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EP-4274339-B1 - SEARCH SPACE GROUP SWITCHING METHOD AND APPARATUS

EP4274339B1EP 4274339 B1EP4274339 B1EP 4274339B1EP-4274339-B1

Inventors

  • LI, Dongru
  • LI, NA
  • SHEN, XIAODONG
  • WU, KAI

Dates

Publication Date
20260506
Application Date
20211231

Claims (15)

  1. A search space group switching method applied to a terminal, wherein the method comprises: switching (S202) between at least two search space groups; and performing (S204) corresponding physical downlink control channel PDCCH monitoring based on a switched-to search space group; characterized in that the at least two search space groups comprise search space group #2, search space group #2 being not linked to a first search space, the first search space comprising a CSS other than a first type CSS; wherein the first type CSS is a type 3 CSS; wherein the at least two search space groups further comprise search space group #0 and search space group #1; and the switching between at least two search space groups comprises: switching from search space group #2 to search space group #0; wherein the switching from search space group #2 to search space group #0 comprises: switching from search space group #2 to search space group #0 after a first timer times out or after a first time interval has elapsed since a first timer times out.
  2. The method according to claim 1, wherein the switching between at least two search space groups further comprises at least one of the following: switching from search space group #0 to search space group #1; and switching from search space group #0 to search space group #2; switching from search space group #2 to search space group #1; and switching from search space group #2 to a default search space group, wherein the default search space group is any one of the at least two search space groups.
  3. The method according to claim 2, wherein the switching from search space group #0 to search space group #1, or the switching from search space group #0 to search space group #2, comprises at least one of the following: switching from search space group #0 to search space group #1 in a case that the terminal is using search space group #0 and that an obtained first indication is a first value; and switching from search space group #0 to search space group #2 in a case that the terminal is using search space group #0 and that an obtained first indication is a second value; wherein the first indication is carried in first downlink control information DCI.
  4. The method according to claim 3, wherein the first DCI further comprises a second indication, and the second indication satisfies at least one of the following: a preset indication field being used for the first indication in a case that the second indication obtained is a third value; and a preset indication field being used for a preset indication in a case that the second indication obtained is a fourth value.
  5. The method according to claim 2, wherein the switching from search space group #0 to search space group #1, or the switching from search space group #0 to search space group #2, comprises at least one of the following: switching from search space group #0 to search space group #1 in a case that the terminal is using search space group #0 and that a minimum available scheduling offset indicated by an obtained minimum available scheduling offset indication is equal to 0; and switching from search space group #0 to search space group #2 in a case that the terminal is using search space group #0 and that a minimum available scheduling offset indicated by an obtained minimum available scheduling offset indication is greater than 0.
  6. The method according to claim 1, wherein the method further comprises: starting or restarting the first timer after switching to search space group #2; wherein the first timer is used for switching from search space group #2 to search space group #0.
  7. The method according to claim 2, wherein switching from search space group #2 to search space group #1, or switching from search space group #2 to a default search space group, comprises: performing at least one of the following in a case that the terminal is using search space group #2 and that second DCI is detected: switching from search space group #2 to search space group #1; and switching from search space group #2 to the default search space group.
  8. The method according to claim 7, wherein the second DCI is scrambled with a specific radio network temporary identity RNTI; and/or a search space carrying the second DCI is a specific type of search space.
  9. The method according to claim 7, wherein the method further comprises: determining, based on at least one of a network-side device configuration, a predefined rule, and the second DCI, to switch from search space group #2 to search space group #1 or from search space group #2 to the default search space group.
  10. The method according to claim 7, wherein the method further comprises: continuing using search space group #2 in a case that the terminal is using search space group #2 and that third DCI is detected.
  11. The method according to claim 8, wherein the third DCI is scrambled with a group common RNTI or a broadcast RNTI; or, wherein the method further comprises: starting or restarting the first timer after the third DCI is detected; wherein the first timer is used for switching from search space group #2 to search space group #0 or from search space group #2 to a default search space group.
  12. The method according to claim 2, wherein a network-side configuration or a protocol stipulates that the terminal does not support direct switching between search space group #2 and search space group #1.
  13. A search space group switching apparatus (300), comprising: a switching module (302) configured to switch between at least two search space groups; and a PDCCH monitoring module (304) configured to perform corresponding PDCCH monitoring based on the switched-to search space group; characterized in that the at least two search space groups comprise search space group #2, search space group #2 being not linked to a first search space, the first search space comprising a CSS other than a first type CSS; wherein the first type CSS is a type 3 CSS; wherein the at least two search space groups further comprise search space group #0 and search space group #1; and the switching module is configured for switching from search space group #2 to search space group #0; wherein the switching from search space group #2 to search space group #0 comprises: switching from search space group #2 to search space group #0 after a first timer times out or after a first time interval has elapsed since a first timer times out.
  14. The apparatus according to claim 13, wherein the switching module is further configured for at least one of the following: switching from search space group #0 to search space group #1; and switching from search space group #0 to search space group #2; switching from search space group #2 to search space group #1; and switching from search space group #2 to a default search space group, wherein the default search space group is any one of the at least two search space groups.
  15. A readable storage medium, wherein the readable storage medium stores a program or instructions, and when the program or instructions are executed by a processor, the search space group switching method according to any one of claims 1 to 12 is implemented.

