Base stations, communication methods, and integrated circuits

Abstract

To improve the efficiency of assigning control information in the uplink. [Solution] The terminal comprises a control circuit that controls the allocation of uplink resources to uplink control information based on the size of information indicating resource allocation related to uplink control information, and a transmission circuit that transmits uplink control information using uplink resources.

Description

[Technical Field]

[0001] This disclosure relates to terminals and communication methods. [Background technology]

[0002] In recent years, driven by the expansion and diversification of wireless services, the Internet of Things (IoT) is expected to develop dramatically. The use of mobile communication is expanding beyond smartphones and other information terminals to encompass a wide range of fields, including cars, homes, home appliances, and industrial equipment. To support this diversification of services, significant improvements in the performance and functionality of mobile communication systems are required, in addition to increased system capacity, as well as various other requirements such as an increase in the number of connected devices and low latency. Against this backdrop, research and development and standardization of the 5th generation mobile communication system (5G) are progressing. Through enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable and low-latency communication (URLLC), it is possible to flexibly provide wireless communication to meet a wide variety of needs.

[0003] The 3rd Generation Partnership Project (3GPP), an international standardization organization, has considered New Radio (NR) as one of the 5G radio interfaces and has completed the development of the Release 15 specification, which implements eMBB and basic URLLC.

[0004] In Release 15, URLLC requires, for example, a wireless section delay of less than 1 ms and a reliability of 99.999% when transmitting a 32-byte packet. On the other hand, in Release 16, in order to extend URLLC to a variety of use cases such as remote driving or industrial IoT, functional enhancements are being considered to meet higher requirements compared to Release 15, such as increased packet size, further reduction of delay, and improved reliability (see, for example, Non-Patent Documents 1 and 2). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] RP-191584, “Revised WID: Physical layer enhancements for NR ultra-reliable and low latency communication (URLLC),” Huawei, HiSilicon, June 2019. [Non-Patent Document 2] RP-191561, “Revised WID: Support of NR industrial Internet of Things (IoT),” Nokia, Nokia Shanghai Bell, June 2019. [Non-Patent Document 3] 3GPP TS 38.211 V15.8.0, "NR; Physical channels and modulation (Release 15)," 2019-12. [Non-Patent Document 4] 3GPP TS 38.212 V15.8.0, "NR; Multiplexing and channel coding (Release 15)," 2019-12. [Non-Patent Document 5] 3GPP TS 38.213 V15.8.0, "NR; Physical layer procedure for control (Release 15)," 2019-12. [Non-Patent Document 6] 3GPP TS 38.214 V15.8.0, "NR; Physical layer procedures for data (Release 15)," 2019-12. [Non-Patent Document 7] 3GPP TS 38.212 V16.0.0, "NR; Multiplexing and channel coding (Release 16)," 2019-12. [Overview of the project]

[0006] However, there is room for further consideration regarding the method of assigning control information in the uplink.

[0007] Non-limiting embodiments of this disclosure contribute to providing terminals and communication methods that can improve the efficiency of control information allocation in uplinks.

[0008] A terminal according to one embodiment of the present disclosure comprises a control circuit that controls the allocation of uplink resources to uplink control information based on the size of information indicating resource allocation related to uplink control information, and a transmission circuit that transmits the uplink control information using the uplink resources.

[0009] These comprehensive or specific embodiments may be implemented as systems, devices, methods, integrated circuits, computer programs, or recording media, or as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0010] According to one embodiment of the present disclosure, the allocation efficiency in wireless communication can be improved.

[0011] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0012] [Figure 1] This diagram shows an example of resource allocation for the Physical Uplink Control Channel (PUCCH). [Figure 2] Figure showing an example of PUCCH resource allocation. [Figure 3] Block diagram showing some example configurations of the terminal. [Figure 4] Block diagram showing an example of a base station configuration. [Figure 5] Block diagram showing an example of terminal configuration [Figure 6] Flowchart showing an example of terminal operation according to Embodiment 1 [Figure 7] A diagram showing an example of PUCCH resource allocation according to Embodiment 1. [Figure 8] A diagram showing an example of PUCCH resource allocation according to Embodiment 1. [Figure 9] A diagram showing an example of PUCCH resource allocation according to Embodiment 1. [Figure 10] A diagram showing an example of PUCCH resource allocation according to Embodiment 1. [Figure 11] A diagram showing an example of PUCCH resource allocation according to Embodiment 1. [Figure 12] A diagram showing an example of PUCCH resource allocation according to Embodiment 1. [Figure 13] Flowchart showing an example of terminal operation according to Embodiment 2 [Figure 14] A diagram showing an example of PUCCH resource allocation according to Embodiment 2. [Figure 15] A diagram showing an example of PUCCH resource allocation according to Embodiment 2. [Figure 16]A diagram showing an example of PUCCH resource allocation according to Embodiment 2. [Figure 17] A diagram showing an example of PUCCH resource allocation according to Embodiment 2. [Figure 18] Flowchart showing an example of terminal operation according to Embodiment 3 [Figure 19] Flowchart showing an example of terminal operation according to Embodiment 4 [Figure 20] Diagram of a representative architecture of a 3GPP NR system [Figure 21] Schematic diagram showing the functional separation between NG-RAN and 5GC. [Figure 22] Sequence diagram of the RRC connection setup / reconfiguration procedure [Figure 23] This schematic diagram illustrates usage scenarios for high-capacity, high-speed communication (eMBB: enhanced Mobile Broadband), massive machine type communications (mMTC: massive machine type communications), and highly reliable, ultra-low-latency communications (URLLC: Ultra Reliable and Low Latency Communications). [Figure 24] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario. [Modes for carrying out the invention]

[0013] Embodiments of this disclosure will be described in detail below with reference to the drawings.

[0014] For example, in the downlink of an NR, a terminal (e.g., also called a UE: User Equipment) receives downlink data (e.g., PDSCH: Physical Downlink Shared Channel) according to resource allocation instructed by the base station (e.g., also called a gNB) (see, for example, Non-Patent Documents 3-6). Information regarding resource allocation may be communicated from the base station to the terminal by, for example, Layer 1 control signals (e.g., DCI: Downlink Control Information) in the downlink control channel (e.g., PDCCH: Physical Downlink Control Channel).

[0015] Furthermore, the terminal feeds back a response signal indicating the success or failure of decoding to the PDSCH (for example, ACK / NACK: Acknowledgement / Negative Acknowledgement, or Hybrid Automatic Repeat Request (HARQ)-ACK) to the base station, for example, using the uplink control channel (for example, PUCCH: Physical Uplink Control Channel) (see, for example, Non-Patent Document 5).

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

[0017] NR Rel.15 employs the following method for identifying PUCCH resources for sending ACK / NACK to PDSCH assigned by DCI (see, for example, Non-Patent Document 5). For example, a base station notifies (in other words, configures or instructs) a quasi-static set of PUCCH resources (for example, called a PUCCH resource set or resource list) by terminal-specific higher-layer signals (for example, radio resource control (RRC) signals, also called higher layer signaling or higher layer parameters). Then, the base station notifies (for example, indicates) which PUCCH resource to assign to the terminal from among the multiple PUCCH resources included in the PUCCH resource set by DCI (in other words, dynamic signaling).

[0018] Here, the PUCCH resource may consist of parameters such as the PUCCH format, time resources (e.g., symbol position or number of symbols), frequency resources (e.g., physical resource block (PRB) number, number of PRBs, whether or not frequency hopping is applied), or code resources (e.g., cyclic shift sequence number or orthogonal code number).

[0019] In NR Rel.15, the PUCCH resource assigned to a terminal from among multiple PUCCH resources included in the PUCCH resource set is controlled, for example, based on the 3-bit PUCCH Resource Indicator (PRI) field of the DCI. For example, a PUCCH resource set containing multiple PUCCH resources is pre-configured on the terminal by a higher-layer signal, and a PUCCH resource is assigned to the terminal by indicating one PUCCH resource from the configured PUCCH resource set via the PRI field of the DCI (see, for example, Non-Patent Document 3).

[0020] Figure 1 shows an example of PUCCH resource allocation (mapping between PRI values ​​and PUCCH resources) when the PUCCH resource set contains 8 PUCCH resources.

[0021] In the example shown in Figure 1, for instance, PUCCH resources 0 to 7 are associated with each of the PRI values ​​(also called PRI field values) from 0 to 7.

[0022] On the other hand, if the number of PUCCH resources in the PUCCH resource set is greater than eight, the PUCCH resources may be assigned based on information about the Control Channel Element (CCE), which is the radio resource unit of the PDCCH transmitting the DCI, in addition to the PRI field of the DCI. For example, the PUCCH resource (e.g., PUCCH resource number r PUCCH ) may be given according to the following equation (1) (see, for example, Non-Patent Document 5).

number

[0023] Here, R PUCCH This indicates the number of PUCCH resources included in the PUCCH resource set, N CCE,p n indicates the number of CCEs included in the control resource set (p) (CORESET(p)) that sends PDCCH. CCE,p indicates the leading CCE number assigned to the PDCCH that transmits DCI, Δ PRI This indicates the value of PRI.

[0024] Furthermore, below, the ceiling function for a value x, as shown in equation (1), may be expressed as "ceiling(x)", and the floor function for a value x may be expressed as "floor(x)".

[0025] FIG. 2 is a diagram showing an example of PUCCH resource allocation (for example, the association between the value of PRI and the CCE number and the PUCCH resource) when the number of PUCCH resources included in the PUCCH resource set is more than 8. In the example shown in FIG. 2, for example, the number of PUCCH resources R PUCCH included in the PUCCH resource set is 16 (PUCCH resources 0 to 15), the number of CCEs N CCE,p is 32, the CCE number n CCE,p is any of 0 to 31, and the value of PRI Δ PRI is any of 0 to 7.

[0026] As shown in FIG. 2, two PUCCH resources are associated with each PRI value (for example, any of 0 to 7). Also, different CCE groups (either CCE0 - 15 or CCE16 - 31) with different CCE numbers are associated with each of the two PUCCH resources associated with one PRI value. The terminal may identify (in other words, determine, or set) the PUCCH resource allocated to the terminal based on, for example, the combination of the value of PRI notified by DCI and the number of the CCE (for example, the leading CCE) used for the transmission of the DCI (in other words, PDCCH).

[0027] Here, in order to achieve high reliability in URLLC, for example, the reliability of PDCCH is required to be equal to or higher than that of PDSCH. For example, for a terminal in URLLC (hereinafter referred to as a URLLC terminal), by setting a larger number of allocated PDCCH resources (for example, CCEs), a low coding rate can be achieved and the reliability of PDCCH can be improved. On the other hand, since the number of PDCCH resources allocated to one terminal increases, for some terminal numbers, the number of available PDCCH resources may be insufficient, and for example, the frequency of blocking may increase.

