Configuration of a control resource set and common search space for initial access by low tier user equipment
Various aspects of the present disclosure relate to wireless communication. In some aspects, a user equipment (UE) may receive a master information block that identifies a first control resource set (CORESET) for a first category of UEs and a first common search space (CSS) associated with the first CORESET. The first CORESET and the first CSS may identify one or more overlapping resource grids that overlap in time and frequency with one or more corresponding resource grids of a second CORESET and a second CSS, associated with the second CORESET, for a second category of UEs, and one or more non-overlapping resource grids that include a corresponding one or more time domain resources that are earlier than a time domain resource of the second CORESET and the second CSS. The UE may monitor for a physical downlink control channel candidate included in the first CORESET and the first CSS.
1. A method of wireless communication performed by a user equipment (UE), comprising:
receiving a master information block that identifies a first control resource set (CORESET) for a first category of UEs and a first common search space (CSS) associated with the first CORESET, wherein the first CORESET and the first CSS identify:
one or more overlapping resource grids that overlap in time and frequency with one or more corresponding resource grids of a second CORESET and a second CSS, associated with the second CORESET, for a second category of UEs, and
one or more non-overlapping resource grids that include a corresponding one or more time domain resources that are earlier than a time domain resource of the second CORESET and the second CSS; and
monitoring for a physical downlink control channel (PDCCH) candidate included in the first CORESET and the first CSS.
2. The method of claim 1 , wherein the corresponding one or more time domain resources are within a first slot that is a number of slots before a second slot that includes the time domain resource of the second CORESET and the second CSS.
3. The method of claim 2 , wherein the corresponding one or more time domain resources are within a threshold number of orthogonal frequency division multiplexing (OFDM) symbols prior to a starting OFDM symbol of a next consecutive slot after the first slot.
4. The method of claim 2 , wherein the number of slots is one slot.
5. The method of claim 2 , wherein the first slot is a downlink slot in any time-division duplex uplink/downlink configuration used by a serving base station.
6. The method of claim 2 , wherein the number of slots is determined based at least in part on a periodicity of a time-division duplex uplink/downlink configuration.
7. The method of claim 2 , wherein the number of slots is determined based at least in part on a frequency range in which the first CORESET and the first CSS are included.
8. The method of claim 2 , wherein the number of slots is determined based at least in part on a numerology or a sub-carrier spacing associated with the PDCCH candidate.
9. The method of claim 2 , wherein the number of slots is determined based at least in part on a slot index of the second slot that includes the time domain resource of the second CORESET and the second CSS.
10. The method of claim 9 , wherein the number of slots is greater than one if a slot that is one slot earlier than the second slot is an uplink slot, wherein the slot that is one slot earlier than the second slot is identified based at least in part on the slot index of the second slot.
11. The method of claim 9 , wherein the number of slots is equal to one if a slot that is one slot earlier than the second slot is a downlink slot, wherein the slot that is one slot earlier than the second slot is identified based at least in part on the slot index of the second slot.
12. The method of claim 2 , wherein the number of slots is determined based at least in part on a synchronization signal block index associated with the second CORESET.
13. The method of claim 1 , wherein a first resource grid, of the one or more non-overlapping resource grids, includes a control channel element with a lower index than an index of a second resource grid, of the one or more non-overlapping resource grids or the one or more overlapping resource grids, that occurs later in time than the first resource grid.
14. The method of claim 1 , wherein each resource grid, of the one or more non-overlapping resource grids and the one or more overlapping resource grids, includes one or more resource element groups of at least one control channel element of the first CORESET.
15. A method of wireless communication performed by a base station, comprising:
configuring a first control resource set (CORESET) for a first category of user equipment (UEs) and a first common search space (CSS) associated with the first CORESET, wherein the first CORESET and the first CSS identify:
one or more overlapping resource grids that overlap in time and frequency with one or more corresponding resource grids of a second CORESET and a second CSS, associated with the second CORESET, for a second category of UEs, and
one or more non-overlapping resource grids that include a corresponding one or more time domain resources that are earlier than a time domain resource of the second CORESET and the second CSS; and
transmitting a master information block that identifies the first CORESET and the first CSS.
