Method and apparatus for SCELL beam failure recovery configuration

Abstract

A user equipment (UE) and a method for secondary cell beam failure recovery (SCell BFR) performed by the UE are provided. The method includes: receiving a first SCell BFR configuration corresponding to a first SCell, the first SCell BFR configuration including a resource list for an NBI; detecting a beam failure condition in the first SCell by measuring at least one BFD reference signal; determining a first new candidate beam index for the first SCell based on the first SCell BFR configuration; and sending a beam failure recovery request, the beam failure recovery request including a cell index of the first SCell in which the beam failure condition is detected and the determined first new candidate beam index.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit and priority of provisional U.S. patent application serial number 62 / 806,081, entitled “Co-existence for multiple SCellBeam Failure Recovery Procedures”, filed on February 15, 2019, with agent docket number US76547 (hereinafter referred to as “US76547 application”). The disclosure of US76547 application is fully incorporated into this application by reference. Technical Field

[0003] The present invention relates generally to wireless communications, and more particularly to a method for beam failure recovery (BFR) in a cellular wireless communication network. Background Art

[0004] Various efforts have been made to improve different aspects of wireless communication in cellular wireless communication systems (e.g., fifth generation (5G) new radio technology (NR)), such as data rate, latency, reliability, and mobility. For example, beam management introduced in NR systems establishes and retains suitable beam pair links, especially transmitter-side beam directions and corresponding receiver-side beam directions that jointly provide good connectivity. In some cases, movement in the environment may cause the established beam pair links to be quickly blocked. In NR, the BFR process is introduced to handle such beam failure events. In addition, carrier aggregation (CA) is supported in NR. The primary cell (PCell) can operate in a sub-6 GHz band (frequency range 1, FR1), while the secondary cell (SCell) can operate in a band above 24 GHz (frequency range 2, FR2). Due to the channel characteristics of millimeter wave propagation, beam failures (e.g., beam blocking) occur more frequently in FR2. Therefore, there is a need in the art for an improved and effective mechanism for user equipment (UE) to handle beam failure recovery in SCell. Summary of the invention

[0005] This case relates to a method for SCell BFR performed by a UE in a next generation wireless communication network.

[0006] According to one aspect of the present case, a UE is provided, which includes: one or more non-temporary computer-readable media, the one or more non-temporary computer-readable media having computer-executable instructions contained thereon; and at least one processor, the at least one processor being coupled to the one or more non-temporary computer-readable media, the at least one processor being configured to execute the computer-executable instructions to: receive a first SCell beam failure recovery BFR configuration corresponding to a first secondary cell SCell, the first SCell BFR configuration including a resource list for a new beam identification NBI; detect a beam failure condition in the first SCell by measuring at least one beam failure detection BFD reference signal; determine a first new candidate beam index for the first SCell based on the first SCell BFR configuration; and send a beam failure recovery request, the beam failure recovery request including a cell index of the first SCell in which a beam failure condition is detected and the determined first new candidate beam index.

[0007] According to another aspect of the present case, a method for secondary cell SCell beam failure recovery BFR performed by a user equipment UE is provided, the method comprising: receiving a first SCell BFR configuration corresponding to a first SCell, the first SCell BFR configuration comprising a resource list for a new beam identification NBI; detecting a beam failure condition in the first SCell by measuring at least one beam failure detection BFD reference signal; determining a first new candidate beam index for the first SCell based on the first SCell BFR configuration; and sending a beam failure recovery request, the beam failure recovery request comprising a cell index of the first SCell in which a beam failure condition is detected and the determined first new candidate beam index. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The aspects of the exemplary disclosure are best understood from the following detailed description when read with the accompanying drawings. The various features are not drawn to scale. The dimensions of the various features may be arbitrarily increased or decreased for clarity of discussion.

[0009] Figure 1 is a flowchart of a method for beam failure recovery performed by a UE according to an example embodiment of the present application.

[0010] Figure 2 is a flowchart of a method for SCell BFR performed by a UE according to an example embodiment of the present application.

[0011] Figure 3 Included is a diagram showing a method for a SCell BFR process according to an example embodiment of the present application.

[0012] Figure 4 is a flow chart of a method for BFRQ transmission when multiple BFRs are triggered according to an example embodiment of the present application.

[0013] Figure 5 Included are diagrams showing example cross-carrier scheduling scenarios according to example implementations of the present application.

[0014] Figure 6 is a block diagram illustrating a node for wireless communication according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0015] The following description contains specific information related to the embodiments of the present application. The drawings in the present application and the detailed description attached thereto are only for example embodiments. However, the present application is not limited to these example embodiments. Other variations and embodiments of the present application will be apparent to those skilled in the art. Unless otherwise specified, similar or corresponding elements in the drawings may be represented by similar or corresponding reference numerals. In addition, the drawings and diagrams in the present application are generally not drawn to scale and are not intended to correspond to actual relative sizes.

