is determined based on whether the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than a number of configured cells which is determined based on a control resource set (CORESET) group identifier configured to each cell or not.
21. The base station of claim 20 , wherein in case that the number of cells associated with the capability to monitor PDCCH candidates is equal to or less than the number of configured cells, the maximum number of PDCCH candidates for a cell is determined as a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell or a multiple of the preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell based on the CORESET group identifier configured to the cell.
22. The base station of claim 20 , wherein in case that the number of cells associated with the capability to monitor PDCCH candidates is not equal to or less than the number of configured cells, the maximum number of PDCCH candidates for a cell is determined based on a number M total,μ corresponding to following equation:
M total,μ =└N cap ×M μ ×N μ /N total ┘,
where N cap is the number of cells associated with the capability to monitor PDCCH candidates, M μ is a preconfigured maximum number of monitored PDCCH candidates corresponding to a subcarrier spacing of the cell μ, N μ is a number of at least one configured cells corresponding to the subcarrier spacing of the cell μ determined based on the CORESET group identifier configured to the cell, and N total is the number of configured cells.
23. The base station of claim 19 , wherein the coefficient is associated with a CORESET group identifier configured to each of the cell in the second set.
24. The base station of claim 23 , wherein to identify the search spaces, the controller is further configured to select a search space to be monitored which corresponds to CORESETs of a first CORESET group identifier (ID) in case that it is needed to select the search space to monitor in a primary cell.