[0028] For example, a blocked terminal may be allocated PDCCH resources for the next transmission opportunity. However, as the frequency of blocking increases, the radio section delay may increase. Also, the frequency of blocking can be reduced, for example, by reducing the number of CCEs shared between terminals. On the other hand, scheduling flexibility may decrease.

[0029] NR Rel.16 specifies a new DCI for URLLC (e.g., DCI Format 1-2) to achieve high reliability of PDCCH while limiting the number of CCEs allocated to each terminal and ensuring scheduling flexibility (see, for example, Non-Patent Document 7). The DCI for URLLC allows for a reduction in the number of DCI bits in the PDCCH. For example, in DCI Format 1-2, the number of bits in PRI (in other words, the PRI field size) can be set to 0, 1, 2, or 3 bits.

[0030] Thus, up to Rel.15, the number of PRI bits was set to a fixed value (e.g., 3 bits), and the mapping between PUCCH resources and the fixed-bit value of PRI (or the PRI value and CCE number) was defined. On the other hand, in URLLC of Rel.16, the number of PRI bits is set to a variable value (e.g., any of 0 to 3 bits). However, the method of allocating PUCCH resources when the number of PRI bits is variable has not been sufficiently considered.

[0031] One embodiment of this disclosure describes a method for improving the efficiency of PUCCH resource allocation based on a variablely set number of PRI bits. For example, a terminal controls PUCCH resource allocation based on the number of bits of PRI notified by DCI. By basing it on the number of bits of PRI (rather than its value), the efficiency of PUCCH resource allocation in URLLC can be improved. Note that "number of bits" may be read interchangeably with "bit size" or "bit length". Similarly, in the following description, the term "number of bits" may be read interchangeably with "size" or "length".

[0032] [Overview of the communication system] Each embodiment of the present disclosure comprises a base station 100 and a terminal 200.

[0033] Figure 3 is a block diagram showing a partial configuration example of a terminal 200 according to one embodiment of the present disclosure. In the terminal 200 shown in Figure 3, the control unit 205 (corresponding to a control circuit, for example) controls the allocation of uplink resources (e.g., PUCCH resources) to uplink control information based on the size of information (e.g., PRI) indicating resource allocation related to uplink control information (e.g., UCI such as ACK / NACK). The transmission unit 209 (corresponding to a transmission circuit, for example) transmits uplink control information using uplink resources.

[0034] (Embodiment 1) [Base station configuration] Figure 4 is a block diagram showing an example configuration of a base station 100 according to Embodiment 1. In Figure 4, the base station 100 includes a control unit 101, a higher-level 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.

[0035] The control unit 101 determines, for example, information regarding PUCCH resources for terminal 200 and outputs the determined information to the higher-level control signal generation unit 102. The information regarding PUCCH resources may include information regarding the number of PUCCH resources included in the PUCCH resource set. The information regarding PUCCH resources may also include, for example, information regarding the correspondence between PUCCH resources and PRI values, or information such as offset values.

[0036] Furthermore, the control unit 101 determines, for example, information regarding DCI reception at terminal 200 and outputs the determined information to the higher-level control signal generation unit 102. Information regarding DCI reception may include, for example, the number of DCI bits (e.g., the number of PRI bits), the setting of CORESET, or the setting of the search space.

[0037] Furthermore, the control unit 101 determines information regarding the downlink signal for transmitting downlink data signals (e.g., PDSCH), higher-level control signals, or downlink control information (e.g., DCI). Information regarding the downlink signal may include, for example, information such as the coding and coding scheme (MCS) and radio resource allocation. The control unit 101 outputs the determined information to, for example, the coding unit 104, the modulation unit 105, and the signal allocation unit 106. The control unit 101 also outputs information regarding the downlink signal, such as data signals or higher-level control signals, to the downlink control information generation unit 103.

[0038] Furthermore, the control unit 101 determines information regarding the PUCCH resource for the terminal to transmit an uplink control signal (e.g., PUCCH), and outputs the determined information to the downlink control information generation unit 103 and the extraction unit 109. The information regarding the PUCCH resource may include, for example, information regarding the value of PRI.

[0039] The higher-level control signal generation unit 102 generates a higher-level control signal bit sequence based on information input from the control unit 101 (for example, information regarding PUCCH resources or information regarding DCI reception), and outputs the higher-level control signal bit sequence to the encoding unit 104.

[0040] The downlink control information generation unit 103 generates a downlink control information (e.g., DCI) bit sequence based on information input from the control unit 101 (e.g., information about PUCCH resources), and outputs the generated DCI bit sequence to the encoding unit 104. The downlink control information generation unit 103 may include, for example, information about PUCCH resources input from the control unit 101 in the PRI field of the DCI bit sequence.

[0041] Furthermore, control information may be transmitted to multiple terminals. For this reason, the downlink control information generation unit 103 may scramble the PDCCH that transmits DCI using terminal-specific identification information. The terminal-specific identification information may be any of the following: TC-RNTI (Temporary Cell Radio Network Temporary Identifier), C-RNTI (Cell RNTI), and MCS-C-RNTI (Modulation and Coding Scheme C-RNTI), or other information (for example, other RNTI). Other RNTI may be, for example, an RNTI introduced for URLLC.

[0042] The encoding unit 104 encodes, for example, downlink data, a bit sequence input from the higher-level control signal generation unit 102, or a DCI bit sequence input from the downlink control information generation unit 103, based on information input from the control unit 101. The encoding unit 104 outputs the encoded bit sequence to the modulation unit 105.

[0043] The modulation unit 105 modulates the encoded bit sequence input from the encoding unit 104 based on information input from the control unit 101, and outputs the modulated signal (e.g., a symbol sequence) to the signal assignment unit 106.

[0044] The signal assignment unit 106 maps the symbol sequence (including, for example, downlink data signals or control signals) input from the modulation unit 105 to the radio resource based on information indicating the radio resource input from the control unit 101. The signal assignment unit 106 outputs the downlink signal to the transmission unit 107.

[0045] The transmitter 107 performs a waveform generation process on the signal input from the signal assignment unit 106, such as orthogonal frequency division multiplexing (OFDM). In the case of OFDM transmission that adds a cyclic prefix (CP), the transmitter 107 also performs an inverse fast Fourier transform (IFFT) on the signal and adds the CP to the signal after the IFFT. The transmitter 107 also performs RF processing on the signal, such as D / A conversion and upconversion, and transmits the wireless signal to the terminal 200 via the antenna.

[0046] The receiving unit 108 performs RF processing, such as downconverting or A / D conversion, on the uplink signal received from the terminal 200 via the 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 extraction unit 109.

[0047] Based on the information input from the control unit 101, the extraction unit 109 extracts the portion of the wireless resource to which the uplink signal transmitted by the terminal 200 is transmitted, and outputs the extracted portion of the wireless resource to the demodulation unit 110.

[0048] The demodulation unit 110 demodulates the uplink signal (e.g., PUCCH) input from the extraction unit 109 based on the information input from the control unit 101. The demodulation unit 110 outputs the demodulation result to the decoding unit 111, for example.

[0049] The decoding unit 111 performs error-correcting decoding of the uplink signal based on the information input from the control unit 101 and the demodulation result input from the demodulation unit 110, and obtains the decoded received bit sequence (for example, UCI such as ACK / NACK).

[0050] [Device Configuration] Figure 5 is a block diagram showing an example configuration of a terminal 200 according to one embodiment of the present disclosure. For example, in Figure 5, the terminal 200 includes a receiving unit 201, an extraction unit 202, a demodulation unit 203, a decoding unit 204, a control unit 205, an encoding unit 206, a modulation unit 207, a signal allocation unit 208, and a transmission unit 209.

[0051] The receiving unit 201 receives downlink signals (e.g., downlink data signals or downlink control information) from the base station 100 via an antenna, and performs RF processing such as downconverting or A / D conversion on the wirelessly received signals to obtain a received signal (baseband signal). In addition, when the receiving unit 201 receives an OFDM signal, it performs FFT processing on the received signal to convert the received signal into the frequency domain. The receiving unit 201 outputs the received signal to the extraction unit 202.

[0052] The extraction unit 202 extracts the portion of the radio resource that may contain downlink control information from the received signal input from the receiving unit 201, based on the information about the radio resource of the downlink control information input from the control unit 205, and outputs it to the demodulation unit 203. The extraction unit 202 also extracts the portion of the radio resource that contains downlink data, based on the information about the radio resource of the data signal input from the control unit 205, and outputs it to the demodulation unit 203.

[0053] The demodulation unit 203 demodulates the signal input from the extraction unit 202 and outputs the demodulation result to the decoding unit 204.

[0054] The decoding unit 204 performs error correction decoding on the demodulation result input from the demodulation unit 203 to obtain, for example, downlink received data, upper-layer control signals, or downlink control information. The decoding unit 204 outputs the upper-layer control signals and downlink control information to the control unit 205 and outputs the downlink received data. The decoding unit 204 may also generate a response signal (for example, ACK / NACK) based on the decoding result of the downlink received data and output it to the encoding unit 206.

[0055] The control unit 205 determines the radio resources of the downlink signal (e.g., PDSCH) and the uplink signal (e.g., PUCCH) based on at least one of the following: information regarding the PUCCH resource, information regarding DCI reception, information regarding PRI included in the DCI, and information regarding the radio resource (e.g., CCE) of the PDCCH that has received downlink control information, which are included in the upper-layer control signal input from the decoding unit 204. The control unit 205 outputs information indicating the determined radio resources of the downlink signal to the extraction unit 202, and outputs information indicating the determined radio resources of the uplink signal to the signal allocation unit 208. The control unit 205 may also determine information regarding the transmission of the uplink signal and output the determined information to the encoding unit 206.

[0056] The encoding unit 206 encodes the uplink signal (e.g., UCI) based on the information input from the control unit 205 and outputs the encoded bit sequence to the modulation unit 207. The UCI may include, for example, the ACK / NACK input from the decoding unit 204.

[0057] The modulation unit 207 modulates the encoded bit sequence input from the encoding unit 206 and outputs the modulated signal (symbol sequence) to the signal assignment unit 208.

[0058] The signal assignment unit 208 maps the signal input from the modulation unit 207 to a wireless resource based on the information input from the control unit 205, and outputs the mapped uplink signal to the transmission unit 209.

[0059] The transmitter 209 generates a transmission signal waveform, such as OFDM, from the signal input from the signal assignment unit 208. Furthermore, in the case of OFDM transmission using CP, the transmitter 209 performs IFFT processing on the signal and adds CP to the IFFT-processed signal. Alternatively, when the transmitter 209 generates a single-carrier waveform, a DFT (Discrete Fourier Transform) unit may be added after the modulation unit 207 or before the signal assignment unit 208 (not shown). The transmitter 209 also performs RF processing, such as D / A conversion and upconversion, on the transmission signal and transmits the radio signal to the base station 100 via the antenna.

