Terminal and communication method

Abstract

This terminal has: a control unit that identifies a first transmission occasion for transmitting a message for use in a two-step random-access procedure through a physical random-access channel and a second transmission occasion for transmitting the message through a physical uplink shared channel; and a transmission unit that transmits the message by using the first and second transmission occasions, wherein the control unit changes a method for identifying the second transmission occasion when the first transmission occasion becomes disabled.

Description

[Technical field]

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

[0002] For NR (New Radio) (also known as "5G"), the successor system to LTE (Long Term Evolution), technologies are being considered that satisfy the requirements of a large-capacity system, high-speed data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, low power consumption, etc. (e.g., Non-Patent Document 1).

[0003] In NR, random access is performed to establish synchronization between a terminal and a base station or to make a scheduling request, similar to LTE. There are two types of random access procedures: a contention-based random access procedure (CBRA) and a contention-free random access procedure (CFRA) (see, for example, Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V15.7.0(2019-09) [Non-Patent Document 2] 3GPP TS 38.321 V15.7.0(2019-09) Summary of the Invention [Problem to be solved by the invention]

[0005] In the contention-based random access procedure of the NR wireless communication system, in addition to the conventional four-step random access procedure, a two-step random access procedure using MsgA and MsgB is being considered. In the two-step random access procedure, the terminal and the base station determine the transmission opportunity of the PRACH (Physical Random Access Channel) of MsgA and The MsgA is associated with a transmission opportunity for a Physical Uplink Shared Channel (PUSCH) that transmits the data portion of the MsgA excluding the random access preamble.

[0006] However, for example, when the PRACH transmission opportunity partially or completely overlaps with the downlink or SSB (SS / PBCH block) in the time domain, the PRACH transmission opportunity is considered to be invalid and is not used. In this case, it is necessary to appropriately change the association between the PRACH transmission opportunity and the PUSCH transmission opportunity.

[0007] The present invention has been made in consideration of the above points, and has an object to determine resources to be used for a two-step random access procedure in a wireless communication system. [Means for solving the problem]

[0008] According to the disclosed technology, A control unit determines, when a transmission opportunity of a random access preamble and a transmission opportunity of uplink channel data that do not overlap in a time domain and a frequency domain, as a valid transmission opportunity when the transmission opportunity of the random access preamble and the transmission opportunity of the uplink channel data are associated in a two-step random access procedure, and a transmission unit transmits a message including the random access preamble and the uplink channel data to a base station by using the determined transmission opportunity of the random access preamble and the transmission opportunity of the uplink channel data. A terminal is provided. Effect of the Invention

[0009] According to the disclosed technique, it is possible to determine resources to be used for a two-step random access procedure in a wireless communication system. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of a configuration of a wireless communication system according to an embodiment of the present invention. [Diagram 2]FIG. 11 is a sequence diagram illustrating an example of a four-step random access procedure. [Diagram 3] FIG. 11 is a sequence diagram illustrating an example of a two-step random access procedure. [Figure 4] FIG. 1 is a diagram showing a resource allocation example (1) of a two-step random access procedure in an embodiment of the present invention. [Figure 5A] FIG. 13 is a diagram showing a resource allocation example (2) of a two-step random access procedure in the embodiment of the present invention. [Figure 5B] FIG. 11 is a diagram showing a resource allocation example (3) of a two-step random access procedure in the embodiment of the present invention. [Figure 6A] FIG. 11 is a diagram showing a resource allocation example (4) of a two-step random access procedure in the embodiment of the present invention. [Figure 6B] FIG. 5 is a diagram showing a resource allocation example (5) of a two-step random access procedure in an embodiment of the present invention. [Figure 6C] FIG. 6 is a diagram showing a resource allocation example (6) of a two-step random access procedure in the embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing a resource allocation example (7) of a two-step random access procedure in an embodiment of the present invention. [Figure 8] 2 is a diagram illustrating an example of a functional configuration of a base station 10 according to an embodiment of the present invention. [Figure 9] 2 is a diagram illustrating an example of a functional configuration of a terminal 20 according to an embodiment of the present invention. [Figure 10] 2 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described 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.

[0012] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are used as appropriate. However, the existing technologies are, for example, existing LTE, but are not limited to existing LTE. In addition, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and systems after LTE-Advanced (e.g., NR) unless otherwise specified.