[0016] For consistency and ease of understanding, similar features (although not shown in some examples) may be identified by the same numbers in the drawings. However, features in different embodiments may differ in other aspects and should not be narrowly limited to the features shown in the drawings.

[0017] The description uses the phrases "in one embodiment," or "in some embodiments," which phrases may all refer to one or more of the same or different embodiments. The term "coupled" is defined as directly connected or indirectly connected through intervening components, and is not necessarily limited to physical connections. The term "comprising" means "including but not necessarily limited to"; it specifically indicates open inclusion or membership in the combinations, groups, series, and equivalents described. The expression "at least one of A, B, and C" or "at least one of the following: A, B, and C" means only "only A, or only B, or only C, or any combination of A, B, and C."

[0018] In addition, for the purpose of explanation and non-limitation, specific details such as functional entities, technologies, protocols, standards, etc. are also set forth to provide an understanding of the described technology. In other examples, detailed descriptions of well-known methods, technologies, systems, architectures, etc. are omitted to avoid making the description unclear with unnecessary details.

[0019] Those skilled in the art will immediately recognize that any network function or algorithm described in this application can be implemented by hardware, software, or a combination of software and hardware. The function may correspond to a module that may be software, hardware, firmware, or any combination thereof. Software implementations may include computer executable instructions stored on a computer-readable medium such as a memory or other type of storage device. For example, one or more microprocessors or general-purpose computers with communication processing capabilities may be programmed with corresponding executable instructions and execute the network function or algorithm. A microprocessor or general-purpose computer may be composed of an application-specific integrated circuit (ASIC), a programmable logic array, and / or one or more digital signal processors (DSP). Although several exemplary embodiments described in this specification are for software installed and executed on computer hardware, alternative implementations implemented as firmware or hardware or a combination of hardware and software are within the scope of this application.

[0020] Computer readable media include, but are not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM), cassettes, magnetic tapes, disk storage, or any other equivalent media capable of storing computer readable instructions.

[0021] The wireless communication network architecture (e.g., Long Term Evolution (LTE) system, LTE-Advanced (LTE-Advanced, LTE-A) system or LTE-Advanced Pro system, 5G NR Radio Access Network (RAN)) generally includes at least one base station (BS), at least one UE, and one or more optional network elements that provide connection to the network. The UE communicates with the network (e.g., Core Network (CN), Evolved Packet Core (EPC) network, Evolved Universal Terrestrial Radio Access Network (E-UTRAN), 5G Core Network (5G Core, 5GC) or the Internet) through the RAN established by one or more BSs.

[0022] It should be noted that in the present application, UE may include but is not limited to a mobile station, a mobile terminal or device, a user communication wireless terminal. For example, UE may be a portable wireless device, including but not limited to a mobile phone, a tablet computer, a wearable device, a sensor, a vehicle or a personal digital assistant (PDA) with wireless communication capabilities. UE is configured to receive / send signals from one or more cells in a wireless access network via an air interface.

[0023] The base station may be configured to provide communication services according to at least one of the following radio access technologies (RAT): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM, commonly referred to as 2G), GSM Evolution Radio Access Network (GERAN) based on Enhanced Datarates for GSM Evolution (EDGE), General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS, commonly referred to as 3G) based on basic Wideband-Code Division Multiple Access (W-CDMA), High-Speed ​​Packet Access (HSPA), LTE, LTE-A, eLTE (evolved LTE, such as LTE connected to 5GC), NR (commonly referred to as 5G) and / or LTE-A Pro. However, the scope of the present application should not be limited to the above-mentioned protocols.

[0024] The base station may include, but is not limited to, a node B (NB) in UMTS, an evolved Node B (eNB) in LTE or LTE-A, a radio network controller (RNC) in UMTS, a base station controller (BSC) in GSM / GERN, an ng-eNB in ​​an Evolved Universal Terrestrial Radio Access (E-UTRA) base station connected to a 5GC, a next generation Node B (gNB) in 5G-RAN, and any other device capable of controlling radio communications and managing radio resources within a cell. The base station may serve one or more UEs through a wireless interface.

[0025] The base station is operable to provide wireless coverage to a specific geographic area using multiple cells that form a wireless access network. The base station supports the operation of the cell. Each cell is operable to provide services to at least one UE within its wireless coverage. More specifically, each cell (commonly referred to as a service cell) provides services to serve one or more UEs within its wireless coverage (for example, each cell schedules downlink (DL) and optional uplink (UL) resources to at least one UE within its wireless coverage for DL ​​and optional UL packet transmission). The base station can communicate with one or more UEs in a wireless communication system through multiple cells. The cell can allocate sidelink (SL) resources to support proximity service (ProSe) or vehicle to everything (V2X) services. Each cell may have a coverage area that overlaps with other cells.

