Method and device for variably applying SSB in next generation mobile communication

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. The disclosure provides a device and a method enabling effective provision of a service in a mobile communication system, the method comprising operations in which a terminal: receives, from a base station in a wireless communication system, a radio resource control (RRC) message for configuring a list of a plurality of synchronization signal block (SSB) periods; receives a first SSB corresponding to a first period from the base station; receives, from the base station, downlink control information (DCI) including information indicating a second period among the plurality of SSB periods; and receives a second SSB corresponding to the second period from the base station.

Description

Method and device for variably applying SSB in next-generation mobile communications

[0001] The present disclosure relates to the operation of a terminal and a base station in a mobile communication system. Specifically, the present disclosure relates to a method for transmitting SSB in a wireless communication system and a device capable of doing so.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] The disclosed embodiment seeks to provide a device and method capable of effectively providing a service in a mobile communication system.

[0009] The present invention, in order to solve the above problems, is characterized by a method for processing a control signal in a wireless communication system, comprising: a step of receiving a first control signal transmitted from a base station; a step of processing the received first control signal; and a step of transmitting a second control signal generated based on the processing to the base station.

[0010] The disclosed embodiment provides a device and method capable of effectively providing a service in a mobile communication system.

[0011] FIG. 1 is a diagram illustrating the structure of a next-generation mobile communication system according to one embodiment of the present disclosure.

[0012] FIG. 2 is a diagram for explaining a wireless connection state transition in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0013] FIG. 3 is a flowchart of a process for receiving SSB period information in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0014] FIG. 4 is a diagram for explaining the relationship between the SSB cycle and the power consumption of the network in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0015] FIG. 5 is a diagram illustrating an example of a method for dynamically changing an SSB cycle in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0016] FIG. 6 is a flowchart illustrating an example of a method for dynamically changing an SSB cycle in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0017] FIG. 7 is a diagram illustrating another example of a method for dynamically changing an SSB periodic pattern in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0018] FIG. 8 is a flowchart illustrating an example of a method for dynamically changing an SSB periodic pattern in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0019] FIG. 9 is a flowchart showing an example of a terminal operation for dynamically changing an SSB period or period pattern in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0020] FIG. 10 is a flowchart illustrating an example of a base station operation that dynamically changes an SSB period or period pattern in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0021] FIG. 11 is a block diagram illustrating the internal structure of a terminal according to one embodiment of the present disclosure.

[0022] FIG. 12 is a block diagram showing the configuration of a base station according to one embodiment of the present disclosure.

[0023] In the following description of the present invention, detailed descriptions of known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present invention. Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.

[0024] FIG. 1 is a diagram illustrating the structure of a next-generation mobile communication system according to one embodiment of the present disclosure.

[0025] Referring to FIG. 1, as illustrated, a wireless access network of a next-generation mobile communication system (New Radio, NR) is composed of a next-generation base station (New Radio Node B, hereinafter referred to as gNB) (110) and an access and mobility management function (AMF) (105) (e.g., New Radio Core Network). A user terminal (New Radio User Equipment) (hereinafter referred to as NR UE or terminal) (115) connects to an external network through the gNB (110) and the AMF (105).

[0026] In Figure 1, the gNB corresponds to the eNB (Evolved Node B) of the existing LTE system. The gNB is connected to the NR UE via a wireless channel and can provide superior service than the existing Node B (120). In the next-generation mobile communication system, all user traffic is serviced through a shared channel, so a device that collects status information such as the buffer status of the UEs, the available transmission power status, and the channel status and performs scheduling is required, and this is handled by the gNB (110). A single gNB typically controls multiple cells. In order to implement ultra-high-speed data transmission compared to the existing LTE, it can have a bandwidth higher than the existing maximum, and beamforming technology can be additionally incorporated using the orthogonal frequency division multiplexing (OFDM) as a wireless access technology. In addition, the adaptive modulation and coding (AMC) method is applied, which determines the modulation scheme and channel coding rate according to the channel status of the terminal. The AMF (105) performs functions such as mobility support, bearer setup, and QoS setup. The AMF is a device that handles various control functions as well as mobility management functions for terminals and is connected to multiple base stations. In addition, the next-generation mobile communication system can be interoperable with the existing LTE system, and the AMF is connected to the mobility management entity (MME) (125) via a network interface. The MME is connected to the existing base station, the eNB (130). Terminals that support LTE-NR Dual Connectivity can transmit and receive data while maintaining a connection to both the gNB and the eNB (135).

