Terminal and communication method

Abstract

To switch efficiently between FDD carrier and SDL carrier without degrading communication quality.SOLUTION: A terminal includes: a communication unit which performs uplink communication and downlink communication using a first carrier, and performs downlink communication using a second carrier; and a control unit which performs switching between the first carrier and the second carrier by time division, using a switching pattern. At least one of a period of the switching pattern or mapping information is set for the switching pattern. The mapping information indicates whether each of slots and symbols in the period of the switching pattern is used for the first carrier or the second carrier.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a terminal and a communication method in a wireless communication system. [Background technology]

[0002] In mobile communication systems, low-frequency bands play an important role in accommodating indoor traffic in urban areas and wide-area traffic in suburban and rural areas due to their excellent propagation characteristics. However, carrier aggregation (CA) between low-frequency bands, such as the 800 MHz FDD (Frequency Division Duplex) band (Band n5) and the 700 MHz SDL (Supplemental Downlink) band (Band n29), has not been realized due to the complexity of the terminal's transceiver circuit design and control.

[0003] In order to eliminate the complexity of terminal implementation and realize low-frequency band carrier aggregation (LBCA), 3GPP (registered trademark) is studying a method of time-division switching between FDD carriers and SDL carriers using a semi-static switching pattern. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V18.4.0(2024-12) [Non-patent document 2] 3GPP TS 38.401 V18.4.0(2024-12) Summary of the Invention [Problem to be solved by the invention]

[0005] However, it has not been clear how to define a semi-static switching pattern. Therefore, if the number of configurable parameters in a semi-static switching pattern is small, the RRC signaling overhead can be reduced, but the flexibility of the switching pattern decreases. On the other hand, if the number of parameters is increased, the flexibility of the switching pattern improves, but the signaling overhead increases. This may reduce the efficiency of the entire system. Furthermore, allowing the configuration of arbitrary switching patterns may have a negative impact on communication quality and operation. [Means for solving the problem]

[0006] The terminal in this embodiment comprises a communication unit that performs uplink communication and downlink communication using a first carrier and downlink communication using a second carrier, and a control unit that performs switching between the first carrier and the second carrier by time division using a switching pattern, wherein at least one of the period of the switching pattern or mapping information is set for the switching pattern, and the mapping information indicates whether each slot or symbol within the period of the switching pattern is used for the first carrier or the second carrier. [Effects of the Invention]

[0007] According to this embodiment, it is possible to efficiently switch between the FDD carrier and the SDL carrier without degrading the communication quality. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram illustrating an example of switching between an FDD band and an SDL band. [Figure 3]FIG. 10 is a diagram illustrating an example of the operation of the terminal according to the present embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of a semi-static switching pattern in the present embodiment. [Figure 5] FIG. 2 is a diagram illustrating an example of a semi-static switching pattern in the present embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of a semi-static switching pattern in the present embodiment. [Figure 7] FIG. 2 is a diagram illustrating an example of a semi-static switching pattern in the present embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of a semi-static switching pattern in the present embodiment. [Figure 9] FIG. 2 is a diagram illustrating an example of a functional configuration of a base station according to the present embodiment. [Figure 10] FIG. 2 is a diagram illustrating an example of a functional configuration of a terminal according to the present embodiment. [Figure 11] FIG. 2 is a diagram illustrating an example of a hardware configuration of a base station or a terminal according to the present embodiment. [Figure 12] 1 is a diagram illustrating an example of a configuration of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present embodiment will be described below with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0010] The wireless communication system of this embodiment operates using existing technology. The existing technology is, for example, a wireless communication technology based on a communication standard such as the 3GPP standard. The existing technology is, for example, NR (New Radio), but is not limited to existing NR. Unless otherwise specified, the term "NR" used in this specification has a broad meaning including NR (5G) and subsequent systems (for example, 6G).

[0011] In the present embodiment described below, terms used in existing communication standards, such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel), are used. This is for convenience of description, and similar signals, functions, etc. may be called by other names.