[0026] As described above, the frame structure for NR needs to support flexible configuration to adapt to various next-generation (e.g., 5G) communication requirements, such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), Ultra-Reliable and Low-Latency Communication (URLLC), while meeting high reliability, high data rate, and low latency requirements. The Orthogonal Frequency-Division Multiplexing (OFDM) technology agreed upon in the 3rd Generation Partnership Project (3GPP) can be used as a benchmark for the NR waveform. Scalable OFDM parameter sets, such as adaptive subcarrier spacing, channel bandwidth, and cyclic prefix (CP) can also be used. In addition, two coding schemes are considered for NR: (1) low-density parity check (LDPC) code and (2) polar code. Coding scheme adaptation can be configured based on channel status and / or service application.

[0027] In addition, it is also considered that within the transmission time interval (TTI) of a single NR frame, at least DL transmission data, protection period and uplink (UL) transmission data should be included. The respective parts of DL transmission data, protection period and UL transmission data should also be configured, for example, based on the network dynamics of NR. In addition, sidelink resources can also be provided in the NR frame to support ProSe services or V2X services.

[0028] The terms "system" and "network" used herein can be used interchangeably. The term "and / or" used herein is only used to describe the association relationship of associated objects, and indicates that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, or B exists alone. In addition, the character " / " used in this article generally indicates that the associated objects are in an "or" relationship.

[0029] Figure 1 1 is a flowchart of a method 100 for beam failure recovery performed by a UE according to an example embodiment of the present application. In action 102, the UE may perform BFD to detect a beam failure condition in a cell (e.g., an SCell). The UE may be explicitly or implicitly configured with a set of BFD reference signals (RS), which may include a channel state information reference signal (CSI-RS) and a synchronization signal block (SSB). In one embodiment, the explicit configuration of the BFD RS may be sent via Radio Resource Control (RRC) signaling. On the other hand, if the BFD RS is implicitly configured, the UE may determine the BFD RS on its own. The UE may detect a beam failure condition by measuring the BFD RS, such as determining a block error rate (BLER) based on a measurement of the BFD RS. In one embodiment, each time the determined BLER exceeds a threshold, it may be regarded as a beam failure instance, and the UE may declare that a beam failure condition is detected when the number of consecutive beam failure instances exceeds a specific value.

[0030] In action 104, the UE may perform NBI to find a new beam pair link on which the connection between the UE and the associated BS may be restored. The UE may be explicitly or implicitly configured with a set of NBI RSs, which may include CSI-RS and / or SSBs. In one embodiment, the explicit configuration of the NBI RS may be sent via RRC signaling. On the other hand, if the NBI RS is implicitly configured, the UE may determine the NBI RS on its own. The set of NBI RSs may correspond to a set of candidate beams. The UE may determine a new candidate beam based on the set of NBI RSs. In one embodiment, the UE may measure the quality of the NBI RS (e.g., L1-RSRP) to select a new candidate beam from the set of NBI RSs. It should be noted that Figure 1The order of actions described in the description is not intended to be construed as limiting. For example, in one embodiment, action 104 may be followed by action 102.

[0031] In action 106, after the UE detects the beam failure condition, the UE may send a beam failure recovery request (BFRQ) to the base station. In one embodiment, the UE may also identify new candidate beams before sending the BFRQ (e.g., in action 104). The BFRQ notifies the network that a beam failure has been detected. In one embodiment, the BFRQ may include information about the new candidate beams.

[0032] In one embodiment, for beam failure occurring in a specific cell (e.g., PCell or PSCell), the BFRQ may be sent on a physical random access channel (PRACH). In principle, both contention-free and contention-based PRACH resources may be used. In one embodiment, contention-free PRACH resources may take precedence over contention-based PRACH resources. The two-step contention-free random access process may include a preamble transmission and a random access response. In one embodiment, each reference signal corresponding to a different candidate beam may be associated with a specific preamble configuration.

[0033] In action 108, the UE may receive a response from the network. In one embodiment, a specific control resource set (CORESET) or search space (e.g., CORESET-BFR or SeachSpace-BFR indicated by a higher layer parameter recoverySearchSpaceId) is defined for response reception. The UE may monitor the Physical Downlink Control Channel (PDCCH) transmission on the CORESET-BFR / SeachSpace-BFR to determine whether the network successfully received the BFRQ. The Downlink Control Information (DCI) format in the CORESET-BFR / SeachSpace-BFR may be considered a successful network response. In one embodiment, the UE may assume that when responding to the BFRQ, the network is sending a PDCCH that is quasi co-located (QCL) with the RS associated with the new candidate beam in the BFRQ.

[0034] It should be noted that the term "beam" can be replaced with "spatial filter". For example, when the UE reports a new candidate beam (e.g., a gNB TX beam), the UE is essentially selecting a spatial filter to be used by the gNB. The term "beam information" may refer to information indicating which beam to use or which spatial filter to select. In one embodiment, a single reference signal may be sent by applying a single beam (or spatial filter). Therefore, the beam information may be represented by a reference signal resource index.

