Terminal, base station, and communication method

Abstract

This terminal comprises: a control circuit that determines, as reception resources for a downlink signal, resource blocks distributed and arranged on a frequency axis from among a plurality of resource blocks obtained by dividing a frequency band, the number of resource blocks included in the reception resources being equal to or less than a prescribed value; and a reception circuit that receives the downlink signal by using the reception resources.

Description

Terminal, base station, and communication method

[0001] The present disclosure relates to a terminal, a base station, and a communication method.

[0002] A communication system known as the fifth-generation mobile communication system (5G) is currently under consideration. The 3rd Generation Partnership Project (3GPP), an international standardization organization, is studying the advancement of the 5G communication system from the perspectives of both the advancement of the LTE / LTE-Advanced system and New Radio Access Technology (also referred to as New RAT or NR), a new method that is not necessarily backward compatible with the LTE / LTE-Advanced system (see, for example, Non-Patent Document 1).

[0003] RP-181726, “Revised WID on New Radio Access Technology”, NTT DOCOMO, September 2018RP-213661, “New SID on Study on further NR RedCap UE complexity reduction”, Ericsson, December 2021

[0004] There is room for further study on the method of allocating downlink resources.

[0005] Non-limiting examples of the present disclosure contribute to providing a terminal, a base station, and a communication method that can appropriately allocate downlink resources.

[0006] A terminal according to one embodiment of the present disclosure includes a control circuit that determines, from among a plurality of resource blocks obtained by dividing a frequency band, resource blocks that are distributed on a frequency axis as reception resources for a downlink signal, and the number of resource blocks included in the reception resources is equal to or less than a specified value, and a reception circuit that receives the downlink signal using the reception resources.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to an embodiment of the present disclosure, downlink resources can be appropriately allocated.

[0009] Further advantages and benefits of one embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features.

[0010] 3. Block diagram showing an example configuration of a portion of a base station; 4. Block diagram showing an example configuration of a portion of a terminal; 5. Block diagram showing an example configuration of a base station; 6. Block diagram showing an example configuration of a terminal; 7. Diagram showing an example operation of a base station and a terminal; 8. Diagram showing an example of resource allocation; 9. Diagram showing an example of resource allocation; 10. Diagram showing an example operation of a base station and a terminal; 11. Diagram showing an example of resource allocation; 12. Diagram showing an example of resource allocation; 13. Diagram showing an example configuration of a Resource Block Group (RBG); 14. Diagram showing an example configuration of an RBG; 15. Diagram showing an example of resource allocation; 16. Diagram showing an example of resource allocation; 17. Diagram of an example architecture of a 3GPP NR system; 18. Schematic diagram showing functional separation between NG-RAN and 5GC; 19. Sequence diagram of Radio Resource Control (RRC) connection setup / reconfiguration procedures; 19. Schematic diagram showing usage scenarios for enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC); 20. Block diagram of an example 5G system architecture for a non-roaming scenario;

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] In the following description, for example, a radio frame, a slot, and a symbol are units of physical resources in the time domain. For example, the length of one frame may be 10 milliseconds. For example, one frame may be composed of multiple slots (e.g., 10, 20, or other values). Furthermore, the number of slots constituting one frame may be variable depending on the slot length. Furthermore, one slot may be composed of multiple symbols (e.g., 14 or 12). For example, one symbol is the smallest physical resource unit in the time domain, and the symbol length may vary depending on the subcarrier spacing (SCS).

[0013] Furthermore, a subcarrier and a resource block (RB) are units of physical resources in the frequency domain. For example, one resource block may consist of 12 subcarriers. For example, one subcarrier may be the smallest physical resource unit in the frequency domain. The subcarrier spacing is variable and may be, for example, 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, 480 kHz, 960 kHz, or other values.

[0014] [About evolved Reduced Capability NR Devices] In Release 18 NR (hereinafter also referred to as Rel-18), specifications are expected to be formulated to realize terminals (e.g., mobile stations or user equipment (UE)) (e.g., referred to as eRedCap terminals) called evolved Reduced Capability NR Devices (eRedCap) (see, for example, Non-Patent Document 2). Compared with Releases 15 / 16 / 17 (e.g., also referred to as Rel-15 / 16 / 17), etc., eRedCap terminals aim to support a variety of use cases by, for example, reducing power consumption or cost through some limitations on supported characteristics or performance (e.g., capabilities).

