Base station, communication method and integrated circuit

Abstract

To provide a terminal and a communication method for improving a transmission quality in a repetitive transmission of uplink control information.SOLUTION: A base station 100 comprises: a transmission circuit which transmits quasi-static PUCCH resource set setting information using a terminal-specific high-order layer signal and transmits instruction information of a PUCCH resource for receiving ACK / NACK for PDSCH allocated by a DCI; and a reception circuit in which the PUCCH resource includes information relating to the presence / absence of PUCCH repetition or information relating to the number of times of repetitions in each repetitive transmission (Repetition) as a parameter constituting the PUCCH resource and the quasi-static PUCCH resource set setting information sets a plurality of reception opportunities to a unit time interval corresponding to a scheduling unit and which performs the repetitive transmission of uplink control information using PUCCH in accordance with the instruction information of the PUCCH resource in the plurality of reception opportunities.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a terminal and a communication method. [Background technology]

[0002] In recent years, the expansion and diversification of wireless services has led to the expectation of rapid development of the Internet of Things (IoT). Mobile communications are now being used in a wide range of applications, from smartphones and other information terminals to automobiles, homes, home appliances, and industrial equipment. To support this diversification, significant improvements in the performance and functionality of mobile communication systems are required, addressing various requirements, such as increased system capacity, an increased number of connected devices, and low latency. Against this backdrop, research, development, and standardization of 5G (5th Generation mobile communication systems) are underway. By leveraging enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low-latency communication (URLLC), 5G promises to provide flexible wireless communications tailored to diverse needs.

[0003] The 3rd Generation Partnership Project (3GPP), an international standardization organization, is working on the specification of New Radio (NR) as one of the 5G wireless interfaces. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS38.104 V15.8.0, “NR Base Station (BS) radio transmission and reception (Release 15),” 2019-12. [Non-licensed document 2] RP-193240, “New SID on NR coverage enhancement,” China Telecom, December 2019. [Non-licensed document 3] 3GPP TS 38.211 V15.8.0, "NR; Physical channels and modulation (Release 15)," 2019-12.

Non-licensed Document 4

Non-licensed Document 5

Non-licensed Document 6

Non-licensed Document 7

Non-licensed literature 9

[0005] However, there is room for further consideration regarding repetition of uplink control information (hereinafter, for convenience, sometimes referred to as "uplink control information").

[0006] Non-limiting examples of the present disclosure contribute to providing a terminal and a communication method that can improve transmission quality in repeated transmission of uplink control information. [Means for solving the problem]

[0007] A terminal according to one embodiment of the present disclosure includes a control circuit that sets multiple first transmission opportunities for a unit time interval corresponding to a scheduling unit, and a transmission circuit that repeatedly transmits uplink control information during the multiple first transmission opportunities.

[0008] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. [Effects of the Invention]

[0009] According to an embodiment of the present disclosure, it is possible to improve the transmission quality in repeated transmission of uplink control information.

[0010] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0011] [Figure 1] A diagram showing an example of a Physical Uplink Control Channel (PUCCH) format [Figure 2] FIG. 1 shows an example of PUCCH repetition [Figure 3] Block diagram showing an example of the configuration of a part of a terminal [Figure 4] Block diagram showing an example of the configuration of a base station [Figure 5] Block diagram showing an example of a terminal configuration [Figure 6] Flowchart showing an example of terminal operation [Figure 7] A diagram showing an example of Physical Uplink Shared Channel (PUSCH) repetition [Figure 8] An example of PUSCH repetition [Figure 9] An example of PUSCH repetition [Figure 10] FIG. 1 shows an example of PUCCH repetition according to the first embodiment. [Figure 11] FIG. 10 is a diagram showing an example of PUCCH repetition according to the second embodiment. [Figure 12] FIG. 10 is a diagram showing an example of PUCCH repetition according to the third embodiment. [Figure 13] An example of an Orthogonal Cover Code (OCC) number [Figure 14] FIG. 13 is a diagram showing an example of PUCCH repetition according to the fifth embodiment. [Figure 15]FIG. 20 is a diagram showing an example of PUCCH repetition according to the sixth embodiment. [Figure 16] Diagram of an example architecture of a 3GPP NR system [Figure 17] Schematic diagram showing functional separation between NG-RAN and 5GC [Figure 18] Sequence diagram of the Radio Resource Control (RRC) connection setup / reconfiguration procedure [Figure 19] Schematic diagram showing usage scenarios for enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). [Figure 20] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0013] In NR, for example, in addition to frequency bands below 6 GHz, such as the 700 MHz to 3.5 GHz band (also referred to as Frequency Range 1 (FR1)), which have been used for cellular communications, millimeter wave bands such as the 28 GHz or 39 GHz band (also referred to as FR2), which can ensure wide bandwidth, may be utilized (see, for example, Non-Patent Document 1). Furthermore, for example, in FR1, a frequency band such as the 3.5 GHz band, which is higher than the frequency bands used in Long Term Evolution (LTE) or 3G (3rd Generation mobile communication systems), may be used. The higher the frequency band, the greater the radio wave propagation loss, and the more likely the radio wave reception quality is to deteriorate. For this reason, in NR, when a frequency band higher than LTE or 3G is used, a method is being considered to ensure a communication area (or coverage) equivalent to that of a radio access technology (RAT) such as LTE or 3G, in other words, to ensure appropriate communication quality (see, for example, Non-Patent Document 2).

[0014] For example, in the NR downlink, a terminal (e.g., also referred to as User Equipment (UE)) receives downlink data (e.g., Physical Downlink Shared Channel (PDSCH)) in accordance with resource allocation by a base station (e.g., also referred to as gNB) (see, for example, Non-Patent Documents 3-6). Information regarding resource allocation may be notified from the base station to the terminal by, for example, a Layer 1 control signal (e.g., Downlink Control Information (DCI)) in a downlink control channel (e.g., Physical Downlink Control Channel (PDCCH)).

[0015] In addition, the terminal feeds back a response signal (e.g., ACK / NACK: Acknowledgement / Negative Acknowledgement, or also called Hybrid Automatic Repeat Request (HARQ)-ACK) indicating whether decoding of the PDSCH was successful to the base station, for example, by using an uplink control channel (e.g., PUCCH: Physical Uplink Control Channel) (see, for example, Non-Patent Document 5).

[0016] Furthermore, the terminal may transmit downlink channel state information (e.g., CSI: Channel State Information) and an uplink radio resource allocation request (e.g., SR: Scheduling Request) in addition to the ACK / NACK to the base station, for example, using the PUCCH. The ACK / NACK, CSI, and SR are also called uplink control information (e.g., UCI: Uplink Control Information).

[0017] In NR Rel.15 and NR Rel.16, for example, the PUCCH may be repeatedly transmitted (also referred to as PUCCH repetition) using a plurality of slots (in other words, a plurality of unit time intervals corresponding to scheduling units) (see, for example, Non-Patent Document 5). Repeated transmission of the PUCCH can improve, for example, the communication quality of the PUCCH.

[0018] For example, information regarding whether the terminal will repeatedly transmit the PUCCH and, if so, the number of repetitions (e.g., the number of slots) may be semi-statically notified (in other words, set or instructed) from the base station to the terminal by a terminal-specific higher layer signal (e.g., a radio resource control (RRC) signal, also called higher layer signaling or higher layer parameter).

[0019] Furthermore, for example, the following method can be adopted for identifying PUCCH resources for transmitting ACK / NACK for PDSCH allocated by DCI (see, for example, Non-Patent Document 5). For example, the base station semi-statically notifies a set of PUCCH resources (for example, referred to as a PUCCH resource set or resource list) by a terminal-specific higher layer signal (for example, an RRC signal). Then, the base station notifies (for example, indicates) a PUCCH resource to be allocated to the terminal from among multiple PUCCH resources included in the PUCCH resource set by DCI (in other words, dynamic signaling).

[0020] Here, the PUCCH resource may be configured by parameters such as a PUCCH format, a time resource (e.g., a symbol position or number of symbols), a frequency resource (e.g., a physical resource block (PRB) number, the number of PRBs, whether frequency hopping is applied), and a code resource (e.g., a cyclic shift sequence number or an orthogonal code number).

[0021] Furthermore, regarding the identification of PUCCH resources for transmitting SR or CSI, for example, the base station may semi-statically notify (or configure) the PUCCH resources by terminal-specific higher layer signaling (for example, RRC signaling).

[0022] In NR Rel.15 and NR Rel.16, for example, when a terminal transmits a certain UCI (which may include, for example, multiple UCIs), only one PUCCH can be transmitted within one slot (in other words, one scheduling unit interval).

[0023] Furthermore, when PUCCH repetition is applied, for example, the same PUCCH resource allocation may be applied across multiple slots. Note that slot-by-slot frequency hopping may be applied to frequency resources.

[0024] NR Rel.15 and NR Rel.16 specify, for example, five PUCCH formats (e.g., PUCCH formats 0 to 4) (see, for example, Non-Patent Documents 7 and 8). FIG. 1 is a diagram illustrating an example of PUCCH formats 0 to 4.

[0025] For example, PUCCH format 0 may be configured with 1 or 2 symbols and may transmit up to 2 bits of UCI (e.g., 1-bit UCI or 2-bit UCI; the same applies below). Also, for example, PUCCH format 1 may be configured with 4 to 14 symbols and may transmit up to 2 bits of UCI. Also, for example, PUCCH format 2 may be configured with 1 or 2 symbols and may transmit more than 2 bits of UCI. Also, for example, PUCCH format 3 may be configured with 4 to 14 symbols and may transmit more than 2 bits of UCI. Also, for example, PUCCH format 4 may be configured with 4 to 14 symbols and may transmit more than 2 bits of UCI.

[0026] Furthermore, PUCCH format 4 may multiplex multiple terminals onto the same time or frequency resource (for example, resource block (RB)) using orthogonal codes (for example, OCC: Orthogonal Cover Code).

[0027] In NR Rel.15 and NR Rel.16, for example, a terminal may identify the type of slot or the type of symbol within a slot (e.g., sometimes referred to as a slot format) by information (e.g., SFI: Slot Format Indicator) received from a base station. The type of symbol may be, for example, any of a downlink symbol (also represented as "D"), an uplink symbol (also represented as "U"), and a flexible symbol (also represented as "F"). The SFI may be notified, for example, by an RRC signal or a group common downlink control signal (Group common PDCCH).

[0028] Here, among the PUCCH resources (in other words, uplink resources) specified by the above-described method, some of the time resources (e.g., symbols) may conflict (in other words, overlap or collide) with information related to the uplink and downlink (hereinafter also referred to as "uplink and downlink patterns") notified by the SFI. For example, some symbols of the PUCCH time resources may be set as downlink symbols or flexible symbols in the SFI. In this case, the terminal does not transmit PUCCH in the slot. In other words, the terminal drops the transmission of PUCCH in a slot where a conflict between the PUCCH resource and the uplink and downlink patterns occurs. Note that symbols set as flexible symbols in the SFI may be regarded as conflicting uplink and downlink patterns in the same way as downlink symbols as described above, and may also be regarded as uplink symbols.

[0029] 2 is a diagram showing an example in which the number of symbols used for PUCCH transmission in each PUCCH repetition interval (hereinafter referred to as the "number of PUCCH transmission symbols") L=14, and the number of PUCCH repetitions K=2. For example, in FIG. 2, some of the symbols allocated to PUCCH transmission in the second slot (for example, the first to third symbols) are set as downlink symbols (D). Therefore, the terminal does not transmit (in other words, drops) the PUCCH in the second slot that includes these symbols.

[0030] In NR, for example, uplink and downlink patterns (e.g., patterns "D," "U," and "F") in Time Division Duplex (TDD) can be controlled semi-statically or dynamically. For example, uplink and downlink patterns can be controlled according to the traffic conditions of the uplink and downlink. For example, if the proportion of downlink traffic is higher than that of the uplink, it is expected that the proportion of downlink symbols in the uplink and downlink patterns will be set to be higher than that of uplink symbols.

[0031] Furthermore, a terminal that applies coverage enhancement (CE) to a PUCCH is expected to repeatedly transmit the PUCCH across multiple slots, for example. For example, if the same PUCCH resource allocation is applied across multiple slots for repeated transmission of the PUCCH as described above, and a conflict with an uplink / downlink pattern (e.g., "D" or "F") occurs in at least a portion of the PUCCH resource (e.g., time resource), the terminal does not transmit the PUCCH in that slot. In this way, the more frequently conflicts with uplink / downlink patterns occur in repeated transmission of the PUCCH, the more likely the PUCCH will not be transmitted, and the more likely the transmission quality of the PUCCH will deteriorate. As a result, it is difficult to achieve the expected coverage enhancement effect.

[0032] On the other hand, for example, when an uplink / downlink pattern is set based on the setting of a terminal to which coverage extension is applied, it is assumed that the ratio of uplink symbols is set to be higher than downlink symbols across multiple slots in which PUCCH is transmitted, which may reduce flexibility in setting uplink / uplink patterns and reduce frequency utilization efficiency of the downlink.

