Terminal and communication method

Abstract

A terminal comprising a communication unit that executes uplink communication and downlink communication using a first carrier and that executes the downlink communication using a second carrier, and a control unit that uses a switching pattern to execute switching between the first carrier and the second carrier via time division, wherein: with respect to the switching pattern, mapping information and / or a period of the switching pattern is set; and the mapping information represents whether each among slots or symbols within the period of the switching pattern are used for the first carrier or the second carrier.

Description

Terminal and Communication Method

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

[0002] In a mobile communication system, due to its excellent propagation characteristics, the low frequency band (Low Band) plays an important role in accommodating indoor traffic in urban areas and extensive traffic in suburban and rural areas. However, conventionally, carrier aggregation (CA (Carrier Aggregation)) between low frequencies such as the 800 MHz band FDD (Frequency Division Duplex) band (Band n5) and the 700 MHz band 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 3GPP (Registered Trademark) (3rd Generation Partnership Project), in order to eliminate the complexity of terminal implementation and realize carrier aggregation (LBCA) in the low frequency band, a method of time-division switching between an FDD carrier and an SDL carrier using a Semi-static (semi-static) switching pattern has been studied.

[0004] 3GPP TS 38.300 V18.4.0(2024-12)3GPP TS 38.401 V18.4.0(2024-12)

[0005] However, conventionally, it has not been clearly defined how the Semi-static switching pattern should be specified. Therefore, when the number of configurable parameters in the Semi-static switching pattern is small, the overhead of RRC signaling can be suppressed, but the flexibility of the switching pattern decreases. On the other hand, increasing the number of parameters improves the flexibility of the switching pattern, but the signaling overhead increases. As a result, the efficiency of the entire system may decrease. Furthermore, allowing the setting of an arbitrary switching pattern may have an adverse effect on communication quality and operation.

[0006] The terminal in this embodiment includes a communication unit that performs uplink and downlink communication using a first carrier and downlink communication using a second carrier, and a control unit that performs time-division switching between the first carrier and the second carrier 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.

[0007] According to this embodiment, it is possible to efficiently switch between FDD carriers and SDL carriers without degrading communication quality.

[0008] This is a diagram illustrating the wireless communication system in this embodiment. This is a diagram illustrating an example of switching operation between the FDD band and the SDL band. This is a diagram illustrating an example of terminal operation in this embodiment. This is a diagram illustrating an example of a semi-static switching pattern in this embodiment. This is a diagram illustrating an example of a semi-static switching pattern in this embodiment. This is a diagram illustrating an example of a semi-static switching pattern in this embodiment. This is a diagram illustrating an example of a semi-static switching pattern in this embodiment. This is a diagram illustrating an example of the functional configuration of a base station in this embodiment. This is a diagram illustrating an example of the functional configuration of a terminal in this embodiment. This is a diagram illustrating an example of the hardware configuration of a base station or terminal in this embodiment. This is a diagram illustrating an example of the configuration of a vehicle in this embodiment.

[0009] This embodiment will be described below with reference to the drawings. Note that the embodiments described below are examples, and the embodiments to which the present invention applies are not limited to those described below.

[0010] The wireless communication system of this embodiment operates using existing technology. Existing technology is, for example, wireless communication technology based on communication standards such as the 3GPP standard. Existing technology is, for example, NR (New Radio), but is not limited to existing NR. As used herein, the term "NR" has a broad meaning that includes NR (5G) and later systems (e.g., 6G), unless otherwise specified.

[0011] In the embodiments described below, we will use terms 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), which are used in existing communication standards. 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 TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or any other method (for example, a Flexible Duplex).

[0013] In this embodiment, "configuring" wireless parameters means either pre-configuring predetermined values, or configuring wireless parameters notified by the base station 10 or terminal 20.

[0014] Figure 1 shows an example of the configuration of a wireless communication system in this embodiment. The wireless communication system in this embodiment includes a base station 10 and a terminal 20, as shown in Figure 1. Although Figure 1 shows one base station 10 and one terminal 20, this is an example, and there may be multiple base stations 10 and terminals 20.