[0015] The processing capability of the eRedCap terminal may be limited to reduce costs. For example, the upper limit of the number of RBs of a downlink data channel (e.g., PDSCH: Physical Downlink Shared Channel) that the eRedCap terminal can process per slot may be as follows: - 25 for 15 kHz SCS - 12 for 30 kHz SCS

[0016] The upper limit of the bandwidth of the Bandwidth part (BWP) set for the eRedCap terminal can be about 20 MHz. The upper limit of the BWP bandwidth (20 MHz) is converted to the number of RBs as follows: - 15 kHz SCS: 106 - 30 kHz SCS: 51

[0017] A method for allocating downlink resources (for example, PDSCH resources) to such eRedCap terminals with limited processing capabilities has not been fully considered.

[0018] Therefore, in a non-limiting embodiment of the present disclosure, a method for appropriately allocating PDSCH resources to an eRedCap terminal will be described.

[0019] For example, a method of allocating PDSCH resources to a terminal uses resource block groups (RBGs). In this method, for example, multiple RBs (RB groups) included in a BWP are divided (grouped) into multiple RBGs. Then, a control signal is used to notify the terminal of which RBGs the PDSCH resources are allocated to. The notification of the allocated RBGs by the control signal may be expressed, for example, by a bitmap, with one bit corresponding to each RBG. As an example, PDSCH resources may be allocated to RBGs whose corresponding bit is 1, and PDSCH resources may not be allocated to RBGs whose corresponding bit is 0.

[0020] In the method using RBG, PDSCH resources can be allocated to RBs distributed on the frequency axis, and therefore reception performance is improved by frequency diversity gain.

[0021] On the other hand, in the method using RBG, if the size of the set RBG (e.g., the number of RBs included in the RBG) is small and the number of RBGs is large, the number of bits in the bitmap used to notify the RBGs will be large, which may increase the overhead of the control signal.

[0022] Furthermore, in the method using RBG, if the size of the RBG to be set (e.g., the number of RBs included in the RBG) is large, the flexibility of the number of allocated RBs may be reduced. As an example, in the case of 15 kHz SCS, a BWP including 106 RBs corresponding to 20 MHz may be set. In this case, if the RBG size is 16, it may not be possible to notify the eRedCap terminal of 25 RBs, which is the upper limit of the processing capacity of the eRedCap terminal, via a control signal. This is because 25 is not a multiple of 16.

[0023] Another method for allocating PDSCH resources to a terminal is to use a Resource Indication Value (RIV). The RIV is a value obtained by encoding the first (e.g., top) RB position (e.g., RB index) and the number of RBs for consecutive RBs to which PDSCH resources are allocated. The terminal can identify the consecutive RBs to which PDSCH resources are allocated by decoding the received RIV.

[0024] While the method using RIV allows for flexible allocation of the number of RBs, it does not allow for allocation of non-contiguous RBs, resulting in small frequency diversity gain and possible degradation of reception performance.

[0025] In the following, for example, a method for improving reception performance by frequency diversity gain and improving flexibility in allocation of PDSCH resources (for example, allocation of the number of RBs) will be described.

[0026] For example, the eRedCap terminal identifies resource blocks (RBs) distributed on the frequency axis as resources to be used for receiving the PDSCH. At this time, the number of identified RBs is equal to or less than a threshold (e.g., an upper limit on the number of RBs depending on the processing capability of the eRedCap terminal). This enables the eRedCap terminal to receive the PDSCH using a number of RBs appropriate for the eRedCap terminal, and also improves reception quality through frequency diversity gain using the RBs distributed on the frequency axis.

[0027] [Outline of Communication System] The communication system according to this embodiment includes a base station 100 and a terminal 200. The terminal 200 is, for example, an eRedCap terminal.