16. The method of claim 15 , further comprising transmitting one or more physical downlink control channel communications in the first CORESET and the first CSS.
17. The method of claim 15 , wherein the corresponding one or more time domain resources are within a first slot that is a number of slots before a second slot that includes the time domain resource of the second CORESET and the second CSS.
18. The method of claim 17 , wherein the corresponding one or more time domain resources are within a threshold number of orthogonal frequency division multiplexing (OFDM) symbols prior to a starting OFDM symbol of a next consecutive slot after the first slot.
19. The method of claim 17 , wherein the number of slots is one slot.
20. The method of claim 17 , wherein the first slot is a downlink slot in any time-division duplex uplink/downlink configuration used by the base station.
21. The method of claim 17 , wherein the number of slots is determined based at least in part on a periodicity of a time-division duplex uplink/downlink configuration or based at least in part on a frequency range in which the first CORESET and the first CSS are included.
22. The method of claim 17 , wherein the number of slots is determined based at least in part on a numerology or a sub-carrier spacing associated with a physical downlink control channel associated with the first CORESET.
23. The method of claim 17 , wherein the number of slots is determined based at least in part on a slot index of the second slot that includes the time domain resource of the second CORESET and the second CSS.
24. The method of claim 23 , wherein the number of slots is greater than one if a slot that is one slot earlier than the second slot is an uplink slot, wherein the slot that is one slot earlier than the second slot is identified based at least in part on the slot index of the second slot.
25. The method of claim 23 , wherein the number of slots is equal to one if a slot that is one slot earlier than the second slot is a downlink slot, wherein the slot that is one slot earlier than the second slot is identified based at least in part on the slot index of the second slot.
26. The method of claim 17 , wherein the number of slots is determined based at least in part on a synchronization signal block index associated with the second CORESET.
27. The method of claim 15 , wherein a first resource grid, of the one or more non-overlapping resource grids, includes a control channel element with a lower index than an index of a second resource grid, of the one or more non-overlapping resource grids or the one or more overlapping resource grids, that occurs later in time than the first resource grid.
28. The method of claim 15 , wherein each resource grid, of the one or more non-overlapping resource grids and the one or more overlapping resource grids, includes one or more resource element groups of at least one control channel element of the first CORESET.
29. A user equipment (UE) for wireless communication, comprising:
a memory; and
one or more processors operatively coupled to the memory, the one or more processors configured to:
receive a master information block that identifies a first control resource set (CORESET) for a first category of UEs and a first common search space (CSS) associated with the first CORESET, wherein the first CORESET and the first CSS identify:
one or more overlapping resource grids that overlap in time and frequency with one or more corresponding resource grids of a second CORESET and a second CSS, associated with the second CORESET, for a second category of UEs, and
one or more non-overlapping resource grids that include a corresponding one or more time domain resources that are earlier than a time domain resource of the second CORESET and the second CSS; and
monitor for a physical downlink control channel (PDCCH) candidate included in the first CORESET and the first CSS.
30. A base station for wireless communication, comprising:
a memory; and
one or more processors operatively coupled to the memory, the one or more processors configured to:
configure a first control resource set (CORESET) for a first category of user equipment (UEs) and a first common search space (CSS) associated with the first CORESET, wherein the first CORESET and the first CSS identify:
one or more overlapping resource grids that overlap in time and frequency with one or more corresponding resource grids of a second CORESET and a second CSS, associated with the second CORESET, for a second category of UEs, and
one or more non-overlapping resource grids that include a corresponding one or more time domain resources that are earlier than a time domain resource of the second CORESET and the second CSS; and
transmit a master information block that identifies the first CORESET and the first CSS.