[0015] Base station 10 is a communication device that provides one or more cells and communicates wirelessly with terminal 20. The physical resources of the radio signal are defined in the time domain and the frequency domain. The time domain may be defined by the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols, and the frequency domain may be defined by the number of subcarriers or resource blocks. Base station 10 transmits synchronization signals and system information to terminal 20. Synchronization signals are, for example, PSS and SSS. System information is transmitted, for example, via PBCH and is also called broadcast information. Synchronization signals and system information may be called SSB (SS / PBCH block). As shown in Figure 1, base station 10 transmits control signals or data to terminal 20 via DL (Downlink) and receives control signals or data from terminal 20 via UL (Uplink). Both base station 10 and terminal 20 are capable of transmitting and receiving signals using beamforming. Furthermore, both base station 10 and terminal 20 are capable of applying MIMO (Multiple Input Multiple Output) communication to DL or UL. Furthermore, both the base station 10 and the terminal 20 may communicate via secondary cells (SCell) and primary cells (PCell) using Carrier Aggregation (CA). In addition, the terminal 20 may communicate via the primary cell of base station 10 and the primary secondary cell group cell (PSCell) of other base stations 10 using Dual Connectivity (DC).

[0016] Terminal 20 is a communication device equipped with wireless communication capabilities, such as a smartphone, mobile phone, tablet, wearable device, or M2M (Machine-to-Machine) communication module. As shown in Figure 1, 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. Terminal 20 also receives various reference signals transmitted from the base station 10 and performs propagation path quality measurements based on the reception results of these reference signals.

[0017] In this embodiment, terminal 20 may perform communication using one serving cell, or it may perform communication using multiple serving cells (e.g., CA or DC).

[0018] In the following explanation, " / " means "and / or" unless otherwise specified, or unless the context makes it clear that it has a different meaning.

[0019] In mobile communication systems, Low Band plays a crucial role in accommodating indoor traffic in urban areas and extensive traffic in suburban and rural areas due to its superior propagation characteristics. However, Low Band Carrier Aggregation (LBCA) is not fully utilized due to the difficulty of implementing it at terminals.

[0020] For example, the use of carrier aggregation (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 designing and controlling the transmit / receive circuits at terminals. On the other hand, SDL (Supplemental Downlink) bands like Band n29 have traditionally been used mainly for multimedia broadcasting (MBS) applications, but in recent years, their repurposing for communication applications has been attracting attention.

[0021] In 3GPP, as shown in Figure 2, it has been proposed to improve low-band capacity while resolving terminal implementation difficulties by switching between the FDD band and the SDL band in CA. This approach considers switching based on the following two cases.

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

[0023] Case 2: Reception is performed on the SDL carrier, but transmission and reception are not performed on the FDD carrier.

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

[0025] However, conventional methods for defining semi-static switching patterns have not been clearly defined. Therefore, while a small number of configurable parameters in a semi-static switching pattern can reduce RRC signaling overhead, it also reduces the flexibility of the switching pattern. Conversely, increasing the number of parameters improves the flexibility of the switching pattern but increases signaling overhead. This can potentially reduce the overall efficiency of the system.

[0026] Furthermore, allowing arbitrary switching pattern settings could lead to the following issues, potentially negatively impacting communication quality and operation.

[0027] - Interference with PCell's SSB timing: When the SDL carrier becomes usable with the FDD carrier (PCell)'s SSB timing, PCell's SSB reception is interfered with, affecting RLM (Radio Link Monitoring), etc.

[0028] - Interference with PCell's PRACH timing: If the SDL carrier becomes available at the same time as the FDD carrier (PCell)'s PRACH opportunity, random access cannot be initiated, affecting operations such as handover (HO).

[0029] - Transmission resource shortage due to continuous use: If the SDL carrier remains available for an extended period, uplink (UL) transmission will be limited, resulting in a shortage of HARQ processes on the SDL carrier.

[0030] - Reduced frequency utilization efficiency: When switching patterns occur at a high frequency, the switching gap increases, and the proportion of time during which transmission and reception are not possible increases, which may reduce frequency utilization efficiency.

[0031] According to this embodiment, by using a semi-static switching pattern to which predetermined constraints are applied, it is possible to efficiently switch between FDD carriers and SDL carriers while ensuring communication quality.

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

[0033] Each embodiment in this embodiment may be performed independently, or any combination of multiple embodiments may be performed.

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

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

[0036] In this embodiment, terminal 20 supports CA (Carrier Access) performed using FDD carriers (Pcells) and SDL carriers (Scells). According to this embodiment, predetermined constraints are defined that apply to the setting of the semi-static switching pattern used for switching between FDD carriers and SDL carriers. These predetermined constraints may also be referred to as predetermined conditions or predetermined rules. Figure 3 shows an example of the operation of terminal 20 in this embodiment.