[0013] In the embodiment of the present invention described below, 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) used in existing LTE are used. This is for convenience of description, and similar signals, functions, etc. may be called by other names. In addition, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even if a signal is used in NR, it is not necessarily specified as "NR-".

[0014] Furthermore, in the embodiment of the present invention, the duplexing method may be a time division duplex (TDD) method, a frequency division duplex (FDD) method, or another method (for example, flexible duplex, etc.).

[0015] Furthermore, in the embodiment of the present invention, when radio parameters, etc. are "configured," this may mean that predetermined values ​​are pre-configured, or that radio parameters notified from base station 10 or terminal 20 are configured.

[0016] Fig. 1 is a diagram showing an example of the configuration of a wireless communication system according to an embodiment of the present invention. As shown in Fig. 1, the wireless communication system according to the embodiment of the present invention 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.

[0017] 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 a time domain and a frequency domain, and 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 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, NR-PSS and NR-SSS. The system information is, for example, transmitted by NR-PBCH and is also called broadcast information. As shown in FIG. 1, the base station 10 transmits a control signal or data to the terminal 20 in DL (Downlink) and receives a control signal or data from the terminal 20 in UL (Uplink). Both the base station 10 and the terminal 20 can transmit and receive signals by performing beamforming. In addition, both the base station 10 and the terminal 20 can apply communication by MIMO (Multiple Input Multiple Output) to 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) by CA (Carrier Aggregation). Furthermore, the terminal 20 may communicate via a primary cell of the base station 10 and a primary secondary cell (PSCell: Primary Secondary Cell) of another base station 10 by DC (Dual Connectivity).

[0018] 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, a communication module for M2M (Machine-to-Machine), etc. As shown in Fig. 1, the terminal 20 receives a control signal or data from the base station 10 via DL and transmits a control signal or data to the base station 10 via UL, thereby using various communication services provided by the wireless communication system.

[0019] Here, in a random access procedure executed for establishing synchronization or making a scheduling request between the terminal 20 and the base station 10, for example, the terminal 20 transmits a random access preamble or a UE (User Equipment) identifier to the base station 10 as a UL signal, and the base station 10 transmits a random access response and information for resolving collisions to the terminal 20 as a DL signal.

[0020] FIG. 2 is a sequence diagram for explaining an example of a four-step random access procedure. The example of the random access procedure shown in FIG. 2 is a contention-based four-step random access procedure. In step S11, the terminal 20 transmits a random access preamble as Msg1 to the base station 10. Then, the base station 10 transmits a random access response as Msg2 to the terminal 20 (S12). Then, the terminal 20 transmits a UE identifier as Msg3 to the base station 10 (S13). Then, the base station 10 transmits information for performing collision resolution as Msg4 to the terminal 20. If the collision resolution is successful, the random access procedure is successfully completed.

[0021] FIG. 3 is a sequence diagram for explaining an example of a two-step random access procedure. The example of the random access procedure shown in FIG. 3 is a collision-type two-step random access procedure. The two-step random access procedure is being considered to complete the random access procedure in a short period of time. In step S21, the terminal 20 transmits a random access preamble via PRACH and data via PUSCH to the base station 10 as MsgA. For example, content equivalent to Msg1 and Msg3 in the four-step random access procedure may be transmitted via PUSCH. Then, the base station 10 transmits a random access response and information for collision resolution as MsgB to the terminal 20 (S22). For example, MsgB may include content equivalent to Msg2 and Msg4 in the four-step random access procedure. When collision resolution is successful, the random access procedure is successfully completed. By adopting the two-step random access procedure, effects such as low delay and reduced power consumption are expected.

[0022] In addition, the four-step random access procedure and the two-step random access procedure can also perform contention-free random access by, for example, allocating a random access preamble from the base station 10 to the terminal 20.

[0023] Details of MsgA in the two-step random access procedure are being considered. For example, MsgA is composed of a random access preamble and a PUSCH. It is assumed that the random access preamble and the PUSCH are not a single resource at least in the physical layer. For example, it is assumed that the random access preamble and the PUSCH, which are separated as physical resources, are defined as MsgA.

[0024] That is, an MsgA-PUSCH transmission opportunity (MsgA PUSCH occasion) may be defined as one MsgA-PUSCH resource. Similarly, an MsgA-PRACH transmission opportunity (MsgA PRACH occasion) may be defined as a resource for transmitting one MsgA-preamble. Hereinafter, the "MsgA-PUSCH transmission opportunity" is also referred to as "MsgA-PO," and the "MsgA-PRACH transmission opportunity" is also referred to as "MsgA-RO."