[0027] FIG. 2 is a diagram for explaining a wireless connection state transition in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0028] In next-generation mobile communication systems, three radio access states (RRC states) can be defined. Connected mode (RRC_CONNECTED) (205) is a radio access state in which the terminal can transmit and receive data. Idle mode (RRC_IDLE) (230) is a radio access state in which the terminal monitors whether paging is being transmitted to itself. These two modes are radio access states also applicable to existing LTE systems, and the detailed technology is identical to that of the existing LTE system. In next-generation mobile communication systems, an inactive (RRC_INACTIVE) radio access state (215) is newly defined. In this radio access state, the UE context is maintained between the base station and the terminal, and RAN-based paging is supported. The characteristics of this new radio access state are listed below.

[0029] - Cell re-selection mobility;

[0030] - CN - NR RAN connection (both C / U-planes) has been established for UE;

[0031] - The UE AS context is stored in at least one gNB and the UE;

[0032] - Paging is initiated by NR RAN;

[0033] - RAN-based notification area is managed by NR RAN;

[0034] - NR RAN knows the RAN-based notification area which the UE belongs to;

[0035] A new INACTIVE wireless connection state can be transitioned from a connected mode or a standby mode using a specific procedure. The transition from INACTIVE mode to a connected mode is performed through a Resume procedure, and the transition from a connected mode to INACTIVE mode is performed through a Release procedure including suspend configuration information (210). The procedure involves transmitting and receiving one or more RRC messages between a terminal and a base station, and consists of one or more steps. Furthermore, the transition from INACTIVE mode to a standby mode can be performed through a Release procedure after Resume (220). The transition between the connected mode and the standby mode can follow existing LTE technology. That is, the transition between the modes can be performed through an establishment or release procedure (225).

[0036] FIG. 3 is a flowchart of a process in which a terminal receives SSB period information in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0037] The terminal can measure the reference signal broadcast by the serving cell in the downlink to determine the status of the wireless channel provided by the serving cell and synchronize time with the serving cell. In the next-generation mobile communication system, a representative downlink reference signal is the Synchronization Signal Block (SSB). The base station (310) can provide the periodic information of the SSB to the terminal (305) through system information (SI) or dedicated RRC signaling. For example, the base station can include the ssb-PeriodicityServingCell field indicating SSB periodic information in the ServingCellConfigCommonSIB IE, which is a parameter stored in SIB1 (315). As shown in Table 1 below, the base station can set the SSB period from 5 ms to a maximum of 160 ms through the field. The SSB indicated in SIB1 is the CD (Cell Defining)-SSB of the PCell. The CD-SSB means the representative SSB of a serving cell. That is, whether a terminal can detect a serving cell may depend on the measurement results of the CD-SSB corresponding to the serving cell. Considering the above configuration information, the terminal measures the CD-SSB of the PCell (320). The terminal may also measure the CD-SSB through blind detection and derive the CD-SSB cycle.

[0038]

[0039] The base station can provide the terminal with periodic information on the (N)CD-SSB of the serving cell or the CD-SSB of the target PCell for handover using a predetermined RRC message as shown in Table 2 below (325). Taking the above configuration information into account, the terminal can measure the (N)CD-SSB of the serving cell or the CD-SSB of the target PCell for handover (330).

[0040]

[0041] Among the configuration information for cell measurement of the terminal, the measObjectNR IE may also include SSB cycle information.

[0042] Transmission of SSB can mean power consumption of the base station. That is, transmitting SSB at a 5ms period can cause more power consumption of the base station than transmitting SSB at a 160ms period. Therefore, if the BS sets the SSB period to a long broadcast period and has low variability in the wireless channel, the base station's power can be saved. However, if the base station changes the SSB period information, an SI update or an RRC reconfiguration is required, so changing the SSB period information causes a signaling burden and a time-consuming reconfiguration procedure. For example, if certain information contained in the SI is changed, the base station can trigger an SI update procedure. To this end, the base station transmits a short message indicating an SI update at each paging occasion during one modification period, and the terminal that receives this message receives an SI message containing the updated information starting from the next modification period. Since RRC reconfiguration also requires a certain processing time, it may require a somewhat longer configuration change time than L1 / L2 signaling-based control. Various embodiments according to the present disclosure propose a method of pre-configuring multiple SSB periods or multiple SSB patterns and dynamically changing the applied SSB period by considering the wireless channel conditions and base station power consumption using L1 / L2 signaling or short messages.