[0037] As shown in Figure 3, in step S11, terminal 20 assumes predetermined constraints on the semi-static switching pattern based on the settings specified by the specification (e.g., 3GPP technical specifications) and / or the settings notified by base station 10. That is, terminal 20 assumes that a switching pattern that conforms to the predetermined constraints (or satisfies the predetermined conditions) will be set. In other words, terminal 20 does not assume that a switching pattern that does not conform to the predetermined constraints (does not satisfy the predetermined conditions) will be set.

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

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

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

[0041] (Setting of the Period of the Semi-static Switching Pattern) The period of the semi-static switching pattern may be a settable candidate value (parameter) or a fixed value. The settable candidate value or fixed value may be, for example, a predetermined value (5 ms, 10 ms, 20 ms, etc.) defined in the specification. FIG. 4 is an example of a switching pattern with a period set to 5 ms. FIG. 5 is an example of a switching pattern with a period set to 10 ms. The settable candidate value or fixed value may be limited according to other parameters (e.g., ssb-PeriodicityServingCell or periodicityAndOffset in SSB-MTC) set from the base station 10, or may be directly specified by other parameters.

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

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

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

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

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

[0047] For example, the specifications may define one or more mapping patterns that show the mapping between slots (or symbols) and carriers (FDD carriers or SDL carriers) within the period of the switching pattern. Each of the mapping patterns may be assigned an index to identify it. For example, configuration information (e.g., RRC settings) transmitted from the base station 10 to the terminal 20 may include an index corresponding to the 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 transmitted from base station 10 to terminal 20 (e.g., RRC settings) may include information specifying the period of the switching pattern, the number of slots (and / or symbols) allocated to the FDD carrier and the number of slots (and / or symbols) allocated to the SDL carrier within the specified period. Terminal 20 may apply a mapping pattern determined (assumed) based on the period of the switching pattern specified by the configuration information and the number of slots (and / or symbols) allocated to the FDD carrier and SDL carrier, respectively, within that period, to the switching pattern.

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

[0050] The predetermined number defining the number of switching operations may be a fixed value independent of the period of the semi-static switching pattern (for example, up to N times in the pattern regardless of the period), or an upper limit value within a predetermined period (for example, N times or less every X ms). In the examples of FIGS. 4 and 5, the number of switching operations per 10 ms period is limited to 2 times or less.

[0051] The predetermined number defining the number of switching operations may be defined as the number of times or the upper limit value per period of the semi-static switching pattern. In the example of FIG. 4, the number of switching operations per period of the semi-static switching pattern is defined 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 defined as 2 times or less.

[0052] (Consideration of SSB occasion and SMTC occasion in the FDD carrier) As shown in FIG. 6, the semi-static switching pattern may necessarily include the SSB occasion and / or the SMTC occasion of the FDD carrier (PCell) at a predetermined period. The predetermined period in this FDD carrier may be a fixed value (for example, 20 ms), a value set by the base station 10 (for example, the value indicated by ssb-PeriodicityServingCell or periodicityAndOffset in SSB-MTC), or a value obtained by multiplying these values by a specific value.

[0053] (Restrictions on the continuous use of SDL carriers) In a semi-static switching pattern, the number of SDL carrier slots or symbols 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 it may be an upper limit within a predetermined period (e.g., 5 slots or less every 10 ms).

[0054] (Consideration of PRACH slots) As shown in Figure 7, the semi-static switching pattern may always include PRACH slots of the FDD carrier (PCell) at a predetermined period or a predetermined number or more 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 all of the PRACH slots set by prach-ConfigurationIndex, or some of them.

[0055] (Consideration of SSB and SMTC occasions in the SDL carrier) As shown in Figure 8, the semi-static switching pattern may always include the SSB occasion and / or SMTC occasion 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 periodicityAndOffset in ssb-PeriodicityServingCell or SSB-MTC), or a value obtained by multiplying these values ​​by a specific value.

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

[0057] Parameters or fixed values ​​that can be set by terminal 20 regarding one or more constraints of the Semi-static switching pattern described above may be included in terminal capability (UE capability). Terminal 20 may report terminal capability, including configurable parameters or fixed values, to base station 10. Base station 10 may transmit to terminal 20 setting information for the Semi-static switching pattern constraints based on the terminal capability reported by terminal 20. Furthermore, terminal capability indicating that switching between FDD carriers and SDL carriers can be performed even if at least some of the constraints of one or more of the Semi-static switching pattern described above are not met may also be reported to base station 10.