[0033] In one non-limiting embodiment of the present disclosure, for example, a method for suppressing a decrease in frequency utilization efficiency of a downlink and improving transmission quality in repeated transmission of a PUCCH will be described.

[0034] [Communication System Overview] A communication system according to each embodiment of the present disclosure includes a base station 100 and a terminal 200.

[0035] 3 is a block diagram illustrating a configuration example of a portion of terminal 200 according to an embodiment of the present disclosure. In terminal 200 illustrated in FIG. 3, control unit 205 (e.g., corresponding to a control circuit) sets multiple first transmission intervals (e.g., PUCCH repetitions) for a unit time interval (e.g., slot) corresponding to a scheduling unit. Transmitting unit 209 (e.g., corresponding to a transmitting circuit) repeatedly transmits uplink control information (e.g., UCI) in the multiple first transmission intervals. Note that the term "transmission interval" may be interpreted as a "transmission occasion" or a "transmission opportunity."

[0036] [Base station configuration] Fig. 4 is a block diagram showing an example configuration of a base station 100 according to embodiment 1. In Fig. 4, the base station 100 includes a control unit 101, a higher control signal generation unit 102, a downlink control information generation unit 103, an encoding unit 104, a modulation unit 105, a signal allocation unit 106, a transmission unit 107, a reception unit 108, an extraction unit 109, a demodulation unit 110, and a decoding unit 111.

[0037] The control unit 101 determines, for example, information (for example, SFI) relating to the slot format for the terminal 200 and outputs the determined information to the higher control signal generation unit 102 or the downlink control information generation unit 103.

[0038] Furthermore, control section 101 determines, for example, information about PUCCH resources for terminal 200, and outputs the determined information to higher control signal generation section 102. The information about PUCCH resources may include, for example, a PUCCH resource set or information about the number of repetitions (for example, number of repetitions K).

[0039] Furthermore, control unit 101 determines resources that terminal 200 will actually use for repeated transmission of PUCCH, for example, based on PUCCH resources for the terminal to transmit an uplink control signal (for example, PUCCH) and slot format information (for example, SFI). Information about the determined resources is output to extraction unit 109, demodulation unit 110, and decoding unit 111, for example.

[0040] In the following, for example, repeated PUCCH transmission actually performed by terminal 200 is referred to as "actual repetition (or actual PUCCH repetition)." Furthermore, repeated PUCCH transmission set in terminal 200 with respect to actual repetition is referred to as "nominal repetition (or nominal PUCCH repetition)."

[0041] Furthermore, the control unit 101 determines information related to a downlink signal for transmitting, for example, a downlink data signal (e.g., PDSCH), an upper control signal (e.g., RRC signal), or downlink control information (e.g., DCI). The information related to the downlink signal may include, for example, information such as a modulation and coding scheme (MCS) and radio resource allocation. The control unit 101 outputs the determined information to, for example, the encoding unit 104, the modulation unit 105, and the signal allocation unit 106. Furthermore, the control unit 101 outputs information related to the downlink signal, such as a data signal or an upper control signal, to the downlink control information generation unit 103.

[0042] The higher-level control signal generating section 102 generates a higher-level layer control signal bit sequence based on information input from the control section 101 , for example, and outputs the higher-level layer control signal bit sequence to the encoding section 104 .

[0043] The downlink control information generating unit 103 generates a downlink control information (e.g., DCI) bit string based on, for example, information input from the control unit 101, and outputs the generated DCI bit string to the encoding unit 104. Note that the control information may be transmitted to multiple terminals.

[0044] For example, based on information input from the control unit 101, the coding unit 104 codes the downlink data, the bit string input from the higher control signal generation unit 102, or the DCI bit string input from the downlink control information generation unit 103. The coding unit 104 outputs the coded bit string to the modulation unit 105.

[0045] The modulation unit 105 modulates the coded bit sequence input from the coding unit 104, for example, based on information input from the control unit 101, and outputs the modulated signal (for example, a symbol sequence) to the signal allocation unit 106.

[0046] The signal allocation unit 106 maps the symbol sequence (including, for example, a downlink data signal or a control signal) input from the modulation unit 105 to the radio resource, for example, based on information indicating the radio resource input from the control unit 101. The signal allocation unit 106 outputs the downlink signal onto which the signal has been mapped to the transmission unit 107.

[0047] For example, transmitting unit 107 performs a transmission waveform generation process such as Orthogonal Frequency Division Multiplexing (OFDM) on the signal input from signal allocation unit 106. Furthermore, in the case of OFDM transmission that adds a cyclic prefix (CP), transmitting unit 107 performs an Inverse Fast Fourier Transform (IFFT) process on the signal and adds a CP to the signal after IFFT. Furthermore, transmitting unit 107 performs RF processing such as D / A conversion and up-conversion on the signal, and transmits the radio signal to terminal 200 via an antenna.

[0048] The receiving unit 108 performs RF processing such as downconvert or A / D conversion on an uplink signal received from the terminal 200 via an antenna. In addition, in the case of OFDM transmission, the receiving unit 108 performs Fast Fourier Transform (FFT) processing on the received signal, and outputs the resulting frequency domain signal to the extracting unit 109.

[0049] The extraction unit 109 extracts the radio resource portion from which the uplink signal (e.g., PUCCH) transmitted by the terminal 200 is transmitted, for example, based on information input from the control unit 101, and outputs the extracted radio resource portion to the demodulation unit 110.

[0050] The demodulation unit 110 demodulates the uplink signal (for example, PUCCH) input from the extraction unit 109, based on, for example, information input from the control unit 101. The demodulation unit 110 outputs the demodulation result to the decoding unit 111, for example.

[0051] The decoding unit 111 performs error correction decoding of the uplink signal based on, for example, information input from the control unit 101 and the demodulation result input from the demodulation unit 110, and obtains a decoded received bit sequence (for example, UCI such as ACK / NACK).

[0052] [Device configuration] 5 is a block diagram illustrating a configuration example of a terminal 200 according to an embodiment of the present disclosure. For example, in FIG. 5, the terminal 200 includes a receiving unit 201, an extracting unit 202, a demodulating unit 203, a decoding unit 204, a control unit 205, an encoding unit 206, a modulating unit 207, a signal allocating unit 208, and a transmitting unit 209.

[0053] The receiver 201 receives, for example, a downlink signal (for example, a downlink data signal or downlink control information) from the base station 100 via an antenna, and performs RF processing such as downconvert or A / D conversion on the radio received signal to obtain a received signal (baseband signal). When receiving an OFDM signal, the receiver 201 performs FFT processing on the received signal to convert the received signal into the frequency domain. The receiver 201 outputs the received signal to the extractor 202.

[0054] For example, based on information relating to the radio resource of the downlink control information input from the control unit 205, the extraction unit 202 extracts a radio resource portion that may include downlink control information from the received signal input from the receiving unit 201, and outputs the extracted radio resource portion to the demodulation unit 203. Furthermore, based on information relating to the radio resource of the data signal input from the control unit 205, the extraction unit 202 extracts a radio resource portion that includes downlink data, and outputs the extracted radio resource portion to the demodulation unit 203.

[0055] Demodulation section 203 demodulates the signal input from extraction section 202 and outputs the demodulation result to decoding section 204, for example.

[0056] The decoding unit 204 performs error correction decoding on the demodulation result input from the demodulation unit 203, for example, to obtain downlink reception data, an upper layer control signal, or downlink control information. The decoding unit 204 outputs the upper layer control signal and the downlink control information to the control unit 205, and outputs the downlink reception data. The decoding unit 204 may also generate a response signal (for example, ACK / NACK) based on the decoding result of the downlink reception data, and output the response signal to the coding unit 206.

[0057] The control unit 205 determines radio resources for a downlink signal (for example, a PDSCH) and an uplink signal (for example, a PUCCH) based on, for example, a signal (for example, a higher layer control signal or downlink control information) input from the decoding unit 204.

[0058] For example, based on information about the PUCCH resource, control unit 205 determines (in other words, sets or identifies) a PUCCH resource to be used for repeated transmission of the PUCCH configured in terminal 200. For example, control unit 205 may identify a PUCCH resource to be used for nominal repetition based on information about the PUCCH resource. Furthermore, control unit 205 may determine a PUCCH resource to be used for actual repetition based on, for example, information about the slot format (e.g., SFI) and a PUCCH resource to be used for nominal repetition.

[0059] The control unit 205 outputs, for example, information indicating the determined radio resource of the downlink signal to the extraction unit 202 and outputs information indicating the determined radio resource of the uplink signal to the signal allocation unit 208.

[0060] The encoding unit 206 encodes an uplink signal (e.g., UCI) based on, for example, information input from the control unit 205, and outputs the encoded bit string to the modulation unit 207. The UCI may include, for example, an ACK / NACK input from the decoding unit 204. Note that, depending on the PUCCH format, encoding may not be performed.

[0061] The modulation unit 207 modulates the coded bit sequence input from the coding unit 206 , for example, and outputs the modulated signal (symbol sequence) to the signal allocation unit 208 .

[0062] The signal allocation unit 208 maps the signal input from the modulation unit 207 to radio resources based on, for example, information input from the control unit 205, and outputs the uplink signal onto which the signal has been mapped to the transmission unit 209.

[0063] Transmitting unit 209 generates a transmission signal waveform, such as OFDM, for the signal input from signal allocating unit 208. Furthermore, in the case of OFDM transmission using a CP, for example, transmitting unit 209 performs IFFT processing on the signal and adds a CP to the signal after IFFT. Alternatively, when transmitting unit 209 generates a single-carrier waveform, a DFT (Discrete Fourier Transform) unit may be added (not shown) after modulating unit 207 or before signal allocating unit 208, for example. Furthermore, transmitting unit 209 performs RF processing, such as D / A conversion and up-conversion, on the transmission signal, and transmits the radio signal to base station 100 via an antenna.

[0064] [Example of Operation of Base Station 100 and Terminal 200] An example of the operation of base station 100 and terminal 200 having the above configuration will be described.

[0065] Fig. 6 is a flowchart showing an example of the operation of terminal 200 according to the present embodiment. Fig. 6 shows, as an example, processing in terminal 200 related to repeated transmission of a PUCCH including an ACK / NACK for a PDSCH.

[0066] 6, terminal 200 acquires, for example, information about the slot format (for example, SFI) (ST101). For example, the SFI may be configured in terminal 200 from base station 100 by signaling of a higher layer (for example, RRC) or a group common downlink control signal (for example, Group common PDCCH).

[0067] Terminal 200 acquires, for example, information about the PUCCH repetition (for example, nominal repetition) and the PUCCH resource (ST102). Note that an example of a method of reporting information about the PUCCH repetition and the PUCCH resource will be described later. Also, the processing in ST101 and ST102 is not limited to being performed in the order shown in FIG. 6, and may be performed in the reverse order or in parallel, for example.

[0068] The terminal 200 receives, for example, a PDCCH including DCI (ST103). The DCI may include, for example, information regarding the allocated resources of a downlink data signal (PDSCH) or information regarding the allocated resources of an uplink signal. The terminal 200 receives, for example, a downlink data signal (e.g., PDSCH) and decodes the received PDSCH (ST104). Further, the terminal 200 generates, for example, an ACK / NACK for the PDSCH based on the decoding result of the PDSCH (ST105).

[0069] The terminal 200 determines, for example, a PUCCH resource to be used for Actual repetition (ST106). For example, the terminal 200 may determine a PUCCH resource to be used for Actual repetition based on a PUCCH resource to be used for Nominal repetition and information regarding a slot format. An example of a method for determining a PUCCH resource to be used for Actual repetition will be described later.

[0070] The terminal 200 transmits, for example, a UCI including ACK / NACK to the base station 100 using the determined PUCCH resource (ST107).

[0071] Note that in FIG. 6, as an example, the transmission process of ACK / NACK has been described. However, the terminal 200 may transmit uplink control information different from ACK / NACK (e.g., SR or CSI). The transmission process of SR or CSI may not include, for example, the PDCCH reception process (e.g., the process of ST103) and the PDSCH reception and decoding process (e.g., the process of ST104) shown in FIG. 6.

[0072] [Method for Determining PUCCH Resource] Next, an example of a method for determining a PUCCH resource according to the present embodiment will be described.

[0073] [Allocation of PUSCH Resource] For example, NR Rel. 16 specifies a method of repeatedly transmitting one or more PUSCHs per slot for transmission of an uplink data channel (e.g., PUSCH) (see, for example, Non-Patent Document 9). In this method, for example, base station 100 notifies terminal 200 of the allocation of time resources (e.g., the number of symbols) for the first (in other words, initial) PUSCH transmission (e.g., 1st repetition) and the number of repetitions. Also, in this method, the allocation of time resources for second and subsequent PUSCH transmissions (in other words, allocation of PUSCH transmission opportunities) may be consecutive and may use the same number of symbols as in the previous PUSCH transmission.

[0074] Fig. 7 is a diagram showing an example of time resources used for repeated transmission of PUSCH when the number of PUSCH symbols L = 7 and the number of repetitions K = 4 are notified to terminal 200. In Fig. 7, for example, one slot includes PUSCH transmission durations for two PUSCH repetitions.