[0028] Fig. 1 is a block diagram showing an example of the configuration of a portion of a base station 100 according to this embodiment. In the base station 100 shown in Fig. 1, a control unit (e.g., corresponding to a control circuit) determines resource blocks, which are distributed on the frequency axis among a plurality of resource blocks obtained by dividing a frequency band, as transmission resources for a downlink signal (e.g., PDSCH). The number of resource blocks included in the transmission resources is equal to or less than a specified value. A transmission unit (e.g., corresponding to a transmission circuit) transmits the downlink signal using the transmission resources.

[0029] Fig. 2 is a block diagram showing an example configuration of a portion of terminal 200 according to this embodiment. In terminal 200 shown in Fig. 2, a control unit (e.g., corresponding to a control circuit) determines resource blocks distributed on the frequency axis from among multiple resource blocks obtained by dividing a frequency band as reception resources for a downlink signal (e.g., PDSCH). The number of resource blocks included in the reception resources is equal to or less than a specified value. A receiving unit (e.g., corresponding to a receiving circuit) receives the downlink signal using the reception resources.

[0030] (Embodiment 1) For example, when the total number of RBs included in a resource block group (RBG) notified by base station 100 is greater than a threshold, terminal 200 identifies some RBs in the notified RBG as resources to be used for receiving the PDSCH. At this time, the total number of RBs included in the identified some RBs is equal to or less than the threshold. This enables terminal 200 to receive the PDSCH with a number of RBs appropriate for terminal 200. Furthermore, reception quality is improved by frequency diversity gain due to RBs distributed on the frequency axis.

[0031] [Configuration of Base Station] Fig. 3 is a block diagram showing an example configuration of base station 100 according to this embodiment. In Fig. 3, base station 100 has a control unit 101, a Downlink Control Information (DCI) generation unit 102, an upper layer signal generation unit 103, an encoding / modulation unit 104, a signal mapping unit 105, a transmission unit 106, an antenna 107, a reception unit 108, a signal separation unit 109, and a demodulation / decoding unit 110.

[0032] For example, at least one of the control unit 101, DCI generation unit 102, upper layer signal generation unit 103, coding / modulation unit 104, signal mapping unit 105, signal separation unit 109, and demodulation / decoding unit 110 shown in Fig. 3 may be included in the receiving unit shown in Fig. 1. For example, at least one of the transmission unit 106 and antenna 107 shown in Fig. 3 may be included in the transmitting unit shown in Fig. 1.

[0033] The control unit 101 may determine, for example, information regarding PDSCH configuration or resource allocation. Furthermore, the control unit 101 may instruct the upper layer signal generating unit 103 to generate an upper layer signal (also referred to as, for example, an upper layer parameter or upper layer signaling) based on the determined information. Furthermore, the control unit 101 may instruct the DCI generating unit 102 to generate control information (for example, DCI) to be included in a downlink control channel (for example, PDCCH: Physical Downlink Control Channel) based on, for example, the determined information.

[0034] Furthermore, the control section 101 outputs (or instructs) information relating to downlink resources (for example, PDSCH resources, PDCCH resources) to the signal mapping section 105 .

[0035] The DCI generating unit 102 may generate DCI based on an instruction from the control unit 101 , for example, and output the generated DCI to the signal mapping unit 105 .

[0036] The upper layer signal generating unit 103 may generate an upper layer signal such as system information based on instructions from the control unit 101, for example, and output the generated upper layer signal to the coding and modulation unit 104.

[0037] The coding / modulation unit 104 may, for example, perform error correction coding and modulation on the downlink data and the upper layer signal input from the upper layer signal generation unit 103, and output the modulated signal to the signal mapping unit 105.

[0038] For example, the signal mapping unit 105 may map the DCI input from the DCI generation unit 102 to a downlink control channel (e.g., a PDCCH) and map the signal input from the coding and modulation unit 104 to the PDSCH, based on information on downlink resources (e.g., PDSCH resources) input from the control unit 101. The signal mapping unit 105 outputs the signals mapped to each resource to the transmission unit 106.

[0039] The transmitting unit 106 performs radio transmission processing, including frequency conversion (e.g., up-conversion) using a carrier wave, on the signal input from the signal placement unit 105, and outputs the signal after the radio transmission processing to the antenna 107.

