Method for receiving downlink control channel in wireless communication system and device therefor
The present invention discloses a method and device for receiving a downlink control channel according to various embodiments. A method and device are disclosed, the method for receiving a downlink control channel according to an aspect of the present invention includes: a step for receiving a subframe including a downlink control region; and a step for performing blind decoding on a search space in the downlink control region, wherein the search space includes a plurality of PDCCH candidates which correspond to respective aggregation levels and include control channel elements (CCEs), and each of the plurality of PDCCH candidates overlaps at least one PDCCH candidate.
1. A method of receiving a downlink control channel by a user equipment (UE) in a wireless communication system, the method comprising:
receiving at least one symbol including a downlink control region; and
performing blind decoding on a search space in the downlink control region,
wherein the search space includes a plurality of physical downlink control channel (PDCCH) candidates, each of the plurality of PDCCH candidates related to an aggregation level and including a control channel element (CCE),
wherein each of the plurality of PDCCH candidates overlaps with at least one PDCCH candidate, and
wherein based on that a virtual aggregation level and a virtual PDCCH candidate related to the virtual aggregation level are used for configuration of the search space:
each of the plurality of PDCCH candidates fully or partially overlaps with the virtual PDCCH candidate,
the virtual aggregation level is configured to be higher than a highest of aggregation levels related to the plurality of PDCCH candidates,
the virtual PDCCH candidate is a PDDCH candidate not to be monitored for the blind decoding, and
(i) first information that the virtual aggregation level and the virtual PDCCH candidate are used for the configuration of the search space and (ii) second information that the virtual PDCCH candidate is not to be monitored for the blind decoding are received at the UE via higher layer signaling.
2. The method according to claim 1 , wherein the plurality of PDCCH candidates include a first PDCCH candidate related to a first aggregation level, and a second PDCCH candidate related to a second aggregation level lower than the first aggregation level, and
wherein the second PDCCH candidate is fully or partially included in the first PDCCH candidate.
3. The method according to claim 2 , wherein the first aggregation level is the highest of aggregation levels related to the plurality of PDCCH candidates.
4. The method according to claim 2 , wherein the first PDCCH candidate is a PDCCH candidate in a common search space, and the second PDCCH candidate is a PDCCH candidate in a UE-specific search space.
5. The method according to claim 2 , wherein a second starting point which is a starting point of the second PDCCH candidate is determined randomly based on at least one of a first starting point which is a starting point of the first PDCCH candidate, the first aggregation level, or the second aggregation level, and
wherein the second starting point is different from the first starting point.
6. The method according to claim 2 , wherein a remaining PDCCH candidate except for the first PDCCH candidate and the second PDCCH candidate among the plurality of PDCCH candidates is arranged to fully or partially overlap with the first PDCCH candidate.
7. The method according to claim 1 , wherein the search space includes a first search space candidate and a second search space candidate which are separate from each other, and
wherein the first search space candidate includes a first PDCCH candidate related to a first aggregation level and a second PDCCH candidate arranged within the first PDCCH candidate and related to a second aggregation level lower than the first aggregation level, and
wherein the second search space candidate includes a third PDCCH candidate related to a third aggregation level and a fourth PDCCH candidate arranged within the third PDCCH candidate and related to a fourth aggregation level lower than the third aggregation level.
8. The method according to claim 7 , wherein the first aggregation level is a highest of aggregation levels related to PDCCH candidates included in the first search space candidate, and the third aggregation level is a highest of aggregation levels related to PDCCH candidates included in the second search space candidate.
9. The method according to claim 7 , wherein the downlink control region includes a first control resource set (CORESET) and a second CORESET, including resources in which the search space is arranged, and
wherein the first search space candidate is arranged in the first CORESET, and the second search space candidate is arranged in the second CORESET.
10. The method according to claim 9 , wherein a number of PDCCH candidates included in each of the first search space candidate and the second search space candidate is determined based on a number of symbols and available resources in each of the first CORESET and the second CORESET.
11. The method according to claim 1 , further comprising:
detecting downlink control information (DCI) based on a control channel element (CCE) detected by the blind decoding.
12. A user equipment (UE) for receiving a downlink control channel in a wireless communication system, the UE comprising:
at least one processor; and
at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations comprising:
receiving at least one symbol including a downlink control region; and
performing blind decoding on a search space in the downlink control region,
wherein the search space includes a plurality of physical downlink control channel (PDCCH) candidates, each of the PDCCH candidates related to an aggregation level and including a control channel element (CCE),
wherein each of the plurality of PDCCH candidates overlaps with at least one PDCCH candidate, and
wherein based on that a virtual aggregation level and a virtual PDCCH candidate related to the virtual aggregation level are used for configuration of the search space:
each of the plurality of PDCCH candidates fully or partially overlaps with the virtual PDCCH candidate,
the virtual aggregation level is configured to be higher than a highest of aggregation levels related to the plurality of PDCCH candidates,
the virtual PDCCH candidate is a PDDCH candidate not to be monitored for the blind decoding, and
(i) first information that the virtual aggregation level and the virtual PDCCH candidate are used for the configuration of the search space and (ii) second information that the virtual PDCCH candidate is not to be monitored for the blind decoding are received at the UE via higher layer signaling.
13. The UE according to claim 12 , wherein the UE is capable of communicating with at least one of another UE, a UE related to an autonomous driving vehicle, the base station or a network.