[0025] It is considered to define a correspondence relationship between MsgA-PUSCH transmission opportunities and MsgA-PRACH transmission opportunities. The correspondence relationship may be, for example, one MsgA-PRACH transmission opportunity and one MsgA-PUSCH transmission opportunity, one MsgA-PRACH transmission opportunity and multiple MsgA-PUSCH transmission opportunities, or multiple MsgA-PRACH transmission opportunities and multiple MsgA-PUSCH transmission opportunities. The terminal 20 identifies the MsgA-PRACH transmission opportunity and the MsgA-PUSCH transmission opportunity, and transmits MsgA to the base station 10.

[0026] As a method of notifying the resource position in the time domain of the MsgA-PUSCH transmission opportunity, when the configuration periodicity of the MsgA-PRACH transmission opportunity and the MsgA-PUSCH transmission opportunity are the same, a method of notifying the resource position in the time domain of the MsgA-PUSCH slot by a time offset from the start position of the MsgA-PRACH slot is under consideration. The MsgA-PRACH slot is a slot that includes the MsgA-PRACH transmission opportunity. The MsgA-PUSCH slot is a slot that includes the MsgA-PUSCH transmission opportunity. The base station 10 notifies the terminal 20 of information indicating the position of the MsgA-PRACH slot in the time domain and information indicating the position of the MsgA-PUSCH slot in the time domain.

[0027] Here, regarding MsgA-RO, if the transmission opportunity of PRACH overlaps partially or completely with the downlink or SSB (SS / PBCH block) in the time domain, it is assumed that MsgA-RO is invalid and not used. In this case, it is necessary to appropriately specify the operation regarding MsgA-PO having a corresponding relationship with the invalidated MsgA-RO. Hereinafter, "downlink" may be DL part specified by TDD configuration.

[0028] Furthermore, when MsgA-PO and MsgA-RO overlap even partially in the time domain and the MsgA-PO and the MsgA-RO have a corresponding relationship, i.e., when terminal 20 that transmits PRACH via the MsgA-RO transmits PUSCH via the MsgA-PO, it is not desirable for terminal 20 to transmit PRACH and PUSCH simultaneously from the viewpoint of the complexity or PSD (Power Spectral Density) of terminal 20.

[0029] In addition, when MsgA-PO and MsgA-RO overlap even partially in the time domain and do not have a corresponding relationship, the base station 10 cannot receive PRACH and PUSCH with an appropriate reception beam in the case of analog beamforming. That is, only either PRACH or PUSCH can be received with an appropriate reception beam.

[0030] Therefore, when MsgA-RO with which MsgA-PO has a corresponding relationship becomes invalid, the terminal 20 may similarly invalidate the MsgA-PO.

[0031] Fig. 4 is a diagram showing a resource allocation example (1) of a two-step random access procedure in an embodiment of the present invention. As shown in Fig. 4, when MsgA-RO and MsgA-PO have a corresponding relationship, when MsgA-RO becomes invalid, terminal 20 may also invalidate MsgA-PO having a corresponding relationship with MsgA-RO. Hereinafter, the line connecting RO and PO shown in the figure indicates that RO and PO have a corresponding relationship.

[0032] Here, in FIG. 4, the correspondence between MsgA-PO and MsgA-RO may be determined before the determination of whether MsgA-RO is invalid or not is executed.

[0033] Fig. 5A is a diagram showing a resource allocation example (2) of a two-step random access procedure in an embodiment of the present invention, and Fig. 5B is a diagram showing a resource allocation example (3) of a two-step random access procedure in an embodiment of the present invention.

[0034] When MsgA-RO becomes invalid, the invalid MsgA-RO may be excluded from the MsgA-RO that is the subject of determining the correspondence between MsgA-RO and MsgA-PO.

[0035] If MsgA-RO is not invalid, the correspondence between MsgA-RO and MsgA-PO is determined as shown in FIG. 5A.

[0036] On the other hand, if MsgA-RO is invalid, the invalid MsgA-RO is excluded from the target when determining the correspondence relationship with MsgA-PO, and therefore, as shown in Figure 5B, the correspondence relationship between the MsgA-RO and MsgA-PO does not need to be determined.