[0040] The antenna 107, for example, emits a signal (for example, a downlink signal) input from the transmitting unit 106 toward the terminal 200. The antenna 107 also receives an uplink signal transmitted from the terminal 200, for example, and outputs the signal to the receiving unit 108.

[0041] The uplink signal may be, for example, a signal of a channel such as an uplink data channel (e.g., PUSCH: Physical Uplink Shared Channel), an uplink control channel (e.g., PUCCH: Physical Uplink Control Channel), or a random access channel (e.g., PRACH: Physical Random Access Channel).

[0042] Receiving section 108 performs radio reception processing including frequency conversion (for example, down-conversion) on the signal input from antenna 107 , and outputs the signal after radio reception processing to signal separating section 109 .

[0043] For example, the signal separating unit 109 extracts (or separates) a signal on a PUCCH resource (for example, Uplink Control Information (UCI)) and a signal on a PRACH (for example, a preamble) from the signals input from the receiving unit 108. Furthermore, the signal separating unit 109 outputs, for example, a signal on a PUSCH resource from the signals input from the receiving unit 108 to the demodulating and decoding unit 110.

[0044] The demodulation / decoding unit 110 demodulates and decodes the signal input from the signal separation unit 109, for example, and outputs uplink data.

[0045] [Configuration of Terminal] FIG. 4 is a block diagram showing an example of the configuration of terminal 200 according to this embodiment.

[0046] In FIG. 4 , terminal 200 has antenna 201, receiving section 202, signal separating section 203, DCI detecting section 204, demodulating / decoding section 205, control section 206, coding / modulating section 207, signal mapping section 208, and transmitting section 209.

[0047] For example, at least one of signal separation section 203, DCI detection section 204, demodulation / decoding section 205, control section 206, coding / modulation section 207, and signal mapping section 208 shown in Fig. 4 may be included in the transmission section shown in Fig. 2. For example, at least one of antenna 201 and receiving section 202 shown in Fig. 4 may be included in the receiving section shown in Fig. 2.

[0048] The antenna 201 receives, for example, a downlink signal (downlink channel) transmitted by the base station 100 and outputs the signal to the receiving unit 202. The antenna 201 also radiates, for example, an uplink signal (uplink channel) input from the transmitting unit 209 to the base station 100.

[0049] The receiving unit 202 performs radio reception processing including frequency conversion (for example, down-conversion) on the signal input from the antenna 201 , and outputs the signal after radio reception processing to the signal separating unit 203 .

[0050] For example, based on information relating to the downlink channel input from the control unit 206, the signal separation unit 203 extracts (e.g., separates) signals on PDCCH resources from the signals input from the receiving unit 202, and outputs the extracted signals to the DCI detection unit 204. Furthermore, for example, based on an instruction from the control unit 206, the signal separation unit 203 outputs signals on PDSCH resources from the signals input from the receiving unit 202 to the demodulation and decoding unit 205.

[0051] For example, the DCI detection unit 204 may detect DCI from the signal (for example, the signal on the PDCCH resource) input from the signal separation unit 203. The DCI detection unit 204 may output the detected DCI to the control unit 206, for example.

[0052] The demodulation and decoding unit 205, for example, demodulates and performs error correction decoding on a signal (e.g., a signal on a PDSCH resource) input from the signal separation unit 203 to obtain at least one of downlink data and an upper layer signal such as system information. The demodulation and decoding unit 205 may, for example, output the upper layer signal obtained by decoding to the control unit 206. The demodulation and decoding unit 205 may also, for example, output the downlink data obtained by decoding.

[0053] The control unit 206 may determine (or identify) downlink resources (e.g., PDSCH resources or PDCCH resources) based on, for example, at least one of the DCI input from the DCI detection unit 204 and the higher layer signal (e.g., system information) input from the demodulation and decoding unit 205. For example, the control unit 206 outputs (e.g., instructs) information on the identified downlink resources to the signal separation unit 203.

[0054] The coding / modulation unit 207 may, for example, code and modulate the uplink data and output the modulated signal to the signal mapping unit 208 .