[0012] In this embodiment, the duplex method may be a time division duplex (TDD) method, a frequency division duplex (FDD) method, or other methods (for example, flexible duplex, etc.).

[0013] In this embodiment, when radio parameters etc. are "configured," it may mean that a predetermined value is pre-configured, or that radio parameters notified from the base station 10 or the terminal 20 are set.

[0014] Fig. 1 is a diagram showing an example of the configuration of a wireless communication system in this embodiment. As shown in Fig. 1, the wireless communication system in this embodiment includes a base station 10 and a terminal 20. Although Fig. 1 shows one base station 10 and one terminal 20, this is an example, and there may be a plurality of each.

[0015] The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of a wireless signal are defined in the time domain and the frequency domain. The time domain may be defined by the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols, and the frequency domain may be defined by the number of subcarriers or the number of resource blocks. The base station 10 transmits a synchronization signal and system information to the terminal 20. The synchronization signal is, for example, a PSS and an SSS. The system information is, for example, transmitted via a PBCH and is also referred to as broadcast information. The synchronization signal and system information may be referred to as an SSB (SS / PBCH block). As shown in FIG. 1 , the base station 10 transmits control signals or data to the terminal 20 in a downlink (DL) and receives control signals or data from the terminal 20 in an uplink (UL). Both the base station 10 and the terminal 20 are capable of transmitting and receiving signals by performing beamforming. Furthermore, both the base station 10 and the terminal 20 are capable of applying MIMO (Multiple Input Multiple Output) communication to the DL or UL. In addition, both the base station 10 and the terminal 20 may communicate via a secondary cell (SCell: Secondary Cell) and a primary cell (PCell: Primary Cell) using CA (Carrier Aggregation). Furthermore, the terminal 20 may communicate via a primary cell of the base station 10 and a primary secondary cell group cell (PSCell: Primary SCG Cell) of another base station 10 using DC (Dual Connectivity).

[0016] The terminal 20 is a communication device equipped with a wireless communication function, such as a smartphone, a mobile phone, a tablet, a wearable terminal, or an M2M (Machine-to-Machine) communication module. As shown in Fig. 1, the terminal 20 receives control signals or data from the base station 10 via DL and transmits control signals or data to the base station 10 via UL, thereby utilizing various communication services provided by the wireless communication system. The terminal 20 also receives various reference signals transmitted from the base station 10 and measures the propagation path quality based on the reception results of the reference signals.

[0017] The terminal 20 in this embodiment may perform communication using one serving cell, or may perform communication using multiple serving cells (for example, CA or DC).

[0018] In the following description, unless otherwise specified or unless a different meaning is clear from the context, " / " means "and / or."

[0019] In mobile communication systems, low bands play an important role in accommodating indoor traffic in urban areas and a wide range of traffic in suburban and rural areas due to their excellent propagation characteristics. However, CA in low bands (LBCA) has not been fully utilized due to the difficulty of implementing it in terminals.

[0020] For example, CA between low frequencies such as the 800MHz FDD band (Band n5) and the 700MHz SDL band (Band n29) has not been widely adopted due to the complexity of the design and control of the transceiver circuits in the terminals. On the other hand, SDL (Supplemental Downlink) bands such as Band n29 have traditionally been used mainly for multimedia broadcasting (MBS), but in recent years there has been interest in converting them to communications applications.

[0021] 3GPP has proposed that CA can be used to improve low band capacity while overcoming the difficulties of terminal implementation by switching between the FDD band and the SDL band, as shown in Figure 2. This approach considers switching based on the following two cases:

[0022] Case 1: Transmit and receive on an FDD carrier (e.g., Band n5) and do not receive on an SDL carrier (e.g., Band n29).

[0023] Case 2: Receive on the SDL carrier, but do not transmit or receive on the FDD carrier.

[0024] For such switching between FDD carriers and SDL carriers, a method of switching by time division multiplexing using a semi-static switching pattern set by radio resource control (RRC) is being considered.