[0035] The previous description involves PRACH-based BFRQ transmission and network response, which can be used in a specific cell BFR process. For BFR in SCell, Figure 1 The BFRQ in action 106 may be sent on a PRACH, a Physical Uplink Shared Channel (PUSCH), or a Physical Uplink Control Channel (PUCCH). In one embodiment, the BFRQ may be sent on the PUSCH. The UE may send a BFR Medium Access Control (MAC) Control Element (CE) on the PUSCH to carry the BFRQ. In one embodiment, the BFRQ (e.g., a BFRMAC CE if the BFRQ is sent on the PUSCH) may include a cell index of the SCell where the beam failure occurred. In one embodiment, the BFRQ (e.g., a BFRMAC CE) may include a cell index of the SCell where the beam failure occurred. Figure 1 The cell index of the SCell where the beam failure occurs determined in action 102 and Figure 1 The new candidate beam index of the SCell determined in action 104. In one embodiment, the PUSCH used to send the BFRQ may be obtained from a previous scheduling request (SR) transmission via the PUCCH, or from a configured granted resource.

[0036] Figure 220 is a flowchart of a method 200 for SCell BFR performed by a UE according to an example embodiment of the present application. In action 202, the UE receives an SCell BFR configuration corresponding to a first SCell, wherein the SCell BFR configuration includes at least one of a resource list for BFD and a resource list for NBI. The SCell BFR configuration may be sent via RRC signaling. If the resource list for BFD is included in the SCell BFR configuration, it may be explicitly configured. If the resource list for BFD is not included in the SCell BFR configuration, it may be implicitly configured. Similarly, if the resource list for NBI is included / not included in the SCell BFR configuration, it may be explicitly / implicitly configured. The SCell BFR configuration may include only a resource list for BFD, only a resource list for NBI, or both a resource list for BFD and a resource list for NBI.

[0037] In carrier aggregation, a UE may be configured with one or more SCells. In one embodiment, the UE may receive one or more SCell BFR configurations, each SCell BFR configuration corresponding to one of the configured SCells. For example, the UE may receive SCell BFR configuration #1 corresponding to SCell #1, SCell BFR configuration #2 corresponding to SCell #2, SCell BFR configuration #3 corresponding to SCell #3, and so on. In one embodiment, the resource list for BFR and / or the resource list for NBI in each SCell BFR configuration may be independently configured.

[0038] In action 204, the UE may detect a beam failure condition in the first SCell by measuring at least one BFD reference signal. In one embodiment, the UE may measure a signal quality (e.g., L1-RSRP) of the BFD reference signal to detect the beam failure condition. In another embodiment, the UE may derive a block error rate (BLER) based on the measurement of the BFD reference signal to detect the beam failure condition.

[0039] Case 1-1: Implicit configuration of BFD reference signals

[0040] In one embodiment, the SCell BFR configuration received in action 202 may not include a resource list for BFD. The UE may determine at least one BFD reference signal based on at least one Transmission Configuration Indicator (TCI) state for each corresponding control resource set (CORESET) that the UE uses to monitor a physical downlink control channel (PDCCH). In one embodiment, the at least one BFD reference signal may include a reference signal index having a QCL type D configuration for a corresponding TCI state. In one embodiment, the implicit determination of the BFD reference signal may follow the same method as the implicit determination of a specific cell BFD reference signal specified in 3GPP TS 38.213 (e.g., V15.4.0).

[0041] In one embodiment, at least one BFD reference signal may be sent via the first SCell. In one embodiment, at least one BFD reference signal may be sent via another serving cell, wherein the first SCell and the another serving cell correspond to different component carriers. For example, the UE may receive SCell BFR configuration #1 for SCell#1 in action 202. SCell BFR configuration #1 may not include a resource list for BFD. In one embodiment, the BFD reference signal implicitly determined by the UE may be sent via SCell#1. In one embodiment, the BFD reference signal implicitly determined by the UE may be sent via SCell#2, which provides coverage on a different component carrier than SCell#1. Therefore, the UE in action 204 may measure the BFD reference signal sent via SCell#2 to detect a beam failure condition in SCell#1.

[0042] Case 1-2: Implicit configuration of BFD reference signals

[0043] In one embodiment, the BFD reference signal may be explicitly configured. At least one BFD reference signal may be configured in a resource list for BFD. In one embodiment, at least one BFD reference signal may be sent via the first SCell. For example, the UE may receive SCell BFR configuration #1 for SCell#1 in action 202. SCell-BFR configuration #1 may include a resource list for BFD, which may include one or more BFD reference signals sent via SCell#1.

