Indication of synchronization signal block type for devices with reduced capabilities

Abstract

Methods, apparatuses, and systems related to indication of synchronization signal block (SSB) type for user equipment with reduced capabilities are disclosed. In one example aspect, a method for wireless communication includes transmitting, by a base station, system information to a terminal device. The system information indicates whether a cell-defined synchronization signal block (SSB) or a non-cell-defined SSB may be applicable to enabling a terminal device with reduction capability to perform measurements.

Description

Technical Field

[0001] This patent document relates to wireless communications. Background Art

[0002] Mobile communication technologies are driving the world towards an increasingly connected and networked society. The rapid development of mobile communications and technological advances have led to greater demands for capacity and connectivity. Other aspects such as energy consumption, equipment cost, spectrum efficiency, and latency are also important to meet the needs of various communication scenarios. Various technologies are currently being discussed, including new ways to provide higher quality of service, longer battery life, and improved performance. Summary of the invention

[0003] Among other things, this patent document describes techniques related to indicating a synchronization signal block (SSB) type for a disclosed user device having reduced capabilities.

[0004] In one example aspect, a method for wireless communication includes sending, by a base station to a terminal device, system information. The system information indicates whether a cell-defining synchronization signal block (SSB) or a non-cell-defining SSB is applicable to enable a terminal device with reduced capability to perform measurements.

[0005] In another example aspect, a method for wireless communication includes receiving, by a terminal device with reduced capabilities, system information from a base station indicating whether a cell-defined synchronization signal block (SSB) or a non-cell-defined SSB is applicable, and performing measurements using the cell-defined SSB or the non-cell-defined SSB based on the system information.

[0006] In another example aspect, a method for wireless communication includes receiving, by a base station, information indicating a reduced capability of a terminal device in a random access procedure.

[0007] In another example aspect, a method for wireless communication includes sending, by a terminal device to a base station, information indicating a reduced capability of the terminal device in a random access procedure.

[0008]

[0011] In another example aspect, a method for wireless communication includes sending, from a first node to a neighboring node, configuration information regarding a non-cell defining synchronization signal block (SSB).

[0009] In another exemplary aspect, a communication device is disclosed, wherein the device includes a processor configured to implement the above method.

[0010] In yet another example aspect, a computer program storage medium is disclosed. The computer program storage medium includes code stored thereon. When the code is executed by a processor, the processor implements the method.

[0011] This document describes these and other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 An example time-frequency structure of a synchronization signal block (SSB) is shown.

[0013] Figure 2A is a flow chart of a method for wireless communication in accordance with one or more embodiments of the present technology.

[0014] Figure 2B is a flow chart of another method for wireless communication in accordance with one or more embodiments of the present technology.

[0015] Figure 3A is a flow chart of another method for wireless communication in accordance with one or more embodiments of the present technology.

[0016] Figure 3B is a flow chart of another method for wireless communication in accordance with one or more embodiments of the present technology.

[0017] Figure 4 is a flow chart of another method for wireless communication in accordance with one or more embodiments of the present technology.

[0018] Figure 5 An example of a wireless communication system to which the technology may be applied according to one or more embodiments of the present technology is shown.

[0019] Figure 6 is a block diagram representation of a portion of a radio station to which one or more embodiments of the present technique may be applied. DETAILED DESCRIPTION

[0020] The section headings used in this document are intended to improve readability only and do not limit the scope of the embodiments and techniques disclosed in each section to that section. In addition, for ease of understanding, some embodiments are described with reference to the Third Generation Partnership Project (3GPP) New Radio (NR) standard ("5G"), and the described techniques may be implemented in different wireless systems that implement protocols other than the 5G protocol.

[0021] In wireless communications, a synchronization signal block (SSB) refers to a synchronization / physical broadcast channel (PBCH) block, which includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH demodulation reference signal (DMRS), and PBCH data. Figure 1An example time-frequency structure of an SSB is shown. The possible time positions of an SSB within a half-frame are determined by the subcarrier spacing, and the period of the half-frame over which the SSB is transmitted is configured by the network. Different SSBs may be transmitted in different spatial directions during a half-frame (e.g., using different beams, across the coverage of a cell). Multiple SSBs may be transmitted within the frequency span of a carrier. When an SSB is associated with the Remaining Minimum System Information (RMSI), the SSB is called a Cell Definition SSB (CD-SSB). The CD-SSB of the primary cell (PCell) is always located on the synchronization grid. For cell reselection based on intra-frequency measurements, the UE performs measurements based on the CD-SSB located on the synchronization grid. Early measurements are also based on the CD-SSB.