[0025] However, it has not been clear how to define a semi-static switching pattern. Therefore, if the number of configurable parameters in a semi-static switching pattern is small, the RRC signaling overhead can be reduced, but the flexibility of the switching pattern decreases. On the other hand, if the number of parameters is increased, the flexibility of the switching pattern improves, but the signaling overhead increases. This may reduce the efficiency of the entire system.

[0026] Furthermore, if arbitrary switching patterns are allowed to be set, the following problems may occur, adversely affecting communication quality and operation.

[0027] - SSB timing and interference of PCell: When the SDL carrier becomes available at the SSB timing of the FDD carrier (PCell), SSB reception of the PCell is disrupted, affecting Radio Link Monitoring (RLM), etc.

[0028] - PCell PRACH timing and interference: If the SDL carrier becomes available at the timing of the PRACH opportunity of the FDD carrier (PCell), random access cannot be initiated, which affects operations such as handover (HO).

[0029] - Insufficient transmission resources due to continuous use: If the SDL carrier remains available for a long period of time, uplink (UL) transmissions are restricted, resulting in an insufficient number of HARQ processes on the SDL carrier.

[0030] - Decrease in frequency utilization efficiency: When switching patterns occur frequently, the switching gap increases, and the proportion of periods during which transmission and reception are not possible increases, which may result in a decrease in frequency utilization efficiency.

[0031] According to this embodiment, a semi-static switching pattern to which a predetermined constraint is applied is used to efficiently switch between an FDD carrier and an SDL carrier while ensuring communication quality.

[0032] In this embodiment, the semi-static switching pattern may be referred to as a switching pattern or a pattern.

[0033] The examples in this embodiment may be implemented independently of each other, or any combination of a plurality of examples may be implemented.

[0034] In this embodiment, when "X" (for example, function or information) is configured in a terminal (or a base station), it indicates that the terminal is configured with "X".

[0035] In this embodiment, the various pieces of information set in the terminal may be included in parameters (e.g., upper layer (RRC) parameters) transmitted from the base station. The terminal may set the various pieces of information in the terminal based on the parameters transmitted from the base station. As another example, the various pieces of information may be set in the terminal in advance based on a standard (e.g., technical specifications of the 3GPP standard).

[0036] The terminal 20 in this embodiment supports CA performed using an FDD carrier (Pcell) and an SDL carrier (Scell). According to this embodiment, a predetermined constraint is defined to be applied to the setting of a semi-static switching pattern used for switching between the FDD carrier and the SDL carrier. The predetermined constraint may also be referred to as a predetermined condition or a predetermined rule. Figure 3 is a diagram showing an example of the operation of the terminal 20 in this embodiment.

[0037] 3, in step S11, the terminal 20 assumes a predetermined constraint on the semi-static switching pattern based on a setting defined by a specification (e.g., 3GPP technical specification) and / or a setting notified from the base station 10. That is, the terminal 20 assumes that a switching pattern that complies with the predetermined constraint (or satisfies a predetermined condition) will be set. In other words, the terminal 20 does not assume that a switching pattern that does not comply with the predetermined constraint (does not satisfy the predetermined condition) will be set.

[0038] In step S12, the terminal 20 performs switching between the FDD carrier and the SDL carrier based on a semi-static switching pattern to which a predetermined constraint is applied.

[0039] An example of a semi-static switching pattern between FDD and SDL in this embodiment is shown in Figure 4. FDD is a communication method in which uplink (UL) communication (i.e., transmission) and downlink (DL) communication (i.e., reception) are performed using different frequency bands. SDL is a mechanism that provides an additional frequency band dedicated to DL. As shown in Figure 4, FDD carriers and SDL carriers are switched in a time-division manner.

[0040] One or any combination of the following predetermined constraints may be applied to the semi-static switching pattern in this embodiment.