[0044] Case 2: Configuration of NBI reference signal

[0045] In action 206, the UE may determine a new candidate beam index for the first SCell based on the SCell BFR configuration. In one embodiment, in order to determine the new candidate beam, the UE may determine the new candidate beam by selecting an NBI reference signal from a resource list for NBI based on a predetermined rule (e.g., based on the index of the NBI reference signal). In a preferred embodiment, the resource list for NBI may be obtained from the SCell BFR configuration. In one embodiment, the UE may measure the signal quality (e.g., L1-RSRP) of the NBI reference signal configured in the resource list for NBI to determine the new candidate beam index (e.g., an NBI reference signal with the best signal quality may be selected, or an NBI reference signal whose signal quality is better than a threshold may be selected).

[0046] In one embodiment, the resource list for NBI may include an NBI reference signal sent via the first SCell. In one embodiment, a reference signal corresponding to a new candidate beam index may be sent via the first SCell. For example, the UE may receive SCell BFR configuration #1 of SCell#1 in action 202. SCell BFR configuration #1 may include a resource list for NBI, which may include one or more NBI reference signals sent via SCell#1. The UE may then select an NBI reference signal from the resource list for NBI as the new candidate beam index. The selected NBI reference signal corresponding to the new candidate beam may be sent via SCell#1.

[0047] In one embodiment, the resource list for NBI may include an NBI reference signal sent via a serving cell other than the first SCell, where the first SCell and the other serving cell may correspond to different component carriers. In one embodiment, a reference signal corresponding to a new candidate beam index may be sent via another serving cell. For example, the UE may receive SCell BFR configuration #1 for SCell#1 in action 202. SCell BFR configuration #1 may include a resource list for NBI, which may include one or more NBI reference signals sent via SCell#2, thereby providing coverage on a component carrier different from SCell#1. The UE in action 206 may measure the NBI reference signal sent via SCell#2 to determine a new candidate beam index for SCell#1. The selected NBI reference signal corresponding to the new candidate beam may be sent via SCell#2.

[0048] In action 208, the UE may send a BFRQ including a cell index of the first SCell where a beam failure occurs and a new candidate beam index of the first SCell. In one embodiment, the UE receives multiple SCell BFR configurations (e.g., including SCell BFR configuration #1 corresponding to SCell#1, SCell BFR configuration #2 corresponding to SCell#2, SCell BFR configuration #3 corresponding to SCell#3, and so on). In one embodiment, the UE may detect beam failure conditions in multiple SCells (e.g., beam failures detected in SCell#1 and SCell#3). The UE may determine a new candidate beam index for each SCell where a beam failure occurs. In one embodiment, the BFRQ sent in action 208 may include multiple cell indices and multiple new candidate beam indices (e.g., the BFRQ may include a cell index of SCell#1, a new candidate beam index of SCell#1, a cell index of SCell#3, and a new candidate beam index of SCell#3).

[0049] Figure 3 is a diagram of a method 300 for a SCell BFR process according to an example embodiment of the present application. In action 330, the UE 310 performs beam failure detection and new beam identification. In one embodiment, the BFRQ may be a BFRMAC CE, which carries the cell index of the SCell where the beam failure occurred and the new candidate beam index of the SCell. In one embodiment, the UE 310 may send a scheduling request (SR) to the base station 320 in action 332 to request UL resources for sending the BFR MAC CE. In one embodiment, the SR in action 332 may be specifically configured for BFR. The SR may be sent on the PUCCH.

[0050] In action 334, UE 310 may receive DCI #1 (e.g., UL grant) scheduling PUSCH transmission from base station 320, and BFR MAC CE may be sent via DCI #1. DCI #1 may be sent on PDCCH. In action 336, UE 310 may send BFR MAC CE on PUSCH scheduled by DCI #1 to base station 320. In action 338, UE 310 may receive DCI #2 (e.g., UL grant) from base station 320 in response to BFR MAC CE. In one embodiment, UE 310 may regard the SCell BFR process as successfully completed after receiving DCI #2 in action 338.

[0051] Case 3: BFRQ transmission when multiple BFRs are triggered

[0052] A UE configured with multiple serving cells may declare that multiple serving cells (e.g., SCells) are in beam failure at the same time. There may be multiple BFRQ messages waiting to be delivered. When multiple BFR processes are triggered simultaneously, there may be BFRQ message delivery issues. For example, BFRQ may be sent on PRACH, PUSCH, or PUCCH. If PRACH is used for BFRQ transmission, the problem may be that only one RACH process is allowed at a time within a single MAC entity. For PUCCH, the problem may be that the PUCCH resources may have only a limited payload size that depends on the configuration. For UL MAC CE sent on PUSCH, the MAC CE may have a fixed or variable payload size.

[0053] In one embodiment, the UE may prioritize BFRQ information from a specific SCell so that the BFRQ information from such SCell may be sent quickly. For other SCells, the corresponding BFRQ information may be abandoned or put on hold until there is an idle / available net load size. For example, the UE may classify the configured SCells into a first subset and a second subset, wherein the first subset has a higher priority than the second subset. The UE may prioritize the transmission of BFRQ information related to the SCells in the first subset, while the transmission of BFRQ information related to the SCells in the second subset may be discarded or delayed. In this way, even if the wireless resources used to send the BFRQ have only a limited net load size, the BFR in the prioritized SCell may be successfully parsed.