[0075] Furthermore, for example, there may be cases where the transmission duration of one PUSCH (e.g., referred to as a nominal PUSCH repetition) allocated by the above-described method crosses a slot boundary. In this case, terminal 200 may transmit the PUSCH by dividing (e.g., splitting) one PUSCH transmission duration (e.g., a nominal PUSCH repetition duration) into multiple PUSCH transmission durations (e.g., actual PUSCH repetition durations).

[0076] FIG. 8 is a diagram showing an example of time resources used for repeated transmission of PUSCH when terminal 200 is notified of the number of PUSCH symbols L=10 and the number of repetitions K=2.

[0077] In FIG. 8, for example, the PUSCH transmission interval for the second Nominal PUSCH repetition crosses the slot boundary. In this case, the terminal 200 may divide, for example, the PUSCH interval for the second Nominal PUSCH repetition that crosses the slot boundary into a plurality of PUSCH intervals at the slot boundary. By this division, PUSCH intervals for three Actual PUSCH repetitions are set.

[0078] Also, for example, in each interval of the Nominal PUSCH repetition assigned by the method described above, a conflict with the uplink pattern may occur. In this case, the terminal 200 may divide the Nominal PUSCH repetition interval into one or more PUSCH transmission intervals (in other words, intervals of Actual PUSCH repetition) and transmit PUSCH.

[0079] FIG. 9 is a diagram showing an example of time resources used for repeated transmission of PUSCH when the number of PUSCH symbols L = 7 and the number of repetitions K = 2 are notified to the terminal 200.

[0080] In FIG. 9, for example, some symbols (for example, the first to fifth symbols) of the third Nominal PUSCH repetition are not used for uplink transmission. In this case, the terminal 200 does not transmit PUSCH (for example, drops PUSCH transmission) in the symbols (for example, the first to fifth symbols) in which a conflict with the uplink pattern occurs among the third Nominal PUSCH repetition intervals (for example, 7 symbols). As a result, as shown in FIG. 9, the transmission interval (or transmission opportunity) of the third Actual PUSCH repetition is set to the remaining two symbols where no conflict with the uplink pattern occurs.

[0081] <Allocation of PUCCH Resources> In this embodiment, terminal 200 may transmit a signal in units of one or more PUCCH repetitions per slot. In other words, terminal 200 may configure multiple transmission intervals (e.g., nominal PUCCH repetition intervals) for repeated transmission of PUCCH (e.g., UCI) per slot.

[0082] Furthermore, in a transmission interval of one nominal repetition, for example, when a conflict with an uplink / downlink pattern occurs, terminal 200 may transmit the PUCCH (in other words, a signal of the actual repetition) using some symbols that do not conflict with the uplink pattern. In other words, when a conflict with the uplink pattern occurs, terminal 200 does not need to drop transmission in units of PUCCH repetitions such as NR Rel.15 and Rel.16.

[0083] For example, in PUCCH repetition, terminal 200 may change (or reset) a nominal repetition interval in which some symbols are set as downlink symbols among multiple nominal repetition intervals, to an actual repetition interval that includes at least one other symbol that is different from the some symbols, based on information about the slot format (e.g., information about the symbol configuration in the slot).

[0084] An example of a method for reporting PUCCH resources for PUCCH repetition will be described later.

[0085] FIG. 10 is a diagram showing an example of time resources used for repeated transmission of PUCCH when the number of PUCCH symbols L=7 (for example, PUCCH format 1) and the number of repetitions K=4 are set for terminal 200 in PUCCH repetition.

[0086] In FIG. 10, for example, some symbols (e.g., the first to fifth symbols) of the third nominal repetition are set as downlink symbols or flexible symbols, and therefore are not used for uplink transmission (in other words, a conflict with the uplink and downlink patterns occurs).

[0087] In this case, terminal 200 determines not to transmit (in other words, drop) PUCCH in symbols (e.g., the first to fifth symbols) that conflict with the uplink / downlink pattern within the transmission interval (e.g., seven symbols) of the third nominal repetition. With this determination, the transmission interval of the third actual repetition is set to the interval including the remaining two symbols that do not conflict with the uplink / downlink pattern, as shown in FIG. 10.

[0088] When the number of PUCCH symbols in the actual repetition is smaller than the number of PUCCH symbols in the nominal repetition, such as the third actual repetition in FIG. 10, the PUCCH transmitted in the actual repetition may be configured, for example, by any of the following methods.

[0089] The first method (hereinafter sometimes referred to as "PUCCH configuration method 1") is a method of configuring an actual repetition by puncturing symbols that have caused a conflict with an uplink / downlink pattern for a PUCCH resource configured in a nominal repetition. In other words, when the number of PUCCH symbols in the transmission interval of the actual repetition is smaller than the number of PUCCH symbols in the transmission interval of the nominal repetition, terminal 200 may puncture PUCCH symbols in the PUCCH format corresponding to the nominal repetition.

[0090] The second method (hereinafter sometimes referred to as "PUCCH configuration method 2") is a method in which the PUCCH is reconfigured according to, for example, the number of PUCCH symbols transmitted in the actual repetition. As described above, in NR, a plurality of PUCCH formats (e.g., FIG. 1) are defined for the PUCCH according to, for example, the number of symbols. For example, in the second method, when terminal 200 transmits a 1- to 2-bit PUCCH (e.g., ACK / NACK), L=7 symbols in the first, second, and fourth actual repetitions shown in FIG. 10, and therefore terminal 200 transmits the PUCCH based on PUCCH format 1. On the other hand, the number of symbols in the third actual repetition shown in FIG. 10 is 2, and therefore terminal 200 may transmit the PUCCH based on PUCCH format 0. In other words, terminal 200 may determine the PUCCH format based on the number of PUCCH symbols in the transmission interval of the actual repetition.

[0091] Although NR Rel. 15 and Rel. 16 do not specify a PUCCH format consisting of three symbols, a new three-symbol PUCCH format may be specified.

[0092] Furthermore, in the present embodiment, a case where a conflict occurs with an uplink / downlink pattern for a PUCCH resource for a nominal repetition has been described as an example, but similar operations may also be applied to a case where a PUCCH resource for a nominal repetition is included in multiple slots (in other words, when a slot boundary is crossed). For example, terminal 200 divides a transmission interval of a nominal repetition that crosses multiple slots into transmission intervals of multiple actual repetitions at slot boundaries. Then, terminal 200 may configure a PUCCH for each of the multiple divided actual repetitions, for example, based on PUCCH configuration method 1 or 2 described above.

[0093] According to the present embodiment, terminal 200 sets multiple transmission durations for PUCCH repetition in a slot, thereby improving the flexibility of PUCCH resource allocation.

[0094] Furthermore, when a slot for PUCCH repetition contains a symbol that is not used for uplink transmission (for example, a symbol that conflicts with an uplink / downlink pattern), terminal 200 changes the nominal repetition interval including that symbol to an actual repetition interval including another symbol. This allows terminal 200 to transmit more PUCCH repetition signals, thereby improving the transmission quality of PUCCH repetition, compared to, for example, the method defined in NR Rel. 15 and Rel. 16, which does not perform PUCCH transmission in a slot if a symbol that is not used for uplink transmission is present in the slot. Furthermore, according to the present embodiment, terminal 200 controls PUCCH repetition based on an uplink / downlink pattern (for example, information indicated in an SFI). In other words, the setting of the uplink / uplink pattern does not depend on the control of PUCCH repetition. Therefore, according to the present embodiment, it is possible to suppress a decrease in flexibility in setting uplink / uplink patterns, and, for example, to suppress a decrease in frequency utilization efficiency for the downlink.

[0095] As described above, according to this embodiment, it is possible to suppress a decrease in frequency utilization efficiency for downlinks and also to improve transmission quality in repeated transmission of PUCCHs.

[0096] (Embodiment 2) In the first embodiment, when a conflict with an uplink / downlink pattern occurs in a transmission interval of a certain nominal repetition in a PUCCH repetition, for example, the PUCCH may be transmitted in a transmission interval of an actual repetition including symbols that do not cause a conflict with the uplink pattern in the transmission interval of the nominal repetition. In this case, the terminal may transmit a signal of an actual repetition having a different number of symbols from the nominal repetition.

[0097] Furthermore, in the case of PUCCH repetition, similar to PUSCH repetition in Rel. 16, if a transmission interval of a certain nominal repetition crosses a slot boundary, the transmission interval of the nominal repetition may be divided into transmission intervals of multiple actual repetitions and the PUCCH may be transmitted. In this case as well, a terminal may transmit a signal of actual repetition having a different number of symbols from the nominal repetition.

[0098] Here, for example, when the actual repetition is configured by puncturing the nominal repetition based on the above-described PUCCH configuration method 1, there is a possibility that the actual repetition does not include a reference signal for channel estimation (for example, a DMRS (Demodulation Reference Signal)).

[0099] FIG. 11 is a diagram illustrating an example of time resources used for repeated transmission of PUCCH when PUCCH format 3 or PUCCH format 4 with the number of PUCCH symbols L=7 and the number of repetitions K=4 are set for PUCCH repetition.

[0100] In PUCCH format 3 or PUCCH format 4 with L=7 symbols as shown in FIG. 11, for example, a DMRS can be allocated to the fourth symbol in the transmission interval of each nominal repetition.

[0101] 11, for example, some symbols (e.g., the first to fifth symbols) of the third nominal repetition are set as downlink symbols or flexible symbols, and therefore are not used for uplink transmission (in other words, a conflict with an uplink / downlink pattern occurs). In this case, for example, the remaining two symbols (e.g., the sixth and seventh symbols) usable for uplink transmission among the third nominal repetition shown in FIG. 11 do not include a DMRS, and therefore the base station may fail to demodulate the PUCCH.

[0102] Furthermore, for example, when a PUCCH (in other words, a PUCCH format) is reconfigured according to the number of PUCCH symbols in the transmission interval of the actual repetition based on the above-described PUCCH configuration method 2, a DMRS may be included in each symbol of the actual repetition. On the other hand, in NR, a PUCCH format according to the number of PUCCH symbols is specified. Therefore, in this case, in the PUCCH repetition, a terminal may transmit a signal of the actual repetition in a different PUCCH format. In this case, the following may occur.

[0103] For example, when PUCCH format 1 (e.g., 4 to 14 symbols) is set in nominal repetition, part of actual repetition may be set to PUCCH format 0 (e.g., 1 to 2 symbols). Here, in PUCCH format 1, for example, in the case of a 14-symbol PUCCH, up to 84 terminals can be multiplexed using a cyclic shift sequence and a time-domain orthogonal code (OCC). On the other hand, in PUCCH format 0, for example, up to 6 terminals can be multiplexed with 1-bit UCI and up to 3 terminals can be multiplexed with 2-bit UCI using a cyclic shift sequence. Therefore, when PUCCH format 1 and PUCCH format 0 are mixed in multiple actual repetitions, the number of terminals that can be multiplexed in the same time and frequency resource (e.g., 1 PRB) may differ between actual PUCCH repetitions.

[0104] Furthermore, when PUCCH format 1 is set for nominal repetition, even if PUCCH format 1 is set for actual repetition, if the number of PUCCH symbols differs, the number of terminals that can be multiplexed in OCC in the time domain may differ between actual PUCCH repetitions.

[0105] Also, for example, when PUCCH format 4 (for example, 4 to 14 symbols) is set in nominal repetition, part of actual repetition may be set to PUCCH format 2 (for example, 1 to 2 symbols). Here, PUCCH format 4 allows multiplexing of two or four terminals using, for example, OCC, whereas PUCCH format 2 does not support multiplexing of multiple terminals in the same PRB. Therefore, when PUCCH format 4 and PUCCH format 2 are mixed in multiple actual repetitions, the number of terminals that can be multiplexed in the same time and frequency resource (for example, 1 PRB) may differ between actual PUCCH repetitions.

[0106] In this way, if the number of terminals that can be multiplexed onto the same time and frequency resource (e.g., 1 PRB) differs between actual repetitions, there is a possibility that, in the transmission interval of a certain actual repetition, the PUCCH transmitted by a terminal will not be multiplexed with the PUCCH of another terminal, causing interference with other terminals (e.g., inter-terminal interference).

[0107] Furthermore, a PUCCH format consisting of three symbols is not specified in NR Rel. 15 and Rel. 16. If a new PUCCH format consisting of three symbols is not specified, the operation of a terminal cannot be specified with actual repetition consisting of three symbols.

[0108] Therefore, in this embodiment, a method for determining PUCCH resources when different PUCCH formats or different numbers of PUCCH symbols are set between actual repetitions will be described.

[0109] The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0110] For example, terminal 200 may transmit a signal in units of one or more PUCCH repetitions per slot. In other words, terminal 200 may set transmission durations of multiple nominal PUCCH repetitions per slot.

[0111] Furthermore, in a transmission interval of one nominal repetition, for example, when a conflict with an uplink / downlink pattern occurs, terminal 200 may transmit the PUCCH (in other words, a signal of the actual repetition) using some symbols that do not conflict with the uplink pattern. In other words, when a conflict with the uplink pattern occurs, terminal 200 does not need to drop transmission in units of PUCCH repetitions such as NR Rel.15 and Rel.16.