[0055] For example, the signal mapping section 208 may map the signal input from the coding and modulation section 207 to a PUSCH resource, map the UCI to a PUCCH resource, and map the preamble to a PRACH resource, based on information regarding the uplink resource input from the control section 206. The signal mapping section 208 outputs the signals mapped to each resource to the transmission section 209.

[0056] The transmitting section 209 performs radio transmission processing including, for example, frequency conversion (for example, up-conversion) on the signal input from the signal mapping section 208 , and outputs the signal after radio transmission processing to the antenna 201 .

[0057] [Example of Operation of Base Station 100 and Terminal 200] Next, an example of operation of the base station 100 and terminal 200 described above will be described.

[0058] [Operation Example 1-1] FIG. 5 is a flowchart showing an example of processing by the base station 100 (for example, a gNB) and the terminal 200 (for example, a UE).

[0059] <S101> The base station 100, for example, arranges DCI including information related to RBG on PDCCH resources and transmits the DCI.

[0060] <S102> The terminal 200 receives DCI on the PDCCH resource, for example, and obtains information about the RBG.

[0061] <S103> If the total number of RBs included in the RBGs notified in S102 (e.g., multiple RBGs set in the terminal 200) is greater than a threshold (e.g., exceeds a threshold), the terminal 200 determines (or sets or identifies) some RBs from the notified RBGs as PDSCH reception resources. For example, the threshold may be set to a value based on the processing capability of the terminal 200 (e.g., an eRedCap terminal). As an example, the threshold may be set to an upper limit value for the number of PDSCH RBs that the eRedCap terminal can process per slot (e.g., 25 in the case of 15 kHz SCS), or another value may be set.

[0062] In this case, the total number of RBs included in the partial RB group identified as the PDSCH reception resources may be equal to or less than a threshold value (for example, 25).

[0063] For example, terminal 200 may select 25 or less RBs from the RBs included in the notified RBG in ascending order of frequency (or RB index), and identify them as RBs for PDSCH reception. Fig. 6 is a diagram showing an example of setting RBs for PDSCH reception.

[0064] As shown in Fig. 6 , two RBGs including a total of 32 RBs, one including RB index (e.g., Common RB (CRB) index) #16-31 and the other including RB index #48-63, are notified to terminal 200. For example, as shown in Fig. 6 , the information on RBGs included in the DCI may be information in a bitmap format, and may indicate that the corresponding RBG is not allocated to terminal 200 when 0 is specified, and that the corresponding RBG is allocated to terminal 200 when 1 is specified.

[0065] In Fig. 6, since the total number of RBs (32) included in the notified RBG exceeds a threshold (e.g., 25), terminal 200 determines (or identifies) 25 or fewer RBs from the 32 RBs as RBs for PDSCH reception. In the example of Fig. 6, terminal 200 may select 25 RBs of CRB indexes #16-31 and CRB indexes #48-56 in ascending order of frequency (e.g., CRB index), and identify them as RBs for PDSCH reception (e.g., represented by "Rx").

[0066] Note that the method of selecting RBs for PDSCH reception is not limited to this, and for example, terminal 200 may select 25 or less RBs from the RBs included in the notified RBG in descending order of frequency (or RB index), and identify them as RBs for PDSCH reception. Figure 7 is a diagram showing an example of setting RBs for PDSCH reception.

[0067] As shown in Fig. 7, terminal 200 is notified of two RBGs including a total of 32 RBs: an RBG with RB index (e.g., CRB index) #16-31, and an RBG with RB index #48-63. In Fig. 7, since the total number of RBs (32) included in the notified RBGs exceeds a threshold (e.g., 25), terminal 200 determines (or identifies) 25 or fewer RBs from the 32 RBs as RBs for PDSCH reception. In the example of Fig. 7, terminal 200 may select 25 RBs with CRB index #63-48 and CRB index #31-23 in descending order of frequency (e.g., CRB index), and identify them as RBs for PDSCH reception.

[0068] <S104> Base station 100, for example, arranges data on PDSCH resources and transmits the data. Note that base station 100 may, for example, arrange data in an RBG set in terminal 200 and transmit the data, or, similar to the processing of S103 in terminal 200, may arrange data in RBs for PDSCH determined according to an RBG set in terminal 200 (for example, the total number of RBs) and a threshold (for example, a value based on the processing capacity of terminal 200) and transmit the data.