[0043] FIG. 4 is a diagram for explaining the relationship between the SSB cycle and the power consumption of the network in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0044] The criteria for determining the SSB (405) period may vary depending on the implementation of the base station. However, considering the purpose of introducing SSB, the base station may determine the period based on the degree of variability in the wireless channel conditions. For example, in an environment where the wireless channel conditions change rapidly, the base station may transmit an SSB with a shorter period (410) so that the terminal receiving it can recognize the rapidly changing channel conditions. On the other hand, in an environment where the wireless channel conditions change slowly, there is no need to transmit an SSB with a short period (415). The SSB period affects the amount of power consumed by the base station. A shorter SSB period means that SSBs must be transmitted more frequently. Therefore, dynamically changing the SSB period according to the aforementioned communication / channel environment can help save the power consumption of the base station. To dynamically change the SI period, a method for changing the SI period more efficiently than before is required.

[0045] FIG. 5 is a diagram illustrating an example of a method for dynamically changing an SSB cycle in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0046] According to one embodiment of the present disclosure, a base station can set multiple SSB cycle values ​​to a terminal and dynamically indicate one cycle value to be applied among the preset SSB cycle values ​​through L1 / L2 signaling or a short message.

[0047] A terminal that is turned on can receive an SSB (520) broadcast from a serving cell through blind detection (505). At this time, the terminal can also determine the SSB cycle (525).

[0048] The terminal can obtain information on a predetermined number of SSB cycle values ​​through SI or dedicated RRC signaling provided by the base station (510). At this time, the base station can indicate the currently applied SSB cycle value to the terminal through SI or dedicated RRC signaling. The terminal can confirm the SSB cycle through the explicitly indicated SSB cycle information.

[0049] The base station can indicate to the terminal the SSB cycle value to be applied from a predetermined point in time through L1 / L2 signaling or a Short Message (515). After the predetermined point in time, the base station broadcasts the SSB by applying the updated SSB cycle (530). For example, the predetermined point in time may be the point in time when the terminal receives the L1 / L2 signaling or the Short Message, or the point in time when the next SI Modification Period of the SI Modification Period corresponding to the point in time when the terminal receives the L1 / L2 signaling or the Short Message starts. According to one embodiment of the present disclosure, the conventional SI Modification Period may be reused for the above purpose (to apply the updated SSB cycle), and a new Modification Period may be introduced to determine the SSB application point in time.

[0050] FIG. 6 is a flowchart illustrating an example of a method for dynamically changing an SSB cycle in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0051] The terminal (605) can receive MIB and SIB1 from the base station (610) (615, 620). In order to prevent terminals that do not support dynamic SIB adaptation according to an embodiment of the present disclosure from camping on the serving cell of the base station, the base station can set the cellBarred field contained in the MIB it broadcasts to 'notBarred'. A new cellBarred field can be introduced in SIB1 to cell barrine terminals that support dynamic SIB adaptation.

[0052] SIB1 may include information on multiple SSB periods. In addition to the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field) used to indicate the SSB period, a field or IE (Information Element) indicating additional SSB periods may be added. In this case, one of the multiple SSB period values ​​may be considered a default value. For example, the SSB period value indicated by the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field) or the SSB period value indicated by a predetermined indicator may be the default value. The new SSB period values ​​according to one embodiment of the present disclosure may be defined as a predetermined value in units of ms or may be indicated as a scaling factor compared to a predetermined reference SSB period value. The reference SSB period value can be an SSB period value indicated by the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field), a predefined SSB period value, or an SSB period value set by a predetermined indicator. The plurality of SSB period values ​​set above are in a multiple relationship, and the offset values ​​that determine the start point of the period can be the same. For example, if the reference SSB period value is 5 ms, other SSB period values, 10 ms, 20 ms, can be set by indicating scaling factors 2 and 4. For compatibility with existing terminals, the SSB period value indicated by the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field) that existing terminals can understand can be set to the longest value among the set SSB period values.The new SSB period values ​​according to one embodiment of the present disclosure, provided through SIB1, can be instructed / set to the terminal per Cell Group (CG), per serving cell, per BWP, or per (N)CD-SSB.

[0053] The terminal may report its capability information to the base station (625). The terminal capability information may include an indicator indicating that the terminal can support the function of dynamically applying the SSB cycle according to one embodiment of the present disclosure.