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

[0059] For example, according to this embodiment, by using a semi-static switching pattern with predetermined constraints applied in the switching between the FDD carrier and the SDL carrier, it becomes possible to design a flexible switching pattern. Furthermore, RRC signaling overhead can be reduced and communication efficiency can be improved. In addition, interference can be avoided and communication quality can be maintained.

[0060] (Device Configuration) Next, an example of the functional configuration of the base station 10 and terminal 20 that perform the processes and operations described above will be explained. The base station 10 and terminal 20 include the functions to carry out the embodiments described above. However, the base station 10 and terminal 20 may each be equipped with only some of the functions in the embodiments.

[0061] <Base Station> Figure 9 is a diagram showing an example of the functional configuration of the base station 10 in this embodiment. As shown in Figure 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 Figure 9 is merely an example. Any functional classification and functional unit names are acceptable as long as they can perform the operations according to this embodiment.

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

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

[0064] As described in the embodiment, the control unit 140 performs control related to setting, instructing, and notifying about low-power wake-up signals and the like. The signal transmission function unit of the control unit 140 may be included in the transmission unit 110, and the signal reception function unit of the control unit 140 may be included in the reception unit 120.

[0065] <Terminal> Figure 10 shows an example of the functional configuration of terminal 20 in this embodiment. As shown in Figure 10, 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 Figure 10 is merely an example. Any functional classification and functional unit names are acceptable as long as they can perform the operations according to this embodiment. The transmitting unit 210 and the receiving unit 220 may be collectively referred to as the communication unit.

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

[0067] As described in the embodiment, the control unit 240 performs control related to setting, instructing, and notifying of low-power wake-up signals. The signal transmission function unit of the control unit 240 may be included in the transmission unit 210, and the signal reception function unit of the control unit 240 may be included in the reception unit 220.

[0068] (Hardware Configuration) The block diagrams (Figures 9 and 10) used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of 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 it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the one device or the multiple devices with software.

[0069] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0070] For example, the base station 10, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 11 is a diagram showing an example of the hardware configuration of the base station 10 and terminal 20 according to one embodiment of the present disclosure. The above-mentioned base station 10 and terminal 20 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 explanation, the term "device" can be read as "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0072] Each function in the base station 10 and terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and storage device 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of the reading and writing of data in the storage device 1002 and auxiliary storage device 1003.

[0073] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, the control unit 140, control unit 240, etc., described above may be implemented by the processor 1001.

[0074] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 140 of the base station 10 shown in Figure 9 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in Figure 10 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-described processes have been explained as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may also be transmitted from the network via a telecommunications line.

[0075] The storage device 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, cache, main memory, etc. The storage device 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of the present disclosure.

[0076] The auxiliary storage device 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc 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 multipurpose disk, a Blu-ray® disk), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The above-mentioned storage medium may also be a database, server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

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

[0078] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., 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 different buses may be configured for each device.

[0080] Furthermore, the base station 10 and terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0081] Figure 12 shows an example of the configuration of vehicle 2001. As shown in Figure 12, 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 this disclosure may be applied to a communication device mounted on vehicle 2001, for example, to the communication module 2013.

[0082] The drive unit 2002 consists of, for example, 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, which is operated by the user.

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

[0084] Signals from various sensors 2021 to 2029 include current signals from current sensor 2021 for sensing motor current, front or rear wheel rotation speed signals acquired by rotation speed sensor 2022, front or rear wheel air pressure signals acquired by air pressure sensor 2023, vehicle speed signals acquired by vehicle speed sensor 2024, acceleration signals acquired by acceleration sensor 2025, accelerator pedal depression signals acquired by accelerator pedal sensor 2029, brake pedal depression signals acquired by brake pedal sensor 2026, shift lever operation signals acquired by shift lever sensor 2027, and detection signals acquired by object detection sensor 2028 for detecting obstacles, vehicles, pedestrians, etc.

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

[0086] The driver assistance system unit 2030 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System)), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driver assistance functions or autonomous driving functions.

[0087] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via its communication port. For example, the communication module 2013 sends and receives data via the communication port 2033 between the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, the microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021-29 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 external devices. For example, it can send and receive various types of information with external devices 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 or a mobile station.

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

[0090] The communication module 2013 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may also be called an output unit, which outputs information (for example, outputs information to devices such as displays and speakers 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 the external device 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 2021-2029, etc., provided in the vehicle 2001.

[0091] (Configuration relating to this embodiment) (Note 1) A terminal comprising: 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 time-division switching between the first carrier and the second carrier 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.

[0092] (Note 2) The terminal according to Note 1, wherein, with respect to the switching pattern, the number of slots or symbols of the second carrier that are consecutive in the switching pattern is further limited to a predetermined number or less.