[0054] In one embodiment, only a subset of SCell BFRQ information (e.g., a prioritized subset) may be sent. In one embodiment, the remaining SCell BFRQ information may be maintained until some BFRQs in the prioritized subset are served and the corresponding BFRs are resolved. In one embodiment, the remaining SCell BFRQ information may be discarded. For example, the UE may discard the beam failure declaration and restart beam failure detection in the corresponding SCell. In one embodiment, the UE may rely on the network to determine when to trigger BFD for the corresponding SCell again. In one embodiment, the prioritized subset may contain only one SCell where a beam failure occurs.

[0055] PRACH may be used for BFRQ transmissions. In one embodiment, if the number of SCells in a subset is greater than one, the UE may be allowed to perform multiple RACH procedures simultaneously. In one embodiment, the maximum number of synchronous RACH procedures may be two or, in other words, the maximum number of SCells in a subset may be two. In one embodiment, there may be no limit on the maximum number of synchronous RACH procedures. The maximum number of synchronous RACH procedures may depend on the implementation of the UE.

[0056] In one embodiment, different subsets of SCell BFRQ information may be carried by multiple transmission instances. For example, multiple PUCCH transmission instances may be used to carry BFRQ information, or multiple UL MAC CEs in multiple MAC protocol data units (PDUs) may be used to carry BFRQ information. In one embodiment, BFRQ information from different subsets may be sent in parallel. For example, when the serving cell is classified into a first subset and a second subset, the transmission of BFRQ information from the second subset may occur before the BFR process of the first subset is resolved, so that the UE may not need to suspend the transmission of BFRQ information from the second subset until the BFR process corresponding to the first subset is resolved.

[0057] In one embodiment, the UE may decide which serving cells belong to the priority subset based on a configured or predetermined priority rule. In one embodiment, the priority rule may be based on the cell index of the serving cell. For example, a serving cell with a lower cell index may be prioritized. In one embodiment, the PCell may be prioritized, and the priority of other serving cells may be based on the UE implementation. In one embodiment for FR2, the lowest index serving cell where a beam failure occurs may be prioritized, and the priority of other serving cells may be based on the UE implementation. In one embodiment, the subset selection (e.g., determining which serving cells belong to the priority subset) may be configured by the network (e.g., the network may configure or indicate a priority for each serving cell). In one embodiment, the subset selection may depend on the UE implementation. In one embodiment, the UL transmission carrying the BFRQ information may also indicate whether the reported SCell BFRQ information includes all SCells with beam failures.

[0058] Figure 44 is a flow chart of a method 400 for BFRQ transmission when multiple BFRs are triggered according to an example embodiment of the present application. In action 402, the UE may determine cells in a first subset and a second subset. The first subset may have a higher priority than the second subset. In action 404, the UE may send BFRQ information from the first subset. In action 406, the UE may not suspend the transmission of BFRQ information from the second subset until the BFR process corresponding to the first subset is resolved. For example, the transmission of BFRQ information from the second subset may be discarded or delayed.

[0059] Case 4: SCell BFR in cross-carrier scheduling

[0060] Figure 5 500 is a diagram of a cross-carrier scheduling scenario according to an example embodiment of the present application. BS 501 can provide coverage on component carrier (CC) #1, and BS 502 can provide coverage on CC #2. As shown in the figure, cell 512 is cross-carrier scheduled by cell 511. In other words, the PDCCH on cell 511 can include scheduling information of the PDSCH on cell 512. Cell 511 can be referred to as a scheduling cell, and cell 512 can be referred to as a scheduled cell. In one embodiment, cell 512 can be an SCell, and cell 511 can be a PCell, a PSCell, or an SCell.

[0061] In one embodiment, the SCell BFR process may be triggered in cell 512 to maintain the control channel quality of CC#2. For example, UE 503 may detect a beam failure condition in cell 512 and subsequently send a BFRQ. BFD may be triggered (e.g., Figure 1 Action 102 in (a) for CC#2 control channel, and may trigger NBI (eg, Figure 1 Action 104 in the above procedure is used to acquire a new beam for CC#2 so as to restore the CC#2 control channel.

[0062] In one embodiment, at least one of a BFD RS and an NBI RS may be provided in a scheduling cell (e.g., cell 512). In one embodiment according to case 1-2, the BFD RS may be explicitly configured and may be sent via cell 512. In one embodiment according to case 1-1, the BFD RS may be implicitly configured and the UE 503 may determine the BFD RS itself. In a cross-carrier scheduling scenario, the BFD RS may be implicitly configured to a cross-carrier scheduling cell (e.g., cell 511). Because the UE 503 monitors the PDCCH on the cell 511, the BFD RS may be sent via the cell 511 when the BFD RS is implicitly configured. Therefore, the UE 503 may measure the BFD RS sent via the cell 511 to detect a beam failure condition in the cell 512.