[0054] The base station can set information about the multiple SSB periods described above to the terminal through a predetermined RRC message (630). In addition to the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field) used to indicate the SSB period, a field or IE (Information Element) indicating additional SSB periods may be added. In addition, when the terminal receives the RRC message, the SSB period value to be applied may be set. Alternatively, when the terminal receives the RRC message, the terminal first applies the SSB period indicated in the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field). Among the multiple SSB period values, one may be considered a default value. For example, the SSB periodicity value indicated by the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field) or the SSB periodicity value indicated by a predetermined indicator may be the default value. The new SSB periodicity values ​​according to one embodiment of the present disclosure may be defined as a predetermined value in ms or indicated by a scaling factor compared to a predetermined reference SSB periodicity value. The reference SSB periodicity value may be the SSB periodicity value indicated by the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field), or a predefined SSB periodicity value or an SSB periodicity value set by a predetermined indicator. The plurality of SSB periodicity values ​​set are in a multiple relationship, and the offset values ​​that determine the start point of the period may be the same. For example, if the reference SSB periodicity value is 5 ms, other SSB periodicity values, 10 ms and 20 ms, may be set by being indicated by scaling factors 2 and 4.For compatibility with existing terminals, the SSB period value indicated in the conventional ssb-PeriodicityServingCell field (or ssb-Periodicity field) that existing terminals can understand may be set to the longest value among the SSB period values ​​set above. The new SSB period values ​​according to an embodiment of the present disclosure provided through the predetermined RRC message may be proposed to the terminal by Cell Group (CG), serving cell, BWP, or (N)CD-SSB. In the connected mode, the terminal receives data transmission and reception service by changing the BWP (bandwidth part), and when the BWP is changed, a predetermined period among a plurality of SSB period values ​​corresponding to the changed BWP may be applied.

[0055] According to various embodiments, the SSB periodic values ​​set to the terminal via the aforementioned SIB1 or RRC message may include periodic values ​​only for NCD-SSB. For example, information regarding multiple periodic values ​​may include periodic values ​​for transmitting the NCD-SSB of the PCell or the NCD-SSB of the SCell.

[0056] The base station can indicate to the terminal the periodic value of the SSB to be applied from a predetermined point in time through L1 / L2 signaling or a Short Message (635). The base station can transmit the L1 / L2 signaling or the Short Message one or more times / multiple times during a predetermined SI Modification Period (640). In order to indicate to the terminal the periodic value of the SSB to be applied, the base station can provide the terminal with an index value or a scaling factor value corresponding to the SSB periodic value. According to various embodiments, the SSB periodic value indicated to the terminal through the above-described L1 / L2 signaling or Short Message may include a periodic value for only the NCD-SSB. For example, information about the indicated periodic value may include a periodic value for transmitting the NCD-SSB of the PCell or the NCD-SSB of the SCell.

[0057] After the predetermined point in time, the terminal receives SSB by applying the updated SSB cycle (645). The predetermined point in time may be the point in time when the terminal receives L1 / L2 signaling or a Short Message, or the point in time when the next SI Modification Period of the SI Modification Period (640) corresponding to the point in time when the terminal receives L1 / L2 signaling or a Short Message starts. The existing SI Modification Period may be reused for the above purpose (to apply the updated SSB cycle), and a new Modification Period may be introduced to determine the SSB application time. The applied SSB cycle value may be considered valid until the base station sets a new SSB cycle value or receives an indicator for releasing the applied SSB cycle. If the terminal receives an indicator for releasing the SSB cycle, the terminal may apply the default SSB cycle value. Alternatively, when the terminal receives L1 / L2 signaling or a Short Message indicating the SSB cycle value to be applied, the terminal may start a predetermined timer, and the terminal may consider the indicated SSB cycle value to be valid until the timer expires. While applying the updated SSB cycle, the terminal may apply cell measurement requirements corresponding to the updated cycle.

[0058] In the cell measurement operation performed by the terminal, the measObjectNR IE used by the base station to provide frequency information may also include information on the period of SSB applied to measure the frequency corresponding to the IE. Since the period of SSB may change dynamically, in this case, the base station may set the terminal to include information on multiple SSB periods for each frequency corresponding to the IE or for each cell belonging to the frequency. The base station may indicate to the terminal the period value of SSB applied from a predetermined time point through L1 / L2 signaling or a short message.

[0059] FIG. 7 is a diagram illustrating another example of a method for dynamically changing an SSB periodic pattern in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0060] According to one embodiment of the present disclosure, a base station can set a plurality of SSB periodic patterns to a terminal, and immediately after setting, indicate to the terminal one pattern to be applied among the preset SSB periodic patterns through L1 / L2 signaling or a short message.

[0061] A terminal that is turned on can receive an SSB (720) broadcast from a serving cell through blind detection (705). At this time, the terminal can also determine the SSB cycle (725).

[0062] A terminal can obtain a predetermined number of SSB periodic pattern information through SI or dedicated RRC signaling provided from a base station (710). An SSB periodic pattern can be composed of one or more SSB periodic values ​​(740, 745) and time interval values ​​(730, 735) to which the period is applied. At this time, the base station can indicate the currently applied SSB periodic pattern value to the terminal through the SI or dedicated RRC signaling. The terminal can confirm the SSB periodic pattern through the explicitly indicated SSB periodic pattern information.