[0022] Research has identified some features to reduce the complexity of UEs and allow UEs with reduced capabilities to operate efficiently in a communication network. UEs with reduced capabilities are also called RedCap UEs. In order to enable RedCE to perform activities such as radio link monitoring (RLM), bidirectional forwarding detection (BFD), and / or serving cell measurements when the active bandwidth part (BWP) does not contain CD-SSB, non-cell defined SSB (NCD-SSB) has been introduced for RedCap UEs in a connected state (e.g., radio resource control (RRC) connected state).

[0023] Regarding whether NCD-SSB is used for RedCap UE in an inactive state (eg, RRC idle state or RRC inactive state), a separate initial BWP has been proposed and two solutions have been discussed.

[0024] Solution 1: An idle / inactive RedCap UE camps on a cell associated with a CD-SSB and receives paging and system information from the initial DL BWP. Upon access, the RedCap UE switches to a separate RedCap specific initial BWP. This solution has little impact on the current cell selection / reselection process. Specifically, intra-frequency cell reselection is still based on the frequency of the CD-SSB on which the UE is camping.

[0025] Scenario 2: An idle / inactive RedCap UE camps on a cell associated with an NCD-SSB, receives paging and performs access using a separate RedCap specific initial BWP. System information is obtained from the initial DL BWP associated with a CD-SSB, for example upon system information modification notification.

[0026] If NCD-SSB is configured for a RedCap UE in an inactive state using Scheme 2, the RedCap UE can use NCD-SSB for intra-frequency / inter-frequency measurements. However, there is a lack of indication of how different types of SSBs (e.g., CD-SSB, NCD-SSB) enable the RedCap UE to correctly receive system information blocks (SIBs) and function in other processes. This patent document discloses techniques that can be implemented in various embodiments, enabling UEs (particularly RedCap UEs) to perform intra-frequency and / or inter-frequency measurements based on NCD-SSB, and to indicate the use of NCD-SSB in the RACH process. Neighboring cells can also use these techniques to transmit information about the use of NCD-SSB.

[0027] Figure 2A 2 is a flowchart representation of a method for wireless communication according to one or more embodiments of the present technology. The method 200 includes, at operation 210, sending system information by a base station to a terminal device. The system information indicates whether a cell-defining synchronization signal block (SSB) or a non-cell-defining synchronization signal block is applicable to enable a terminal device with reduced capabilities to perform measurements.

[0028] Figure 2B is a flowchart representation of a method for wireless communication according to one or more embodiments of the present technology. The method 250 includes, at operation 260, receiving system information from a base station by a terminal device with reduced capabilities, the information indicating whether a cell-defined synchronization signal block (SSB) or a non-cell-defined SSB is applicable. The method 250 also includes, at operation 270, performing measurements using a cell-defined SSB or a non-cell-defined SSB based on the system information.

[0029] In some embodiments, the system information is transmitted in a system information block (SIB) for intra-frequency measurements. In some embodiments, the system information is transmitted in a SIB for inter-frequency measurements. In some embodiments, in response to non-cell defining SSBs being applicable, non-cell defining SSBs are associated with cell group resources.

[0030] Figure 3A is a flowchart representation of a method for wireless communication according to one or more embodiments of the present technology. The method 300 includes, at operation 310, receiving, by a base station, information indicating the following: a reduced capability of a terminal device in a random access procedure.

[0031] Figure 3B is a flowchart representation of a method for wireless communication according to one or more embodiments of the present technology. The method 350 includes, at operation 360, sending, by the terminal device to the base station, information indicating the following items: a reduced capability of the terminal device in a random access procedure.

[0032] In some embodiments, the use of dedicated resources of Msg1 for the random access procedure indicates reduced capabilities of the terminal device. In some embodiments, the information indicating the reduced capabilities is defined in a feature combination information element.

[0033] In some embodiments, the information indicating the reduced capability is transmitted in Msg3 of the random access procedure. For example, the information indicating the reduced capability may be transmitted in the logical channel identifier value of Msg3.

[0034] Figure 4 is a flowchart representation of a method for wireless communication according to one or more embodiments of the present technology. The method 400 includes, at operation 410, sending configuration information about a non-cell defining synchronization signal block (SSB) from a first node to a neighboring node.

[0035] In some embodiments, the configuration information includes at least one of the following: a carrier frequency for a non-cell-defined SSB, or an SSB type. In some embodiments, the configuration information is transmitted in at least one of the following: an access node configuration update confirmation message, an Xn setup response message, or an Xn setup request message.

[0036] Some examples of the disclosed technology are further described below.