Description

TECHNICAL FIELD This application pertains to the field of communication technologies and specifically relates to a search space group switching method and apparatus, and a readable storage medium. BACKGROUND In a communication system, two search space groups (Search Space group, SS group) are introduced. A type 3 physical downlink control channel common search space set (Type3- Physical Downlink Control Channel Common Search Space set, Type3-PDCCH CSS set) or a UE specific search space (UE specific search space, USS) set can be linked (link) to these two search space groups, while the other Type0/0A/1/2 common search space sets that are not part of the above search space groups need to be monitored continuously by terminals. Currently, switching between two SS groups has limited PDCCH monitoring effects and therefore is not conducive to energy saving for terminals. US 2020314898A1 discloses dynamic physical downlink control channel (PDCCH) monitoring mode switching, configuration, and control. SUMMARY Embodiments of this application provide a search space group switching method and apparatus, as defined in the appended set of claims, to solve the problem that only two search space groups have limited PDCCH monitoring effects, which is unfavorable to terminal energy saving. In the embodiments of this application, introducing search space group #2 can implement more flexible and diverse PDCCH monitoring. In the case that search space group #2 is not linked to any search space, the terminal switching to search space group #2 can implement PDCCH skipping, thereby achieving the purpose of terminal energy saving. In the case that search space group #2 is not linked to the first search space and that the terminal switches to search space group #2, at least the first search space does not need to be monitored, also facilitating terminal energy saving. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram of a wireless communications system according to an embodiment of this application;FIG. 2 is a schematic flowchart of a search space group switching method according to an embodiment of this application;FIG. 3 is a schematic structural diagram of a search space group switching apparatus according to an embodiment of this application;FIG. 4 is a schematic structural diagram of a communication device according to an illustrative embodiment of this application not in accordance with the appended claims; andFIG. 5 is a schematic structural diagram of a terminal according to an illustrative embodiment of this application not in accordance with the appended claims. DETAILED DESCRIPTION OF EMBODIMENTS The following clearly describes the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are only some rather than all of the embodiments of this application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of this application shall fall within the protection scope of this application as defined by the appended claims. The terms "first", "second", and the like in the specification and claims of this application are used to distinguish between similar objects rather than to describe a specific order or sequence. It should be understood that terms used in this way are interchangeable in appropriate circumstances so that the embodiments of this application can be implemented in other orders than the order illustrated or described herein. In addition, "first" and "second" are usually used to distinguish objects of a same type and do not limit the quantity of objects. For example, there may be one or a plurality of first objects. In addition, in this specification and claims, "and/or" indicates at least one of the connected objects, and the character "/" generally indicates an "or" relationship between the contextually associated objects. It should be noted that the technologies described in the embodiments of this application are not limited to long term evolution (Long Term Evolution, LTE)/LTE-Advanced (LTE-Advanced, LTE-A) systems, but may also be used in other wireless communications systems such as code division multiple access (Code Division Multiple Access, CDMA), time division multiple access (Time Division Multiple Access, TDMA), frequency division multiple access (Frequency Division Multiple Access, FDMA), orthogonal frequency division multiple access (Orthogonal Frequency Division Multiple Access, OFDMA), single-carrier frequency division multiple access (Single-carrier Frequency-Division Multiple Access, SC-FDMA), and other systems. The terms "system" and "network" in the embodiments of this application are often used interchangeably, and the technology described herein may be used in the above-mentioned systems and radio technologies as well as other systems and radio technologies. In the following descriptions, the new radio (New Radio,