[0063] The base station can instruct the terminal about the SSB periodic pattern to be applied from a predetermined point in time through L1 / L2 signaling or a Short Message (715). From the predetermined point in time, the base station can broadcast SSB by applying the updated SSB periodic pattern. For example, the predetermined point in time may be the point in time when the terminal receives L1 / L2 signaling or a Short Message, or the point in time when the next SI Modification Period of the SI Modification Period corresponding to the point in time when the terminal receives L1 / L2 signaling or a Short Message starts. Alternatively, the terminal can receive the SSB by considering the SSB periodic pattern immediately or from a predetermined point in time after receiving the pattern information. According to one embodiment of the present disclosure, the conventional SI Modification Period may be reused for the purpose (to apply the updated SSB period), and a new Modification Period may be introduced to determine the SSB application point in time.

[0064] FIG. 8 is a flowchart illustrating an example of a method for dynamically changing an SSB periodic pattern in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0065] The terminal (805) can receive MIB and SIB1 from the base station (810) (815, 820). In order to prevent terminals that do not support dynamic SIB adaptation according to an embodiment of the present disclosure from camping on the serving cell of the base station, the base station can set the cellBarred field contained in the MIB it broadcasts to 'notBarred'. A new cellBarred field can be introduced in SIB1 to cell barrine terminals that support dynamic SIB adaptation.

[0066] SIB1 may include information on multiple SSB periodic patterns. Among the multiple SSB periodic patterns, one may be considered a default value. An SSB periodic pattern value indicated by a predetermined indicator may be the default value. An SSB periodic pattern may be composed of one or more SSB periodic values ​​and time interval values ​​to which the period is applied. The SSB periodicity and time interval may be indicated in absolute time units (e.g., ms) or slot units. New SSB periodic patterns according to an embodiment of the present disclosure provided through SIB1 may be indicated / configured to a UE by Cell Group (CG), by serving cell, by bandwidth part (BWP), or by (N)CD-SSB.

[0067] The terminal may report its capability information to the base station (825). The terminal capability information may include an indicator indicating that the terminal can support the function of dynamically applying SSB periodic patterns according to one embodiment of the present disclosure.

[0068] The base station can set the plurality of SSB periodic pattern information described above to the terminal through a predetermined RRC message (830). The SSB periodic pattern can be composed of one or more SSB periodic values ​​and time interval values ​​to which the period is applied. The SSB periodicity and time interval can be indicated in absolute time units (e.g., ms) or slot units. When indicated in slot units, the length of the slot can be the slot length applied to a cell (or a predetermined BWP of the cell) in which an SSB according to the SSB periodicity pattern is transmitted. The new SSB periodicity values ​​according to an embodiment of the present disclosure provided through a predetermined RRC message can be indicated / set to the terminal by Cell Group (CG), serving cell, BWP, or (N)CD-SSB.

[0069] According to various embodiments, the information about SSB periodic patterns set to the terminal via the aforementioned SIB1 or RRC message may also include information about periodic patterns exclusively for NCD-SSB. For example, the information about multiple periodic patterns may include periodic patterns for transmitting NCD-SSB of a PCell or NCD-SSB of an SCell.

[0070] The base station can indicate to the terminal the periodic pattern of SSB to be applied from a predetermined time point through L1 / L2 signaling or Short Message (835). The base station can transmit L1 / L2 signaling or Short Message one or more times / multiple times during a predetermined SI Modification Period (840). In order to indicate to the terminal the periodic pattern of SSB to be applied, the base station can provide the terminal with an index value corresponding to the SSB periodic pattern. According to various embodiments, the periodic pattern of SSB indicated to the terminal through the above-described L1 / L2 signaling or Short Message may include a periodic pattern for NCD-SSB only. For example, information about the indicated periodic pattern may include a periodic pattern for transmitting NCD-SSB of PCell or NCD-SSB of SCell.

[0071] After the above-described predetermined point in time, the terminal can receive SSB by applying the updated SSB periodic pattern (845). The above-described predetermined point in time may be the point in time when the terminal receives L1 / L2 signaling or a Short Message, or the point in time when the next SI Modification Period of the SI Modification Period (840) corresponding to the point in time when the terminal receives L1 / L2 signaling or a Short Message starts. The existing SI Modification Period may be reused for the above-described purpose (to apply the updated SSB periodic pattern), and a new Modification Period may be introduced to determine the point in time when the SSB periodic pattern is applied.