[0112] Furthermore, for example, when a transmission interval of one nominal repetition straddles a slot boundary, terminal 200 may divide the transmission interval of one nominal repetition into transmission intervals of multiple actual repetitions at the slot boundary.

[0113] Furthermore, for example, when a certain condition is satisfied in the transmission interval of the actual repetition, terminal 200 determines not to transmit the PUCCH in the actual repetition (in other words, does not transmit the PUCCH).

[0114] The condition may be, for example, (i) that the PUCCH formats for nominal repetition and actual repetition are different, (ii) that the number of PUCCH symbols in actual repetition is less than a threshold, or (iii) that DMRS is not included in the transmission duration of actual repetition. Note that, for example, different conditions may be applied for each PUCCH format. Furthermore, if a new PUCCH format consisting of three symbols is not defined, the condition may be that the number of PUCCH symbols in actual repetition is three symbols.

[0115] For example, as described above, in the example shown in FIG. 11, some symbols (e.g., the first to fifth symbols) included in the third nominal repetition are not used for uplink transmission, and an actual repetition can be set that includes the remaining two symbols (e.g., the sixth and seventh symbols) that can be used for uplink transmission.

[0116] In this case, for example, PUCCH format 2 may be set to the third actual repetition that can be set, while PUCCH format 3 or 4 may be set to the other actual repetitions. In other words, in the third PUCCH repetition shown in Fig. 11, the PUCCH format of the nominal repetition and the PUCCH format of the actual repetition may differ, and therefore the above-mentioned condition (i) may be satisfied.

[0117] Furthermore, for example, the number of symbols of the third Actual Repetition that can be set can be less than a threshold value (for example, 4 symbols), and therefore the above-mentioned condition (ii) can be satisfied.

[0118] Furthermore, the third Actual repetition that can be set does not include a DMRS, and therefore can satisfy the above-mentioned condition (iii).

[0119] 11, terminal 200 may drop the transmission of the signal of the third actual repetition. In other words, terminal 200 may transmit signals of the first, second, and fourth actual repetitions, but may not transmit the signal of the third actual repetition.

[0120] As described above, according to the present embodiment, terminal 200 performs PUCCH transmission appropriate for the number of PUCCH symbols in the actual repetition. For example, if the number of PUCCH symbols in the actual repetition is not appropriate for PUCCH transmission, terminal 200 does not transmit a signal for that actual repetition. In other words, terminal 200 may vary its PUCCH transmission operation depending on the number of PUCCH symbols in the actual repetition. With this type of transmission control, for example, when the number of multiplexed terminals differs between actual repetitions, it is possible to suppress signal transmission that could cause interference to other terminals, thereby suppressing performance degradation of PUCCH repetition due to interference between terminals.

[0121] In PUCCH format 0, for example, even if nominal repetition is set to 2 symbols and actual repetition is set to 1 symbol, the number of terminals multiplexed by cyclic shift sequences does not change. Furthermore, DMRS is not included in PUCCH format 0. Therefore, for PUCCH format 0, terminal 200 may transmit a signal of actual repetition regardless of the above-mentioned conditions.

[0122] Furthermore, in the present embodiment, a case where a conflict occurs with an uplink / downlink pattern for a PUCCH resource for a nominal repetition has been described as an example, but the same operation may also be applied to a case where a PUCCH resource for a nominal repetition is included in multiple slots (in other words, a case where a slot boundary is crossed). For example, when the above-mentioned condition (for example, at least one of conditions (i) to (iii)) is satisfied in the transmission intervals of multiple actual repetitions after division, terminal 200 does not need to transmit a signal of the actual repetition (in other words, it may drop the transmission).

[0123] (Embodiment 3) The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0124] In this embodiment, for example, terminal 200 may transmit a signal in units of one or more PUCCH repetitions per slot. In other words, terminal 200 may set transmission durations of multiple nominal PUCCH repetitions per slot.

[0125] Furthermore, in a transmission interval of one nominal repetition, for example, when a conflict with an uplink / downlink pattern occurs, terminal 200 may transmit the PUCCH (in other words, a signal of the actual repetition) using some symbols that do not cause a conflict with the uplink / uplink pattern. In other words, when a conflict with an uplink pattern occurs, terminal 200 does not need to drop transmission in PUCCH repetition units such as NR Rel.15 and Rel.16.

[0126] Furthermore, for example, when a transmission interval of one nominal repetition straddles a slot boundary, terminal 200 may divide the transmission interval of one nominal repetition into transmission intervals of multiple actual repetitions at the slot boundary.

[0127] Furthermore, a PUCCH format with a specified symbol length (for example, duration) equal to or less than a threshold may be applied to a PUCCH format corresponding to UCI in PUCCH repetition. In other words, terminal 200 does not need to apply a PUCCH format with a symbol length longer than a threshold in PUCCH repetition. As an example, terminal 200 may use a Short PUCCH such as PUCCH format 0 or PUCCH format 2.

[0128] Also, in the present embodiment, for example, the number of PUCCH symbols for nominal repetition notified or set to terminal 200 is set to L = 1 or 2. In other words, when PUCCH repetition is set, terminal 200 does not assume that a value other than L = 1 or 2 will be notified for the number of PUCCH symbols for nominal repetition.

[0129] FIG. 12 is a diagram showing an example of time resources used for repeated transmission of PUCCH when the number of PUCCH symbols L=2 and the number of repetitions K=14 are set in PUCCH repetition.

[0130] In FIG. 12, in nominal repetition, for example, a short PUCCH (for example, 1 to 2 symbols) such as PUCCH format 0 or PUCCH format 2 is configured, and a long PUCCH such as PUCCH formats 1, 3, and 4 does not need to be configured.

[0131] For example, in the example shown in Fig. 12, the transmission intervals of the eighth and ninth nominal repetitions are not used for uplink transmission. Also, for example, in the example shown in Fig. 12, some symbols (for example, the first symbol) included in the tenth nominal repetition are not used for uplink transmission, and an actual repetition including the remaining one symbol (for example, the second symbol) that can be used for uplink transmission can be set.

[0132] Here, for example, in PUCCH format 0, the number of terminals multiplexed does not depend on the number of PUCCH symbols. Therefore, for example, as shown in Fig. 12, even when a part (for example, 1 symbol) of the nominal repetition (for example, 2 symbols) is set as the actual repetition (in other words, when the number of PUCCH symbols is different), the number of terminals multiplexed does not change between the nominal repetition and the actual repetition. For example, in Fig. 12, the number of terminals multiplexed does not change between the 10th actual repetition (1 symbol) and the other actual repetitions (2 symbols).

[0133] Also, for example, in PUCCH format 2, DMRS is included in each symbol. Therefore, for example, as shown in FIG. 12, even when a part (for example, one symbol) of nominal repetition (for example, two symbols) is set as actual repetition, DMRS is included in actual repetition.

[0134] As described above, in this embodiment, even when the number of symbols differs between nominal repetition and actual repetition in PUCCH repetition, it is possible to reduce the probability that DMRS is absent in actual repetition or the probability that the number of terminals multiplexed changes. Thus, according to this embodiment, terminal 200 can increase the probability of transmitting a signal of actual repetition without dropping transmission of actual repetition whose number of symbols differs from that of nominal repetition. Thus, according to this embodiment, it is possible to suppress performance degradation of PUCCH repetition and improve PUCCH transmission quality.

[0135] Note that, in the present embodiment, a case where a conflict occurs between an uplink and downlink pattern for a PUCCH resource for a nominal repetition has been described as an example, but similar operations may also be applied to a case where the PUCCH resource for a nominal repetition is included in multiple slots (in other words, a case where a slot boundary is crossed). For example, in the present embodiment, when, for example, PUCCH format 0 or PUCCH format 2 is set for the nominal repetition, as described above, it is possible to reduce the probability that a DMRS is absent or the probability that the number of terminals multiplexed changes even for multiple actual repetitions after division. Therefore, terminal 200 can transmit a signal of an actual repetition without dropping the transmission of the actual repetition whose number of symbols is different from that of the nominal repetition.

[0136] (Fourth embodiment) The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0137] In this embodiment, for example, terminal 200 may transmit a signal in units of one or more PUCCH repetitions per slot. In other words, terminal 200 may set transmission durations of multiple nominal PUCCH repetitions per slot.

[0138] Furthermore, for example, in a transmission interval of one nominal repetition, when a conflict with an uplink / uplink pattern occurs, terminal 200 may transmit a PUCCH (in other words, a signal of an actual repetition) using some symbols that do not conflict with the uplink / uplink pattern. In other words, when a conflict with an uplink pattern occurs, terminal 200 does not need to drop transmission in PUCCH repetition units such as NR Rel.15 and Rel.16.

[0139] Furthermore, for example, when a transmission interval of one nominal repetition straddles a slot boundary, terminal 200 may divide the transmission interval of one nominal repetition into transmission intervals of multiple actual repetitions at the slot boundary.

[0140] Furthermore, similar to embodiment 3, terminal 200 may apply a PUCCH format whose specified symbol length (for example, duration) is equal to or less than a threshold to the PUCCH format corresponding to UCI in PUCCH repetition. In other words, terminal 200 does not need to apply a PUCCH format whose symbol length is longer than a threshold in PUCCH repetition. As an example, terminal 200 may use a Short PUCCH such as PUCCH format 0 or PUCCH format 2.

[0141] Furthermore, in the third embodiment, the number of PUCCH symbols for nominal repetition is L=1 or 2, whereas in the present embodiment, the number of PUCCH symbols for nominal repetition notified to or set in terminal 200 may be L>3, for example.

[0142] A transmission interval of nominal repetition L>3 may be configured by a combination of short PUCCHs such as PUCCH format 0 or PUCCH format 2. In other words, a transmission interval of nominal repetition L>3 may be configured by a combination of symbols in units of the number of symbols corresponding to short PUCCHs. As an example, when a nominal repetition of L=7 is set, a signal of this nominal repetition may be configured by a combination of seven short PUCCHs of L=1 symbol.

[0143] According to the present embodiment, as described in embodiment 3, even when the number of symbols differs between nominal repetition and actual repetition in PUCCH repetition, as in PUCCH configuration method 1, it is possible to reduce the probability that DMRS is absent in actual repetition or the probability that the number of terminals multiplexed changes. Thus, according to the present embodiment, terminal 200 can increase the probability of transmitting a signal of actual repetition without dropping transmission of actual repetition that has a different number of symbols from nominal repetition. Thus, according to the present embodiment, it is possible to suppress the influence of performance degradation of PUCCH repetition and improve PUCCH transmission quality.

[0144] Furthermore, in the present embodiment, notification or setting of the number L of PUCCH symbols for nominal repetition may also include a PUCCH format where L>3. Therefore, in the present embodiment, for example, the range of values for notification (or setting) of the number of repetitions K can be narrowed compared to, for example, Embodiment 3 (for example, L=1 or 2). As an example, for PUCCH repetition in an interval corresponding to a length of two slots (for example, 28 symbols), in Embodiment 3 (FIG. 12), when the number of PUCCH symbols L=2, the number of repetitions is set to K=14, and when the number of PUCCH symbols L=1, the number of repetitions is set to K=28. In contrast, in the present embodiment, for example, when the number of PUCCH symbols L=7, the number of repetitions is set to K=4, and when the number of PUCCH symbols L=14, the number of repetitions is set to K=2. Therefore, in the present embodiment, the setting range of the number of repetitions K can be narrowed compared to Embodiment 3, and an increase in notification bits can be suppressed.

[0145] (Modification of the fourth embodiment) In the fourth embodiment, a case has been described in which nominal repetition of L>3 is configured by a combination of short PUCCHs (for example, PUCCH format 0 or PUCCH format 2).

[0146] When PUCCH repetition is set, terminal 200 may apply the method of the above-described fourth embodiment depending on the conditions, for example.

[0147] For example, when the number of symbols in a plurality of actual repetitions is the same as the nominal repetition, terminal 200 may apply, to the actual repetition, a PUCCH format corresponding to the number of symbols set in the nominal repetition.

[0148] On the other hand, when the number of symbols in at least one of the multiple actual repetitions is different from the nominal repetition or is equal to or less than a threshold (for example, 2 symbols), terminal 200 may reconstruct the nominal repetition by combining short PUCCHs based on the method of embodiment 4.

[0149] When nominal repetition is configured by a combination of short PUCCHs, the number of terminals that can be multiplexed may be reduced compared to when, for example, long PUCCHs are used. In contrast, according to this modification, when terminal 200 does not transmit actual repetitions having different numbers of symbols in PUCCH repetition, there is no need to configure long PUCCHs by a combination of short PUCCHs, which has the advantage that the number of terminals multiplexed does not need to be reduced.

[0150] (Embodiment 5) The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0151] In this embodiment, for example, terminal 200 may transmit a signal in units of one or more PUCCH repetitions per slot. In other words, terminal 200 may set transmission durations of multiple nominal PUCCH repetitions per slot.