[0060] [Example of operation of base station 100 and terminal 200] An example of operation in a base station 100 and terminal 200 having the above configuration will be described below.

[0061] Figure 6 is a flowchart showing an example of the operation of terminal 200 according to this embodiment.

[0062] In Figure 6, terminal 200 obtains information about PUCCH resources (e.g., a PUCCH resource set) (ST101). Information about PUCCH resources may be set from base station 100 to terminal 200 by terminal-specific higher-layer signaling (e.g., RRC). Information about PUCCH resources may also include information about a set of PUCCH resources that are set quasi-statically (e.g., a PUCCH resource set).

[0063] Terminal 200 obtains information, for example, about the number of PRI bits included in the DCI (PRI bit count) (ST102). Information about the PRI bit count may be set from base station 100 to terminal 200 by signaling at a higher layer (e.g., RRC). By notifying (or setting) this information about the PRI bit count, terminal 200 can receive a DCI in which the PRI bit count can be set variably.

[0064] Terminal 200 receives a PDCCH including, for example, a DCI (ST103). The DCI may include, for example, information regarding the allocation resources for downlink data signals (PDSCH) or information regarding the allocation resources for uplink signals. The information regarding the allocation resources for uplink signals may include, for example, information regarding the PUCCH resource assigned to terminal 200 from among multiple PUCCH resources included in the PUCCH resource set configured on terminal 200 (e.g., PRI).

[0065] Terminal 200, for example, the number of PUCCH resources included in the PUCCH resource set (for example, R PUCCH ) is compared with the specified values ​​(8 in this case) (ST104).

[0066] Number of PUCCH resources included in the PUCCH resource set (R PUCCH If there are 8 or fewer of these, terminal 200 will have a PRI value (for example, Δ PRI The PUCCH resource is determined based on (ST105). For example, terminal 200 may determine that the PUCCH resource included in the PUCCH resource set that has a one-to-one correspondence with the PRI value is the PUCCH resource assigned to terminal 200.

[0067] On the other hand, the number of PUCCH resources included in the PUCCH resource set (R PUCCH If there are more than eight of these, terminal 200 determines the PUCCH resource based on the combination of the PRI value and the CCE number used for the received PDCCH (e.g., the starting CCE number) (ST106). For example, terminal 200 may determine that the PUCCH resource included in the PUCCH resource set that is associated with a combination of the PRI value and the CCE number is the PUCCH resource assigned to terminal 200.

[0068] Terminal 200, for example, receives a downlink data signal (e.g., PDSCH) and decodes the received PDSCH (ST107). Terminal 200 also generates an ACK / NACK for the PDSCH based on the decoding result of the PDSCH (ST108).

[0069] Terminal 200, for example, sends an ACK / NACK to base station 100 using the determined PUCCH resource (ST109).

[0070] In Figure 6, the order of processing for obtaining information about the PUCCH resource (ST101) and obtaining information about the number of PRI bits in the DCI (ST102) is not limited (for example, they may be processed in reverse order or in parallel) (the same applies in the following explanation). Also, in Figure 6, the order of processing for determining the PUCCH resource (for example, ST104, ST105, and ST106) and for receiving and decoding the PDSCH and generating ACK / NACK (for example, ST107 and ST108) is not limited (for example, they may be processed in reverse order or in parallel) (the same applies in the following explanation).

[0071] [Example of PUCCH resource allocation] Next, an example of a method for allocating PUCCH resources (in other words, a determination method) according to this embodiment will be described.

[0072] In this embodiment, terminal 200 supports the reception of DCI with a variable PRI bit count (e.g., N bits) (for example, 0, 1, 2, or 3 bits can be set).

[0073] Terminal 200 controls the allocation of PUCCH resources (e.g., ACK / NACK) from among multiple PUCCH resources included in the PUCCH resource set, based on the N bits of PRI included in the received DCI. Then, terminal 200 transmits the PUCCH according to the control of the PUCCH resource allocation.

[0074] [If the number of PUCCH resources included in the PUCCH resource set is 8 or less] If the number of PUCCH resources included in the PUCCH resource set is eight or less, terminal 200 may, for example, identify (in other words, determine or set; the same applies hereinafter) a PUCCH resource from among the PUCCH resources included in the PUCCH resource set (in other words, candidate PUCCH resources) that is associated one-to-one with the PRI value included in DCI.

[0075] Figure 7 shows an example of PUCCH resource allocation (e.g., the mapping between the value of PRI and PUCCH resources) when N=1 bit (e.g., PRI=0 or 1). Also in Figure 7, the number of PUCCH resources (R) included in the PUCCH resource set is shown. PUCCH ) is 8 (in other words, 8 or less). Also, in Figure 7, the value of PRI (Δ PRI )0 and 1 are mapped one-to-one to PUCCH resources 0 and 1, respectively.

[0076] In Figure 7, terminal 200 determines PUCCH resource 0 if the value of PRI included in DCI is 0, and PUCCH resource 1 if the value of PRI included in DCI is 1.

[0077] Note that the mapping between the PRI value and the PUCCH resource may be such that the PRI value is associated with a PUCCH resource of the same number as the PRI value, as shown in the example in Figure 7, or it may be associated with a PUCCH resource of a different number than the PRI value. For example, Figure 8 shows N=1 bit (for example, Δ PRI This figure shows an example of the correspondence between the value of PRI and the PUCCH resource number of the value of PRI plus an offset value when N = 0 or 1). Also, for example, Figure 9 shows the correspondence between the value of PRI and the value of PRI plus a specified value (for example, 8 / 2 in equation (4) described later) when N = 1 bit (for example, PRI = 0 or 1). N This figure shows an example of the correspondence between the PUCCH resource and the number obtained by multiplying the value by ).

[0078] For example, the PUCCH resource number (r) in the examples in Figures 7, 8, and 9. PUCCH ) may be given according to equations (2), (3), and (4).

number

number

number

[0079] Here, r PUCCH indicates the number of the PUCCH resource included in the PUCCH resource set, Δ PRI This indicates the value of PRI. Also, N offset This shows the offset value shown in Figure 8. Note that Figure 8 is N offset We will show the case where =2, but N offset The value of is not limited to 2; it can be any other value.

[0080] Note that Figures 7 to 9 illustrate the case where the number of PRI bits N=1 as an example, but the number of PRI bits N can be any value other than 1. For example, if N=2, there are 4 values ​​for each of the 4 possible values ​​of PRI (e.g., 0 to 3), and 4 (=2 N Each PUCCH resource may be associated on a one-to-one basis.

[0081] Therefore, terminal 200 can identify the PUCCH resource based on the number of PRI bits included in DCI, when the number of PRI bits is variable.

[0082] Furthermore, the mapping between PRI values ​​and PUCCH resources is not limited to the example above; for example, the mapping between PRI values ​​and PUCCH resources is not limited to the example above. N The number of PUCCH resources and the value of PRI (2 NIt is sufficient that there is a one-to-one correspondence between the values ​​of the PUCCH resource and the PRI value. The correspondence between the PUCCH resource and the PRI value may be defined in the standard, or it may be notified to the terminal 200 by a higher layer signal. Also, for example, in the example shown in Figure 8 (Equation (3)), the offset value (N offset ) may be defined in the standard, or it may be notified to terminal 200 by a higher layer signal.

[0083] [If the number of PUCCH resources included in the PUCCH resource set is greater than 8] Number of PUCCH resources included in the PUCCH resource set (R PUCCH If there are more than eight of them, terminal 200 may, for example, identify a PUCCH resource from among the PUCCH resources included in the PUCCH resource set based on information about the PRI included in DCI and the CCE of the PDCCH which includes DCI.

[0084] For example, PUCCH resource number (r PUCCH ) may be given according to the following equation (5).

number

[0085] Here, N CCE,p n indicates the number of CCEs included in the control resource set (p) that sends PDCCH. CCE,p indicates the leading CCE number assigned to the PDCCH that transmits DCI, Δ PRI This indicates the value of PRI.

[0086] Figure 10 shows N=1 bit (for example, Δ PRI This figure shows an example of PUCCH resource allocation (the mapping between the PRI value and CCE number and the PUCCH resource) when = 0 or 1. Also, Figure 10 shows the number of PUCCH resources included in the PUCCH resource set (R PUCCH There are 16 of them (in other words, more than 8). Also, in Figure 10, the number of CCEs NCCE,p There are 32 of them.

[0087] As shown in Figure 10, PUCCH resources 0 and 1 are associated with PRI=0, and PUCCH resources 2 and 3 are associated with PRI=1. In other words, two PUCCH resources are associated with one PRI value.

[0088] Furthermore, as shown in Figure 10, among the PUCCH resources associated with PRI=0, PUCCH resource 0 is associated with CCE group CCE numbers 0-15, and PUCCH resource 1 is associated with CCE group CCE numbers 16-31. Similarly, in Figure 10, among the PUCCH resources associated with PRI=1, PUCCH resource 2 is associated with CCE group CCE numbers 0-15, and PUCCH resource 3 is associated with CCE group CCE numbers 16-31.

[0089] In Figure 10, terminal 200, for example, among the PUCCH resources 0 to 15 included in the PUCCH resource set, has a PRI value (Δ included in DCI) PRI The PUCCH resource assigned to terminal 200 is determined to be the PUCCH resource associated with the combination of the PDCCH transmission including DCI and the CCE number used for transmission (e.g., the starting CCE number).

[0090] Furthermore, in the mapping between the PRI value and the CCE number combination and the PUCCH resource, the PRI value may be mapped sequentially starting from the first PUCCH resource (PUCCH resource 0), as shown in the example in Figure 10. Alternatively, as shown in Figure 11, the PRI value may be mapped sequentially starting from the PUCCH resource number obtained by adding an offset value to the PRI value, or as shown in Figure 12, the PRI value may be set to a predetermined value (for example, 8 / 2 in equation (7) described later). N The PUCCH resource number obtained by multiplying the value by ) may also be associated with it.

[0091] For example, the PUCCH resource number (r PUCCH ) may be given according to equations (6) and (7).

number

number

[0092] Here, N offset This shows the offset value shown in Figure 11. Note that Figure 11 is N offset We will show the case where =4, but N offset The value is not limited to 4; other values ​​are also acceptable.

[0093] Note that Figures 10 to 12 illustrate the case where the number of PRI bits N=1 as an example, but the number of PRI bits N can be any value other than 1. For example, when N=2, for each of the four possible values ​​of PRI (e.g., 0 to 3), there are two (= ceiling(R PUCCH 8) PUCCH resources may be associated with this.

[0094] Therefore, terminal 200 can identify the PUCCH resource based on the number of PRI bits included in DCI, when the number of PRI bits is variable.