[0041] (Setting the period of the semi-static switching pattern) The period of the semi-static switching pattern may be a configurable candidate value (parameter) or a fixed value. The configurable candidate value or fixed value may be, for example, a predetermined value (5 ms, 10 ms, 20 ms, etc.) defined in the specifications. Fig. 4 shows an example of a switching pattern in which the period is set to 5 ms. Fig. 5 shows an example of a switching pattern in which the period is set to 10 ms. The configurable candidate value or fixed value may be limited depending on other parameters (e.g., ssb-PeriodicityServingCell or periodicityAndOffset in SSB-MTC) set by the base station 10, or may be directly specified by other parameters.

[0042] The configurable candidate values ​​may be included in the terminal capability (UE capability). The terminal 20 may report the terminal capability including the configurable candidate values ​​to the base station 10. The terminal 20 may support a specific value set as the periodicity by default.

[0043] (setting granularity) The setting granularity of the FDD carrier and the SDL carrier in the semi-static switching pattern may be a slot or a symbol.

[0044] The configurable granularity may be included in the terminal capability. The terminal 20 may report the terminal capability including the configurable granularity to the base station 10. The terminal 20 may support a specific granularity by default among the configuration granularities of the FDD carrier and the SDL carrier.

[0045] (Mapping of slots (symbols) and carriers in switching patterns) Within a period of the semi-static switching pattern, it may be configured whether each slot (or each symbol) is mapped as a resource used for an FDD carrier or an SDL carrier. In other words, within a period of the semi-static switching pattern, it may be configured which slots (or symbols) are mapped as resources used for an FDD carrier and which slots (or symbols) are mapped as resources used for an SDL carrier.

[0046] The mapping of slots (or symbols) and carriers within the period of the switching pattern may be defined as a mapping pattern or mapping information applied to the switching pattern.

[0047] For example, the specification may define one or more mapping patterns that indicate the mapping between slots (or symbols) and carriers (FDD carriers or SDL carriers) within a period of the switching pattern. An index that identifies each mapping pattern may be assigned. For example, configuration information (e.g., RRC configuration) transmitted from the base station 10 to the terminal 20 may include an index corresponding to a mapping pattern to be applied to the terminal 20. The terminal 20 may apply the mapping pattern corresponding to the index included in the configuration information to the switching pattern.

[0048] For example, configuration information (e.g., RRC configuration) transmitted from the base station 10 to the terminal 20 may include information specifying the period of the switching pattern, and the number of slots (and / or the number of symbols) allocated to the FDD carrier and the number of slots (and / or the number of symbols) allocated to the SDL carrier within the specified period. The terminal 20 may apply, to the switching pattern, a (presumed) mapping pattern determined based on the period of the switching pattern specified by the configuration information and the number of slots (and / or the number of symbols) allocated to the FDD carrier and the SDL carrier within the period.

[0049] (Limit on number of switching times) The number of times that switching between the FDD carrier and the SDL carrier occurs within a predetermined period in the semi-static switching pattern may be limited to a predetermined number or less.

[0050] The predetermined number of times that specifies the number of switching times may be a fixed value that does not depend on the period of the semi-static switching pattern (for example, up to N times in the pattern regardless of the number of periods), or may be an upper limit value within the predetermined period (for example, N times or less every X ms). In the examples of Figures 4 and 5, the number of switching times per 10 ms period is limited to two or two or less.

[0051] The predetermined number of times that specifies the number of switching operations may be specified as the number of times per period of the semi-static switching pattern or an upper limit value. In the example of Fig. 4, the number of switching operations per period of the semi-static switching pattern is specified as 1 time or less. In the example of Fig. 5, the number of switching operations per period of the semi-static switching pattern is specified as 2 times or less.

[0052] (Consideration of SSB occasion and SMTC occasion on FDD carrier) As shown in Fig. 6, the semi-static switching pattern may always include SSB occasions and / or SMTC occasions of the FDD carrier (PCell) at a predetermined period. This predetermined period of the FDD carrier may be a fixed value (e.g., 20 ms), a value set by the base station 10 (e.g., a value indicated by ssb-PeriodicityServingCell or periodicityAndOffset in SSB-MTC), or a value obtained by multiplying these values ​​by a specific value.