[0152] Furthermore, in a transmission interval of one nominal repetition, for example, when a conflict with an uplink / downlink pattern occurs, terminal 200 may transmit the PUCCH (in other words, a signal of the actual repetition) using some symbols that do not cause a conflict with the uplink / uplink pattern. In other words, when a conflict with an uplink pattern occurs, terminal 200 does not need to drop transmission in PUCCH repetition units such as NR Rel.15 and Rel.16.

[0153] Furthermore, for example, when a transmission interval of one nominal repetition straddles a slot boundary, terminal 200 may divide the transmission interval of one nominal repetition into transmission intervals of multiple actual repetitions at the slot boundary.

[0154] Furthermore, for example, in PUCCH repetition, terminal 200 may transmit a signal of actual repetition in a PUCCH format different from the PUCCH format of nominal repetition. For example, terminal 200 may reconfigure the PUCCH (or the PUCCH format) according to the number of PUCCH symbols transmitted in actual repetition, as in PUCCH configuration method 2 described above.

[0155] Furthermore, in this embodiment, the following method may be applied to suppress the influence on terminal multiplexing caused by a difference in the PUCCH format or the number of PUCCH symbols between actual repetitions.

[0156] First, a case where the PUCCH format differs between nominal repetition and actual repetition will be described.

[0157] For example, when PUCCH format 1 is configured for nominal repetition, the PUCCH resource includes a cyclic shift sequence number and a time domain OCC (TD-OCC) number.

[0158] Here, the cyclic shift sequence number may be any value from 0 to 11, for example.

[0159] Furthermore, the value range of the OCC number differs depending on, for example, the number of PUCCH symbols of nominal repetition (also referred to as nominal PUCCH length, for example) and whether or not frequency hopping within a repetition is used (also referred to as intra-repetition hopping, for example). Fig. 13 is a diagram showing an example of the number of PUCCH symbols of nominal repetition (for example, any one of 4 to 14 symbols) and the number of terminals multiplexed by OCC depending on the number of PUCCH symbols of nominal repetition and whether or not frequency hopping within a repetition is used. For example, when the number of terminals multiplexed by OCC is N, the OCC number may be any value from 0 to N-1.

[0160] For example, as shown in FIG. 1, in PUCCH format 1, a maximum of 36 terminals can be multiplexed when there is no frequency hopping, and a maximum of 84 terminals can be multiplexed when there is frequency hopping.

[0161] Also, for example, in PUCCH format 0, as described above, a maximum of six terminals can be multiplexed with a 1-bit UCI using a cyclic shift sequence (for example, any of cyclic shift sequence numbers 0 to 5), and a maximum of three terminals can be multiplexed with a 2-bit UCI (for example, any of cyclic shift sequence numbers 0 to 2). Note that PUCCH format 0 does not support terminal multiplexing using OCC numbers.

[0162] In the present embodiment, for example, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 0 to 5 and OCC number 0 (in other words, equivalent to no terminal multiplexing by OCC), terminal 200 may transmit 1-bit UCI in an actual repetition for which PUCCH format 0 is set. On the other hand, for example, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 6 to 11 or any of OCC numbers 1 or greater, terminal 200 may drop transmission of 1-bit UCI in an actual repetition for which PUCCH format 0 is set.

[0163] Similarly, for example, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 0 to 2 and OCC number 0 (in other words, equivalent to no terminal multiplexing by OCC), terminal 200 may transmit 2-bit UCI in the actual repetition for which PUCCH format 0 is set. On the other hand, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 3 to 11 or any of OCC numbers 1 or greater, terminal 200 may drop the transmission of 2-bit UCI in the actual repetition for which PUCCH format 0 is set.

[0164] In this way, terminal 200 may decide to transmit UCI in the transmission interval of the actual repetition when parameters related to terminal multiplexing (e.g., cyclic shift sequence number and OCC number) notified to or configured in terminal 200 are included in parameters related to terminal multiplexing (e.g., cyclic shift sequence number and OCC number) specified in the PUCCH format determined for the actual repetition. On the other hand, terminal 200 may decide not to transmit UCI in the transmission interval of the actual repetition when parameters related to terminal multiplexing (e.g., cyclic shift sequence number and OCC number) notified to or configured in terminal 200 are not included in parameters related to terminal multiplexing specified in the PUCCH format determined for the actual repetition.

[0165] In a PUCCH format that supports terminal multiplexing by OCC, the OCC with OCC number #0 may be, for example, a code in which all code elements are "+1." In this case, a signal (e.g., PUCCH) to which OCC number #0 is applied (e.g., multiplied) remains the same as the signal before OCC number #0 is applied. Therefore, for example, with regard to PUCCH format 0 that does not support terminal multiplexing by OCC, even when OCC number #0 is notified of or configured in terminal 200, it may be considered to correspond to no terminal multiplexing by OCC. In addition to PUCCH format 0, the same applies to other PUCCH formats (e.g., PUCCH format 2) that do not support terminal multiplexing by OCC.

[0166] FIG. 14 is a diagram showing an example of time resources used for repeated PUCCH transmission when the number of PUCCH symbols L=7 and the number of repetitions K=4 are set for two terminals 200 (e.g., UE#1 and UE#2) in PUCCH repetition.

[0167] In FIG. 14, for example, cyclic shift sequence number #0 and OCC number #0 are set for UE #1, and cyclic shift sequence number #0 and OCC number #1 are set for UE #2.

[0168] For example, in Fig. 14, some symbols (e.g., the first to fifth symbols) of the third nominal repetition are set as downlink symbols or flexible symbols, and therefore are not used for uplink transmission (in other words, a conflict with an uplink / downlink pattern occurs). In this case, for example, an actual repetition of PUCCH format 0 may be set, which includes the remaining two symbols (e.g., the sixth and seventh symbols) that can be used for uplink transmission out of the third nominal repetition shown in Fig. 14.

[0169] In Fig. 14, for example, UE#1 is configured with cyclic shift sequence number #0 and OCC number #0 (where OCC number #0 corresponds to no terminal multiplexing by OCC) specified in PUCCH format 0, and therefore UE#1 may transmit signals of the first to fourth actual repetitions. In other words, signals transmitted from UE#1 can be multiplexed between terminals even if PUCCH format 0 of the third actual repetition is different from PUCCH format 1 of the nominal repetition.

[0170] On the other hand, in Fig. 14, for example, OCC number #1, which is not specified in PUCCH format 0, is configured for UE #2, so UE #2 may drop the transmission of the third actual repetition. In Fig. 14, PUCCH format 0 configured for the third actual repetition of UE #2 does not support terminal multiplexing using the OCC number configured for UE #2, so the signal of this actual repetition may cause interference to other terminals. Therefore, by UE #2 not transmitting the signal of the actual repetition, it is possible to suppress interference (e.g., interference between terminals) caused by UE #2 to other UEs.

[0171] As another example, when PUCCH format 4 is configured for nominal repetition, the PUCCH resource includes an OCC number (for example, Frequency Domain OCC (FD-OCC)). Here, the OCC number is a value of 0 to 1 (in other words, the number of terminals multiplexed is 2) or 0 to 3 (in other words, the number of terminals multiplexed is 4).

[0172] Also, for example, PUCCH format 2 does not support terminal multiplexing using OCC numbers.

[0173] In this case, for example, when OCC number 0 (in other words, corresponding to no terminal multiplexing by OCC) is notified or set to terminal 200, terminal 200 may transmit UCI in the actual repetition in which PUCCH format 2 is set.

[0174] On the other hand, when OCC number 1 or any of OCC numbers 1 to 3 is notified of or configured for terminal 200, terminal 200 may drop transmission of UCI in the actual repetition for which PUCCH format 2 is set. PUCCH format 2 does not support terminal multiplexing by OCC number, and therefore a signal of actual repetition in PUCCH format 2 transmitted from terminal 200 for which OCC number 1 or higher is configured may cause interference to other terminals. Therefore, by terminal 200 not transmitting a signal of actual repetition in PUCCH format 2, it is possible to suppress interference from terminal 200 to other UEs (for example, interference between terminals).

[0175] Next, a case where the PUCCH symbols differ between the nominal repetition and the actual repetition will be described.

[0176] For example, when PUCCH format 1 is set in nominal repetition, PUCCH format 1 may also be set in actual repetition, resulting in a difference in the number of PUCCH symbols. As described above, when the number of PUCCH symbols differs, the number of terminals that can be multiplexed by OCC may differ, as shown in FIG. 13 .

[0177] Therefore, in the present embodiment, for example, if the OCC number notified to or configured in terminal 200 is included in the OCC number (e.g., FIG. 13 ) defined in PUCCH format 1 based on the number of PUCCH symbols in the actual repetition, terminal 200 may transmit UCI in the actual repetition. On the other hand, if the OCC number notified to or configured in terminal 200 is not included in the OCC number defined in PUCCH format 1, terminal 200 may drop the transmission of UCI in the actual repetition.

[0178] For example, a case will be described in which PUCCH format 1 with 14 symbols is set in nominal repetition, and PUCCH format 1 with 7 symbols is set in actual repetition. As shown in FIG. 13 , when the number of PUCCH symbols in PUCCH format 1 is 7, the number of terminals multiplexed is 3, and the OCC number is any one of 0 to 2.

[0179] In this case, if any of OCC numbers 0 to 2 has been notified or configured for terminal 200, terminal 200 may transmit UCI in actual repetition with 7 PUCCH symbols. On the other hand, if any of OCC numbers 3 to 6 has been notified or configured for terminal 200, terminal 200 does not need to transmit UCI in actual repetition with 7 PUCCH symbols. As shown in FIG. 13 , PUCCH format 1 with 7 PUCCH symbols does not support terminal multiplexing using OCCs with OCC numbers 3 and above, and therefore a signal with actual repetition with 7 PUCCH symbols transmitted from terminal 200 with these OCCs configured may cause interference to other terminals. Therefore, by terminal 200 not transmitting this signal with actual repetition, it is possible to suppress interference from terminal 200 to other UEs (for example, inter-terminal interference).

[0180] As described above, according to the present embodiment, terminal 200 can adjust the number of terminals multiplexed in actual repetition based on the PUCCH format in actual repetition or the number of PUCCH symbols in actual repetition, thereby suppressing performance degradation of PUCCH repetition due to interference between terminals.

[0181] Furthermore, in this embodiment, some terminals 200 (for example, UE#1 in FIG. 14) can transmit UCI without dropping transmission of actual repetition, thereby improving the transmission quality of PUCCH repetition.

[0182] Note that, in the present embodiment, a case where a conflict occurs with an uplink / downlink pattern for a PUCCH resource for a nominal repetition has been described as an example, but similar operations may also be applied to a case where a PUCCH resource for a nominal repetition is included in multiple slots (in other words, a case where a slot boundary is crossed). For example, in the present embodiment, terminal 200 may determine whether terminal multiplexing is possible for multiple divided actual repetitions based on parameters notified to or set in terminal 200, and control transmission of the actual repetitions.

[0183] Furthermore, although a PUCCH format consisting of three symbols is not defined in NR Rel. 15 and Rel. 16, a new PUCCH format consisting of three symbols may be defined. For example, the PUCCH format consisting of three symbols may be an existing Short PUCCH (e.g., PUCCH format 0 and PUCCH format 2) or a Long PUCCH (e.g., PUCCH format 1, PUCCH format 3 and PUCCH format 4). Furthermore, if a new PUCCH format consisting of three symbols is not defined, terminal 200 may not transmit the actual repetition if the number of PUCCH symbols in the actual repetition is three.

[0184] (Embodiment 6) The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0185] In this embodiment, for example, terminal 200 may transmit a signal in units of one or more PUCCH repetitions per slot. In other words, terminal 200 may set transmission durations of multiple nominal PUCCH repetitions per slot.

[0186] Furthermore, in a transmission interval of one nominal repetition, for example, when a conflict with an uplink / downlink pattern occurs, terminal 200 may transmit the PUCCH (in other words, a signal of the actual repetition) using some symbols that do not cause a conflict with the uplink / uplink pattern. In other words, when a conflict with an uplink pattern occurs, terminal 200 does not need to drop transmission in PUCCH repetition units such as NR Rel.15 and Rel.16.

[0187] Furthermore, for example, when a transmission interval of one nominal repetition straddles a slot boundary, terminal 200 may divide the transmission interval of one nominal repetition into transmission intervals of multiple actual repetitions at the slot boundary.

[0188] Furthermore, terminal 200 may transmit a signal of actual repetition in a PUCCH format different from the PUCCH format of nominal repetition in PUCCH repetition, for example, as in embodiment 5. For example, terminal 200 may reconfigure the PUCCH (or the PUCCH format) depending on the number of PUCCH symbols transmitted in actual repetition, as in PUCCH configuration method 2 described above.

[0189] Furthermore, in this embodiment, the following method may be applied to suppress the influence on terminal multiplexing caused by a difference in the PUCCH format or the number of PUCCH symbols between actual repetitions.