[0069] <S105> Terminal 200 receives data on the PDSCH using the RB group (PDSCH reception resources) identified in S103.

[0070] According to operation example 1-1, terminal 200 can receive PDSCH using a number of RBs appropriate for the processing capability of terminal 200, even if the total number of RBs included in the RBG notified from base station 100 is greater than the number of RBs appropriate for the processing capability of terminal 200. Furthermore, as shown in Figures 6 and 7, terminal 200 can receive PDSCH using RBs distributed on the frequency axis, thereby improving reception quality through frequency diversity gain. Furthermore, in operation example 1-1, the method of selecting RBs is simple, so an increase in the amount of calculation processing in terminal 200 can be suppressed.

[0071] [Operation Example 1-2] The processing of the base station 100 and the terminal 200 in Operation Example 1-2 may be, for example, the same as the processing shown in Fig. 5. In Operation Example 1-2, the processing of S101, S102, S104, and S105 is the same as in Operation Example 1-1, but the method of selecting RBs in the processing of S103 is different from that in Operation Example 1-1.

[0072] <S103> If the total number of RBs included in the RBG notified in S102 (e.g., multiple RBGs set in the terminal 200) is greater than a threshold (e.g., 25), the terminal 200 determines (or sets or identifies) a group of RBs from the notified RBG as resources for receiving the PDSCH.

[0073] In this case, the total number of RBs included in the partial RB group identified as the PDSCH reception resources may be equal to or less than a threshold value (for example, 25).

[0074] For example, terminal 200 may select 25 or less RBs including the RB with the lowest frequency (or RB index) and the RB with the highest frequency (or RB index) from the RBs included in the notified RBG, and specify these as RBs for PDSCH reception. Fig. 8 is a diagram showing an example of setting RBs for PDSCH reception.

[0075] As shown in FIG. 8, terminal 200 is notified of two RBGs including a total of 32 RBs: an RBG including RB indexes (for example, CRB indexes) #16-31, and an RBG including RB indexes #48-63.

[0076] In Fig. 8, since the total number of RBs (32) included in the notified RBG exceeds a threshold (e.g., 25), terminal 200 determines (or identifies) 25 or fewer RBs from the 32 RBs as RBs for PDSCH reception. In the example of Fig. 8, terminal 200 may select a group of 25 RBs from the notified RBG, including CRB index #16 with the lowest frequency (e.g., CRB index) and CRB index #63 with the highest frequency (e.g., CRB index), and identify these as RBs for PDSCH reception (e.g., represented by "Rx"). In the example of Fig. 8, CRB indexes #16-31 and CRB indexes #53-63 are selected as RBs for PDSCH reception.

[0077] In addition, in FIG. 8, RBs selected as RBs for PDSCH reception other than CRB indexes #16 and #63 are not limited to CRB indexes #17-31 and #53-62, and may be other RBs.

[0078] According to Operation Example 1-2, terminal 200 can receive the PDSCH using a number of RBs that is appropriate for the processing capability of terminal 200, even if the total number of RBs included in the RBG notified by base station 100 is greater than the number of RBs that is appropriate for the processing capability of terminal 200. Also, as shown in Fig. 8, terminal 200 can receive the PDSCH using RBs that are distributed on the frequency axis, and therefore the reception quality is improved by frequency diversity gain. Also, in Operation Example 1-2, the frequency range of the RBs selected as RBs for PDSCH reception is wide, and therefore the frequency diversity gain is greater than in Operation Example 1-1.

[0079] An example of the operation of the base station 100 and the terminal 200 has been described above.

[0080] As described above, in the present embodiment, terminal 200 determines, as PDSCH reception resources, RBs that are distributed on the frequency axis from among multiple RBs obtained by dividing a frequency band (for example, BWP). At this time, the number of RBs included in the PDSCH reception resources is equal to or less than a threshold (for example, a value based on the processing capability of terminal 200). For example, when the total number of RBs included in multiple RBGs configured in terminal 200 is greater than a threshold, terminal 200 determines, as PDSCH reception resources, RBs in the RBG that are equal to or less than the threshold. Then, terminal 200 receives a PDSCH signal using the PDSCH reception resources.