[0037] Example 1

[0038] If NCD-SSB is configured for a RedCap UE in an inactive state using Scheme 2, both CD-SSB and NCD-SSB can be configured in the neighboring cell for cell selection. Therefore, neighboring cell measurements can be performed based on CD-SSB and / or NCD-SSB. Correct indication of the SSB type (e.g., CD-SSB or NCD-SSB) is required to allow the RedCap UE to perform neighboring cell measurements accordingly. In addition, when a cell is selected based on measurement results and / or cell reselection rules, if NCD-SSB is used for measurement, the UE needs to switch to the CD-SSB ARFCN to correctly receive the SIB. Therefore, the type of SSB (e.g., CD-SSB or NCD-SSB) needs to be indicated to the UE together with the CD-SSB ARFCN.

[0039] Currently, UE performs intra-frequency measurements based on CD-SSB located on the synchronization raster for cell reselection. When NCD-SSB is introduced for RedCap UE in RRC_IDLE / RRC_INACTIVE state, NCD-SSB in a separate initial DL BWP can be used for intra-frequency measurements. In some embodiments, NCD-SSB is configured in some neighboring cells so that NCD-SSB or CD-SSB can be used for cell reselection measurements.

[0040] In the NR communication system, system information block 3 (SIB3) provides neighboring cell information related to intra-frequency cell reselection, including cells with specific reselection parameters and blacklist cell information. Therefore, SSB types related to intra-frequency measurements can be included in SIB3. Table 1 shows example configuration information that can be included in SIB3.

[0041] Table 1

[0042]

[0043] The UE also performs inter-frequency measurements based on the CD-SSB located on the synchronization grid for cell reselection. In the NR communication system, system information block 4 (SIB4) provides information related to inter-frequency cell reselection, including information about other NR frequencies and inter-frequency neighboring cells related to cell reselection. It also includes cell reselection parameters that are common to the frequency and cell-specific reselection parameters. Therefore, the SSB type related to inter-frequency measurements can be included in SIB4. Table 2 shows example configuration information that can be included in SIB4.

[0044] Table 2

[0045]

[0046]

[0047] Example 2

[0048] When CD-SSB is used for intra-frequency measurement, inter-frequency measurement, and / or early measurement, neighbor cell information can be exchanged via inter-node messages. For example, CD-SSB can be transmitted in a MeasurementTimingConfiguration message, which is used to convey auxiliary information for measurement timing.

[0049] When NCD-SSB is configured for intra-frequency measurement, inter-frequency measurement, and / or early measurement, NCD-SSB related information also needs to be exchanged between the current serving cell and / or the camping cell. NCD-SSB related information includes at least one of NCD-SSBARFCN, period, and / or time offset. Table 3 shows an example of NCD-SSB information that can be transmitted in an inter-node message (e.g., MeasurementTimingConfiguration message).

[0050] Table 3

[0051]

[0052]

[0053] NCD-SSB related information can be transmitted in inter-node messages, which are exchanged between adjacent nodes. In particular, the Xn interface supports the exchange of signaling information between two radio access nodes (RAN). For example, NCB-SBB related information can be transmitted in the following messages (e.g., via MeasurementTimingConfiguration): RAN node configuration update confirmation message, Xn establishment response message, Xn establishment request message, other existing or new messages on the Xn interface.

[0054] Example 3

[0055] Currently, for the small data transfer (SDT) process based on configuration grant (CG), the CD-SSB is the SSB associated with the CG resources. If the NCD-SSB is configured in a separate initial DLBWP corresponding to the initial UL BWP configured with CG resources according to scheme 2 discussed above, appropriate indication is required to show that the NCD-SSB is the SSB associated with the CG resources.

[0056] In some embodiments, when certain conditions are met (e.g., SSB measurement results exceed a threshold), small data can be sent via CG resources in an RRC inactive state. Currently, only CD-SSB can be an SSB associated with CG resources. When NCD-SSB is configured in a separate initial DL BWP corresponding to the initial BWP configured for CG resources, NCD-SSB becomes an SSB associated with CG resources.

[0057] Example 4

[0058] In the random access (RACH) procedure, the NCD-SSB may be configured in a separate initial DL BWP corresponding to the initial UL BWP configured with RACH common resources. An appropriate indication is needed to show that the NCD-SSB is an SSB associated with a RACH opportunity.