[0037] Here, in Figures 5A and 5B, the arrangement of MsgA-PO may be performed before a determination is made as to whether MsgA-RO is invalid, and the correspondence between MsgA-PO and MsgA-RO may be determined after a determination is made as to whether MsgA-RO is invalid.

[0038] Fig. 6A is a diagram showing a resource allocation example (4) of a two-step random access procedure in an embodiment of the present invention. Fig. 6B is a diagram showing a resource allocation example (5) of a two-step random access procedure in an embodiment of the present invention. Fig. 6C is a diagram showing a resource allocation example (6) of a two-step random access procedure in an embodiment of the present invention.

[0039] When MsgA-RO becomes invalid, the invalid MsgA-RO may be excluded from the target MsgA-RO when the MsgA-PUSCH slot is specified by a time offset from the MsgA-PRACH slot.

[0040] For example, the MsgA-PRACH slot including only the invalid MsgA-RO may not specify the MsgA-PUSCH slot by the time offset. Also, the MsgA-PRACH slot not specified by the time offset may be invalid.

[0041] Alternatively, when a MsgA-PUSCH slot is specified by a time offset from a MsgA-PRACH slot that includes only an invalid MsgA-RO, the terminal 20 may determine that the specified MsgA-PUSCH slot is invalid.

[0042] If MsgA-RO is not invalid, the MsgA-PUSCH slot is specified by a time offset from the MsgA-PRACH slot containing MsgA-RO, and the correspondence between MsgA-RO and MsgA-PO is further determined, as shown in FIG. 6A.

[0043] On the other hand, when MsgA-RO is invalid, no MsgA-PUSCH slot is specified by a time offset from the MsgA-PRACH slot that includes only the invalid MsgA-RO. Therefore, as shown in FIG. 6B, the MsgA-RO does not need to have a correspondence relationship with MsgA-PO, and the MsgA-PRACH slot may be invalid.

[0044] Also, as shown in FIG. 6C, when some MsgA-ROs in the MsgA-PRACH slot are invalid, when a MsgA-PUSCH slot is specified by a time offset from the MsgA-PRACH slot, the MsgA-PO corresponding to the invalid MsgA-RO among the MsgA-POs included in the specified MsgA-PUSCH slot may not be placed or may be invalid. Note that, when some MsgA-ROs in the MsgA-PRACH slot are invalid, a MsgA-PUSCH slot may not be specified by a time offset from the MsgA-PRACH slot. Also, when some MsgA-ROs in the MsgA-PRACH slot are invalid, the MsgA-PRACH slot may be invalid. All MsgA-ROs included in the invalid MsgA-PRACH slot may be invalid.

[0045] Here, in FIG. 6A, FIG. 6B, and FIG. 6C, after it is determined whether or not MsgA-RO is invalid, the correspondence between MsgA-PO and MsgA-RO may be determined.

[0046] 7 is a diagram showing a resource allocation example (7) of the two-step random access procedure in the embodiment of the present invention. When MsgA-RO and MsgA-PO overlap in the time domain, terminal 20 may invalidate either one of them.

[0047] For example, as shown in FIG. 7, when there is a portion in the time domain of MsgA-RO that overlaps with MsgA-PO, the terminal 20 may prioritize MsgA-RO and invalidate Msg-PO.

[0048] Also, for example, if there is a portion where MsgA-RO and MsgA-PO overlap in the time domain, the terminal 20 may give priority to the one that is placed earlier in the time domain and invalidate the other.

[0049] Also, for example, when there is a portion where MsgA-RO and MsgA-PO overlap in the time domain, which one is to be invalidated may be determined based on other conditions. The other conditions may be, for example, a condition that FR2 (Frequency Range 2) is used. The other conditions may be, for example, a condition that analog beamforming is used. The other conditions may be, for example, a condition that MsgA-RO and MsgA-PO overlapping in the time domain do not have a corresponding relationship, or a condition that MsgA-RO and MsgA-PO overlapping in the time domain do not have a corresponding relationship may be added to the above other conditions.

[0050] If MsgA-RO and MsgA-PO have overlapping portions in the time domain, and furthermore, if they have overlapping portions in the frequency domain, the terminal 20 may invalidate either one of them.