[0081] This allows terminal 200 to flexibly set (or identify) RBs for PDSCH reception according to the processing capacity of terminal 200. Furthermore, since non-contiguous RBs can be allocated as RBs for PDSCH reception, reception quality can be improved by frequency diversity gain.

[0082] As described above, according to this embodiment, downlink resource allocation can be appropriately set.

[0083] [Note on First Embodiment] In the first embodiment, an example of operation has been described in which the total number of RBs included in the RBG notified to terminal 200 exceeds a threshold (for example, 25). On the other hand, if the total number of RBs included in the RBG notified to terminal 200 is equal to or less than the threshold, terminal 200 may receive the PDSCH using all RBs included in the notified RBG.

[0084] Also, in this embodiment (or in embodiments described below), the "threshold" may be derived based on the processing capability of terminal 200. For example, the threshold may be set based on the processing capability of the eRedCap terminal (25 or less for 15 kHz SCS, 12 or less for 30 kHz SCS).

[0085] Alternatively, the "threshold" may be derived based on an identification number of terminal 200, etc. For example, the threshold may be derived based on a terminal-specific number such as a Cell-Radio Network Temporary Identity (C-RNTI), a cell ID, etc.

[0086] Alternatively, the "threshold" may be defined in advance and may be notified (or set) to terminal 200 by a control signal (e.g., Radio Resource Control (RRC), Medium Access Control (MAC), or DCI, etc.).

[0087] Alternatively, the "threshold" may be derived based on multiple of the processing capacity of the terminal 200, the identification number of the terminal 200, the specified value, and the notified value.

[0088] Furthermore, in this embodiment (or embodiments described later), the method by which terminal 200 selects an RB group may be determined based on the processing capability of terminal 200 or an identification number of terminal 200, or may be defined in advance, or may be notified to terminal 200 by a control signal (for example, at least one of RRC, MAC, and DCI). Alternatively, the threshold may be determined by a combination of these methods.

[0089] Furthermore, in this embodiment, a case has been described in which RB groups that are contiguous on the frequency axis within each RBG are selected, but RB groups may be selected using other methods. For example, RB groups that are discontinuous on the frequency axis may be selected within each RBG, and these RBs may be equally spaced or unequally spaced on the frequency axis. Also, for example, RBs for PDSCH reception may be set evenly across multiple RBGs set in terminal 200.

[0090] Second Embodiment The base station 100 and the terminal 200 according to this embodiment may be the same as those in the first embodiment.

[0091] In this embodiment, terminal 200 specifies, for each of a plurality of RBGs notified from base station 100, a "sub-RBG," which is a portion of the RBs included in each RBG, as resources to be used for PDSCH reception. At this time, parameters related to the sub-RBG may be notified to terminal 200 or may be defined in advance. According to this embodiment, RBs can be used more flexibly.

[0092] An example of the operation of base station 100 and terminal 200 according to this embodiment will be described below.

[0093] [Operation Example 2-1] FIG. 9 is a flowchart showing an example of processing by the base station 100 (for example, a gNB) and the terminal 200 (for example, a UE).

[0094] <S201> The base station 100, for example, arranges DCI including information related to RBG on PDCCH resources and transmits the DCI (similar to S101 in the first embodiment, for example).

[0095] <S202> Terminal 200 receives DCI on the PDCCH resource, for example, and obtains information about RBG (similar to S102 in the first embodiment, for example).

[0096] <S203> For each of the multiple RBGs notified in S202, terminal 200 determines (or sets or identifies) sub-RBGs, which are a portion of the RBs included in the RBG, as PDSCH reception resources.

[0097] For example, terminal 200 may identify a sub-RBG of each RBG based on parameters related to the sub-RBG. The parameters related to the sub-RBG may include, for example, an "offset" and a "size." The offset may be, for example, a value for identifying the number of RBs from a specified position of each RBG (for example, the edge (or beginning) of the RBG) to the sub-RBG (for example, the position of the edge of the sub-RBG). The size may be, for example, a value for identifying the number of RBs that make up the sub-RBG.