[0063] In one embodiment, it may be necessary to explicitly or forcibly configure the NBI RS. The configuration of the NBI RS may be referred to as case 2. In one embodiment, the resource list for NBI may include the NBI RS transmitted via the cell 512. The UE 503 may determine a new candidate beam index according to the configured resource list for NBI, and a reference signal corresponding to the new candidate beam index may be transmitted via the cell 512.

[0064] In one embodiment, the resource list for NBI may include an NBI RS transmitted via cell 511. UE 503 may determine a new candidate beam index according to the configured resource list for NBI, and a reference signal corresponding to the new candidate beam index may be transmitted via cell 511. Therefore, UE 503 may measure the NBI RS transmitted via cell 511 to determine a new candidate beam index for cell 512. In one embodiment, the resource list for NBI may include an NBI RS transmitted via a serving cell other than cell 511 and cell 512, and a reference signal corresponding to the new candidate beam index may be transmitted via the serving cell.

[0065] Figure 6 is a block diagram of a node for wireless communication according to the present application. Figure 6 As shown, the node 600 may include a transceiver 620, a processor 628, a memory 634, one or more presentation components 638, and at least one antenna 636. The node 600 may also include an RF band module, a base station (BS) communication module, a network communication module, and a system communication management module, an input / output (I / O) port, an I / O component, and a power supply ( Figure 6Each of these components can communicate with each other directly or indirectly via one or more buses 640. In one embodiment, node 600 can be a processor that performs the operations described herein. Figures 1 to 5 UE or base station with various functions described above.

[0066] A transceiver 620 having a transmitter 622 (e.g., a transmission / transmission circuit) and a receiver 624 (e.g., a receiving circuit) can be configured to transmit and / or receive time and / or frequency resource partitioning information. In some embodiments, the transceiver 620 can be configured to transmit in different types of subframes and time slots, including but not limited to available, unavailable, and flexibly available subframe and time slot formats. The transceiver 620 can be configured to receive data and control channels.

[0067] Node 600 may include various computer-readable media. Computer-readable media may be any available media that can be accessed by node 600, and include volatile and non-volatile media, removable media, and non-removable media. By way of example and not limitation, computer-readable media may include computer storage media and communication media. Computer storage media include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or data.

[0068] Computer storage media include RAM, ROM, EEPROM, flash memory or other storage technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage device, magnetic cassette, magnetic tape, magnetic disk storage device or other magnetic storage device. Computer storage media do not contain propagated data signals. Communication media typically contain computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and include any information transmission media. The term "modulated data signal" refers to a signal: one or more of its characteristics is set or changed by encoding information in the signal. By way of example and not limitation, communication media include wired media, such as a wired network or a direct wired connection; and wireless media, such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media.

[0069] The memory 634 may include computer storage media in the form of volatile and / or non-volatile memory. The memory 634 may be removable, non-removable, or a combination thereof. Example memories include solid-state memory, hard drives, optical drives, etc. Figure 6As shown, the memory 634 can store computer-readable computer-executable instructions 632 (eg, software codes) configured to cause the processor 628 to perform the operations described herein, for example, with reference to Figures 1 to 5 Alternatively, the instructions 632 may not be directly executable by the processor 628, but may be configured to cause the node 600 (eg, when compiled and executed) to perform the various functions described herein.

[0070] The processor 628 (e.g., having processing circuitry) may include an intelligent hardware device, such as a central processing unit (CPU), a microcontroller, an ASIC, etc. The processor 628 may include a memory. The processor 628 may process data 630 and instructions 632 received from the memory 634, as well as information sent and received via the transceiver 620, the baseband communication module, and / or the network communication module. The processor 628 may also process information to be sent to the transceiver 620 for transmission to the network communication module via the antenna 636 for transmission to the core network.

[0071] One or more presentation components 638 present the data indication to a person or other device. Examples of presentation components 638 include display devices, speakers, printing components, and vibration components, etc.

[0072] In view of the present case, it is apparent that various techniques may be used to implement the concepts in the present application without departing from the scope of these concepts. In addition, although the concepts have been described with specific reference to certain embodiments, it will be appreciated by those of ordinary skill in the art that changes may be made in form and detail without departing from the scope of those concepts. Thus, the described embodiments are to be considered illustrative and not restrictive in all respects. It should also be understood that the present application is not limited to the above-mentioned specific embodiments, but that many rearrangements, modifications, and substitutions are possible without departing from the scope of the present case.