[0095] Furthermore, the mapping between the PRI value and CCE number combination and the PUCCH resource is not limited to the examples described above. For example, the PUCCH resource included in the PUCCH resource set (e.g., ceiling(R PUCCH / 8)·2 N (Number of PUCCH resources) and the value of PRI (2 N The value of each option) and ceiling(R PUCCH / 8) A one-to-one correspondence is established, and each PRI value is associated with the ceiling(R PUCCH There may be a one-to-one correspondence between PUCCH resources and CCE groups (1 / floor(ceiling(R PUCCH / 8) / N CCE,p This is a set containing ) CCE numbers (for example, CCE0-15 or CCE16-31 in Figures 10-12).

[0096] Furthermore, the correspondence between the PRI value and the CCE number combination and the PUCCH resource may be defined in a standard, for example, or it may be notified to the terminal 200 in advance by a higher-layer signal. Also, for example, in the example shown in Figure 11 (Equation (6)), the offset value (N offset ) may be defined in the standard, or may be notified to terminal 200 in advance by a higher layer signal.

[0097] According to this embodiment, terminal 200 controls the allocation of PUCCH resources to UCI based on the size of PRI, which indicates resource allocation related to UCI such as ACK / NACK. For example, when the number of PRI bits included in DCI is variable, terminal 200 can determine which PUCCH resources to allocate to terminal 200 from among the PUCCH resources included in the PUCCH resource set based on the value of PRI, or a combination of the value of PRI and the CCE number. Therefore, according to this embodiment, for example, the efficiency of PUCCH resource allocation can be improved according to the variable number of PRI bits.

[0098] For example, the settings for mapping PRI values ​​to PUCCH resources (e.g., Figures 7-9), or the settings for mapping combinations of PRI values ​​and CCE numbers to PUCCH resources (e.g., Figures 10-12), may differ among terminals 200. Applying different mappings among terminals can increase the number of PUCCH resources that can be simultaneously allocated to multiple terminals 200 sharing a PUCCH resource set.

[0099] (Embodiment 2) In Embodiment 1, for example, if the number of PRI bits is N, the number of PUCCH resources that can be dynamically allocated by the value of PRI, or a combination of the value of PRI and the CCE number, is 2 if there are 8 or fewer PUCCH resources in the PUCCH resource set. N If there are more than 8 PUCCH resources in the PUCCH resource set, then ceiling(R PUCCH / 8)·2 N Therefore, for example, the smaller the number of PRI bits N, the fewer PUCCH resources can be dynamically allocated.

[0100] For example, the smaller the number of PRI bits N, the fewer PUCCH resources can be allocated to multiple terminals simultaneously when the PUCCH resource set is shared between terminals, making PUCCH resource collisions more likely. PUCCH resource collisions can increase the frequency of blocking. On the other hand, if different PUCCH resource sets are configured for each of the multiple terminals, the frequency of blocking may decrease. However, the overhead of PUCCH resources may increase.

[0101] Furthermore, for example, different settings can be applied to multiple terminals for configuring the mapping between PRI values ​​and PUCCH resources, or the mapping between combinations of PRI values ​​and CCE numbers and PUCCH resources. However, applying different mapping settings to each terminal may increase the overhead required to notify each terminal of the different mapping settings.

[0102] Therefore, in this embodiment, we will describe a method for dynamically allocating multiple PUCCH resources included in a PUCCH resource set, regardless of the number of PUCCH resources and PRI bits included in the PUCCH resource set.

[0103] The configuration of the base station and terminal according to this embodiment may be the same as the configuration of the base station 100 and terminal 200 according to Embodiment 1.

[0104] Figure 13 is a flowchart showing an example of the operation of terminal 200 according to this embodiment. In Figure 13, the same reference numerals are used for operations similar to those in Figure 6 (Embodiment 1), and their descriptions are omitted.

[0105] In Figure 13, terminal 200 determines (for example, calculates) parameters related to the control of PUCCH resource allocation based on the number of PRI bits (N) (ST201). The parameters related to the control of PUCCH resource allocation are, for example, the number of PUCCH resources (R) included in the PUCCH resource set. PUCCH This is the threshold X for ). For example, the threshold X is 2 N This setting may be used. With this setting, the threshold X will be set to a smaller value as the number of PRI bits N decreases.

[0106] Then, terminal 200, for example, the number of PUCCH resources included in the PUCCH resource set (R PUCCH ) and the determined threshold X (here, 2 N Compare with (ST202).

[0107] Number of PUCCH resources included in the PUCCH resource set (R PUCCH If the number of ) is X or less, terminal 200 determines the PUCCH resource based on the value of PRI (ST105). For example, terminal 200 may determine that the PUCCH resource included in the PUCCH resource set that has a one-to-one correspondence with the value of PRI is the PUCCH resource assigned to terminal 200.

[0108] On the other hand, the number of PUCCH resources included in the PUCCH resource set (R PUCCHIf there are more than X of these, terminal 200 determines the PUCCH resource based on the number of PRI bits N and the combination of the PRI value and the CCE number used for the received PDCCH (e.g., the starting CCE number) (ST203). For example, terminal 200 may determine that the PUCCH resource included in the PUCCH resource set that is associated with a combination of PRI value and CCE number is the PUCCH resource assigned to terminal 200. In this case, the setting of the association between the combination of PRI value and CCE number and the PUCCH resource may differ depending on the number of PRI bits N (an example will be described later).

[0109] Thus, in this embodiment, the terminal 200 determines how to allocate PUCCH resources based on the result of comparing the number of PUCCH resources (in other words, PUCCH resource candidates) included in the PICCH resource set with a threshold X based on the number of PRI bits.

[0110] [Example of PUCCH resource allocation] Next, an example of a method for allocating PUCCH resources (in other words, a determination method) according to this embodiment will be described.

[0111] In this embodiment, terminal 200 controls the allocation of PUCCH resources based, for example, the number of PRI bits (e.g., N) included in DCI.

[0112] For example, terminal 200 may, in controlling PUCCH resource allocation, determine (in other words, switch) which of several PUCCH resource allocation methods to apply based on the number of PRI bits.

[0113] Possible PUCCH resource allocation methods include, for example, PUCCH resource control based on PRI, and PUCCH resource control based on a combination of PRI and CCE number. PUCCH resource control based on PRI can be described as control by explicit notification of PUCCH resources. PUCCH control based on a combination of PRI and CCE number can be described as a combination of control by explicit notification of PUCCH resources and control by implicit notification of PUCCH resources.

[0114] Furthermore, for example, in PUCCH resource control based on a combination of PRI value and CCE number, terminal 200 may determine the correspondence between the PRI value and CCE number and the PUCCH resource based on the number of PRI bits.

[0115] For example, a method for allocating PUCCH resources based on PRI values ​​and CCE numbers may include mapping PRI values ​​to PUCCH resources and mapping CCE numbers to PUCCH resources.

[0116] For example, information regarding the mapping between PRI values ​​and PUCCH resources may be the number of PUCCH resources that can be associated with a single PRI value. For instance, in the mapping between PRI values ​​and PUCCH resources, the number of PUCCH resources associated with each PRI value may differ for each PRI bit length N.

[0117] Furthermore, for example, information regarding the mapping between a CCE number and a PUCCH resource may be the number of CCEs included in the CCE group that is mapped one-to-one with the PUCCH resource. For example, in the mapping between a CCE number and a PUCCH resource, the number of CCEs that are mapped one-to-one with the PUCCH resource may differ for each PRI bit count N.

[0118] For example, terminal 200 supports receiving DCI with a variable PRI bit count (e.g., N bits) (e.g., it can be set to 0, 1, 2, or 3 bits).

[0119] For example, terminal 200 has a PUCCH resource count R. PUCCH Based on the comparison result with threshold X, either PUCCH resource control based on N bits of PRI, or PUCCH resource control based on a combination of PRI value and CCE number is performed.

[0120] In this embodiment, the threshold X is set based on, for example, the number of PRI bits N. For example, the threshold X is 2 N When set to this value, the threshold X increases (decreases) as the number of PRI bits increases (decreases). Note that the threshold X is 2 N This is not limited to the case where it is set to this value, but may be any other value determined based on the PRI bit count N, for example.

[0121] [If the number of PUCCH resources included in the PUCCH resource set is X or less] The number of PUCCH resources included in the PUCCH resource set R PUCCH If the value is less than or equal to threshold X, terminal 200 may, for example, identify a PUCCH resource from among the PUCCH resources included in the PUCCH resource set that is associated one-to-one with the PRI value included in DCI.

[0122] Figure 14 shows that N=1 bit (e.g., RPI=0 or 1), and the number of PUCCH resources R included in the PUCCH resource set. PUCCH This figure shows an example of PUCCH resource allocation (for example, the mapping between the value of PRI and the PUCCH resource) when the threshold X = 2. In Figure 14, the threshold X = 2 N = 2, and the number of PUCCH resources R PUCCH It is below the threshold X.

[0123] As shown in Figure 14, the value of PRI (Δ PRI)0 and 1 are associated one-to-one with PUCCH resources 0 and 1, respectively. In Figure 14, terminal 200, for example, determines PUCCH resource 0 when the value of PRI included in DCI is 0, and determines PUCCH resource 1 when the value of PRI included in DCI is 1.

[0124] Note that in Figure 14, as an example, the number of PRI bits N=1 and the number of PUCCH bits R are shown. PUCCH We have explained the case where =2, but the number of PRI bits N can be any other value different from 1, and the number of PUCCH bits R PUCCH The value of can be anything other than 2. For example, if N=2, the PUCCH number R PUCCH ga 2 N If it is less than or equal to 4, then for each of the four possible values ​​of PRI (for example, 0 to 3), there are 4 (=2 N Each PUCCH resource may be associated on a one-to-one basis.

[0125] In this embodiment, PUCCH resource control based on the PRI value (for example, a one-to-one correspondence between the PRI value and the PUCCH resource) is performed on the number of PUCCH resources R PUCCH ga 2 N This applies in the following cases. In other words, PUCCH resource control based on the PRI value is applied when a one-to-one correspondence is possible between each PRI value and multiple PUCCH resources included in the PUCCH resource set. Therefore, when the number of PRI bits included in DCI is variable, multiple PUCCH resources in the PUCCH resource set configured on terminal 200 can be dynamically allocated to terminal 200. In other words, it is possible to prevent some PUCCH resources in the PUCCH resource set from becoming unallocable to terminal 200.

[0126] [If the number of PUCCH resources included in the PUCCH resource set is greater than X] Number of PUCCH resources included in the PUCCH resource set (R PUCCHIf there are more than X of these, terminal 200 may, for example, identify a PUCCH resource from among the PUCCH resources included in the PUCCH resource set based on information about the PRI included in the DCI and the CCE of the PDCCH which includes the DCI.