[0190] For example, in the fifth embodiment, when the PUCCH format or the number of symbols in the actual repetition differs from the nominal repetition, the transmission or non-transmission of the actual repetition is determined based on parameters related to the number of terminals multiplexed, such as a cyclic shift sequence number and an OCC number notified to or set in terminal 200. In this case, the characteristics of the PUCCH repetition may be degraded in terminals to which the actual repetition is not transmitted (in other words, terminals that are not multiplexed by a cyclic shift sequence and an OCC in the actual repetition).

[0191] Therefore, in this embodiment, terminal signals that are not multiplexed by a cyclic shift sequence and an OCC in the actual repetition are frequency-division multiplexed (FDM). For example, terminal 200 may transmit the actual repetition signal in a PRB (or a PRB position) associated with the notified or set cyclic shift sequence number or OCC number in the transmission section of the actual repetition.

[0192] For example, when PUCCH format 1 is configured for nominal repetition, the PUCCH resource may include a PRB number n, a cyclic shift sequence number, and a time domain OCC number.

[0193] Here, the cyclic shift sequence number may be any value from 0 to 11.

[0194] The range of values of the OCC number varies depending on, for example, the number of PUCCH symbols of nominal repetition and whether or not frequency hopping is performed within the repetition. For example, if the number of terminals multiplexed by OCC is N, the OCC number may be any value from 0 to N-1.

[0195] Also, for example, in PUCCH format 0, as described above, a maximum of six terminals can be multiplexed with a 1-bit UCI using a cyclic shift sequence (for example, any of cyclic shift sequence numbers 0 to 5), and a maximum of three terminals can be multiplexed with a 2-bit UCI (for example, any of cyclic shift sequence numbers 0 to 2). Note that PUCCH format 0 does not support terminal multiplexing using OCC numbers.

[0196] In this embodiment, for example, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 0 to 5 and OCC number 0 (in other words, corresponding to no terminal multiplexing by OCC), terminal 200 may transmit an Actual repetition signal in which PUCCH format 0 is set, in a PRB with PRB number n.

[0197] On the other hand, for example, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 6 to 11 or any of OCC numbers 1 or greater, terminal 200 may transmit a signal of actual repetition to which PUCCH format 0 is set in a PRB with a PRB number different from PRB number n. For example, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 6 to 11 and OCC number 0, terminal 200 may transmit a signal of actual repetition to which PUCCH format 0 is set in a PRB with PRB number n+1. Furthermore, when terminal 200 is notified of or configured with any of cyclic shift sequence numbers 0 to 5 and OCC number 1, terminal 200 may transmit a signal of actual repetition to which PUCCH format 0 is set in a PRB with PRB number n+2. Furthermore, when, for example, any one of cyclic shift sequence numbers 6 to 11 and OCC number 1 is notified or set, terminal 200 may transmit a signal of actual repetition in which PUCCH format 0 is set, in a PRB with PRB number n+3.

[0198] In this way, if the parameters related to terminal multiplexing (e.g., cyclic shift sequence number and OCC number) notified or set to terminal 200 are not included in the parameters related to terminal multiplexing (e.g., cyclic shift sequence number and OCC number) specified in the PUCCH format for the actual repetition, terminal 200 may transmit UCI using a PRB associated with the parameters notified or set to terminal 200 in that actual repetition.

[0199] The association between the PRB number and the combination of the cyclic shift sequence number and the OCC number is not limited to the above example, and it is sufficient that the PRB number is determined based on the cyclic shift sequence number and the OCC number, for example.

[0200] FIG. 15 is a diagram showing an example of time resources used for repeated transmission of PUCCH when the number of PUCCH symbols L=7 and the number of repetitions K=4 are set for two terminals 200 (e.g., UE#1 and UE#2) in PUCCH repetition.

[0201] In FIG. 15, for example, cyclic shift sequence number #0 and OCC number #0 are set for UE #1, and cyclic shift sequence number #0 and OCC number #1 are set for UE #2.

[0202] For example, in Fig. 15, some symbols (e.g., the first to fifth symbols) of the third nominal repetition are set as downlink symbols or flexible symbols and are therefore not used for uplink transmission (in other words, a conflict with an uplink / downlink pattern occurs). In this case, for example, an actual repetition of PUCCH format 0 can be set that includes the remaining two symbols (e.g., the sixth and seventh symbols) that can be used for uplink transmission out of the third nominal repetition shown in Fig. 15.

[0203] 15, for example, UE#1 is configured with cyclic shift sequence number #0 and OCC number #0 (which corresponds to no terminal multiplexing by OCC) specified in PUCCH format 0, and therefore UE#1 may transmit signals of the first to fourth actual repetitions in a PRB with PRB number n. In other words, signals transmitted from UE#1 can be multiplexed between terminals even if PUCCH format 0 of the third actual repetition is different from PUCCH format 1 of the nominal repetition.

[0204] 15, for example, OCC number #1, which is not defined in PUCCH format 0, is set for UE #2. Therefore, UE #2 may transmit, for example, the first, second, and fourth PUCCH format 1 actual repetition signals in a PRB with PRB number n, and may transmit the third actual repetition signal in, for example, a PRB with PRB number n+2 associated with cyclic shift sequence number 0 and OCC number 1.

[0205] 15, PUCCH format 0 set for the third actual repetition of UE#2 does not support terminal multiplexing using the OCC number set for UE#2, and therefore the signal of this actual repetition may cause interference to other terminals if transmitted, for example, on a PRB with PRB number n. On the other hand, in this embodiment, the signal of the third actual repetition of UE#2 is transmitted on a PRB different from the PRB with PRB number n on which signals of other actual repetitions are transmitted, and therefore interference from UE#2 to other UEs (e.g., interference between terminals) can be suppressed and the transmission quality of the PUCCH for UE#2 can be improved.

[0206] As another example, when PUCCH format 4 is configured for nominal repetition, the PUCCH resource includes an OCC number (for example, FD-OCC). Here, the OCC number is a value of 0 to 1 (in other words, the number of terminals multiplexed is 2) or 0 to 3 (in other words, the number of terminals multiplexed is 4).

[0207] Also, for example, PUCCH format 2 does not support terminal multiplexing using OCC numbers.

[0208] In this case, for example, when OCC number 0 (in other words, corresponding to no terminal multiplexing by OCC) is notified or set to terminal 200, terminal 200 may transmit an Actual repetition signal in which PUCCH format 2 is set in a PRB with PRB number n.

[0209] Furthermore, when OCC number 1 or any of OCC numbers 1 to 3 is notified or set to terminal 200, terminal 200 may transmit an Actual repetition signal in which PUCCH format 2 is set on a PRB different from the PRB with PRB number n (for example, PRB number n+1).

[0210] The association between the PRB number and the OCC number is not limited to the above example, and it is sufficient if the PRB number is determined based on the OCC number, for example.

[0211] Thus, according to the present embodiment, terminal 200 can transmit a signal of actual repetition without dropping the transmission of actual repetition, regardless of the parameters related to terminal multiplexing that are notified or configured (for example, cyclic shift sequence number and OCC number). This can improve the transmission quality of PUCCH repetition.

[0212] Note that in the present embodiment, a similar operation may be applied to a case where PUCCH symbols differ between nominal repetition and actual repetition. Furthermore, in the present embodiment, a case where contention with an uplink / downlink pattern occurs for a PUCCH resource for nominal repetition has been described as an example, but a similar operation may be applied to a case where a PUCCH resource for nominal repetition is included in multiple slots (in other words, when it straddles a slot boundary). For example, in the present embodiment, terminal 200 may determine, for actual repetition, either multiplexed transmission using a cyclic shift sequence and OCC, or frequency multiplexed transmission, based on parameters notified to or set in terminal 200.

[0213] Furthermore, although a PUCCH format consisting of three symbols is not defined in NR Rel.15 and Rel.16, a new PUCCH format consisting of three symbols may be defined. For example, the PUCCH format consisting of three symbols may be an existing Short PUCCH (e.g., PUCCH format 0 and PUCCH format 2) or a Long PUCCH (e.g., PUCCH format 1, PUCCH format 3 and PUCCH format 4). Furthermore, if a new PUCCH format consisting of three symbols is not defined, the terminal may not transmit the actual repetition if the number of PUCCH symbols in the actual repetition is three.

[0214] (Embodiment 7) The configurations of a base station and a terminal according to the present embodiment may be the same as the configurations of base station 100 and terminal 200 according to the first embodiment.

[0215] In this embodiment, for example, terminal 200 may transmit a signal in units of one or more PUCCH repetitions per slot. In other words, terminal 200 may set transmission durations of multiple nominal PUCCH repetitions per slot.

[0216] Furthermore, in a transmission interval of one nominal repetition, for example, when a conflict with an uplink / downlink pattern occurs, terminal 200 may transmit the PUCCH (in other words, a signal of the actual repetition) using some symbols that do not cause a conflict with the uplink / uplink pattern. In other words, when a conflict with an uplink pattern occurs, terminal 200 does not need to drop transmission in PUCCH repetition units such as NR Rel.15 and Rel.16.

[0217] Furthermore, for example, when a transmission interval of one nominal repetition straddles a slot boundary, terminal 200 may divide the transmission interval of one nominal repetition into transmission intervals of multiple actual repetitions at the slot boundary.

[0218] Furthermore, terminal 200 may transmit a signal of actual repetition in a PUCCH format different from the PUCCH format of nominal repetition in PUCCH repetition, for example, as in embodiment 5. For example, terminal 200 may reconfigure the PUCCH (or the PUCCH format) depending on the number of PUCCH symbols transmitted in actual repetition, as in PUCCH configuration method 2 described above.

[0219] Furthermore, in this embodiment, the following method may be applied to suppress the influence on PUCCH coding caused by a difference in the PUCCH format or the number of PUCCH symbols between actual repetitions.

[0220] For example, when PUCCH format 3 or PUCCH format 4 is configured in nominal repetition, coding (e.g., channel coding) is applied to the UCI bits, and they may be mapped to a number of time and frequency resources based on the PUCCH symbols. Also, for example, when PUCCH format 2 is configured in actual repetition, or when nominal repetition and PUCCH format are the same but the number of symbols is different, the amount of time and frequency resources based on the PUCCH symbols may be reduced compared to nominal repetition. Therefore, the coding rate of the PUCCH transmitted in actual repetition becomes high, which may degrade transmission performance.

[0221] Therefore, in this embodiment, terminal 200 may increase frequency resources (for example, the number of PRBs or the PRB size) in the actual repetition compared to the nominal repetition, and transmit a signal of the actual repetition.

[0222] For example, when PUCCH format 3 is set in nominal repetition, the PUCCH resource may include PRB number n and the number of PRBs. In the present embodiment, for example, in actual repetition where PUCCH format 2 is set, terminal 200 may increase the number of PRBs compared to nominal repetition and transmit a signal of actual repetition.

[0223] Also, for example, when PUCCH format 4 is set in nominal repetition, the number of PRBs in the PUCCH resource is 1. In the present embodiment, for example, terminal 200 may increase the number of PRBs in actual repetition in which PUCCH format 2 is set compared to nominal repetition, and transmit a signal of actual repetition.

[0224] The number of PRBs in the actual repetition may be set to the number of PRBs that can realize the coding rate in the nominal repetition, or may be a value determined based on at least one of the number of symbols in the nominal repetition and the number of symbols in the actual repetition.

[0225] Thus, according to the present embodiment, terminal 200 can suppress degradation of coding characteristics of actual repetition even when the PUCCH format or the number of symbols differs between nominal repetition and actual repetition.

[0226] Note that, in the present embodiment, a case where the PUCCH formats differ between nominal repetition and actual repetition has been described as an example, but similar operations may also be applied to a case where, for example, the number of PUCCH symbols differs between nominal repetition and actual repetition. Also, in the present embodiment, a case where a conflict with an uplink / downlink pattern occurs for a PUCCH resource for nominal repetition has been described as an example, but similar operations may also be applied to a case where the PUCCH resource for nominal repetition is included in multiple slots (in other words, when it straddles a slot boundary). For example, in the present embodiment, terminal 200 may increase the number of PRBs in actual repetition compared to nominal repetition, and transmit a signal for actual repetition.

[0227] Furthermore, although a PUCCH format consisting of three symbols is not defined in NR Rel. 15 and Rel. 16, a new PUCCH format consisting of three symbols may be defined. For example, the PUCCH format consisting of three symbols may be an existing Short PUCCH (e.g., PUCCH format 0 and PUCCH format 2) or a Long PUCCH (e.g., PUCCH format 1, PUCCH format 3 and PUCCH format 4). Furthermore, if a new PUCCH format consisting of three symbols is not defined, terminal 200 may not transmit the actual repetition if the number of PUCCH symbols in the actual repetition is three.

[0228] The above describes the embodiments according to the example of the present disclosure.

[0229] (Other embodiments) [Method of notifying PUCCH resources for PUCCH repetition] A method for notifying a PUCCH resource for PUCCH repetition and a method for notifying the number of repetitions will be described. Note that the PUCCH resource notified or set by the following method is, for example, the PUCCH resource for "nominal repetition" in the above-mentioned embodiment. For example, after determining the PUCCH resource for nominal repetition, terminal 200 may determine the PUCCH resource for actual repetition based on information on the uplink / downlink pattern of the slot or on the slot boundary, and transmit a PUCCH repetition signal.