[0053] (Limitation on continuous use of SDL carrier) In a semi-static switching pattern, the number of slots or symbols of an SDL carrier that can be used continuously may be limited to a predetermined number or less. This predetermined number may be a fixed value that does not depend on the period (e.g., 5 slots) or an upper limit within a predetermined period (e.g., 5 slots or less per 10 ms).

[0054] (Consideration of PRACH slots) As shown in Fig. 7, the semi-static switching pattern may always include PRACH slots of an FDD carrier (PCell) at a predetermined period or at least a predetermined number of PRACH slots within the predetermined period. This predetermined period may be a fixed value (e.g., 20 ms), a value set by the base station 10 (e.g., the period of the PRACH slots set by prach-ConfigurationIndex), or a value obtained by multiplying these values ​​by a specific value. The predetermined number may be, for example, all the PRACH slots set by prach-ConfigurationIndex, or a part of the PRACH slots.

[0055] (Consideration of SSB occasion and SMTC occasion in SDL carrier) As shown in Fig. 8, the semi-static switching pattern may always include SSB occasions and / or SMTC occasions of the SDL carrier (SCell) at a predetermined period. This predetermined period in the SDL carrier may be a fixed value (e.g., 20 ms), a value set by the base station 10 (e.g., a value indicated by ssb-PeriodicityServingCell or periodicityAndOffset in SSB-MTC), or a value obtained by multiplying these values ​​by a specific value.

[0056] The number of SSB occasions or SMTC occasions included in an SDL carrier (SCell) in a semi-static switching pattern may be smaller than the number of SSB occasions or SMTC occasions in an FDD carrier (PCell). That is, the period of SSB occasions or SMTC occasions included in an SDL carrier (SCell) in a semi-static switching pattern may be longer than the period of SSB occasions or SMTC occasions in an FDD carrier (PCell).

[0057] Parameters or fixed values ​​configurable in the terminal 20 regarding one or more constraints of the above-mentioned semi-static switching pattern may be included in the terminal capability (UE capability). The terminal 20 may report the terminal capability including the configurable parameters or fixed values ​​to the base station 10. The base station 10 may transmit to the terminal 20 configuration information of the constraints of the semi-static switching pattern based on the terminal capability reported from the terminal 20. Furthermore, the terminal may report to the base station 10 a terminal capability indicating that switching between the FDD carrier and the SDL carrier can be performed even if at least some of the one or more constraints of the above-mentioned semi-static switching pattern are not satisfied.

[0058] According to the above-described embodiment, it is possible to efficiently switch between the FDD carrier and the SDL carrier without degrading the communication quality.

[0059] For example, according to this embodiment, when switching between an FDD carrier and an SDL carrier, a semi-static switching pattern to which a predetermined constraint is applied is used, thereby enabling flexible switching pattern design. Furthermore, RRC signaling overhead can be reduced, communication efficiency can be improved, and interference can be avoided to maintain communication quality.

[0060] (Device configuration) Next, a description will be given of an example of the functional configuration of the base station 10 and the terminal 20 that execute the processes and operations described above. The base station 10 and the terminal 20 include functions for implementing the above-described embodiments. However, the base station 10 and the terminal 20 may each include only a part of the functions of the embodiments.

[0061] <Base station> Fig. 9 is a diagram showing an example of the functional configuration of the base station 10 in this embodiment. As shown in Fig. 9, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 9 is merely an example. The functional divisions and names of the functional units may be any names as long as they can execute the operations according to this embodiment.

[0062] The transmitter 110 includes a function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The transmitter 110 also transmits setting information, instructions, notifications, etc. related to a low-power wake-up signal to the terminal 20. The transmitter 110 also transmits notifications related to switching of monitoring operations to the terminal. The receiver 120 includes a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of higher layers from the received signals. The transmitter 110 also has a function of transmitting PSS, SSS, PBCH, DL / UL control signals, etc. to the terminal 20. The receiver 120 also receives inter-network node messages from other network nodes.