[0059] In order to minimize the impact on existing UEs (e.g., non-RedCap UEs and / or legacy UEs with reduced capabilities), early identification of RedCap UEs is required in the RACH procedure (e.g., when the physical downlink shared channel (PDSCH) decoding time N1 and / or the physical uplink shared channel (PUSCH) preparation time N2 is relaxed). In addition, for RedCap UEs, a single UE type can be used in the identification / indication to further reduce complexity. In some embodiments, early identification of the new generation of RedCap UEs can be included in the RACH procedure messaging, such as Msg1 and / or Msg3. Some examples of Msg1 and / or Msg3 with RedCap UE identification are described below.

[0060] Example 1: Early identification of RedCap UE based on Msg1. In this example, the use of early RedCap UE identification in Msg1 (e.g., in a 4-step RACH procedure) or MSGA (e.g., in a 2-step RACH procedure) can be implicitly indicated by the presence of a dedicated RACH configuration or the use of dedicated RACH resources. For example, the presence of a dedicated RACH configuration associated with the RedCap UE in Msg1 indicates that the RACH resources are used by the RedCap UE. That is, the RedCap UE selects the dedicated RACH resources to send the preamble so that the base station knows that it is a RedCap UE. In some embodiments, there is an indication indicating whether the RACH resources can be used by the RedCap UE.

[0061] In some embodiments, the reserved / spare bits in the FeatureCombination Information Element (IE) of UE capabilities may be used to provide an indication of RedCap UE. Table 4 shows an example of RedCap UE indication in the FeatureCombination IE.

[0062] Table 4

[0063]

[0064] Example 2: Early identification of RedCap UE based on Msg3. In this example, the use of early RedCap UE identification can be included in Msg3 of the RACH procedure. For example, as shown in Table 5, when Msg3 includes common control channel (CCCH) data, the dedicated logical channel identifier (LCID) can include a value identifying the RedCap UE.

[0065] Table 5

[0066]

[0067] Figure 5 An example of a wireless communication system 500 is shown in which the technology according to one or more embodiments of the present technology can be applied. The wireless communication system 500 may include one or more base stations (BS) 505a, 505b, one or more wireless devices (or UEs) 510a, 510b, 510c, 510d, and a core network 525. The base stations 505a, 505b may provide wireless services to user equipment 510a, 510b, 510c, and 510d in one or more wireless sectors. In some embodiments, the base stations 505a, 505b include directional antennas to generate two or more directional beams to provide wireless coverage in different sectors. The core network 525 may communicate with one or more base stations 505a, 505b. The core network 525 provides connections with other wireless communication systems and wired communication systems. The core network may include one or more service subscription databases for storing information related to subscribed user equipment or terminal devices 510a, 510b, 510c, and 510d. The first base station 505a can provide wireless services based on a first radio access technology, and the second base station 505b can provide wireless services based on a second radio access technology. Depending on the deployment scheme, the base stations 505a and 505b can be co-located or can be installed on site separately. User equipment 510a, 510b, 510c, and 510d can support a variety of different radio access technologies. The techniques and embodiments described in this document can be implemented by a base station of a wireless device described in this document.

[0068] Figure 6605 is a block diagram representation of a portion of a radio station that can be applied according to one or more embodiments of the present technology. A radio station 605, such as a network node, a base station, or a wireless device (or user equipment, UE), may include a processor electronic device 610, such as a microprocessor, which may implement one or more wireless technologies introduced in this document. The radio station 605 may include a transceiver electronic device 615 for sending and / or receiving wireless signals through one or more communication interfaces such as an antenna 620. The radio station 605 may include other communication interfaces for sending and receiving data. The radio station 605 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some embodiments, the processor electronic device 610 may include at least a portion of the transceiver electronic device 615. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using the radio station 605. In some embodiments, the radio station 605 may be configured to perform the methods described herein.

[0069] The disclosed and other embodiments, modules and functional operations described in this document can be implemented in digital electronic circuits or computer software, firmware or hardware, including the structures disclosed in this document and their structural equivalents, or a combination of one or more structures therein. The disclosed and other embodiments can be implemented as one or more computer program products, that is, one or more computer program instruction modules encoded on a computer-readable medium for data processing devices to execute or control their operations. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a storage device, a combination of substances that affect machine-readable propagation signals, or a combination of one or more of them. The term "data processing device" includes all devices, equipment and machines for processing data, such as programmable processors, computers or multiple processors or computers. In addition to hardware, the device may include code that creates an execution environment for the computer program in question, such as code that constitutes processor firmware, protocol stacks, database management systems, operating systems, or a combination of one or more of these systems. A propagation signal is an artificially generated signal, such as a machine-generated electrical signal, optical signal, or electromagnetic signal, which is generated to encode information for transmission to a suitable receiving device.