[0127] For example, PUCCH resource number (r PUCCH ) may be given according to the following equation (8).

number

[0128] Here, N CCE,p n indicates the number of CCEs included in the Control resource set (p) that sends PDCCH. CCE,p indicates the leading CCE number assigned to the PDCCH that transmits DCI, Δ PRI This indicates the value of PRI. As shown in equation (8), the PUCCH resource number r PUCCH This can be set to different values ​​depending on the number of PRI bits N.

[0129] Figure 15 shows N=1 bit (for example, Δ PRI = 0 or 1) and the number of PUCCH resources included in the PUCCH resource set is R PUCCH This figure shows an example of PUCCH resource allocation (correspondence between PRI value and CCE number and PUCCH resource) when = 8. Figure 15 also shows an example of CCE number N. CCE,p There are 32 of them.

[0130] As shown in Figure 15, PUCCH resources 0-3 are associated with PRI=0, and PUCCH resources 4-7 are associated with PRI=1. In other words, four PUCCH resources are associated with one PRI value.

[0131] Furthermore, as shown in Figure 15, among the PUCCH resources associated with PRI=0, PUCCH resource 0 is associated with CCE groups with CCE numbers 0-7, PUCCH resource 1 is associated with CCE groups with CCE numbers 8-15, PUCCH resource 2 is associated with CCE groups with CCE numbers 16-23, and PUCCH resource 3 is associated with CCE groups with CCE numbers 24-31. Similarly, in Figure 15, among the PUCCH resources associated with PRI=1, PUCCH resource 4 is associated with CCE groups with CCE numbers 0-7, PUCCH resource 5 is associated with CCE groups with CCE numbers 8-15, PUCCH resource 6 is associated with CCE groups with CCE numbers 16-23, and PUCCH resource 7 is associated with CCE groups with CCE numbers 24-31.

[0132] In Figure 15, terminal 200, for example, among PUCCH resources 0 to 7 included in the PUCCH resource set, has a PRI value (Δ included in DCI) PRI The PUCCH resource assigned to terminal 200 is determined to be the PUCCH resource associated with the combination of the PDCCH transmission including DCI and the CCE number used for transmission (e.g., the starting CCE number).

[0133] Note that Figure 15 illustrates the case where the number of PRI bits N=1 as an example, but the number of PRI bits N can be any value other than 1. For example, Figure 16 shows the case where N=2 bits (for example, Δ PRI = any of 0 to 3, and the number of PUCCH resources included in the PUCCH resource set is R. PUCCH = 8, and the number of CCEs N CCE,p This figure shows an example of PUCCH resource allocation when =32. As shown in Figure 16, when N=2, for each of the four possible values ​​of PRI (e.g., 0-3), 2 (= ceiling(R) PUCCH( / 8) PUCCH resources are associated, and for these 2 PUCCH resources, a CCE group (CCE0 - 15 or CCE16 - 31) composed of 8 CCEs is associated.

[0134] As shown in FIGS. 15 and 16, when the number of PUCCH resources (R PUCCH ) in the PUCCH resource set is more than the threshold X, the smaller the number of PRI bits N, the more the number of PUCCH resources associated with one PRI value increases, and the fewer the number of CCEs included in the CCE group associated with the PUCCH resources one - to - one decreases.

[0135] Thus, when the number of PRI bits N included in the DCI is variable, the terminal 200 can control the association between the PRI value based on the number of PRI bits and the PUCCH resources, and the association between the CCE number based on the number of PRI bits N and the PUCCH resources, so that a plurality of PUCCH resources included in the PUCCH resource set can be dynamically allocated to the terminal 200. In other words, it is possible to suppress the situation where some PUCCH resources in the PUCCH resource set become un - allocatable to the terminal 200.

[0136] According to this embodiment, the terminal 200 controls the allocation of PUCCH resources based on the number of PRI bits.

[0137] For example, the terminal 200 determines the threshold X based on the number of PRI bits. In other words, the threshold X varies (increases or decreases) according to the number of PRI bits N. Thus, for example, when PUCCH resource control based on the value of PRI is applied, the number of PUCCH resources R PUCCH can vary according to the number of PRI bits N. For example, the fewer the number of PRI bits N, the fewer the number of values that PRI can take, so the number of PUCCH resources R PUCCH to which PUCCH resource control based on the value of PRI can be applied is smaller.

[0138] Furthermore, the terminal 200 determines the mapping between PRI and PUCCH resources (for example, the number of PUCCH resources that can be mapped to one PRI value) and the mapping between CCE numbers and PUCCH resources (for example, the number of CCEs that make up a CCE group that can be mapped to one PUCCH resource) based on the number of PRI bits. As a result, for example, as shown in Figures 15 and 16, the number of PUCCH resources mapped to a combination of PRI value and CCE number can be set variably by the number of PRI bits N.

[0139] These controls allow, for example, the base station 100 to dynamically allocate multiple PUCCH resources (e.g., all PUCCH resources) included in the PUCCH resource set to the terminal 200, regardless of the number of PUCCH resources and PRI bits included in the PUCCH resource set. Furthermore, the terminal 200 can control the dynamic allocation of PUCCH resources based on the PRI (or combination of PRI and CCE numbers) included in the DCI, for example, based on the set number of PRI bits.

[0140] This allocation control ensures flexibility in PUCCH resource allocation while, for example, sharing a PUCCH resource set among multiple terminals 200. Furthermore, according to this embodiment, since the PUCCH resource set can be shared among multiple terminals 200, the increase in PUCCH resource overhead can be suppressed compared to, for example, a case where a different PUCCH resource set is set for each of the multiple terminals 200.

[0141] Note that, as shown in FIG. 15, the association between the combination of the PRI value and the CCE number and the PUCCH resource may be such that the PRI value is associated in order from the head of the PUCCH resource. As shown in FIG. 17, the PRI value may be associated alternately from the head of the PUCCH resource. In the example of FIG. 17, between a terminal that supports DCI reception with a fixed number of PRI bits (for example, 3 bits) and the terminal 200, the PRI corresponding to PUCCH resource 0 and PUCCH resource 1 can be shared. Therefore, for example, there is an advantage that coexistence with a terminal that supports Rel. 15 is facilitated.

[0142] Also, the association between the combination of the PRI value and the CCE number and the PUCCH resource is not limited to the above-described examples (for example, FIGS. 15, 16, or 17). For example, R PUCCH PUCCH resources included in the PUCCH resource set and the PRI value are associated in a ceiling(R PUCCH / 2 N ) to 1 correspondence, and ceiling(R PUCCH / 2 N ) PUCCH resources associated with each PRI value and the CCE group may be associated in a 1-to-1 correspondence. Here, one CCE group is a set including 1 / floor(ceiling(R PUCCH / 2 N ) / N CCE,p ) CCE numbers.

[0143] Also, the association between the combination of the PRI value and the CCE number and the PUCCH resource may be defined in the standard, for example, or may be notified in advance to the terminal 200 by a higher layer signal.

[0144] (Embodiment 3) The configurations of the base station and the terminal according to this embodiment may be common to the configurations of the base station 100 and the terminal 200 according to Embodiment 1.

[0145] Figure 18 is a flowchart showing an example of the operation of terminal 200 according to this embodiment. In Figure 18, the same reference numerals are used for operations similar to those in Figure 6 (Embodiment 1), and their descriptions are omitted.

[0146] In Figure 18, terminal 200 controls parameters related to the allocation of PUCCH resources (for example, the number of PUCCH resources R). PUCCH The threshold X) is obtained (ST301). For example, the threshold X may be defined in a standard, or it may be notified to the terminal 200 by a higher layer signal. In this embodiment, the threshold X may be eight, for example, as in Rel.15, or it may be any other value. In other words, the threshold X may be a threshold that does not depend on the number of PRI bits.

[0147] Then, terminal 200, for example, the number of PUCCH resources included in the PUCCH resource set (R PUCCH ) Then, compare it with the acquired threshold X (ST302).

[0148] Number of PUCCH resources included in the PUCCH resource set (R PUCCH If the number of ) is X or less, terminal 200 determines the PUCCH resource based on the value of PRI (ST105). For example, terminal 200 may determine that the PUCCH resource included in the PUCCH resource set that has a one-to-one correspondence with the value of PRI is the PUCCH resource assigned to terminal 200.

[0149] On the other hand, the number of PUCCH resources included in the PUCCH resource set (R PUCCHIf there are more than X of these, terminal 200 determines the PUCCH resource based on the number of PRI bits N and the combination of the PRI value and the CCE number used for the received PDCCH (e.g., the starting CCE number) (ST303). For example, terminal 200 may determine that the PUCCH resource included in the PUCCH resource set that is associated with a combination of the PRI value and the CCE number is the PUCCH resource assigned to terminal 200. In this case, the setting of the association between the combination of the PRI value and the CCE number and the PUCCH resource may differ depending on the number of PRI bits N (an example will be described later).

[0150] [Example of PUCCH resource allocation] Next, an example of a method for allocating PUCCH resources (in other words, a determination method) according to this embodiment will be described.

[0151] For example, terminal 200 supports receiving DCI with a variable PRI bit count (e.g., N bits) (e.g., it can be set to 0, 1, 2, or 3 bits).

[0152] For example, terminal 200 has a PUCCH resource count R in the PUCCH resource set. PUCCH Based on the comparison result with threshold X, either PUCCH resource control based on PRI, or PUCCH resource control based on a combination of PRI value and CCE number, is performed.

[0153] The threshold X can be a fixed value, for example. For example, the threshold X can be a value independent of the number of PRI bits. For example, it can be set to X=8, as in Rel. 15.

[0154] If the number of PUCCH resources in the PUCCH resource set is greater than X, the terminal 200 may identify the PUCCH resources based on information about the PRI included in the DCI and the CCE of the PDCCH including the DCI, for example, as shown in Figure 15 (or Figure 16 or Figure 17). For example, the terminal 200 may identify the PUCCH resources according to equation (8).

[0155] In other words, the number of PUCCH resources R PUCCH If the value is greater than the threshold X, terminal 200 will be R in Embodiment 2. PUCCH The same operation as when there are more than X may be applied. For example, terminal 200 may control the allocation of PUCCH resources based on the combination of PRI and CCE number (e.g., mapping of PRI values ​​to PUCCH resources, or mapping of CCE numbers to PUCCH resources) based on the number of PRI bits (e.g., N) included in DCI. As in Embodiment 2, the information regarding the mapping of PRI values ​​to PUCCH resources may be, for example, the number of PUCCH resources that can be associated with one PRI value. Also, as in Embodiment 2, the information regarding the mapping of CCE numbers to PUCCH resources may be, for example, the number of CCEs included in a CCE group that is mapped one-to-one with a PUCCH resource. The number of PUCCH resources that can be associated with one PRI value, and the number of CCEs included in a CCE group that is mapped one-to-one with a PUCCH resource, may differ for each PRI bit count N.

