US-12621839-B2 - System and method for physical downlink control channel monitoring based on user equipment capability

US12621839B2US 12621839 B2US12621839 B2US 12621839B2US-12621839-B2

Abstract

Methods and apparatuses are provided for monitoring a physical downlink control channel (PDCCH). A user equipment (UE) reports capability information indicating one or more tuples. Each tuple indicates a combination of serving cells configured for per-slot and per-span monitoring that the UE is capable of supporting. An indication is received in response to the capability information. A pair of values is determined based on the indication. A first value is a maximum number of serving cells configured for per-slot monitoring, and a second value is a maximum number of serving cells configured for per-span monitoring. A monitored candidate limit per slot is determined based on the first value. A monitored candidate limit per span is determined based on the second value.

Inventors

HAMID SABER
Jung Hyun Bae

Assignees

SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20230320

Claims (20)

1 . A method comprising: receiving, by a user equipment (UE), from a base station (BS), capability indication information, the capability indication information relating to a plurality of tuples, wherein each tuple indicates a combination of serving cells configured for per-slot and per-span monitoring; and determining, by the UE, based at least in part on the received capability indication information, a monitoring value pair including a first value and second value, wherein the UE is configured, using the monitoring value pair, to monitor a physical downlink control channel (PDCCH) according to a monitored candidate limit per slot based on the first value and a monitored candidate limit per span based on the second value.
2 . The method of claim 1 , further comprising sending, by the UE, to the BS, tuple data including the plurality of tuples.
3 . The method of claim 2 , wherein the capability indication information is generated by the BS based on the plurality of tuples and one or more of a number of the serving cells configured for slot based monitoring, a number of the serving cells configured for span based monitoring, and a unique function shared by the UE.
4 . The method of claim 1 , further comprising, in response to receiving the capability indication information, by the UE, from the BS, detecting, by the UE, that one or more cells are configured with slot-based monitoring and one or more cells are configured with span-based monitoring.
5 . The method of claim 1 , further comprising determining the monitoring value pair by: calculating a first complexity value for one or more configured cells with slot-based monitoring and one or more configured cells with span-based monitoring; calculating complexity values for each tuple of the plurality of tuples; determining a tuple having a complexity value closest to the first complexity value; and determining a pair of values of the monitoring pair value as the determined tuple.
6 . The method of claim 1 , wherein the capability indication information is generated according to an index value that corresponds to the monitoring value pair in a table shared by the UE.
7 . The method of claim 1 , wherein the capability indication information comprises a single pair of values or a set index.
8 . The method of claim 1 , wherein: the monitored candidate limit per slot is determined based on a number of cells configured for per-slot monitoring, a per-slot candidate single cell limit, a subcarrier spacing (SCS) configuration, and a number of cells scheduled with the SCS configuration; and the monitored candidate limit per span is determined based on a number of cells configured for per-span monitoring, a per-span candidate single cell limit, the SCS configuration, and the number of cells scheduled with the SCS configuration.
9 . The method of claim 1 , wherein the capability indication information is generated based on at least one of a per-UE basis, a per-band basis, a per-band combination basis, a per-feature set basis, and a per-feature set, per-component carrier basis.
10 . The method of claim 1 , wherein the capability indication information comprises one or more of: a plurality of feature groups for a monitoring behavior of the UE; a feature group from the plurality of feature groups based on a predetermined guideline; and capability information for the feature group.
11 . A method comprising: receiving, by a base station (BS), from a user equipment (UE), a plurality of tuples, wherein each tuple of the plurality of tuples indicates a combination of serving cells configured for per-slot and per-span monitoring that the UE is capable of supporting; and generating, by the BS, capability indication information, wherein the capability indication information is usable by the UE to configure the UE to monitor a physical downlink control channel (PDCCH) according to a monitored candidate limit per slot based on the first value and a monitored candidate limit per span based on the second value in a pair of values, wherein the UE determines the first value and second value from the capability indication information; and sending the capability indication information to the UE.
12 . The method of claim 11 , wherein the capability indication information is further generated based on one or more of a number of one or more cells configured with slot based monitoring, a number of one or more cells configured with span based monitoring, and a unique function shared by the UE.
13 . The method of claim 11 , wherein, in response to receiving the capability indication information generated by the BS, the UE is configured to detect that one or more cells are configured with slot-based monitoring and one or more cells are configured with span-based monitoring.
14 . The method of claim 11 , wherein the capability indication information is further generated by: calculating a first complexity value for one or more configured cells with slot-based monitoring and one or more configured cells with span-based monitoring; calculating complexity values for each tuple of the plurality of tuples; determining a tuple having a complexity value closest to the first complexity value; and determining the pair of values of a monitoring pair value as the determined tuple.
15 . The method of claim 11 , further comprising receiving, by the BS, from the UE, a value table, wherein the capability indication information is generated according to an index value that corresponds to the pair of values in the table.
16 . The method of claim 11 , wherein the capability indication information comprises a single pair of values or a set index.
17 . The method of claim 11 , wherein: the monitored candidate limit per slot is determined based on a number of cells configured for per-slot monitoring, a per-slot candidate single cell limit, a subcarrier spacing (SCS) configuration, and a number of cells scheduled with the SCS configuration; and the monitored candidate limit per span is determined based on a number of cells configured for per-span monitoring, a per-span candidate single cell limit, the SCS configuration, and the number of cells scheduled with the SCS configuration.
18 . The method of claim 11 , wherein the capability indication information is generated based on at least one of a per-UE basis, a per-band basis, a per-band combination basis, a per-feature set basis, and a per-feature set, per-component carrier basis.
19 . The method of claim 11 , wherein the capability indication information comprises one or more of: a plurality of feature groups for a monitoring behavior of the UE; a feature group from the plurality of feature groups based on a predetermined guideline; and capability information for the feature group.
20 . A user equipment (UE) comprising: a processor; and a non-transitory computer readable storage medium storing instructions that, when executed, cause the processor to: receive, from a base station (BS), capability indication information, the capability indication information relating to a plurality of tuples, wherein each tuple indicates a combination of serving cells configured for per-slot and per-span monitoring; determine, based at least in part on the received capability indication information, a monitoring value pair including a first value and second value, wherein the UE is configured, using the monitoring value pair, to monitor a physical downlink control channel (PDCCH) according to a monitored candidate limit per slot based on the first value and a monitored candidate limit per span based on the second value.