[0051] For an MsgA-PO, if the downlink or SSB overlaps partially or completely in the time domain, the MsgA-PO may be invalidated. Also, for an MsgA-PO, if a period following the downlink or SSB overlaps partially or completely in the time domain, the MsgA-PO may be invalidated. When an MsgA-PO is invalidated, the MsgA-PO may be excluded from the target MsgA-POs when determining the correspondence between MsgA-RO and MsgA-PO.

[0052] In addition, the specification may specify a resource allocation method and a method of defining a correspondence relationship that guarantees that there is no overlap between MsgA-RO and MsgA-PO in the time domain. Here, the guarantee that there is no overlap between MsgA-RO and MsgA-PO in the time domain may be only between MsgA-RO and MsgA-PO that have a correspondence relationship, only between MsgA-RO and MsgA-PO that do not have a correspondence relationship, or both.

[0053] For example, in the case of periodically arranged MsgA-RO and MsgA-PO, the correspondence between MsgA-RO and MsgA-PO may be determined within a certain period, i.e., only MsgA-RO and MsgA-PO may have a correspondence relationship within a certain periodically repeated period. It is also possible that the correspondence between MsgA-RO and MsgA-PO is not determined across different periods within a certain periodically repeated period.

[0054] According to the above embodiment, when MsgA-RO is invalid, the terminal 20 can invalidate MsgA-PO having a corresponding relationship with the MsgA-RO to be used and efficiently specify MsgA-PO having a corresponding relationship with the MsgA-RO. When MsgA-RO is invalid, the terminal 20 can exclude the MsgA-RO and efficiently specify MsgA-PO having a corresponding relationship with another MsgA-RO. When MsgA-RO is invalid, the terminal 20 can invalidate MsgA-PRACH slot including the MsgA-RO and prevent MsgA-PUSCH slot from being specified by a time offset from the MsgA-PRACH slot.

[0055] That is, in a wireless communication system, it is possible to determine resources to be used for a two-step random access procedure.

[0056] (Device configuration) Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described above will be described. The base station 10 and the terminal 20 include functions for implementing the above-mentioned embodiments. However, the base station 10 and the terminal 20 may each include only a part of the functions in the embodiments.

[0057] <Base station 10> Fig. 8 is a diagram showing an example of a functional configuration of base station 10 in the embodiment of the present invention. As shown in Fig. 8, 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. 8 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 related to the embodiment of the present invention.

[0058] The transmitting unit 110 includes a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The transmitting unit 110 also transmits an inter-network node message to another network node. The receiving unit 120 includes a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signal. The transmitting unit 110 also has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, etc. to the terminal 20. The receiving unit 120 also receives an inter-network node message from another network node.

[0059] 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 the setting of two-step random access.

[0060] The control unit 140 performs control related to two-step random access as described in the embodiment. The function unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and the function unit related to signal reception in the control unit 140 may be included in the receiving unit 120.

[0061] <Terminal 20> Fig. 9 is a diagram showing an example of a functional configuration of terminal 20 in the embodiment of the present invention. As shown in Fig. 9, terminal 20 has transmitting unit 210, receiving unit 220, setting unit 230, and control unit 240. 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 related to the embodiment of the present invention.

[0062] The transmitter 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiver 220 wirelessly receives various signals and acquires a higher layer signal from the received physical layer signal. The receiver 220 also has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, and the like transmitted from the base station 10. For example, the transmitter 210 transmits a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), and the like to another terminal 20 as D2D communication, and the receiver 220 receives the PSCCH, the PSSCH, the PSDCH, or the PSBCH, and the like from the other terminal 20.

[0063] 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 setting information that is set in advance. The setting information includes, for example, settings for two-step random access.

[0064] The control unit 240 performs control related to two-step random access as described in the embodiment. The function unit related to signal transmission in the control unit 240 may be included in the transmission unit 210, and the function unit related to signal reception in the control unit 240 may be included in the reception unit 220.

[0065] (Hardware configuration) The block diagrams (FIGS. 8 and 9) 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 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 combined, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected (e.g., using wires, wirelessly, etc.) and these multiple devices. The functional blocks may be realized by combining the one device or the multiple devices with software.

[0066] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocation, mapping, assignment, etc. For example, a functional block (component) that performs the function of transmission is called a transmitting unit or a transmitter. In either case, as described above, there is no particular limitation on the method of realization.

[0067] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 10 is a diagram showing an example of a hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The above-mentioned base station 10 and the 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.