[0230] <option 0> In Option 0, for example, with regard to identifying PUCCH resources for transmitting ACK / NACK for PDSCH allocated by DCI, base station 100 may notify terminal 200 of a semi-static set of PUCCH resources (e.g., referred to as a PUCCH resource set) by a terminal-specific upper layer signal (e.g., an RRC signal), and may notify terminal 200 by DCI of the PUCCH resources to be used by terminal 200 from among the multiple PUCCH resources included in the PUCCH resource set.

[0231] Here, the PUCCH resource may be configured by parameters such as the PUCCH format, time resource (e.g., symbol position or number of symbols), frequency resource (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resource (e.g., cyclic shift sequence number and orthogonal code number).

[0232] Furthermore, in Option 0, for example, with regard to identifying PUCCH resources for transmitting SR or CSI, base station 100 may semi-statically notify terminal 200 of the PUCCH resources by terminal-specific higher layer signaling (for example, RRC signaling).

[0233] Furthermore, in Option 0, base station 100 may semi-statically notify terminal 200 of the presence or absence of PUCCH repetition and the number of repetitions, for example, by using a terminal-specific higher layer signal (for example, an RRC signal).

[0234] In Option 0, base station 100 may notify terminal 200 of, for example, the PUCCH resource allocation for the first (in other words, initial) PUCCH transmission and the number of repetitions. Furthermore, the PUCCH resources for the second and subsequent PUCCH transmissions may be allocated, for example, the same PUCCH resources in consecutive slots. Furthermore, the time domain resource allocation may be, for example, consecutive to the previous PUCCH transmission, and the same number of symbols may be allocated.

[0235] < / option> <option 1> In Option 1, for example, with regard to identifying PUCCH resources for transmitting ACK / NACK for PDSCH allocated by DCI, base station 100 may notify terminal 200 of a semi-static set of PUCCH resources (e.g., a PUCCH resource set) by a terminal-specific upper layer signal (e.g., an RRC signal), and may notify terminal 200 by DCI of the PUCCH resources to be used by terminal 200 from among the multiple PUCCH resources included in the PUCCH resource set.

[0236] Here, the PUCCH resource may be configured by parameters such as the PUCCH format, time resource (e.g., symbol position or number of symbols), frequency resource (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resource (e.g., cyclic shift sequence number and orthogonal code number).

[0237] In Option 1, the parameters configuring the PUCCH resource may further include, for example, information regarding the presence or absence of PUCCH repetition or information regarding the number of repetitions.

[0238] Furthermore, in Option 1, for example, with regard to identifying PUCCH resources for transmitting SR or CSI, base station 100 may semi-statically notify terminal 200 of the PUCCH resources by terminal-specific higher layer signaling (for example, RRC signaling).

[0239] In Option 1, base station 100 may notify terminal 200 of, for example, the PUCCH resource allocation for the first (in other words, initial) PUCCH transmission and the number of repetitions. Furthermore, the PUCCH resources for the second and subsequent PUCCH transmissions may be allocated, for example, the same PUCCH resources in consecutive slots. Furthermore, the time domain resource allocation may be, for example, consecutive to the previous PUCCH transmission, and the same number of symbols may be allocated.

[0240] According to Option 1, base station 100 can dynamically notify terminal 200 of at least one of whether PUCCH repetition is enabled and the number of repetitions.

[0241] Furthermore, by including information regarding the presence or absence of PUCCH repetition and the number of repetitions in the PUCCH resource set, base station 100 can notify at least one of dynamic notification of the presence or absence of PUCCH repetition and the number of repetitions, and PUCCH resource notification, using the same bit field of DCI (e.g., PUCCH resource indicator (PRI)), thereby suppressing an increase in the number of DCI bits.

[0242] < / option> <option 2> In Option 2, for example, with regard to identifying PUCCH resources for transmitting ACK / NACK for PDSCH allocated by DCI, base station 100 may notify terminal 200 of a semi-static set of PUCCH resources (e.g., a PUCCH resource set) by a terminal-specific upper layer signal (e.g., an RRC signal), and may notify terminal 200 by DCI of the PUCCH resources to be used by terminal 200 from among the multiple PUCCH resources included in the PUCCH resource set.

[0243] Here, the PUCCH resource may be configured by parameters such as the PUCCH format, time resource (e.g., symbol position or number of symbols), frequency resource (e.g., PRB number, number of PRBs, or whether frequency hopping is applied), and code resource (e.g., cyclic shift sequence number and orthogonal code number) for each Repetition.

[0244] Furthermore, the parameters configuring the PUCCH resource may include, for example, information regarding the presence or absence of a PUCCH repetition for each repetition, or information regarding the number of repetitions.

[0245] Furthermore, in Option 2, for example, with regard to identifying PUCCH resources for transmitting SR or CSI, base station 100 may semi-statically notify terminal 200 of the PUCCH resources by terminal-specific higher layer signaling (for example, RRC signaling).

[0246] According to Option 2, base station 100 notifies terminal 200 of PUCCH resource allocation and the number of repetitions for PUCCH transmission for each repetition. This allows base station 100 to notify, for example, different PUCCH resources for each PUCCH repetition, thereby improving the flexibility of PUCCH repetition transmission for terminal 200.

[0247] < / option> <option 3> In Option 3, for example, any of the methods of Options 0 to 2 described above may be used to identify PUCCH resources for transmitting ACK / NACK for PDSCH allocated by DCI.

[0248] In Option 3, base station 100 may transmit information (e.g., a pattern) about invalid symbols for semi-static PUCCH repetition, for example, by a terminal-specific higher layer signal (e.g., an RRC signal). The "invalid symbol" may be, for example, a symbol that does not require PUCCH repetition, even if it is set as an uplink symbol by information about the slot format.

[0249] Furthermore, base station 100 may notify, by a terminal-specific higher layer signal (RRC signal), whether or not a bit field indicating whether or not to apply information on invalid symbols in DCI to which a PDSCH is allocated is present.

[0250] For example, if the DCI to which the PDSCH is assigned does not have a bit field indicating whether or not to apply information about invalid symbols, and if an invalid symbol is included in the transmission interval of one PUCCH repetition, terminal 200 may determine that a conflict with the uplink / downlink pattern has occurred in the invalid symbol, and may apply the same operation as in the above-described embodiment.

[0251] Furthermore, for example, if the DCI to which the PDSCH is allocated has a bit field indicating whether or not to apply information about invalid symbols, and if 0 is indicated in the bit field of the DCI, and if an invalid symbol is included in the transmission interval of one PUCCH repetition, terminal 200 may determine that a conflict with an uplink / downlink pattern has occurred in the invalid symbol, and apply the same operation as in the above-described embodiment.On the other hand, for example, if 1 is indicated in the bit field of the DCI, and if an invalid symbol is included in the transmission interval of one PUCCH repetition, terminal 200 may determine that the invalid symbol is an uplink symbol, and apply the same operation as in the above-described embodiment.

[0252] The value of the bit field is not limited to the above example (for example, 0: apply, 1: not apply).

[0253] Furthermore, information about invalid symbols in Option 3 may be signaled for, for example, PUSCH repetition. Information about invalid symbols for PUSCH repetition and a method for invalid symbols for PUCCH repetition may be signaled by the same higher layer signal (for example, an RRC signal) or may be signaled by different higher layer signals (for example, an RRC signal).

[0254] Furthermore, each of the information regarding the PUCCH resources for the above-mentioned PUCCH repetitions is not limited to being notified by the above-mentioned signals, but may be notified or set by, for example, a terminal-specific higher layer signal or DCI, or may be specified in a standard.

[0255] The method of notifying PUCCH resources for PUCCH repetition has been described above.

[0256] In the above embodiment, a method of allocating PUCCH resources to ACK / NACK (e.g., a response signal to a downlink data signal) has been described as an example, but the target of PUCCH resource allocation is not limited to ACK / NACK. For example, uplink control information (UCI) different from ACK / NACK, such as CSI or SR, may be used, or an uplink data signal (e.g., PUSCH).

[0257] In addition, in the above embodiment, uplink communication in which a signal is transmitted from a terminal to a base station is assumed. However, an embodiment of the present disclosure is not limited to this and may be applied to communication between terminals (for example, sidelink communication).

[0258] Furthermore, the downlink control channel, the downlink data channel, the uplink control channel, and the uplink data channel are not limited to PDCCH, PDSCH, PUCCH, and PUSCH, respectively, and may be control channels with other names.

[0259] Furthermore, in the above-described embodiment, RRC signaling is assumed as the signaling of the higher layer, but this may be replaced with Medium Access Control (MAC) signaling and notification by DCI, which is physical layer signaling.

[0260] Furthermore, in the above-described embodiments, the unit of time resource (e.g., scheduling unit) is not limited to slot, but may be time resource unit such as frame, subframe, slot, subslot, or symbol, or may be other time resource unit. Furthermore, the unit of frequency resource is not limited to resource block (e.g., PRB), but may be frequency resource unit such as bandwidth part (BWP), resource block group (RBG), subcarrier, or resource element group (REG), or may be other frequency resource unit.

[0261] Furthermore, the parameters applied in the above-described embodiments are merely examples and are not limited to these. For example, at least one of the parameters such as the number of symbols L, the number of repetitions K, the cyclic shift sequence number, the OCC number, or the uplink / downlink pattern indicated in the SFI is not limited to the values in the above-described embodiments and may be other values.

[0262] Furthermore, in the above-described embodiments, the cases where PUCCH formats 0 to 4 are applied have been described, but the PUCCH formats are not limited to these. For example, other PUCCH formats may be applied that have different combinations of parameters such as the number of UCI bits (in other words, use case), symbol length (in other words, duration), RB size, number of terminals multiplexed, multiplexing method (for example, cyclic shift sequence number and OCC number), or encoding method. Furthermore, parameters related to the PUCCH formats are not limited to the values shown in FIG. 1, and may be other values.

[0263] <5G NR system architecture and protocol stack> 3GPP is working on the next release of fifth-generation cellular technology (also known as 5G), which includes the development of New Radio Access Technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, allowing for the prototyping and commercial deployment of 5G NR compliant devices (e.g., smartphones).

[0264] For example, the system architecture assumes a Next Generation - Radio Access Network (NG-RAN) with gNBs. The gNBs provide UE-side termination of NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are connected to each other via an Xn interface. The gNBs are also connected to a Next Generation Core (NGC) via a Next Generation (NG) interface, more specifically to an Access and Mobility Management Function (AMF) (e.g., a specific core entity that performs AMF) via an NG-C interface, and to a User Plane Function (UPF) (e.g., a specific core entity that performs UPF) via an NG-U interface. The NG-RAN architecture is shown in Figure 16 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0265] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the Packet Data Convergence Protocol (PDCP) sublayer (see, for example, TS 38.300, section 6.4), the Radio Link Control (RLC) sublayer (see, for example, TS 38.300, section 6.3), and the Medium Access Control (MAC) sublayer (see, for example, TS 38.300, section 6.2), which are terminated on the network side at the gNB. A new Access Stratum (AS) sublayer (Service Data Adaptation Protocol (SDAP)) has also been introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). A control plane protocol stack has also been defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functions is given in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in clauses 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in clause 7 of TS 38.300.

[0266] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0267] For example, the physical layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include the Physical Random Access Channel (PRACH), the Physical Uplink Shared Channel (PUSCH), and the Physical Uplink Control Channel (PUCCH) as uplink physical channels, and the Physical Downlink Shared Channel (PDSCH), the Physical Downlink Control Channel (PDCCH), and the Physical Broadcast Channel (PBCH) as downlink physical channels.

[0268] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communication (mMTC), which have diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps in the downlink and 10 Gbps in the uplink) and effective (user-experienced) data rates that are approximately three times higher than those offered by IMT-Advanced. On the other hand, URLLC imposes stricter requirements for ultra-low latency (0.5 ms user-plane latency for UL and DL, respectively) and high reliability (1-10-5 within 1 ms). Finally, mMTC preferably requires high connection density (1,000,000 devices / km in urban environments). 2 ), wide coverage in adverse environments, and extremely long battery life (15 years) for low-cost devices may be desired.

[0269] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be valid for another use case. For example, low-latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with small delay spreads. Subcarrier spacing may be optimized accordingly to maintain similar CP overhead. NR may support one or more subcarrier spacing values. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, etc. are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related by the equation Δf = 1 / Tu. Similar to LTE systems, the term "resource element" can be used to mean the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0270] In the new radio system 5G-NR, a resource grid of subcarriers and OFDM symbols is defined for each numerology and each carrier in the uplink and downlink. Each element of the resource grid is called a resource element and is specified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0271] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 17 shows the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0272] For example, the gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, encryption, and integrity protection of data; - AMF selection at UE attach time if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data towards UPF; - Routing of control plane information towards AMF; - Setting up and tearing down connections; - scheduling and sending of paging messages; - Scheduling and transmission of system broadcast information (originating from AMF or Operation, Admission, Maintenance (OAM) Function); - Configuring measurements and measurement reporting for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; - Network slicing support; - QoS flow management and mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - NAS message delivery function; - Sharing of radio access networks; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0273] The Access and Mobility Management Function (AMF) hosts the following main functions: - Ability to terminate Non-Access Stratum (NAS) signaling; - NAS signaling security; - Access Stratum (AS) security control; - 3GPP Core Network (CN) inter-node signaling for mobility between access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Managing the registration area; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization, including checking roaming privileges; - Mobility management control (subscription and policy); - Network slicing support; - Selection of Session Management Function (SMF).