[0093] (Note 3) The terminal according to Note 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] (Note 4) The first carrier included in the switching pattern is the terminal described in Note 1, which periodically includes a PRACH (Physical Random Access Channel) slot.

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

[0096] (Appendix 6) A communication method performed by a terminal, comprising the steps of: performing uplink communication and downlink communication using a first carrier and performing downlink communication using a second carrier; and performing time-division switching between the first carrier and the second carrier using a switching pattern, wherein at least one of the 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] In any of the above configurations, the FDD carrier and SDL carrier can be efficiently switched without degrading communication quality by using a switching pattern between FDD and SDL to which predetermined constraints are applied.

[0098] (Supplement to Embodiments) Although these embodiments have been described above, the disclosed invention is not limited to these embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but 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, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. The processing procedures described in the embodiments may be rearranged as long as they do not contradict each other. For the convenience of explaining the processing, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be realized in 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 be stored in any suitable storage medium such as random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or other appropriate storage medium.

[0099] Furthermore, notification of information is not limited to the embodiments described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or combinations thereof. Also, RRC signaling may be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0100] Each aspect / embodiment described in this disclosure may be applied to at least one of systems utilizing LTE (Long Term Evolution), LTE-A (LTE-Advanced), 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®, GSM®, CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth®, and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0101] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

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

[0103] The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

[0104] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0105] The determination in this disclosure may be made by a value represented by one bit (0 or 1), by a Boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0106] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0107] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

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

[0109] In addition, terms used 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 the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0110] The terms “system” and “network” as used in this disclosure are interchangeable.

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

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

[0113] In this disclosure, terms such as "Base Station (BS)", "wireless base station", "base station equipment", "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. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0115] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform control or operation based on the information.

[0116] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" 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 several other appropriate terms.

[0118] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to a movable object, and its speed of movement is arbitrary. This also includes the case when the mobile body is stationary. The mobile body includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and items mounted on them. The mobile body may also be a mobile body that moves autonomously based on operation commands. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Furthermore, at least one of the base station and the mobile station may include devices that do 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, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything)). In this case, the terminals 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel.

[0120] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the user terminal described above.

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

[0122] The terms “connected,” “coupled,” and any variations thereof mean 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” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

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

[0124] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0125] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the first and second elements do not imply that only two elements may be employed, or that the first element must precede the second element in any way.

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

[0127] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0128] A wireless frame may consist of one or more frames in the time domain. Each of these frames in the time domain may be called a subframe. A subframe may further consist 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] Numerical logic may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerical logic may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

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

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

[0132] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[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. In other words, at least one of a subframe and a TTI may be a subframe in existing LTE (1 ms), 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 unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each terminal 20 to allocate wireless resources (such as the frequency bandwidth and transmission power available to each terminal 20) in TTI units. However, the definition of TTI is not limited to this.

[0135] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Note that when a TTI is given, the actual time interval (e.g., number of symbols) in which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0136] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute the minimum time unit of scheduling may be controlled.

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

[0138] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

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

[0140] Furthermore, the time domain of the RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0141] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

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

[0143] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a particular neurology in a given carrier. These common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. The PRBs may be defined and numbered within a given BWP.

[0144] A BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be set within a single carrier for a UE.

[0145] At least one of the configured BWPs may be active, and the UE does not need to assume that it will transmit or receive a predetermined signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0146] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless 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, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways.

[0147] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0148] In this 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 "combine" may be interpreted similarly to "different."

[0149] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0150] Although the present disclosure has been described in detail above, it will be 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 intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way.

[0151] This patent application claims priority based on Japanese Patent Application No. 2025-009501, filed on 22 January 2025, and the entire contents of Japanese Patent Application No. 2025-009501 are incorporated herein by reference.

[0152] 10 Base station 110 Transmitting unit 120 Receiving unit 130 Setting unit 140 Control unit 20 Terminal 210 Transmitting unit 220 Receiving unit 230 Setting unit 240 Control unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Front wheel 2008 Rear wheel 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 Rotation speed 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 Driver assistance system unit 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port (I / O port)

Claims

1. A terminal comprising: 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 time-division switching between the first carrier and the second carrier 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.

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

3. 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 terminal capability information to a base station, which includes 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 the steps of: performing uplink communication and downlink communication using a first carrier and performing downlink communication using a second carrier; and performing time-division switching between the first carrier and the second carrier using a switching pattern, wherein at least one of the 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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