Flexible search space configuration and overbooking handling

Patent metadata

Field	Value
Publication number	US-2019254025-A1
Application number	US-201916275247-A
Country	US
Kind code	A1
Filing date	Feb 13, 2019
Priority date	Feb 15, 2018
Publication date	Aug 15, 2019
Grant date	—

Abstract

Methods, systems, and devices for wireless communications are described. In some wireless communications systems, a base station may transmit control information to a user equipment (UE) in search space candidates within a configured search space. To flexibly configure the search space, the base station may determine a reference aggregation level. The base station may add a number of pseudo search space candidates to the reference aggregation level such that the control channel element (CCE) footprint of the reference aggregation level can handle nesting all of the candidates for other aggregation levels. In some cases, the base station may overbook the search space past a CCE limit. The base station may implement an overbooking rule to determine search space candidates to drop from the configuration. The base station may transmit using the search space configuration, and the UE may monitor and decode information according to the configuration.

First claim

What is claimed is:

1 . A method for wireless communications, comprising:
configuring a user equipment (UE) with one or more control resource sets (CORESETs) in a bandwidth part, wherein the one or more CORESETs comprise one or more search space candidates; determining that a total number of control channel elements (CCEs) configured for the one or more search space candidates within a transmission time interval (TTI) is greater than a CCE limit for the TTI; identifying a CORESET of the one or more CORESETs based at least in part on an overbooking handling rule; dropping one or more search space candidates from the identified CORESET until a total number of remaining CCEs of the one or more CORESETs within the TTI is less than or equal to the CCE limit for the TTI; and transmitting control information within one or more remaining search space candidates comprising the remaining CCEs of the one or more CORESETs.

2 . The method of claim 1 , wherein:
the identified CORESET comprises a common search space (CS S), a UE specific search space, or a combination thereof; and the one or more search space candidates correspond to the CSS, the UE specific search space, or a combination thereof.

3 . The method of claim 1 , wherein at least one CORESET of the one or more CORESETs comprises a number of search space candidates that overlap in CCEs for different aggregation levels.

4 . The method of claim 3 , wherein dropping the search space candidates comprises:
determining a search space candidate of the identified CORESET to drop; and dropping the determined search space candidate and any additional search space candidates that include CCEs overlapping with CCEs corresponding to the determined search space candidate.

5 . The method of claim 1 , further comprising:
identifying an additional CORESET of the one or more CORESETs based at least in part on the overbooking handling rule; and dropping additional search space candidates from the identified additional CORESET until the total number of remaining CCEs of the one or more CORESETs within the TTI is less than or equal to the CCE limit for the TTI.

6 . The method of claim 5 , wherein identifying the additional CORESET is further based at least in part on dropping every search space candidate of the identified CORESET and determining that dropping the every search space candidate of the identified CORESET results in the total number of remaining CCEs of the one or more CORESETs within the TTI being greater than the CCE limit for the TTI.

7 . The method of claim 5 , wherein identifying the additional CORESET is further based at least in part on dropping a first search space candidate of the identified CORESET and determining that dropping the first search space candidate of the identified CORESET results in the total number of remaining CCEs of the one or more CORESETs within the TTI being greater than the CCE limit for the TTI.

8 . The method of claim 1 , further comprising:
determining the search space candidates to drop based at least in part on candidate indices for the search space candidates, control information formats associated with the search space candidates, radio network temporary identifiers (RNTIs), or a combination thereof.

9 . The method of claim 1 , wherein dropping the search space candidates comprises:
dropping a subset of CCEs of the identified CORESET or dropping the identified CORESET.

10 . The method of claim 1 , wherein identifying the CORESET based at least in part on the overbooking handling rule comprises:
identifying the CORESET according to a priority value of the CORESET.

11 . The method of claim 10 , further comprising:
transmitting an indication of priority values for the one or more CORESETs.

12 . The method of claim 1 , wherein identifying the CORESET based at least in part on the overbooking handling rule comprises:
identifying the CORESET according to a CORESET identifier.

13 . The method of claim 1 , wherein identifying the CORESET based at least in part on the overbooking handling rule comprises:
determining at least one CORESET of the one or more CORESETs that does not comprise a common search space; and identifying the CORESET from the determined at least one CORESET.

14 . The method of claim 1 , further comprising:
determining that a total number of blind decoding attempts for decoding the remaining search space candidates is greater than a blind decoding attempt limit for the TTI; identifying one or more additional search space candidates of the one or more CORESETs to drop based at least in part on a blind decoding overbooking rule; and dropping the identified one or more additional search space candidates until the total number of blind decoding attempts for decoding the remaining search space candidates is less than or equal to the blind decoding attempt limit for the TTI.

15 . The method of claim 14 , wherein identifying the one or more additional search space candidates based at least in part on the blind decoding overbooking rule comprises:
identifying each search space candidate of the one or more additional search space candidates according to a CORESET identifier, an index of the search space candidate, an aggregation level of the search space candidate, a control information format associated with the search space candidate, a radio network temporary identifier (RNTI), or a combination thereof.

16 . A method for wireless communications, comprising:
receiving a configuration for one or more control resource sets (CORESETs) in a bandwidth part, wherein the one or more CORESETs comprise one or more search space candidates; identifying one or more dropped search space candidates of the one or more search space candidates based at least in part on the configuration, wherein a total number of remaining control channel elements (CCEs) of the one or more CORESETs within a transmission time interval (TTI) is less than or equal to a CCE limit for the TTI; monitoring, according to the configuration, for one or more remaining search space candidates of the one or more search space candidates within the TTI based at least in part on the one or more dropped search space candidates; and decoding the one or more remaining search space candidates.

17 . The method of claim 16 , wherein:
each CORESET of the one or more CORESETs comprises a common search space (CSS), a UE specific search space, or a combination thereof; and the one or more dropped search space candidates correspond to the CSS, the UE specific search space, or a combination thereof.

18 . The method of claim 16 , wherein identifying the one or more dropped search space candidates is further based at least in part on an overbooking handling rule.

19 . The method of claim 16 , wherein identifying the one or more dropped search space candidates comprises:
identifying a dropped search space candidate based at least in part on a CORESET identifier, an index of the dropped search space candidate, an aggregation level of the dropped search space candidate, a control information format associated with the dropped search space candidate, a radio network temporary identifier (RNTI), or a combination thereof.

20 . The method of claim 16 , wherein decoding the one or more remaining search space candidates comprises:
performing blind decoding attempts for the one or more remaining search space candidates.

21 . The method of claim 20 , wherein a total number of blind decoding attempts for

Assignees

• Qualcomm Inc

Inventors

• Lee Heechoon
• Sun Jing
• Gaal Peter
• Chen Wanshi
• Xu Huilin

Classifications

• H04L5/0092

  Indication of how the channel is divided · CPC title

• H04L5/0053 Primary

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04W72/12

  Wireless traffic scheduling · CPC title

• H04W72/0446 Primary

  Resources in time domain, e.g. slots or frames · CPC title

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title