[0068] In the following description, the term "apparatus" can be interpreted 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 devices shown in the figure, or may be configured to exclude some of the devices.

[0069] Each function in the base station 10 and the terminal 20 is realized by loading a specific software (program) onto hardware such as a processor 1001, a memory device 1002, etc., so that the processor 1001 performs calculations, controls communications by the communication device 1004, and controls at least one of reading and writing of data in the memory device 1002 and the auxiliary memory device 1003.

[0070] 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.

[0071] Moreover, the processor 1001 reads out a program (program code), a software module, data, or the like from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and executes various processes according to the program. As the program, a program that causes a computer to execute at least a part of the operations described in the above-mentioned embodiment is used. For example, the control unit 140 of the base station 10 shown in FIG. 8 may be realized 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 FIG. 9 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-mentioned various processes have been described as being executed by one processor 1001, they may be executed by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunication line.

[0072] The storage device 1002 is a computer-readable recording medium, and may be configured by at least one of, for example, 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 (primary storage device), etc. The storage device 1002 can store a program (program code), software modules, etc. that are executable to implement a communication method according to an embodiment of the present disclosure.

[0073] The auxiliary 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 (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) 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 auxiliary storage device 1003.

[0074] The communication device 1004 is hardware (transmission and reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to realize at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, a transmission and reception antenna, an amplifier unit, a transmission and reception unit, a transmission line interface, etc. may be realized by the communication device 1004. The transmission and reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated from each other.

[0075] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0076] In addition, 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.

[0077] Furthermore, the base station 10 and the 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), a field programmable gate array (FPGA), etc., and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0078] (Summary of the embodiment) As described above, according to an embodiment of the present invention, there is provided a terminal having a control unit that identifies a first transmission opportunity for transmitting a message to be used in a two-step random access procedure on a physical random access channel and a second transmission opportunity for transmitting the message on a physical uplink shared channel, and a transmission unit that transmits the message using the first transmission opportunity and the second transmission opportunity, wherein the control unit changes a method for identifying the second transmission opportunity when the first transmission opportunity becomes invalid.

[0079] With the above configuration, when MsgA-RO is invalid, terminal 20 can invalidate MsgA-PO corresponding to MsgA-RO to be used and efficiently specify MsgA-PO corresponding to MsgA-RO. When MsgA-RO is invalid, terminal 20 can efficiently specify MsgA-PO corresponding to other MsgA-RO by excluding MsgA-RO. When MsgA-RO is invalid, terminal 20 can invalidate MsgA-PRACH slot including MsgA-RO and prevent MsgA-PUSCH slot by time offset from MsgA-PRACH slot. That is, in the wireless communication system, resources to be used for the two-step random access procedure can be determined.

[0080] The control unit may invalidate the second transmission opportunity when the first transmission opportunity is invalid. With this configuration, when the MsgA-RO is invalid, the terminal 20 invalidates the MsgA-PO that has a corresponding relationship with the MsgA-RO, and can efficiently identify the MsgA-PO that has a corresponding relationship with the MsgA-RO to be used.

[0081] The control unit may exclude the first transmission opportunity from the target to which the second transmission opportunity is associated when the first transmission opportunity is invalid. With this configuration, when an MsgA-RO is invalid, the terminal 20 can efficiently identify an MsgA-PO having a corresponding relationship with another MsgA-RO by excluding the MsgA-RO.

[0082] When the first transmission opportunity is invalidated, the control unit may invalidate the second transmission opportunity included in a slot of a physical uplink shared channel specified by a time offset from a slot of a physical random access channel including the first transmission opportunity and a valid transmission opportunity. With this configuration, when an MsgA-RO is invalidated, the terminal 20 can invalidate an MsgA-PO having a corresponding relationship with the MsgA-RO to be used, and efficiently identify an MsgA-PO having a corresponding relationship with the MsgA-RO.

[0083] The control unit may invalidate either the first transmission opportunity or the second transmission opportunity when the first transmission opportunity and the second transmission opportunity overlap in part or in whole in the time domain. With this configuration, the terminal 20 can invalidate either MsgA-RO or MsgA-PO that overlaps in the time domain, and efficiently identify MsgA-PO that has a corresponding relationship with MsgA-RO to be used.