[0156] On the other hand, the number of PUCCH resources included in the PUCCH resource set is R. PUCCH If the value is less than or equal to the threshold X, terminal 200 may, for example, identify a PUCCH resource from among the PUCCH resources included in the PUCCH resource set that is associated one-to-one with the PRI value included in DCI, as shown in any of Figures 7 to 9. In other words, the number of PUCCH resources R PUCCH If the threshold is less than or equal to the threshold X, terminal 200 will be R in Embodiment 1. PUCCHThe same operation as when there are 8 or fewer may be applied. Thus, in this embodiment, the terminal 200 does not need to rely on the number of PRI bits N in controlling the allocation of PUCCH resources based on PRI.

[0157] In this NR, settings related to the number of DCI bits (e.g., the number of PRI bits) and settings related to PUCCH resources (e.g., PUCCH resource set) can be configured separately. In this embodiment, terminal 200 determines whether or not to apply the allocation of PUCCH resources based on the CCE number, based on a fixed threshold X, regardless of the number of DCI bits (e.g., the number of PRI bits).

[0158] In other words, when terminal 200 determines the PUCCH resource allocation method, it uses a value based on the setting for the number of DCI bits (for example, a value based on the number of PRI bits N) and a value based on the setting for PUCCH resources (for example, R PUCCH This eliminates the need to perform a comparison with (). This simplifies the processing for terminal 200.

[0159] Furthermore, in this embodiment, terminal 200 can control the allocation of PUCCH resources according to the same criteria as Rel.15 NR (for example, X=8), regardless of the number of PUCCH resources included in the PUCCH resource set.

[0160] (Embodiment 4) In this embodiment, for example, similar to Embodiment 3, we will describe a case where a fixed threshold (for example, 8, similar to Rel. 15) is applied to the criteria for deciding whether to switch between PRI-based PUCCH resource control (in other words, explicit PUCCH resource control) and PUCCH resource control based on a combination of PRI and CCE number (in other words, a combination of explicit and implicit PUCCH resource control).

[0161] Furthermore, this embodiment describes an example in which implicit PUCCH resource control is applied when the number of PUCCH resources included in the PUCCH resource set is below a threshold and the number of PRI bits is a specific number of bits (for example, 0 bits).

[0162] The configuration of the base station and terminal according to this embodiment may be the same as the configuration of the base station 100 and terminal 200 according to Embodiment 1.

[0163] Figure 19 is a flowchart showing an example of the operation of terminal 200 according to this embodiment. In Figure 19, the same reference numerals are used for operations similar to those in Figure 6 (Embodiment 1), and their descriptions are omitted.

[0164] In Figure 19, terminal 200 controls parameters related to the allocation of PUCCH resources (for example, the number of PUCCH resources R). PUCCH The threshold X) is obtained (ST401). For example, the threshold X may be defined in the standard, or it may be notified to terminal 200 by a higher layer signal. The threshold X may be 8, as in Rel.15, or it may be any other value.

[0165] Terminal 200 determines whether the number of DCI bits (e.g., PRI bits N) is a specific value (e.g., 0 bits) (ST402). The specific value may be defined in a standard, for example, or it may be notified to terminal 200 by a higher-layer signal (e.g., information regarding DCI reception).

[0166] Furthermore, if the number of DCI bits in terminal 200 is not a specific value (in Figure 19, N=1, 2, or 3 bits), for example, the number of PUCCH resources included in the PUCCH resource set (R PUCCH ) Then, compare it with the acquired threshold X (ST403).

[0167] The number of DCI bits is not a specific value, and the number of PUCCH resources (R PUCCHIf the number of ) is X or less, terminal 200 determines the PUCCH resource based on the value of PRI (ST105). For example, terminal 200 may determine that the PUCCH resource included in the PUCCH resource set that has a one-to-one correspondence with the value of PRI is the PUCCH resource assigned to terminal 200.

[0168] On the other hand, if the number of DCI bits is a specific value, or if the number of PUCCH resources (R PUCCH If the number of ) is greater than X, terminal 200 determines the PUCCH resource based on the number of PRI bits N and the combination of the PRI value and the CCE number used for the received PDCCH (e.g., the starting CCE number) (ST404). For example, terminal 200 may determine the PUCCH resource included in the PUCCH resource set that is associated with a combination of the PRI value and the CCE number as the PUCCH resource assigned to terminal 200. Also, if the number of DCI bits is a specific value, terminal 200 may determine the PUCCH resource included in the PUCCH resource set that is associated with the CCE number as the PUCCH resource assigned to terminal 200. The settings for these PUCCH resource associations may differ depending on, for example, the number of PRI bits N (an example will be described later).

[0169] [Example of PUCCH resource allocation] Next, an example of a method for allocating PUCCH resources (in other words, a determination method) according to this embodiment will be described.

[0170] For example, terminal 200 supports receiving DCI signals with a variable PRI bit count (for example, it can be set to 0, 1, 2, or 3 bits).

[0171] For example, terminal 200 has a PUCCH resource count R in the PUCCH resource set. PUCCHBased on the comparison result with threshold X, either PUCCH resource control based on PRI, or PUCCH resource control based on a combination of PRI value and CCE number, is performed.

[0172] The threshold X can be a fixed value, for example. For example, the threshold X can be a value independent of the number of PRI bits. For example, it can be set to X=8, as in Rel. 15.

[0173] The number of PUCCH resources included in the PUCCH resource set R PUCCH If the value is less than or equal to the threshold X, and the number of PRI bits N is not a specific number of bits, the terminal 200 may, for example, identify a PUCCH resource from among the PUCCH resources included in the PUCCH resource set that is associated one-to-one with the value of PRI included in DCI, as shown in any of Figures 7 to 9. In other words, the number of PUCCH resources R PUCCH If the threshold X is less than or equal to the threshold X, and the number of PRI bits N is not a specific number of bits, then terminal 200 will perform R in Embodiment 1. PUCCH The same behavior as when there are 8 or fewer elements may be applied.

[0174] On the other hand, if the number of PUCCH resources included in the PUCCH resource set is greater than X, or if the number of PRI bits N is a specific number of bits, the terminal 200 may identify the PUCCH resources based on at least one of the PRI included in the DCI and the information regarding the CCE of the PDCCH including the DCI, as shown in Figure 15 (or Figure 16 or Figure 17). For example, the terminal 200 may identify the PUCCH resources according to equation (8). In other words, the number of PUCCH resources R PUCCH If the value is greater than the threshold X, or if the number of PRI bits N is a specific number of bits, the terminal 200 will be R in Embodiment 2. PUCCH The same behavior as when there are more than X items may be applied.

[0175] For example, if the number of PUCCH resources included in the PUCCH resource set is greater than X, and the number of PRI bits N is not a specific number of bits, terminal 200 may control the mapping between the combination of PRI value and CCE number and the PUCCH resource based on the number of PRI bits N, similar to Embodiment 2. This control allows terminal 200 to dynamically allocate PUCCH resources according to the number of PRI bits N, thereby ensuring flexibility in PUCCH resource allocation.

[0176] Furthermore, for example, if the number of PRI bits is a specific number of bits (e.g., 0 bits), terminal 200 may control the mapping between CCE number combinations and PUCCH resources based on the number of PRI bits N. This control allows terminal 200 to dynamically allocate PUCCH resources according to the number of PRI bits N when the number of PRI bits is 0 bits, thus ensuring flexibility in PUCCH resource allocation.

[0177] The specific number of bits may be defined in a standard (e.g., 0 bits), or it may be notified to terminal 200 by a higher-layer signal. Furthermore, the specific number of bits is not limited to 0 bits, and may be any other number of bits.

[0178] In NR, settings related to the number of DCI bits (e.g., the number of PRI bits) and settings related to PUCCH resources (e.g., the PUCCH resource set) can be configured separately.

[0179] In this embodiment, terminal 200 determines whether to apply PUCCH resource allocation based on the CCE number (in other words, implicit PUCCH resource control) based on the number of DCI bits (e.g., the number of PRI bits) (for example, the process of ST402 in Figure 19). On the other hand, in this embodiment, terminal 200 determines whether to apply PUCCH resource allocation based on the CCE number based on a fixed threshold X, regardless of the number of DCI bits (for example, the process of ST403 in Figure 19). Therefore, when terminal 200 determines the PUCCH resource allocation method, it considers a value based on the setting regarding the number of DCI bits (e.g., a value based on the number of PRI bits N) and a value based on the setting regarding PUCCH resources (e.g., R PUCCH This eliminates the need to perform a comparison with (). This simplifies the processing for terminal 200.

[0180] Furthermore, according to this embodiment, when the number of PRI bits N is less than or equal to the threshold X, and the number of PRI bits N is a specific number of bits, PUCCH resource allocation based on the CCE number is applied, thus improving the flexibility of PUCCH resource allocation compared to Embodiment 3.

[0181] (Modified form of Embodiment 4) In this embodiment, for example, a case was described in which terminal 200 applies PUCCH resource allocation based on the CCE number when the number of PRI bits is a specific number of bits. As an example in this case, a case in which terminal 200 identifies a PUCCH resource according to equation (8) was described, but in a modified example, terminal 200 may determine the PUCCH resource according to equation (5), for example. Alternatively, terminal 200 may determine the PUCCH resource according to equation (5) when the number of PUCCH resources included in the PUCCH resource set is less than or equal to a threshold, and determine the PUCCH resource according to equation (8) when the number of PUCCH resources included in the PUCCH resource set is greater than the threshold.

[0182] In a modified version, for example, when a terminal supporting DCI reception with a fixed number of PRI bits (e.g., 3 bits) and terminal 200 share a PUCCH resource set, the mapping between CCE numbers and PUCCH resources can be standardized between the terminals. This has the advantage of simplifying the coexistence of a terminal supporting DCI reception with a fixed number of PRI bits (e.g., a terminal supporting Rel. 15) and terminal 200.

[0183] The embodiments of one example of this disclosure have been described above.

[0184] (Other embodiments) (1) In the above-described embodiment, as an example, a case was described in which terminal 200 supports receiving DCI in which the number of PRI bits can be set variably (for example, to 0, 1, 2, or 3 bits). Here, DCI in which the number of PRI bits can be set variably may be, for example, DCI Format 1-2 as defined in NR Rel.16 (see, for example, Non-Patent Document 7).

[0185] Furthermore, terminal 200 may receive a DCI other than DCI Format 1-2, for example. In this case, for example, if terminal 200 is assigned a PDSCH by DCI Format 1-2, it may apply the operation based on any of the embodiments described above. On the other hand, if terminal 200 is assigned a PDSCH by a DCI other than DCI Format 1-2, it may apply the operation shown in Figure 1 or Figure 2.

[0186] Furthermore, for example, terminal 200 may determine the PUCCH resource allocation method based on the type of DCI Format. For example, terminal 200 may apply the operation of Embodiment 2 when a PDSCH is allocated by DCI Format 1-2, and apply the operation of Embodiment 1 when a PDSCH is allocated by a DCI different from DCI Format 1-2. Note that the operation to be applied is not limited to Embodiment 1 or 2, but may be any operation from Embodiments 1 to 4.