Claims

1. A user equipment UE, It is characterized in that The UE includes: a transceiver; one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and at least one processor coupled to the transceiver and to the one or more non-transitory computer-readable media, the at least one processor configured to execute the computer-executable instructions to: Receiving, by the transceiver, a first SCell beam failure recovery BFR configuration corresponding to a first secondary cell SCell, wherein the first SCell BFR configuration includes a resource list for a new beam identification NBI, the resource list indicating at least one NBI reference signal for BFR, each of the at least one NBI reference signal corresponding to a candidate beam, and the at least one NBI reference signal is received from a base station for BFR; Detecting a beam failure condition in the first SCell by measuring at least one beam failure detection (BFD) reference signal; Determine a first new candidate beam index for the first SCell from the resource list for NBI; and A beam failure recovery request is sent through the transceiver, where the beam failure recovery request includes a cell index of the first SCell in which the beam failure condition is detected and the determined first new candidate beam index.

2. The UE according to claim 1, It is characterized in that The resource list for NBI indicates an NBI reference signal received from a base station of the first SCell, and the NBI reference signal corresponds to a candidate beam.

3. The UE according to claim 1, It is characterized in that The resource list for NBI indicates an NBI reference signal received from a base station of another serving cell, the NBI reference signal corresponds to a candidate beam, and the first SCell and the another serving cell correspond to different component carriers.

4. The UE according to claim 1, It is characterized in that at least one processor, the at least one processor being further configured to execute the computer executable instructions to: When the first SCell BFR configuration does not include a resource list for BFD, the at least one BFD reference signal is determined based on at least one transmission configuration indicator TCI state of each control resource set CORESET for monitoring a physical downlink control channel PDCCH.

5. The UE according to claim 4, It is characterized in that The at least one BFD reference signal is received from a base station in the first SCell.

6. The UE according to claim 4, It is characterized in that The at least one BFD reference signal is received from a base station of another serving cell, and the first SCell is different from the another serving cell.

7. The UE according to claim 6, It is characterized in that The first SCell is cross-carrier scheduled by the other serving cell.

8. The UE according to claim 1, It is characterized in that The first SCellBFR configuration includes a resource list for BFD.

9. The UE according to claim 1, It is characterized in that The at least one BFD reference signal is configured in the resource list for BFD, and the at least one BFD reference signal is received from a base station in the first SCell.

10. The UE according to claim 1, It is characterized in that The at least one processor is further configured to execute the computer executable instructions to: An NBI reference signal is selected from the resource list for NBI included in the first SCell BFR configuration to determine the first new candidate beam index.

11. The UE according to claim 1, It is characterized in that The at least one processor is further configured to execute the computer executable instructions to: receiving a second SCell BFR configuration corresponding to a second SCell; The beam failure recovery request further includes a second cell index of the second SCell where the beam failure occurs and a second new candidate beam index for the second SCell.

12. A method for secondary cell (SCell) beam failure recovery (BFR) performed by a user equipment (UE), It is characterized in that The method comprises: receiving a first SCell BFR configuration corresponding to a first SCell, wherein the first SCell BFR configuration includes a resource list for a new beam identification NBI, the resource list indicating at least one NBI reference signal for BFR, each of the at least one NBI reference signal corresponding to a candidate beam, and the at least one NBI reference signal is received from a base station for BFR; Detecting a beam failure condition in the first SCell by measuring at least one beam failure detection (BFD) reference signal; Determine a first new candidate beam index for the first SCell from the resource list for NBI; and A beam failure recovery request is sent, wherein the beam failure recovery request includes a cell index of the first SCell in which the beam failure condition is detected and the determined first new candidate beam index.

13. The method according to claim 12, It is characterized in that The resource list for NBI indicates an NBI reference signal received from a base station of the first SCell, and the NBI reference signal corresponds to a candidate beam.

14. The method according to claim 12, It is characterized in that The resource list for NBI indicates an NBI reference signal received from a base station of another serving cell, and the NBI reference signal corresponds to a candidate beam; the reference signal corresponding to the determined first new candidate beam index is transmitted through the other cell, and the first SCell and the other serving cell correspond to different component carriers.

15. The method according to claim 12, It is characterized in that The method further comprises: When the first SCell BFR configuration does not include a resource list for BFD, the at least one BFD reference signal is determined based on at least one transmission configuration indicator TCI state of each control resource set CORESET for monitoring a physical downlink control channel PDCCH.

16. The method of claim 15, It is characterized in that The at least one BFD reference signal is received from a base station in the first SCell.

17. The method of claim 15, It is characterized in that The at least one BFD reference signal is received from a base station of another serving cell, and the first SCell and the another serving cell correspond to different component carriers.

18. The method of claim 12, It is characterized in that The first SCell BFR configuration includes a resource list for BFD.

19. The method of claim 18, It is characterized in that The at least one BFD reference signal is configured in the resource list for BFD, and the at least one BFD reference signal is received from a base station in the first SCell.

20. The method of claim 12, It is characterized in that The method further comprises: receiving a second SCell BFR configuration corresponding to a second SCell; The beam failure recovery request further includes a second cell index of the second SCell where the beam failure occurs and a second new candidate beam index for the second SCell.

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