[0084] Also, according to an embodiment of the present invention, there is provided a communication method in which a terminal executes a control procedure for identifying a first transmission opportunity for transmitting a message used for a two-step random access procedure on a physical random access channel and a second transmission opportunity for transmitting the message on a physical uplink shared channel, and a transmission procedure for transmitting the message using the first transmission opportunity and the second transmission opportunity, the control procedure including a procedure for changing a method for identifying the second transmission opportunity when the first transmission opportunity becomes invalid.

[0085] With the above configuration, when MsgA-RO is invalid, terminal 20 can invalidate MsgA-PO corresponding to MsgA-RO to be used and efficiently specify MsgA-PO corresponding to MsgA-RO. When MsgA-RO is invalid, terminal 20 can efficiently specify MsgA-PO corresponding to other MsgA-RO by excluding MsgA-RO. When MsgA-RO is invalid, terminal 20 can invalidate MsgA-PRACH slot including MsgA-RO and prevent MsgA-PUSCH slot by time offset from MsgA-PRACH slot. That is, in the wireless communication system, resources to be used for the two-step random access procedure can be determined.

[0086] (Supplementary embodiment) Although the embodiment of the present invention has been described above, the disclosed invention is not limited to such an embodiment, and those skilled in the art will understand various modifications, modifications, alternatives, replacements, and the like. Although the description has been given using specific numerical examples to facilitate understanding of the invention, unless otherwise specified, those 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 used in combination as necessary, and matters described in one item may be applied to matters described in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operations of multiple functional units may be physically performed by one part, or the operations of one functional unit may be physically performed by multiple parts. The order of the processing procedures described in the embodiment may be changed as long as there is no contradiction. For convenience of the processing description, the base station 10 and the terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software operated by the processor possessed by the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor possessed by the terminal 20 in accordance with an embodiment of the present invention may each be stored in a random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0087] 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 of these. Furthermore, the RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0088] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using 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 (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-WideBand), Bluetooth (registered trademark), and other suitable systems, and next-generation systems extended based on these. In addition, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) may be applied.

[0089] The steps, sequences, flow charts, etc. of each aspect / embodiment described herein may be reordered unless inconsistent. 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.

[0090] In this specification, a specific operation performed by the base station 10 may 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 other network nodes other than the base station 10 (e.g., MME or S-GW, etc., but are not limited to these). Although the above example illustrates a case in which 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 (e.g., MME and S-GW).

[0091] 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.

[0092] The input and output information may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be transmitted to another device.

[0093] 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).

[0094] 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.

[0095] Additionally, software, instructions, information, etc. may be transmitted or received over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired and / or wireless technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave, etc.), then these wired and / or wireless technologies are included within the definition of transmission media.

[0096] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. 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 voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0097] In addition, the terms described in this disclosure and the 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). Also, a signal may be a message. Also, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0098] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0099] In addition, the information, parameters, etc. described in the present disclosure may be represented using absolute values, may be represented using relative values ​​from a predetermined value, or may be represented using other corresponding information. For example, a radio resource may be indicated by an index.

[0100] The names used for the above-mentioned parameters are not limiting in any way. Moreover, the formulas 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 limiting in any way.

[0101] In the present disclosure, terms such as "base station (BS)", "wireless 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", "component carrier", etc. may be used interchangeably. A base station may also be referred to by terms such as a macro cell, a small cell, a femto cell, a pico cell, etc.

[0102] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services 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 a base station subsystem that provides communication services in this coverage.

[0103] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0104] 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.

[0105] 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 be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving body (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 include a device that does not necessarily move during communication operation. 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.

[0106] Furthermore, the base station in the present disclosure may be read as a user terminal. For example, each aspect / embodiment 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, an uplink channel, a downlink channel, etc. may be read as a side channel.

[0107] Similarly, a user terminal in the present disclosure may be read as a base station. In this case, the base station may be configured to have the functions of the above-mentioned user terminal.

[0108] 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, search, inquiry (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 a memory), and the like. In addition, "judgment" and "decision" can include considering resolving, selecting, choosing, establishing, comparing, etc., to be a "judgment" or "decision." In other words, "judgment" and "decision" can include considering some action to be a "judgment" or "decision." In addition, "judgment" can be interpreted as "assuming," "expecting," "considering," etc.

[0109] 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.

[0110] The reference signal may be abbreviated as RS (Reference Signal) and may be called a pilot depending on the applicable standard.

[0111] 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."

[0112] Any reference to an element using a designation such as "first," "second," etc., 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 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 precede the second element in some way.