[0072] The applied SSB periodic pattern may be considered valid until the base station sets a new SSB periodic pattern or receives an indication to release the applied SSB periodic pattern. When the terminal receives an indication to release the SSB periodic pattern, the terminal applies the default SSB periodic pattern. Alternatively, when the terminal receives L1 / L2 signaling or Short Message indicating the SSB periodic pattern to be applied, the terminal may start a predetermined timer, and the terminal may consider the indicated SSB periodic pattern to be valid until the timer expires. The terminal may apply the cell measurement requirements corresponding to the period while applying the updated SSB periodic pattern.

[0073] In the cell measurement operation performed by the terminal, the measObjectNR IE used by the base station to provide frequency information may also include periodic information of the SSB applied to measure the frequency corresponding to the IE. Since the SSB may also be broadcast with a predetermined periodic pattern, the measObjectNR IE may also include periodic pattern information of the SSB measured by the terminal. In the cell measurement operation performed by the terminal, the measObjectNR IE used by the base station to provide frequency information may also include periodic pattern information of the SSB applied to measure the frequency corresponding to the IE. Since the periodic pattern of the SSB may also change dynamically, in this case, the base station may include multiple SSB periodic pattern information in the IE for each frequency corresponding to the IE or for each cell belonging to the frequency and configure it for the terminal. The base station may indicate to the terminal the periodic pattern of the SSB applied from a predetermined time point through L1 / L2 signaling or a short message.

[0074] Since the CD-SSB of the PCell must be received by terminals in standby and inactive modes as well as in connected mode, in embodiments of the present disclosure, a short message may be used to change the SSB period or periodic pattern of the CD-SSB of the PCell applied by the base station from a predetermined point in time. On the other hand, L1 or L2 signaling may be used to change the SSB period or periodic pattern of the NCD-SSB of the PCell or the (N)CD-SSB of the SCell.

[0075] Since the Short Message has 4 reserved bits, there may be limitations in indicating a large number of SSB cycles. Therefore, for the PCell's CD-SSB, a limited number of SSB cycle values ​​can be set.

[0076] In embodiments of the present disclosure, L2 signaling means a predetermined MAC (medium access control) CE (control element), and the MAC CE can store an index value or scaling factor of a period or period pattern of SSB applied from a predetermined point in time.

[0077] FIG. 9 is a flowchart illustrating an example of terminal operations for dynamically changing an SSB cycle or cycle pattern in a next-generation mobile communication system according to an embodiment of the present disclosure. Among the steps disclosed in FIG. 9, processes that overlap with those disclosed in FIGS. 3 to 8 may be omitted and described.

[0078] In operation 905, the terminal can receive system information from the base station.

[0079] In operation 910, the terminal can obtain information about multiple SSB cycles or cycle patterns stored in the received system information.

[0080] In operation 915, the terminal may report its capability information to the base station. The capability information may include an indicator indicating that the terminal has the capability to measure using a dynamically changing SSB cycle or cycle pattern.

[0081] In operation 920, the terminal may receive a predetermined RRC message from the base station including information about multiple SSB periods or period patterns.

[0082] In operation 925, the terminal may receive a predetermined L1 / L2 signaling or short message from the base station. The control signal (the predetermined L1 / L2 signaling or short message) may include information indicating an SSB cycle or cycle pattern that the terminal should apply from a predetermined point in time.

[0083] In operation 930, the terminal can apply a changed SSB cycle or cycle pattern from a predetermined point in time and receive an SSB corresponding to the changed SSB cycle or cycle pattern.

[0084] In operation 935, the terminal may apply Radio Resource Management (RRM) measurement requirements corresponding to the applied SSB cycle, if necessary.

[0085] FIG. 10 is a flowchart illustrating an example of base station operations for dynamically changing SSB cycles or cycle patterns in a next-generation mobile communication system according to an embodiment of the present disclosure. Among the steps disclosed in FIG. 10, processes that overlap with those disclosed in FIGS. 3 to 8 may be omitted and described.

[0086] In operation 1005, the base station may broadcast system information including information about multiple SSB cycles or cycle patterns.

[0087] In operation 1010, the base station may receive certain capability information from the terminal. The capability information may include an indicator indicating that the terminal has the capability to measure using a dynamically changing SSB cycle or cycle pattern.

[0088] In operation 1015, the base station may transmit to the terminal a predetermined RRC message including information about multiple SSB periods or periodic patterns.

[0089] In operation 1020, the base station may transmit to the terminal a predetermined L1 / L2 signaling or short message containing information indicating the SSB cycle or cycle pattern to be applied by the terminal from a predetermined point in time.