Description

PRIORITY This application is a Continuation Application of U.S. application Ser. No. 17/029,831, filed in the U.S. Patent and Trademark Office (USPTO) on Sep. 23, 2020, and is based on and claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Applications filed on Apr. 17, 2020, Apr. 21, 2020, and Apr. 22, 2020 in the USPTO and assigned Serial Nos. 63/012,055, 63/013,526, and 63/014,112, respectively, the contents of each of which are incorporated herein by reference. FIELD The present disclosure relates generally to channel monitoring, and more particularly, to physical downlink control channel (PDCCH) monitoring based on user equipment (UE) capability. BACKGROUND In mobile communication systems, a UE may report one or more capabilities to a base station, a NodeB, or the like. For example, a UE may report capabilities relating to blind detection (BD) and/or control channel elements (CCE). According to 3rd Generation Partnership Project (3GPP) 5th Generation (5G) Release 15 (Rel-15) of new radio (NR) technology, a UE that supports a carrier aggregation (CA) may report a capability for blind detection (BD) of PDCCH over a certain number of serving cells or component carriers (CCs). The capability signaling may be referred to as pdcch-BlindDetection, which may be in form of an integer ranging from 4 to 16. This capability helps to define a maximum number of serving cells (Ncellsc⁢a⁢p≥4) for which the UE can support PDCCH BD and non-overlapped CCE. Rel-15 BD/CCE limits are defined per slot. FIG. 1A illustrates table showing a maximum number of BD (MPDCCHmax,slot,μ) that the UE is able to perform per slot for operation with a single serving cell based on subcarrier spacing (SCS) configuration (μ) of the serving cell. FIG. 1B illustrates a table showing a maximum number of non-overlapped CCE (CPDCCHmax,slot,μ) that the UE is able to monitor per slot for operation with a single serving cell based on SCS configuration (μ) of the serving cell. According to 3GPP 5G Release 16 (Rel-16) of NR technology, increased PDCCH monitoring per slot may be supported by defining per-span limits. Generally, a span is defined as time unit within and smaller than a slot. A span pattern in a slot may be defined by a next generation NodeB (gNB), according to a search space configuration. FIG. 2 is a diagram illustrating a span pattern in a slot. Specifically, monitoring occasions (MOs) are shown in symbols 1, 5, 9, 11, and 13, and a span pattern is defined based on a UE capability that defines a minimum spacing between the beginning symbols of each span, and a number of symbols in each span. For example, span patterns based on capabilities (2, 2) and (2, 1) are illustrated in FIG. 2. Similar to the tables of FIGS. 1A and 1B, Rel-16 provides tables in which BD/CCE limits are defined per span. The BD/CCE limits are defined for single cell operation as a function of the SCS configuration of the active bandwidth part (BWP) of the cell. A Rel-16 UE may perform the BD/CCE monitoring according to per-slot limits or per-span limits. For a UE operating with CA, all the configured serving cells may follow per-slot monitoring limits and the UE may report pdcch-BlindDetectionCA, all the configured serving cells may follow per-span monitoring limits and the UE may report pdcch-BlindDetectionCA-R16, or some serving cells may be configured with per-slot monitoring limits and some serving cells may be configured with per-span monitoring limits and the UE may report a pair (pdcch-BlindDetectionCA-R15, pdcch-BlindDetectionCA-R16). When serving cells are configured with per-slot and per-span monitoring limits, a constraint may be placed on the reported pair, as set forth in Equation (1) below. pdcch-BlindDetectionCA-R15+pdcch-BlindDetectionCA-R16≤4 (1) For example, the UE may report the pair (1, 3), which indicates that the UE supports up to one cell with per-slot BD/CCE monitoring and up to 3 cells with per-span BD/CCE monitoring. However, the UE may also support monitoring with respect to the pair (3, 1). In order for a UE to indicate its supports for both pairs, the UE would need to report the pair (3, 3), which is not possible given the constraint noted in Equation 1 (i.e., 3+3=6>4). SUMMARY According to one embodiment, a method is provided for monitoring a PDCCH, by a UE. The UE reports capability information indicating one or more tuples. Each of the one or more tuples indicates a combination of serving cells configured for per-slot and per-span monitoring that the UE is capable of supporting. An indication is received in response to the capability information. A pair of values is determined based on the indication. A first value in the pair of values is a maximum number of serving cells configured for per-slot monitoring, and a second value in the pair of values is a maximum number of serving cells configured for per-span monitoring. A monitored candidate limit per slot is determined based on the first value in the pair of values