[0113] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0114] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Further, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0115] 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.

[0116] The numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as, for example, at least one of a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), a number of symbols per TTI, a radio frame structure, a particular filtering operation that the transceiver performs in the frequency domain, a particular windowing operation that the transceiver performs in the time domain, etc.

[0117] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time domain. A slot may be a time unit based on numerology.

[0118] A slot may include multiple minislots. Each minislot may be composed of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may be composed 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.

[0119] A radio frame, a subframe, a slot, a minislot, and a symbol each represent a time unit for transmitting a signal. The radio frame, the subframe, the slot, the minislot, and the symbol may each be referred to by a different name.

[0120] 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 the existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit expressing the TTI may be called a slot, a minislot, or the like, instead of a subframe.

[0121] Here, TTI refers to, for example, the minimum 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.

[0122] 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) in which a transport block, a code block, a code word, etc. are actually mapped may be shorter than the TTI.

[0123] In addition, when one slot or one minislot is called TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. Also, the number of slots (minislots) constituting the minimum time unit of scheduling may be controlled.

[0124] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a slot, etc.

[0125] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length exceeding 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.

[0126] A resource block (RB) is a resource allocation unit in the time domain and the 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 the numerology, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0127] In addition, the time domain of the RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each of one TTI, one subframe, etc. may be composed of one or more resource blocks.

[0128] Note that one or more RBs may 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.

[0129] 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.

[0130] 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 numerology on a carrier, where the common RBs may be identified by an index of the RBs relative to a common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0131] 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.

[0132] 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 replaced with "BWP".

[0133] The above-mentioned 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.

[0134] In this disclosure, where articles have been added due to translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0135] 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."

[0136] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched according to execution. In addition, notification of specific information (e.g., notification that "X is the case") is not limited to being done explicitly, but may be done implicitly (e.g., not notifying the specific information).

[0137] In the present disclosure, MsgA is an example of a message used in a two-step random access procedure. PRACH is an example of a physical random access channel. PUSCH is an example of a physical uplink shared channel. MsgA-RO is an example of a first transmission opportunity. MsgA-PO is an example of a second transmission opportunity.

[0138] 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 in the present disclosure. 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]

[0139] 10 base station 110 Transmitter 120 Receiving unit 130 Setting section 140 Control section 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

Claims

1. In a two-step random access procedure, when a random access preamble transmission opportunity corresponds to an uplink channel data transmission opportunity, the random access preamble transmission opportunity and the uplink channel data transmission opportunity overlap in a time domain and a frequency domain, and a control unit invalidates the overlapping uplink channel data transmission opportunity; A transmitter that transmits a message including the random access preamble and the uplink channel data to a base station using a transmission opportunity of the random access preamble and a transmission opportunity of the uplink channel data that does not overlap with the transmission opportunity of the random access preamble in a time domain and a frequency domain; A terminal comprising:

2. The terminal according to claim 1, wherein the transmitting unit does not use the uplink channel data transmission opportunity to transmit the uplink channel data when the transmission opportunity of the random access preamble to which the uplink channel data transmission opportunity corresponds becomes invalid.

3. A communication system having a terminal and a base station, The terminal includes: In a two-step random access procedure, when a random access preamble transmission opportunity and an uplink channel data transmission opportunity are associated with each other, the random access preamble transmission opportunity and the uplink channel data transmission opportunity overlap in a time domain and a frequency domain, and the overlapping uplink channel data transmission opportunity is invalidated; Transmitting a message including the random access preamble and the uplink channel data to a base station using a transmission opportunity of the random access preamble and a transmission opportunity of the uplink channel data that does not overlap with the transmission opportunity of the random access preamble in a time domain and a frequency domain; The base station receives a message including the random access preamble and the uplink channel data from a terminal.

4. In a two-step random access procedure, when a random access preamble transmission opportunity corresponds to an uplink channel data transmission opportunity, the random access preamble transmission opportunity and the uplink channel data transmission opportunity overlap in a time domain and a frequency domain, and the overlapping uplink channel data transmission opportunity is invalidated; Transmitting a message including the random access preamble and the uplink channel data to a base station using a transmission opportunity of the random access preamble and a transmission opportunity of the uplink channel data that does not overlap with the transmission opportunity of the random access preamble in a time domain and a frequency domain; A communication method for a terminal comprising:

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