[0063] The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20. The content of the setting information is, for example, information related to measurements of low-power signals.

[0064] As described in the embodiments, the control unit 140 controls settings, instructions, and notifications related to low-power wake-up signals, etc. A functional unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the receiving unit 120.

[0065] <terminal> Fig. 10 is a diagram showing an example of the functional configuration of the terminal 20 in this embodiment. As shown in Fig. 10, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 10 is merely an example. As long as the operations according to this embodiment can be performed, the names of the functional divisions and functional units may be any. The transmitting unit 210 and the receiving unit 220 may be collectively referred to as a communication unit.

[0066] The transmitter 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The transmitter 210 also transmits capability information related to the low-power wake-up signal to the base station 10. The receiver 220 receives various signals wirelessly and acquires higher layer signals from the received physical layer signals. The receiver 220 also has a function of receiving PSS, SSS, PBCH, DL / UL / SL control signals, and the like transmitted from the base station 10. The receiver 220 also receives paging notification information and configuration information, instructions, and notifications related to the low-power wake-up signal from the base station 10. For example, the receiver 220 receives the low-power wake-up signal from the base station 10. The configuration unit 230 stores various configuration information received by the receiver 220 from the base station 10. The configuration unit 230 also stores pre-configured configuration information. The configuration information includes, for example, information related to measurements of the low-power signal.

[0067] As described in the embodiments, the control unit 240 controls the settings, instructions, and notifications related to the low-power wake-up signal. The function unit related to signal transmission in the control unit 240 may be included in the transmitting unit 210, and the function unit related to signal reception in the control unit 240 may be included in the receiving unit 220.

[0068] (Hardware configuration) The block diagrams (FIGS. 9 and 10) used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or may be realized using two or more devices that are physically or logically separated and connected directly or indirectly (for example, by wire, wirelessly, etc.). The functional block may be realized by combining software with the one device or the multiple devices.

[0069] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, regard, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

[0070] For example, the base station 10, the terminal 20, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 11 is a diagram illustrating an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The base station 10 and the terminal 20 described above may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0071] In the following description, the term "apparatus" can be read as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0072] Each function in the base station 10 and the terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001, the memory device 1002, etc., so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls at least one of reading and writing data in the memory device 1002 and the auxiliary memory device 1003.

[0073] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0074] Furthermore, the processor 1001 reads programs (program codes), software modules, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes in accordance with the programs. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 140 of the base station 10 shown in FIG. 9 may be implemented by a control program stored in the storage device 1002 and executed by the processor 1001. Furthermore, for example, the control unit 240 of the terminal 20 shown in FIG. 10 may be implemented by a control program stored in the storage device 1002 and executed by the processor 1001. While the above-described various processes have been described as being executed by one processor 1001, they may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may be transmitted from a network via a telecommunications line.

[0075] The storage device 1002 is a computer-readable recording medium and may be configured, for example, by at least one of a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory, etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing a communication method according to an embodiment of the present disclosure.

[0076] The secondary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of the storage device 1002 and the secondary storage device 1003.

[0077] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, a transmission / reception antenna, an amplifier unit, a transmission / reception unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmission / reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated.

[0078] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0079] Furthermore, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0080] Furthermore, base station 10 and terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, processor 1001 may be implemented using at least one of these pieces of hardware.

[0081] Fig. 12 shows an example configuration of a vehicle 2001. As shown in Fig. 12, the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in the present disclosure may be applied to a communication device mounted on the vehicle 2001, and may be applied to the communication module 2013, for example.

[0082] The drive unit 2002 is configured, for example, by an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle), and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

[0083] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2029 provided in the vehicle 2001. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0084] The signals from the various sensors 2021 to 2029 include a current signal from a current sensor 2021 that senses the current of the motor, a front or rear wheel rotation speed signal obtained by a rotation speed sensor 2022, a front or rear wheel air pressure signal obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0085] The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing (outputting) various types of information, such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information acquired from external devices via the communication module 2013 or the like to provide various types of multimedia information and multimedia services to the occupants of the vehicle 2001. The information service unit 2012 may include input devices (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, a touch panel, etc.) that accept input from the outside, and may also include output devices (e.g., a display, a speaker, an LED lamp, a touch panel, etc.) that output information to the outside.