[0090] In operation 1025, the base station can broadcast SSB with a changed SSB period or period pattern from a predetermined point in time.

[0091] Figure 11 is a block diagram showing the internal structure of a terminal to which the present invention is applied.

[0092] Referring to the above drawing, the terminal includes an RF (Radio Frequency) processing unit (1110), a baseband processing unit (1120), a storage unit (1130), and a control unit (1140).

[0093] The RF processing unit (1110) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1110) up-converts the baseband signal provided from the baseband processing unit (1120) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1110) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. In the drawing, only one antenna is illustrated, but the terminal may be equipped with multiple antennas. In addition, the RF processing unit (1110) may include multiple RF chains. Furthermore, the RF processing unit (1110) may perform beamforming. For the above beamforming, the RF processing unit (1110) can adjust the phase and size of each signal transmitted and received through multiple antennas or antenna elements. In addition, the RF processing unit can perform MIMO, and can receive multiple layers when performing the MIMO operation.

[0094] The baseband processing unit (1120) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (1120) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (1120) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (1110). For example, in the case of following the OFDM (orthogonal frequency division multiplexing) method, when transmitting data, the baseband processing unit (1120) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by performing an inverse fast Fourier transform (IFFT) operation and inserting a cyclic prefix (CP). In addition, when receiving data, the baseband processing unit (1120) divides the baseband signal provided from the RF processing unit (1110) into OFDM symbol units, restores signals mapped to subcarriers through FFT (fast Fourier transform) operation, and then restores the received bit string through demodulation and decoding.

[0095] The baseband processing unit (1120) and the RF processing unit (1110) transmit and receive signals as described above. Accordingly, the baseband processing unit (1120) and the RF processing unit (1110) may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. Furthermore, at least one of the baseband processing unit (1120) and the RF processing unit (1110) may include a plurality of communication modules to support a plurality of different wireless access technologies. In addition, at least one of the baseband processing unit (1120) and the RF processing unit (1110) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (e.g., IEEE 802.11), a cellular network (e.g., LTE), etc. Additionally, the different frequency bands may include a super high frequency (SHF) (e.g., 2.NRHz, NRhz) band and a millimeter wave (mm wave) (e.g., 60GHz) band.

[0096] The storage unit (1130) stores data such as basic programs, application programs, and setting information for the operation of the terminal. In particular, the storage unit (1130) can store information related to a second access node that performs wireless communication using a second wireless access technology. In addition, the storage unit (1130) provides the stored data at the request of the control unit (1140).

[0097] The control unit (1140) controls the overall operations of the terminal. For example, the control unit (1140) transmits and receives signals through the baseband processing unit (1120) and the RF processing unit (1110). In addition, the control unit (1140) records and reads data in the storage unit (1140). For this purpose, the control unit (1140) may include at least one processor. For example, the control unit (1140) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs.

[0098] Figure 12 is a block diagram showing the configuration of a base station according to the present invention.

[0099] As shown in the above drawing, the base station is configured to include an RF processing unit (1210), a baseband processing unit (1220), a backhaul communication unit (1230), a storage unit (1240), and a control unit (1250).

[0100] The RF processing unit (1210) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1210) up-converts the baseband signal provided from the baseband processing unit (1220) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1210) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. In the drawing, only one antenna is illustrated, but the first access node may have multiple antennas. In addition, the RF processing unit (1210) may include multiple RF chains. Furthermore, the RF processing unit (1210) may perform beamforming. For the above beamforming, the RF processing unit (1210) can adjust the phase and size of each signal transmitted and received through multiple antennas or antenna elements. The RF processing unit can perform a downlink MIMO operation by transmitting one or more layers.

[0101] The baseband processing unit (1220) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the first wireless access technology. For example, when transmitting data, the baseband processing unit (1220) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (1220) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (1210). For example, in the case of OFDM, when transmitting data, the baseband processing unit (1220) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processing unit (1220) divides the baseband signal provided from the RF processing unit (1210) into OFDM symbol units, restores the signals mapped to subcarriers through FFT operation, and then restores the received bit string through demodulation and decoding. The baseband processing unit (1220) and the RF processing unit (1210) transmit and receive signals as described above. Accordingly, the baseband processing unit (1220) and the RF processing unit (1210) may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0102] The backhaul communication unit (1230) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (1230) converts a bit string transmitted from the main base station to another node, such as an auxiliary base station or core network, into a physical signal, and converts a physical signal received from the other node into a bit string.