[0187] (2) In the above-described embodiment, DCI may notify terminal 200 of information regarding the priority of ACK / NACK.

[0188] In this case, terminal 200 may determine the PUCCH resource allocation method based, for example, on the priority of ACK / NACK. For example, terminal 200 may apply the operation of Embodiment 2 when the priority of ACK / NACK is high, and apply the operation of Embodiment 1 when the priority of ACK / NACK is low. Note that the operation to be applied is not limited to Embodiment 1 or 2, but may be any operation of Embodiments 1 to 4.

[0189] Furthermore, the priority of ACK / NACK may be explicitly indicated, for example, in the DCI priority information field, or implicitly indicated by other information such as the DCI format, DCI size, the search space of the PDCCH sending the DCI, or the control resource set.

[0190] (3) In the embodiments described above, the PDCCH that transmits DCI may be scrambled by terminal-specific RNTI such as C-RNTI or MCS-C-RNTI.

[0191] In this case, terminal 200 may determine the PUCCH resource allocation method based, for example, on the type of RNTI. For example, terminal 200 may apply the operation of Embodiment 2 when PDCCH is scrambled by MCS-C-RNTI, and apply the operation of Embodiment 1 when PDCCH is scrambled by C-RNTI. Note that the operation to be applied is not limited to Embodiment 1 or 2, but may be any operation from Embodiments 1 to 4.

[0192] Furthermore, the type of RNTI associated with the PUCCH resource allocation method is not limited to MCS-C-RNTI or C-RNTI, but may include other RNTIs. For example, the PUCCH resource allocation method may be associated based on the coding rate expected when each RNTI is used.

[0193] (4) The base station 100 may, for example, notify the terminal 200 of the PUCCH resource allocation method (in other words, which embodiment to apply) by a higher layer signal (for example, an RRC signal) (in other words, set it quasi-statically). For example, if the operation of Embodiment 2 is set to be applied by an RRC signal, and there is no notification regarding the PUCCH resource allocation method, the operation of Embodiment 1 may be set to be applied. Note that the operation to be applied is not limited to Embodiment 1 or 2, but may be any operation of Embodiments 1 to 4.

[0194] Other embodiments have been described above.

[0195] In the embodiment described above, as an example, we assumed a case where the settings for the number of DCI bits (e.g., the number of PRI bits) and the settings for PUCCH resources are set individually. However, the settings for the number of PRI bits and the settings for PUCCH resources may be associated. For example, the number of PRI bits may be determined (e.g., calculated) based on the number of PUCCH resources included in the PUCCH resource set. For example, the number of PUCCH resources included in the PUCCH resource set R PUCCH For this, the number of PRI bits N = ceiling(log2R PUCCH ) may be determined.

[0196] Furthermore, the above-described embodiment explained the case where the allocation method of PUCCH resources is switched based on a threshold. However, the embodiment of this disclosure is not limited thereto, and for example, the number of PUCCH resources R included in the PUCCH resource set is independent of a threshold. PUCCHFurthermore, based on the number of PRI bits, a mapping between the PRI value and the CCE number and the PUCCH resource may be set. For example, R included in the PUCCH resource set PUCCH The individual PUCCH resources and the PRI value are ceiling(R PUCCH / 2 N ) A one-to-one correspondence is established, and each PRI value is associated with the ceiling(R PUCCH / 2 N It is sufficient that there is a one-to-one correspondence between the ) PUCCH resources and the CCE group. This PUCCH resource allocation enables dynamic allocation of PUCCH resources according to the number of PRI bits, regardless of the number of PUCCH resources included in the PUCCH resource set.

[0197] Furthermore, while the above embodiment described a method for allocating PUCCH resources to ACK / NACK (for example, a response signal to a downlink data signal) as an example, the allocation target for PUCCH resources is not limited to ACK / NACK. For example, it may be uplink control information (UCI) different from ACK / NACK, such as CSI or SR, or it may be an uplink data signal (for example, PUSCH).

[0198] Furthermore, the above embodiment assumes uplink communication, where a signal is transmitted from a terminal to a base station. However, one embodiment of this disclosure is not limited to this and may also be applied to communication between terminals (for example, sidelink communication).

[0199] Furthermore, the downlink control channel, downlink data channel, uplink control channel, and uplink data channel are not limited to PDCCH, PDSCH, PUCCH, and PUSCH, respectively; other control channel names may also be used.

[0200] Furthermore, the parameters applied in the above-described embodiment are examples only and are not limited. For example, the number of PUCCH resources included in the PUCCH resource set (e.g., R PUCCHAt least one of the following values ​​(=2, 8, or 16), the number of CCEs (e.g., 32), and the number of PRI bits (e.g., any of N=0 to 3) is not limited to the values ​​in the embodiments described above, but may be other values.

[0201] <5G NR System Architecture and Protocol Stack> 3GPP is continuing work on the next release of fifth-generation mobile phone technology (also simply called "5G"), which includes the development of new radio access technologies (NR) operating in the frequency range up to 100 GHz. The initial version of the 5G standard was completed at the end of 2017, which will enable the prototyping and commercial deployment of devices (e.g., smartphones) that comply with the 5G NR standard.

[0202] For example, the system architecture as a whole assumes an NG-RAN (Next Generation - Radio Access Network) with gNBs. The gNBs provide the UE-side termination for the user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols of the NG radio access. The gNBs are connected to each other by Xn interfaces. Furthermore, the gNBs are connected to the NGC (Next Generation Core) by Next Generation (NG) interfaces, more specifically to the AMF (Access and Mobility Management Function) (e.g., a specific core entity performing AMF) by NG-C interfaces, and to the UPF (User Plane Function) (e.g., a specific core entity performing UPF) by NG-U interfaces. The NG-RAN architecture is shown in Figure 20 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0203] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the PDCP (Packet Data Convergence Protocol (see section 6.4 of TS 38.300)) sublayer, RLC (Radio Link Control (see section 6.3 of TS 38.300)) sublayer, and MAC (Medium Access Control (see section 6.2 of TS 38.300)) sublayer, which are terminated on the network side in gNB. Additionally, a new Access Stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) is introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). Furthermore, a control plane protocol stack is defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functionality is described in section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in section 7 of TS 38.300.

[0204] For example, the Medium-Access-Control layer handles scheduling and scheduling-related functions, including the multiplexing of logical channels and the handling of various neural networks.

[0205] For example, the Physical Layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. The Physical Layer also handles the 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 particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include uplink physical channels such as PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel), and downlink physical channels such as PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0206] Use cases / deployment scenarios for NR may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communications (mMTC), each with diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps on the downlink and 10 Gbps on the uplink) and effective (user-experienced) data rates approximately three times that of IMT-Advanced. URLLC, on the other hand, imposes more stringent requirements for ultra-low latency (0.5 ms for UL and DL respectively for user plane latency) and high reliability (1-10⁻⁵ within 1 ms). Finally, mMTC may preferably require high connectivity density (1,000,000 devices / km² in urban environments), wide coverage in harsh environments, and extremely long-lasting batteries (15 years) for low-cost devices.

[0207] Therefore, an OFDM neurology suitable for one use case (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may not be effective for other use cases. For example, low-latency services may preferably require a shorter symbol length (and thus a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also known as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with short delay spreads. The subcarrier spacing may be optimized on a case-by-case basis to maintain similar CP overhead. There may be one or more subcarrier spacing values ​​supported by NR. Accordingly, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc. are currently being 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.

[0208] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined for each neurology and each carrier, for both the uplink and downlink. Each element of the resource grid is called a resource element and is identified based on the frequency index in the frequency domain and the symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0209] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 21 shows the functional separation between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0210] For example, gNB and ng-eNB host the following main functions: - Functions of radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic allocation (scheduling) of resources to the UE in both the uplink and downlink; - IP header compression, encryption, and integrity protection of data; - Selection of the AMF at the time of UE attachment when it is not possible to determine the routing to the AMF from the information provided by the UE; - Routing of user plane data towards the UPF; - Routing of control plane information towards the AMF; - Setup and release of connections; - Scheduling and transmission of paging messages; - Scheduling and transmission of system information messages (with the AMF or the operation, admission, maintenance function (OAM) as the source); - Configuration of measurements and measurement reports for mobility and scheduling; - Transport-level packet marking in the uplink; - Session management; - Support for network slicing; - Management of QoS flows and mapping to data radio bearers; - Support for UEs in the RRC_INACTIVE state; - Delivery function of NAS messages; - Sharing of the radio access network; - Dual connectivity; - Tight cooperation between NR and E-UTRA.

[0211] The Access and Mobility Management Function (AMF) hosts the following main functions: - A function to terminate Non-Access Stratum (NAS) signaling; - Security of NAS signaling; - Security control of Access Stratum (AS); - Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; - Reachability of the UE in idle mode (including control and execution of paging retransmissions); - Management of registration areas; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including roaming permission checks; - Mobility management and control (enrollment and policies); - Support for network slicing; - Selection of Session Management Function (SMF).

[0212] Furthermore, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT mobility / inter-RAT mobility (where applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Routing and forwarding of packets; - Packet inspection and enforcement of policy rules in the user plane. - Reporting traffic usage; - Uplink classifier to support routing of traffic flow to data networks; - 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 QoS flows of SDFs); - Downlink packet buffering and triggering function for downlink data notification.

[0213] 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 appropriate destinations; - Enforcement of control plane policies and QoS; - Notification of downlink data.

[0214] <Procedures for RRC connection setup and reconfiguration> Figure 22 shows some of the interactions between the UE, gNB, and AMF (5GC entity) in the NAS part when the UE transitions from RRC_IDLE to RRC_CONNECTED (see TS 38.300 v15.6.0).

[0215] RRC is a higher-layer signaling protocol used for configuring UEs and gNBs. During this transition, the AMF prepares UE context data (including, for example, PDU session context, security key, UE Radio Capability, UE Security Capabilities, etc.) and sends it to the gNB along 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, to which the UE responds with a SecurityModeComplete message. Subsequently, the gNB sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures itself to set up the Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration step is omitted because SRB2 and DRB are not set up. Finally, gNB notifies AMF that the setup procedure is complete with an Initial Context Setup Response.

[0216] Accordingly, this disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) comprising a control circuit that establishes a Next Generation (NG) connection with a gNodeB during operation, and a transmission unit that sends an initial context setup message to the gNodeB via the NG connection during operation so that a signaling radio bearer between the gNodeB and the user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling, including an Information Element (IE), to the UE via the signaling radio bearer. The UE then transmits on the uplink or receives on the downlink based on the resource allocation setting.