[0086] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as a millimeter-wave radar, a LiDAR (Light Detection and Ranging), a camera, a positioning locator (e.g., GNSS, etc.), map information (e.g., high-definition (HD) map, autonomous vehicle (AV) map, etc.), a gyro system (e.g., an IMU (Inertial Measurement Unit), an INS (Inertial Navigation System), etc.), an AI (Artificial Intelligence) chip, and an AI processor, as well as one or more ECUs that control these devices. The driving assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize the driving assistance function or the autonomous driving function.

[0087] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 29, which are provided in the vehicle 2001.

[0088] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0089] The communication module 2013 may transmit at least one of signals from the above-mentioned various sensors 2021-2028 input to the electronic control unit 2010, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 2012 to an external device via wireless communication. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include information based on the above-mentioned input.

[0090] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle-to-vehicle information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from external devices in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021 to 2029, etc. provided in the vehicle 2001.

[0091] (Configuration of this embodiment) (Additional note 1) a communication unit that performs uplink communication and downlink communication using a first carrier and that performs downlink communication using a second carrier; a control unit that performs switching between the first carrier and the second carrier by time division using a switching pattern; At least one of a period of the switching pattern or mapping information is set for the switching pattern; A terminal, wherein the mapping information indicates whether each slot or symbol within a period of the switching pattern is used for the first carrier or the second carrier.

[0092] (Additional note 2) The terminal according to Supplementary Item 1, wherein the number of consecutive slots or symbols of the second carrier in the switching pattern is further limited to a predetermined number or less.

[0093] (Additional note 3) The terminal described in Appendix 1, wherein at least one of the first carrier or the second carrier included in the switching pattern periodically includes an SSB (Synchronization Signal Block) occasion or an SMTC (SSB Measurement Timing Configuration) occasion.

[0094] (Additional note 4) The terminal according to Supplementary Item 1, wherein the first carrier included in the switching pattern periodically includes a PRACH (Physical Random Access Channel) slot.

[0095] (Additional note 5) The terminal according to claim 1, wherein the communication unit transmits terminal capability information to a base station, the terminal capability information including at least one of the period of the switching pattern that can be set in the terminal or the mapping information.

[0096] (Additional note 6) A communication method performed by a terminal, comprising: performing uplink communication and downlink communication using a first carrier and performing downlink communication using a second carrier; and performing switching between the first carrier and the second carrier in a time-division manner using a switching pattern; A communication method, wherein at least one of a period of the switching pattern or the number of times the first carrier and the second carrier are switched in the switching pattern is set for the switching pattern.

[0097] With any of the above configurations, it is possible to efficiently switch between the FDD carrier and the SDL carrier without degrading communication quality by using an FDD / SDL switching pattern to which predetermined constraints are applied.

[0098] (Supplementary explanation of the embodiment) Although the present embodiment has been described above, the disclosed invention is not limited to such an embodiment, and those skilled in the art will understand various modifications, alterations, alternatives, and substitutions. While specific numerical examples have been used to facilitate understanding of the invention, unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention; matters described in two or more items may be used in combination as needed, and matters described in one item may apply to matters described in another item (unless inconsistent). The boundaries between functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries between physical components. The operations of multiple functional units may be performed by a single physical component, or the operations of a single functional unit may be performed by multiple physical components. The order of the processing steps described in the embodiments may be reversed as long as there is no contradiction. For convenience of processing description, the base station 10 and terminal 20 have been described using functional block diagrams. However, such devices may be implemented using hardware, software, or a combination thereof. The software operated by the processor of the base station 10 according to this embodiment and the software operated by the processor of the terminal 20 according to this embodiment may each be stored in random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0099] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0100] Each aspect / embodiment described in the present disclosure may be applied to at least one of a system using LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark), IEEE 802.20, UWB (Ultra-Wide Band), Bluetooth (registered trademark), or other appropriate system, and a next-generation system extended based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G) may also be applied.