[0274] Additionally, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT / inter-RAT mobility (if applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Packet routing and forwarding; - Packet inspection and policy rule enforcement for the user plane part; - Traffic usage reporting; - uplink classifier to support routing of traffic flows to the data network; - Branching Point for supporting multi-homed PDU sessions; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of uplink traffic (mapping to the QoS flow of the SDF); - Downlink packet buffering and trigger function for downlink data notification.

[0275] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - Traffic steering setting function in the User Plane Function (UPF) for routing traffic to the appropriate destination; - Enforcement of control plane policies and QoS; - Notification of downlink data.

[0276] <Procedures for RRC connection setup and reconfiguration> Figure 18 shows some of the interactions between the UE, gNB, and AMF (5GC entity) when the UE moves from RRC_IDLE to RRC_CONNECTED in the NAS part (see TS 38.300 v15.6.0).

[0277] RRC is a higher layer signaling protocol used to configure the UE and the gNB. With this transition, the AMF prepares UE context data (including, for example, PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sends it to the gNB with an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message. The gNB then sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures the UE to set up a Signaling Radio Bearer 2 (SRB2) and a Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration steps are omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0278] Therefore, the present disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) that includes: control circuitry that, in operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that, in operation, transmits an initial context setup message to the gNodeB via the NG connection so that a signaling radio bearer between the gNodeB and a user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling that includes a resource allocation configuration information element (IE) to the UE via the signaling radio bearer. Then, the UE performs uplink transmission or downlink reception based on the resource allocation configuration.

[0279] <IMT usage scenarios from 2020 onwards> Figure 19 shows some use cases for 5G NR. The 3rd Generation Partnership Project New Radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC), in addition to expanding support for eMBB. Figure 19 shows some example use scenarios envisioned for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0280] URLLC use cases have stringent performance requirements, such as throughput, latency, and availability. URLLC use cases are envisioned as one of the enabling technologies for future applications, such as wireless control of industrial production or manufacturing processes, remote medical surgery, automated power transmission and distribution in smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913. Key requirements for NR URLLC in Release 15 include a target user plane latency of 0.5 ms on the uplink (UL) and 0.5 ms on the downlink (DL). The overall URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size at a user plane latency of 1 ms.

[0281] From a physical layer perspective, reliability can be improved in many possible ways. Current reliability improvement room includes defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and developed. Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0282] Additionally, technology enhancements targeted by NR URLLC aim to improve latency and reliability. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition in the data channel, and preemption in the downlink. Preemption means that a transmission with previously allocated resources is stopped and the allocated resources are used for another transmission with a later requested lower latency / higher priority requirement. Thus, a previously allowed transmission is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0283] The use case for massive machine-type communication (mMTC) is characterized by a very large number of connected devices that typically transmit relatively small amounts of data that are not sensitive to latency. These devices are required to be low cost and have very long battery life. From an NR perspective, using very narrow bandwidth portions is one solution that saves power and allows for long battery life from the UE perspective.

[0284] As mentioned above, the scope of reliability improvement in NR is expected to be broader. One of the key requirements for all cases, for example for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can improve reliability from a radio perspective and a network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0285] For NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution: high reliability (up to 10-6 level), high availability, packet sizes up to 256 bytes, and time synchronization down to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and low latency in the 0.5 ms to 1 ms range (e.g., 0.5 ms latency on the targeted user plane)).

[0286] Furthermore, for NR URLLC, several physical layer enhancements are possible. These enhancements include enhancements to the PDCCH (Physical Downlink Control Channel) related to compact DCI, repetition of the PDCCH, and increased monitoring of the PDCCH. Also, the enhancement of UCI (Uplink Control Information) is related to the enhancement of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. There may also be enhancements to the PUSCH related to mini-slot level hopping, and enhancements to retransmission / repetition. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0287] <QoS Control> The 5G QoS (Quality of Service) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR: Guaranteed Bit Rate QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) that is carried in an encapsulation header via the NG-U interface.

[0288] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for each PDU session, e.g., as shown above with reference to Figure 18. Additional DRBs for the QoS flows of that PDU session can be configured later (when this is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and the 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and the NG-RAN associate UL and DL QoS flows with DRBs.

[0289] Figure 20 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (e.g., an external application server hosting 5G services, as illustrated in Figure 19) interacts with the 3GPP core network to provide services. For example, it accesses a Network Exposure Function (NEF) to support applications that affect traffic routing, or interacts with a policy framework (see Policy Control Function (PCF)) for policy control (e.g., QoS control). Based on the operator's deployment, Application Functions that are considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions that are not authorized by the operator to directly access Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0290] Figure 20 further illustrates further functional units of the 5G architecture, namely, Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN, e.g., operator-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0291] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of 5GC functions (e.g., an NEF, an AMF, an SMF, a PCF, an UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0292] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may be called an IC, system LSI, super LSI, or ultra LSI.

[0293] The integrated circuit method is not limited to LSI, but may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0294] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology can be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0295] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a wireless transceiver and processing / control circuitry. The wireless transceiver may include a receiver and a transmitter, or both functions. The wireless transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0296] Communications equipment is not limited to portable or mobile equipment, but also includes non-portable or fixed equipment, devices, and systems of any kind, such as smart home devices (such as appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0297] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0298] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0299] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0300] A terminal according to one embodiment of the present disclosure includes a control circuit that sets multiple first transmission opportunities for a unit time interval corresponding to a scheduling unit, and a transmission circuit that repeatedly transmits uplink control information during the multiple first transmission opportunities.

[0301] In one embodiment of the present disclosure, the control circuit changes a transmission opportunity among the plurality of first transmission opportunities, in which some symbols are set as downlink symbols, to a second transmission opportunity that includes other symbols different from the some symbols, based on information regarding the symbol configuration in the unit time interval.

[0302] In one embodiment of the present disclosure, the control circuit divides, among the plurality of first transmission opportunities, transmission opportunities that span a plurality of the unit time intervals into a plurality of second transmission opportunities at boundaries of the unit time intervals.

[0303] In one embodiment of the present disclosure, when the number of symbols of the second transmission opportunity is less than the number of symbols of the first transmission opportunity, the control circuit punctures the uplink control information in a format corresponding to the first transmission opportunity.

[0304] In one embodiment of the present disclosure, the control circuit determines a format of the uplink control information based on the number of symbols of the second transmission opportunity.

[0305] In one embodiment of the present disclosure, the control circuit determines not to transmit the uplink control information at the second transmission opportunity when a certain condition is satisfied at the second transmission opportunity.

[0306] In one embodiment of the present disclosure, the condition is that a format corresponding to the second transmission opportunity is different from a format corresponding to the first transmission opportunity.

[0307] In one embodiment of the present disclosure, the condition is that the number of symbols in the second transmission opportunity is less than a threshold.

[0308] In one embodiment of the present disclosure, the condition is that a reference signal is not included in the second transmission opportunity.

[0309] In one embodiment of the present disclosure, the format corresponding to the uplink control information is a format in which the number of symbols specified is equal to or less than a threshold.

[0310] In one embodiment of the present disclosure, the first transmission opportunity is configured by a combination of symbols in units of the number of symbols corresponding to the format.

[0311] In one embodiment of the present disclosure, the control circuit determines to transmit the uplink control information at the second transmission opportunity if a first parameter related to terminal multiplexing set in the terminal is included in a second parameter specified in the format determined for the second transmission opportunity.

[0312] In one embodiment of the present disclosure, the control circuit determines not to transmit the uplink control information at the second transmission opportunity if the first parameter is not included in the second parameter for the second transmission opportunity.

[0313] In one embodiment of the present disclosure, if the first parameter is not included in the second parameter for the second transmission opportunity, the transmission circuit transmits the uplink control information at the second transmission opportunity using a frequency resource associated with the first parameter.

[0314] In one embodiment of the present disclosure, the transmission circuit transmits the uplink control information using a plurality of frequency resources at the second transmission opportunity.

[0315] In a communication method according to an embodiment of the present disclosure, a terminal sets a plurality of transmission opportunities for a unit time interval corresponding to a scheduling unit, and repeatedly transmits uplink control information during the plurality of transmission opportunities.

[0316] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2020-020721, filed on February 10, 2020, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0317] One embodiment of the present disclosure is useful in wireless communication systems. [Explanation of symbols]

[0318] 100 base stations 101,205 Control unit 102 Upper control signal generation unit 103 Downlink control information generation unit 104,206 Encoding section 105,207 Modulation section 106,208 Signal allocation section 107,209 Transmitter 108,201 Receiver 109,202 Extraction part 110,203 Demodulation section 111,204 Decoding section 200 devices< / option>

Claims

1. Transmitting quasi-static Physical Uplink Control Channel (PUCCH) resource set configuration information via terminal-specific higher layer signaling; A transmission circuit transmits, by Downlink Control Information (DCI), indication information of a PUCCH resource for receiving an ACK / NACK for a Physical Downlink Shared Channel (PDSCH) allocated by the DCI, among a plurality of PUCCH resources included in the PUCCH resource set; The PUCCH resource includes, as a parameter configuring the PUCCH resource, information regarding the presence or absence of PUCCH repetition in each repetition reception (Repetition), or information regarding the number of repetitions, The semi-static PUCCH resource set configuration information configures a plurality of reception opportunities for a unit time interval corresponding to a scheduling unit, a receiving circuit that repeatedly receives uplink control information by a PUCCH according to the PUCCH resource indication information at the plurality of receiving opportunities; A base station comprising:

2. The parameters configuring the PUCCH resource include at least one of a parameter related to a PUCCH format, a parameter related to a time resource including a symbol position or the number of symbols, a parameter related to a frequency resource including a Physical Resource Block (PRB) number, the number of PRBs, or whether frequency hopping is applied, or a parameter related to a code resource including a cyclic shift sequence number or an orthogonal code number. The base station of claim 1 .

3. When some symbols of the time resource of the PUCCH are set to downlink symbols or flexible symbols in the SFIs in the plurality of reception opportunities, the PUCCH is not received in the unit time interval based on information about the symbol configuration in the unit time interval. The base station of claim 1 .

4. The base station is Transmitting quasi-static PUCCH resource set configuration information of the Physical Uplink Control Channel (PUCCH) by terminal-specific upper layer signaling; transmit, by Downlink Control Information (DCI), indication information of a PUCCH resource for receiving an ACK / NACK for a Physical Downlink Shared Channel (PDSCH) allocated by the DCI, among a plurality of PUCCH resources included in the PUCCH resource set; The PUCCH resource includes, as a parameter configuring the PUCCH resource, information regarding the presence or absence of PUCCH repetition in each repetition reception (Repetition), or information regarding the number of repetitions, According to the semi-static PUCCH resource set configuration information, a plurality of reception opportunities are configured for a unit time interval corresponding to a scheduling unit; At the plurality of reception opportunities, uplink control information is repeatedly received by the PUCCH according to the instruction information of the PUCCH resource. Communication method.

5. The parameters configuring the PUCCH resource include at least one of a parameter related to a PUCCH format, a parameter related to a time resource including a symbol position or the number of symbols, a parameter related to a frequency resource including a Physical Resource Block (PRB) number, the number of PRBs, or whether frequency hopping is applied, or a parameter related to a code resource including a cyclic shift sequence number or an orthogonal code number. The communication method according to claim 4.

6. When some symbols of the time resource of the PUCCH are set to downlink symbols or flexible symbols in the SFIs in the plurality of reception opportunities, the PUCCH is not received in the unit time interval based on information about the symbol configuration in the unit time interval. The communication method according to claim 4.

7. An integrated circuit for controlling processing of a base station, the processing comprising: Transmitting quasi-static PUCCH resource set configuration information of the Physical Uplink Control Channel (PUCCH) by terminal-specific upper layer signaling; transmit, by Downlink Control Information (DCI), indication information of a PUCCH resource for receiving an ACK / NACK for a Physical Downlink Shared Channel (PDSCH) allocated by the DCI, among a plurality of PUCCH resources included in the PUCCH resource set; The PUCCH resource includes, as a parameter configuring the PUCCH resource, information regarding the presence or absence of PUCCH repetition in each repetition reception (Repetition), or information regarding the number of repetitions, According to the semi-static PUCCH resource set configuration information, a plurality of reception opportunities are configured for a unit time interval corresponding to a scheduling unit; At the plurality of reception opportunities, uplink control information is repeatedly received by the PUCCH according to the instruction information of the PUCCH resource. Integrated circuit.

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