[0217] <IMT Usage Scenarios from 2020 Onward> Figure 23 shows some use cases for 5G NR. The 3rd generation partnership project for 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 specification development for enhanced mobile-broadband (eMBB) has been completed. Current and future work will include expanding eMBB support, as well as standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC). Figure 23 shows some examples of conceptual use scenarios for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0218] URLLC use cases have strict requirements for performance such as throughput, latency (delay), and availability. The URLLC use case is envisioned as one of the enabling technologies for future applications such as wireless control of industrial production processes or manufacturing processes, telemedicine surgery, automation of power transmission and distribution in smart grids, and traffic safety. The ultra-high reliability of URLLC is supported by identifying technologies that meet the requirements set by TR 38.913. In NR URLLC in Release 15, an important requirement includes that the target user plane latency is 0.5 ms in UL (uplink) and 0.5 ms in DL (downlink). The general URLLC requirement for a single packet transmission is that when the user plane latency is 1 ms, the block error rate (BLER) is 1E-5 for a 32-byte packet size.

[0219] From the perspective of the physical layer, reliability can be improved in many ways. The current room for reliability improvement includes defining a separate CQI table for URLLC, a more compact DCI format, repetition of PDCCH, etc. However, this room can expand for the realization of ultra-high reliability as NR becomes more stable and more developed (regarding the important requirements of NR URLLC). Specific use cases of NR URLLC in Release 15 include extended reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0220] Furthermore, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable neurology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level iteration on data channels, and preemption on downlink. Preemption means that a transmission for which a resource has already been allocated is stopped, and that allocated resource is used for other transmissions with lower latency / higher priority requirements that are requested later. Thus, transmissions that were already permitted are replaced by later transmissions. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be replaced by a transmission of service type B (eMBB, etc.). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for the 1E-5 target BLER.

[0221] A key characteristic of mMTC (massive machine type communication) use cases is the extremely large number of connected devices that typically transmit relatively small amounts of data that are less susceptible to latency. These devices require low cost and very long battery life. From a noise reduction (NR) perspective, utilizing a very narrow bandwidth is one solution that saves power from the user interface (UE) and extends battery life.

[0222] As mentioned above, the scope of reliability improvements in NR is expected to broaden. High reliability or very high reliability is a critical requirement in all cases, for example, for URLLC and mMTC. Several mechanisms can improve reliability from both a radio and 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 improvements regardless of the specific communication scenario.

[0223] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution. These stringent requirements include high reliability (up to 10⁻⁶ levels), high availability, packet size up to 256 bytes, and time synchronization down to a few microseconds (depending on the use case, the value can be 1 microsecond or a few microseconds depending on the frequency range and short latency of approximately 0.5 ms to 1 ms (e.g., 0.5 ms latency in the target user plane)).

[0224] Furthermore, for NR URLLC, several technical enhancements may be available from the perspective of the physical layer. These technical 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. Additionally, there may 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).

[0225] <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 flow) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flow). Therefore, at the NAS level, a QoS flow is the finest granularity QoS classification 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.

[0226] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearers (DRB) in accordance with the PDU session, as shown above, for example, referring to Figure 22. Additional DRBs for the QoS flow of that PDU session can be configured later (when this is done is up to the NG-RAN). The NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0227] Figure 24 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (for example, an external application server hosting 5G services, as illustrated in Figure 23) interacts with the 3GPP core network to provide services. This may involve accessing the Network Exposure Function (NEF) to support applications that affect traffic routing, or interacting with the policy framework for policy control (e.g., QoS control) (see Policy Control Function (PCF)). Based on operator deployment, Application Functions considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions not authorized by the operator to directly access the Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0228] Figure 24 further illustrates the functional units of the 5G architecture, namely the 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 services, internet access, or third-party services). All or part of the core network functions and application services may be deployed and operate in a cloud computing environment.

[0229] Accordingly, the Disclosure provides an application server (e.g., AF in a 5G architecture) comprising: a transmitter that, in operation, transmits a request to at least one of the 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) that includes QoS requirements for at least one of the URLLC service, eMMB service, and mMTC service, in order to establish a PDU session including a radio bearer between the gNodeB and UE in accordance with QoS requirements; and a control circuit that, in operation, performs the service using the established PDU session.

[0230] This disclosure can be implemented in software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments may be implemented in part or in whole as an integrated circuit (LSI), and each process described in the above embodiments may be controlled in part or in whole by a single LSI or a combination of LSIs. An LSI may consist of individual chips, or it may consist of a single chip that includes some or all of the functional blocks. An LSI may have data inputs and outputs. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs.

[0231] The method of integration is not limited to LSIs; it may also be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (Field Programmable Gate Arrays) that can be programmed after LSI manufacturing, or reconfigurable processors that allow for the reconfiguration of the connections and settings of circuit cells within the LSI, may also be used. This disclosure may be implemented as digital or analog processing.

[0232] Furthermore, if advancements in semiconductor technology or other derived technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, it would be possible to use those technologies to integrate functional blocks. The application of biotechnology, for example, is a possibility.

[0233] This disclosure is applicable to all types of devices, systems, and equipment having communication capabilities (collectively referred to as communication equipment). Communication equipment may include a radio transceiver and a processing / control circuit. A radio transceiver may include a receiver and a transmitter, or both as functions. A radio transceiver (transmitter, receiver) may include an RF (Radio Frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or similar. Non-exclusive examples of communication devices include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, vehicles or mobile transport with communication capabilities (cars, airplanes, ships, etc.), and combinations of the above-mentioned devices.

[0234] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0235] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0236] Furthermore, the communication device also includes devices such as controllers and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this includes controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0237] Furthermore, communication equipment includes infrastructure facilities such as base stations, access points, and any other devices, devices, and systems that communicate with or control the aforementioned non-limited types of equipment.

[0238] A terminal according to one embodiment of the present disclosure comprises a control circuit that controls the allocation of uplink resources to uplink control information based on the size of information indicating resource allocation related to uplink control information, and a transmission circuit that transmits the uplink control information using the uplink resources.

[0239] In one embodiment of the present disclosure, the correspondence between the value of the information indicating the resource allocation and the candidate resource for the resource allocation differs depending on the size.

[0240] In one embodiment of the present disclosure, the number of candidate resources associated with each value of the information indicating resource allocation differs for each size in the correspondence.

[0241] In one embodiment of the present disclosure, the correspondence between the value of the resource allocation information and the downlink resource used to transmit the resource allocation information and the candidate resource for the resource allocation differs depending on the size.

[0242] In one embodiment of the present disclosure, the number of downstream resources that are associated one-to-one with the candidate resources in the mapping differs for each size.

[0243] In one embodiment of the present disclosure, the control circuit determines the allocation method based on a comparison of the number of candidate resources for resource allocation with a threshold based on size.

[0244] In one embodiment of the present disclosure, if the number of candidate resources is less than or equal to the threshold, the control circuit determines the upstream resource among the candidate resources that is associated one-to-one with the value of the information indicating resource allocation as the allocated resource for the upstream control information.

[0245] In one embodiment of the present disclosure, if the number of candidate resources is greater than the threshold, the control circuit determines among the candidate resources a resource associated with a combination of resource allocation information and a downlink resource used to transmit the resource allocation information as the allocated resource for the uplink control information.

[0246] One embodiment of the present disclosure includes a receiving circuit for receiving information relating to the size.

[0247] In one embodiment of the present disclosure, the size information is information indicating a variable number of bits.

[0248] In a communication method according to one embodiment of the present disclosure, the terminal controls the allocation of uplink resources to the uplink control information based on the size of the information indicating resource allocation for the uplink control information, and transmits the uplink control information using the uplink resources.

[0249] All disclosures in the specification, drawings, and abstract contained in the Japanese application 2020-017987, filed on February 5, 2020, are incorporated herein by reference. [Industrial applicability]

[0250] One embodiment of this disclosure is useful for wireless communication systems. [Explanation of symbols]

[0251] 100 base stations 101,205 Control Unit 102 Higher-level control signal generation unit 103 Downlink control information generation unit 104,206 Encoding section 105,207 Modulation section 106,208 Signal assignment section 107,209 Transmitter 108,201 Receiving Unit 109,202 Extraction part 110,203 Demodulation section 111,204 Decoding section 200 terminals

Claims

1. A control circuit that controls the allocation of uplink resources to uplink control information based on a variable number of bits of information indicating resource allocation related to uplink control information, The aforementioned uplink resource includes a receiving circuit that receives the uplink control information, It is equipped with, The control circuit, in controlling the allocation of the upstream resource, uses 8 as a constant regardless of the variable number of bits. Base station.

2. The correspondence between the value of the information indicating the resource allocation and the candidate resource for the resource allocation differs depending on the variable number of bits. The base station according to claim 1.

3. If the number of candidate resources is less than or equal to a threshold, the value of the information indicating resource allocation is associated one-to-one with the candidate resources. The base station according to claim 2.

4. The correspondence between the value of the information indicating the resource allocation and the downstream resource used to receive the information indicating the resource allocation, and the candidate resource for the resource allocation, differs depending on the variable number of bits. The base station according to claim 1.

5. The threshold is 8, and the variable number of bits in the information indicating resource allocation is selected from 0, 1, 2, or 3 bits. The base station according to claim 3.

6. The control circuit determines the allocation method based on a comparison between the number of candidate resources for resource allocation and a threshold based on the variable number of bits. The base station according to claim 1.

7. If the number of candidate resources is less than or equal to the threshold, the control circuit determines the upstream resource among the candidate resources that is associated one-to-one with the value of the resource allocation information as the allocated resource for the upstream control information. The base station according to claim 6.

8. If the number of candidate resources exceeds the threshold, the control circuit determines, among the candidate resources, the resource associated with a combination of resource allocation information and a downlink resource used to receive the resource allocation information as the allocated resource for the uplink control information. The base station according to claim 6.

9. The system includes a transmission circuit that transmits information regarding the variable number of bits. The base station according to claim 1.

10. Information regarding candidate resources for the aforementioned resource allocation is indicated by terminal-specific upper-layer signals. The base station according to claim 1.

11. The resource allocation information related to the aforementioned uplink control information is notified using the downlink control information. The base station according to claim 1.

12. If the number of candidate resources is greater than the threshold, the number of candidate resources associated with each value of the resource allocation information is the same regardless of the variable number of bits in the resource allocation information. The base station according to claim 3.

13. The base station is, Based on a variable number of bits in the information indicating resource allocation related to the uplink control information, the allocation of uplink resources to the uplink control information is controlled. In the aforementioned uplink resource, the uplink control information is received, In the control of the allocation of the upstream resources, 8 is used as a constant regardless of the variable number of bits. Communication method.

14. A process that controls the allocation of uplink resources to the uplink control information based on a variable number of bits in the information indicating resource allocation related to uplink control information, The upstream resource controls the process of receiving the upstream control information, In the control of the allocation of the upstream resources, 8 is used as a constant regardless of the variable number of bits. Integrated circuit.

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