Aspects of new radio PDCCH design
The present disclosure describes various aspects of the implementation and design of Physical Downlink Control Channel (PDCCH) in 5G new radio (NR) applications. Aspects include methods, apparatuses, and computer-readable medium for one or more of multiple PDCCH search spaces, control resource block (CRB), irregular multiple slots or mini-slots grants, or fast control channel signaling for grant-free uplink (UL). For example, different scheduling entities can each have one or two search spaces defined (e.g., common and/or user equipment (UE)-centric search spaces). Also, CRBs can be used as units for PDCCH transmission instead of resource element groups/control channel elements (REGs/CCEs). In addition, irregularities in time domain, frequency domain, or both can be introduced in the granting of resource blocks (RBs) over multiple slots or mini-slots. Moreover, signaling can be used to indicate to a UE configured for grant-free UL the portion of the pool of resources available for grant-free UL.
1 . A method for wireless communication at a user equipment (UE), comprising:
identifying a plurality of search spaces, each search space associated with a respective transmission reception points (TRPs) scheduling entity of a plurality of TRP scheduling entities, wherein each of the plurality of search spaces is associated with a common resource element group/control channel element (REG/CCE) space with each search space hashing to a different range of CCEs in the common REG/CCE space;
monitoring each of at least two of the identified search spaces for downlink control information (DCI) specific to the respective scheduling entity;
decoding DCI from each of the at least two monitored search spaces; and
communicating with the respective scheduling entities associated with the decoded DCI.
2 . The method of claim 1 , wherein each search space is a search space for decoding a physical downlink control channel (PDCCH) for a single TRP scheduling entity of the plurality of TRP scheduling entities.
3 . The method of claim 2 , wherein both control and data resource elements of the PDCCH for at least one TRP scheduling entity are precoded using beamforming.
4 . The method of claim 1 , wherein at least one of the plurality of search spaces is characterized by nested CCEs, and a quantity of the nested CCEs is based on a condition of a control channel.
5 . The method of claim 1 , wherein each of the plurality of search spaces is associated with a respective cell identifier (ID).
6 . The method of claim 1 , wherein each of the plurality of search spaces is associated with separately managed characteristics including at least one of: a set of slots to monitor, a number of decoding candidates, a downlink control information (DCI) format, or a Radio Network Temporary Identifier (RNTI).
7 . The method of claim 1 , wherein identifying comprises receiving, via a control channel, an update regarding a location of at least one search space.
8 . An apparatus for wireless communications, comprising:
a transceiver;
a memory storing instructions; and
a processor communicatively coupled to the transceiver and the memory, the processor being configured to execute the instructions to:
identify a plurality of search spaces, each search space associated with a respective transmission reception points (TRPs) scheduling entity of a plurality of TRP scheduling entities wherein each of the plurality of search spaces is associated with a common resource element group/control channel element (REG/CCE) space with each search space hashing to a different range of CCEs in the common REG/CCE space;
monitor each of at least two of the identified search spaces for downlink control information (DCI) specific to the respective scheduling entity;
decode DCI from each of the at least two monitored search spaces; and
communicate with the respective scheduling entities associated with the decoded DCI.
9 . The apparatus of claim 8 , wherein each search space is a search space for decoding a physical downlink control channel (PDCCH) for a single TRP scheduling entity of the plurality of TRP scheduling entities.
10 . The apparatus of claim 9 , wherein both control and data resource elements of the PDCCH for at least one TRP scheduling entity are precoded using beamforming.
11 . The apparatus of claim 8 , wherein at least one of the plurality of search space is characterized by nested CCEs, and a quantity of the nested CCEs is based on a condition of a control channel.
12 . A non-transitory computer-readable medium storing processor-executable code, the code when read and executed by at least one processor of a user equipment (UE), causes the UE to:
identify a plurality of search spaces, each search space associated with a respective transmission reception points (TRPs) scheduling entity of a plurality of TRP scheduling entities, wherein each of the plurality of search spaces is associated with a common resource element group/control channel element (REG/CCE) space with each search space hashing to a different range of CCEs in the common REG/CCE space;
monitor each of at least two of the identified search spaces for downlink control information (DCI) specific to the respective scheduling entity;
decode DCI from each of the at least two monitored search spaces; and
communicate with the respective scheduling entities associated with the decoded DCI.
13 . The computer-readable medium of claim 12 , wherein each search space is a search space for decoding a physical downlink control channel (PDCCH) for a single TRP scheduling entity of the plurality of TRP scheduling entities.
14 . The computer-readable medium of claim 13 , wherein both control and data resource elements of the PDCCH for at least one TRP scheduling entity are precoded using beamforming.
15 . The computer-readable medium of claim 12 , wherein at least one of the plurality of search space is characterized by nested CCEs, and a quantity of the nested CCEs is based on a condition of a control channel.
16 . An apparatus for wireless communications, comprising:
means for identifying a plurality of search spaces, each search space associated with a respective transmission reception points (TRPs) scheduling entity of a plurality of TRP scheduling entities wherein each of the plurality of search spaces is associated with a common resource element group/control channel element (REG/CCE) space with each search space hashing to a different range of CCEs in the common REG/CCE space;
monitoring each of at least two of the identified search spaces for downlink control information (DCI) specific to the respective scheduling entity;
decoding DCI from each of the at least two monitored search spaces; and
communicating with the respective scheduling entities associated with the decoded DCI.
17 . The apparatus of claim 16 , wherein each search space is a search space for decoding a physical downlink control channel (PDCCH) for a single TRP scheduling entity of the plurality of TRP scheduling entities.
18 . The apparatus of claim 17 , wherein both control and data resource elements of the PDCCH for at least one TRP scheduling entity are precoded using beamforming.
19 . The apparatus of claim 16 , wherein at least one of the plurality of search space is characterized by nested CCEs, and a quantity of the nested CCEs is based on a condition of a control channel.