[0101] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described herein may be changed unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

[0102] In this specification, a specific operation that is described as being performed by the base station 10 may also be performed by its upper node in some cases. In a network consisting of one or more network nodes having the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and another network node other than the base station 10 (such as, but not limited to, an MME or an S-GW). Although the above example illustrates a case where there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (such as an MME and an S-GW).

[0103] The information or signals described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0104] Input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be sent to another device.

[0105] In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0106] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0107] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0108] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0109] Note that terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0110] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0111] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0112] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0113] In the present disclosure, terms such as "base station (BS)," "radio base station," "base station device," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0114] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0115] In the present disclosure, the base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control or operate based on the information.

[0116] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0117] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0118] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, the mobile object itself, etc. The mobile object refers to a movable object, and may move at any speed. Naturally, this also includes cases where the mobile object is stationary. Examples of the mobile object include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and objects mounted thereon. The mobile object may also be a mobile object that moves autonomously based on an operational command. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0119] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between a plurality of terminals 20 (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel.

[0120] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station may be configured to have the functions of the user terminal described above.

[0121] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0122] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0123] The reference signal may be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

[0124] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0125] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0126] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0127] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0128] A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0129] Numerology may be communication parameters applied to at least one of transmission and reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

[0130] A slot may be configured of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may be a time unit based on numerology.

[0131] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0132] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0133] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0134] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0135] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0136] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0137] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0138] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0139] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0140] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0141] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0142] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0143] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within the BWP.

[0144] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0145] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0146] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0147] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0148] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0149] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0150] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0151] 10 base station 110 Transmitter 120 Receiver 130 Setting section 140 Control Unit 20 terminals 210 Transmitter 220 Receiving unit 230 Setting Section 240 Control Unit 1001 processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication equipment 1005 Input Device 1006 Output Device 2001 Vehicle 2002 Drive unit 2003 Steering Section 2004 accelerator pedal 2005 brake pedal 2006 Shift Lever 2007 front wheel 2008 rear wheel 2009 Axle 2010 Electronic Control Unit 2012 Information Services Department 2013 Communication Module 2021 Current Sensor 2022 RPM Sensor 2023 Air Pressure Sensor 2024 Vehicle speed sensor 2025 Acceleration Sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030 Driving Assistance Systems Department 2031 microprocessor 2032 memory (ROM, RAM) 2033 Communication port (IO port)

Claims

1. a communication unit that performs uplink communication and downlink communication using a first carrier and that performs downlink communication using a second carrier; a control unit that performs switching between the first carrier and the second carrier by time division using a switching pattern; At least one of a period of the switching pattern or mapping information is set for the switching pattern; A terminal, wherein the mapping information indicates whether each slot or symbol within a period of the switching pattern is used for the first carrier or the second carrier.

2. The terminal according to claim 1 , wherein the number of consecutive slots or symbols of the second carrier in the switching pattern is further limited to a predetermined number or less.

3. 2. The terminal according to claim 1, wherein at least one of the first carrier or the second carrier included in the switching pattern periodically includes an SSB (Synchronization Signal Block) occasion or an SMTC (SSB Measurement Timing Configuration) occasion.

4. The terminal according to claim 1 , wherein the first carrier included in the switching pattern periodically includes a PRACH (Physical Random Access Channel) slot.

5. The terminal according to claim 1 , wherein the communication unit transmits, to a base station, terminal capability information including at least one of the period of the switching pattern that can be set in the terminal or the mapping information.

6. A communication method performed by a terminal, comprising: performing uplink and downlink communications using a first carrier and performing downlink communications using a second carrier; and performing switching between the first carrier and the second carrier in a time-division manner using a switching pattern; A communication method, wherein at least one of a period of the switching pattern or the number of times the first carrier and the second carrier are switched in the switching pattern is set for the switching pattern.

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