[0103] The storage unit (1240) stores data such as basic programs, application programs, and configuration information for the operation of the main base station. In particular, the storage unit (1240) can store information on bearers assigned to connected terminals, measurement results reported from connected terminals, and the like. In addition, the storage unit (1240) can store information that serves as a judgment criterion for whether to provide or terminate multiple connections to a terminal. In addition, the storage unit (1240) provides the stored data at the request of the control unit (1250).

[0104] The control unit (1250) controls the overall operations of the base station. For example, the control unit (1250) transmits and receives signals through the baseband processing unit (1220) and the RF processing unit (1210) or through the backhaul communication unit (1230). In addition, the control unit (1250) records and reads data in the storage unit (1240). For this purpose, the control unit (1250) may include at least one processor.

[0105] In the specific embodiments of the present disclosure described above, components included in the invention are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0106] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical contents of the present disclosure and to help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, the above-mentioned embodiments can be combined and operated with each other as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment can be combined with each other to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above-mentioned embodiments have been presented based on an FDD LTE system, other modifications based on the technical idea of ​​the above-mentioned embodiments can be implemented with other systems such as a TDD LTE system, a 5G or NR system.

[0107] Meanwhile, the order of description in the drawings explaining the method of the present invention does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0108] Alternatively, the drawings illustrating the method of the present invention may omit some components and include only some components within a scope that does not harm the essence of the present invention.

[0109] In addition, the method of the present invention may be implemented by combining some or all of the contents included in each embodiment within a scope that does not harm the essence of the invention.

[0110] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a wireless communication system, the terminal (user equipment) transceiver; and Including a controller coupled to the above transmitter and receiver, The above controller, Receive an RRC (radio resource control) message from a base station that sets a list of multiple SSB (synchronization signal block) periods, From the above base station, receive a first SSB according to a first cycle, Receive DCI (downlink control information) including information indicating a second cycle among a plurality of SSB cycles from the base station, and A terminal configured to receive a second SSB according to the second cycle from the base station.

2. In claim 1, the first SSB and the second SSB are terminals including NCD (non cell defining) SSBs.

3. In claim 1, the terminal includes information indicating the second cycle, including information on a pattern for the second cycle or information on a duration for which the second cycle is applied.

4. In claim 1, the terminal includes a list of the plurality of SSB periods, a value indicating a default SSB period and one or more scaling values according to the default SSB period.

5. In a wireless communication system, a base station, transceiver; and Including a controller coupled to the above transmitter and receiver, The above controller, Transmitting an RRC (radio resource control) message to the terminal (user equipment) that sets a list of multiple SSB (synchronization signal block) periods, Transmit the first SSB according to the first cycle, Transmitting to the terminal, DCI (downlink control information) including information indicating a second cycle among a plurality of SSB cycles, and A base station configured to transmit a second SSB according to the second cycle.

6. In claim 5, the first SSB and the second SSB are base stations including NCD (non cell defining) SSBs.

7. In claim 5, a base station in which the information indicating the second cycle includes information about a pattern for the second cycle or information about a duration for which the second cycle is applied.

8. A base station according to claim 5, wherein the list of the plurality of SSB periods includes a value indicating a default SSB period and one or more scaling values according to the default SSB period.

9. In a wireless communication system, a method performed by a terminal (user equipment) comprises: A step of receiving an RRC (radio resource control) message setting a list of multiple SSB (synchronization signal block) periods from a base station; A step of receiving a first SSB according to a first cycle from the base station; A step of receiving DCI (downlink control information) including information indicating a second cycle among a plurality of SSB cycles from the base station; and A method comprising the step of receiving a second SSB according to the second cycle from the base station.

10. A method according to claim 9, wherein the first SSB and the second SSB include a non-cell defining (NCD) SSB.

11. A method according to claim 9, wherein the information indicating the second cycle includes information about a pattern for the second cycle or information about a duration for which the second cycle is applied.

12. A method according to claim 9, wherein the list of the plurality of SSB periods includes a value indicating a default SSB period and one or more scaling values according to the default SSB period.

13. In a wireless communication system, a method performed by a base station, A step of transmitting an RRC (radio resource control) message setting a list of multiple SSB (synchronization signal block) periods to a terminal (user equipment); A step of transmitting a first SSB according to a first cycle; A step of transmitting, to the terminal, DCI (downlink control information) including information indicating a second cycle among a plurality of SSB cycles; and A method comprising the step of transmitting a second SSB according to the second cycle.

14. A method according to claim 13, wherein the first SSB and the second SSB include a non-cell defining (NCD) SSB.

15. A method according to claim 13, wherein the information indicating the second cycle includes information about a pattern for the second cycle or information about a duration for which the second cycle is applied.

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