[0070] A computer program (also referred to as a program, software, software application, script, or code) may be written in any form of programming language, including compiled or interpreted languages, and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or portions of code). A computer program may be deployed to execute on one computer, or may be deployed to execute on multiple computers, which may be located at the same location, or may be distributed across multiple locations and interconnected by a communications network.

[0071] The processes and logic flows described in this document can be performed by one or more programmable processors that execute one or more computer programs to perform functions by operating input data and generating outputs. These processes and logic flows can also be performed by dedicated logic circuits, and the device can also be implemented as a dedicated logic circuit, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). For example, processors suitable for executing computer programs include both general-purpose and special-purpose microprocessors, and one or more processors of any kind of digital computer. In general, the processor will receive instructions and data from a read-only memory or a random access memory or both. The basic elements of a computer are a processor for executing instructions and one or more storage devices for storing instructions and data. In general, a computer also includes one or more large-capacity storage devices for storing data, such as a disk, a magneto-optical disk, or an optical disk, or is operatively coupled thereto to receive data from it or transmit data to it, or both. However, a computer does not necessarily need these devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and storage devices, including, for example, semiconductor memory devices, such as EPROM, EEPROM and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory may be supplemented or integrated with special purpose logic circuits.

[0072] Although this patent document contains many details, these details should not be construed as limitations on the scope of any invention or what may be claimed, but rather as descriptions of specific features of particular embodiments of particular inventions. Certain features described in this patent document in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. In addition, although the features described above may work in certain combinations and may even be initially claimed to work in this way, in some cases one or more features in the claimed combination may be deleted from the combination, and the claimed combination may be directed to a sub-combination or a variation of the sub-combination.

[0073] Similarly, although the operations are depicted in a particular order in the figures, this should not be understood as requiring that the operations be performed in the specific order shown or in a sequential order, or that all illustrated operations be performed to achieve the desired results. In addition, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

[0074] Only a few embodiments and examples are described, and other embodiments, improvements, and variations are possible based on what is described and illustrated in this patent document.

Claims

1. A method for wireless communication, comprising: The base station sends system information to the terminal device. Wherein the system information indication is a cell-defining synchronization signal block (SSB) or a non-cell-defining synchronization signal block applicable to enable the terminal device with reduced capability to perform measurements, and wherein the cell-defining SSB is an SSB associated with remaining minimum system information (RMSI).

2. A method for wireless communication, comprising: receiving, by a terminal device with reduced capability, system information from a base station, the system information indicating whether a cell-defining synchronization signal block (SSB) or a non-cell-defining SSB is applicable, wherein the cell-defining SSB is an SSB associated with remaining minimum system information (RMSI); as well as Based on the system information, measurement is performed using the cell-defining SSB or the non-cell-defining SSB.

3. The method according to any one of claims 1 or 2, wherein the system information is transmitted in a system information block (SIB) for intra-frequency measurements.

4. The method according to any one of claims 1 to 3, wherein the system information is transmitted in a SIB for inter-frequency measurements.

5. The method according to any one of claims 1 to 4, wherein in response to the non-cell defining SSB being applicable, the non-cell defining SSB is associated with a cell group resource.

6. A method for wireless communication, comprising: Information indicating a reduced capability of a terminal device during a random access procedure is received by a base station.

7. A method for wireless communication, comprising: Information indicating the following items is sent by the terminal device to the base station: the reduced capability of the terminal device during the random access process.

8. The method according to claim 6 or 7, wherein the use of dedicated resources for Msg1 of the random access procedure indicates a reduced capability of the terminal device.

9. The method of claim 8, wherein the information indicative of the reduced capability is defined in a feature combination information element.

10. The method according to claim 6 or 7, wherein the information indicating the reduced capability is transmitted in Msg3 of the random access procedure.

11. The method according to claim 10, wherein the information indicating the reduced capability is transmitted in a logical channel identifier value of the Msg3.

12. A method for wireless communication, comprising: Configuration information about a non-cell defining synchronization signal block (SSB) is sent from a first node to a neighboring node, wherein the non-cell defining SSB is an SSB that is not associated with remaining minimum system information (RMSI).

13. The method of claim 12, wherein the configuration information comprises at least one of: a carrier frequency for the non-cell defining SSB, or an SSB type.

14. The method of claim 12, wherein the configuration information is transmitted in at least one of the following messages: an Access Node Configuration Update Confirmation message, an Xn Setup Response message, or an Xn Setup Request message.

15. A communication device comprising a processor configured to implement the method according to any one or more of claims 1 to 14.

16. A computer program product having codes stored thereon, which, when executed by a processor, cause the processor to implement the method according to any one or more of claims 1 to 14.

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