[0098] FIG. 10 is a diagram showing an example of setting RBs for PDSCH reception.

[0099] 10, two RBGs including a total of 32 RBs, one including RB index #16-31 and the other including RB index #48-63, are notified to terminal 200. Also, in FIG. 10, the sub-RBG offset = 4 RBs and the size = 5 RBs.

[0100] In Fig. 10, for example, for an RBG including RB index #16-31, terminal 200 specifies five RBs (CRB index #20-#24) starting from CRB index #16+4=#20 as sub-RBGs (e.g., also expressed as "sub"). Similarly, in Fig. 10, for example, for an RBG including RB index #48-63, terminal 200 specifies five RBs (CRB index #52-#56) starting from CRB index #48+4=#52 as sub-RBGs. Therefore, in Fig. 10, terminal 200 specifies sub-RBGs of CRB index #20-#24 and sub-RBGs of CRB index #52-#56 as RBs for PDSCH reception.

[0101] <S204> Base station 100, for example, allocates data to PDSCH resources and transmits the data (similar to, for example, S104 in the first embodiment). Note that base station 100 may, for example, allocate data to an RBG configured in terminal 200 and transmit the data, or, similar to the processing of S103 in terminal 200, may allocate data to RBs for PDSCH determined according to an RBG configured in terminal 200 (for example, the total number of RBs) and a threshold (for example, a value based on the processing capacity of terminal 200) and transmit the data.

[0102] <S205> Terminal 200 receives data on the PDSCH using the RB group (PDSCH reception resource) included in the sub-RBG identified in S203.

[0103] According to operation example 2-1, the number of RBs and the RB positions within an RBG can be flexibly set, and terminal 200 can receive PDSCH using flexibly set RBs. Furthermore, as shown in Fig. 10, terminal 200 can receive PDSCH using RBs distributed on the frequency axis, improving reception quality through frequency diversity gain. Furthermore, in operation example 2-1, the number of parameters related to sub-RBGs is relatively small, so that an increase in overhead of control signals can be suppressed.

[0104] In addition, in Figure 10, a method of identifying a sub-RBG in each RBG based on an RB with a low frequency (or a low CRB index) has been described, but this is not limited to this, and for example, a sub-RBG may be identified based on an RB with a high frequency (or a high CRB index).

[0105] [Operation Example 2-2] In operation example 2-2, for example, each RBG may include multiple sub-RBGs.

[0106] The processing of the base station 100 and the terminal 200 in the operation example 2-2 may be, for example, the same as the processing shown in Fig. 9. In the operation example 2-2, the processing of S201, S202, S204, and S205 is the same as that in the operation example 2-1, but the method of selecting an RB in the processing of S203 is different from that in the operation example 2-1.

[0107] <S203> For each of the multiple RBGs notified in S202, terminal 200 determines (or sets or identifies) sub-RBGs, which are a portion of the RBs included in the RBG, as PDSCH reception resources.

[0108] For example, terminal 200 may identify a sub-RBG of each RBG based on parameters related to the sub-RBG. The parameters related to the sub-RBG may include, for example, an "offset," a "size," and an "interval." The offset may be, for example, a value for identifying the number of RBs from a specified position of each RBG (for example, the edge (or beginning) of the RBG) to the first sub-RBG (for example, the position of the edge of the sub-RBG). The size may be, for example, a value for identifying the number of RBs constituting the sub-RBG. The interval may be, for example, a value for identifying the distance (for example, the number of RBs) between multiple sub-RBGs within each RBG.

[0109] FIG. 11 is a diagram showing an example of setting RBs for PDSCH reception.

[0110] 11, two RBGs including a total of 32 RBs, one including RB index #16-31 and the other including RB index #48-63, are notified to terminal 200. Also, in FIG. 11, the sub-RBG offset = 2 RBs, size = 3 RBs, and interval = 4 RBs.

[0111] In FIG. 11, for example, for an RBG including RB index #16-31, terminal 200 identifies three RBs (CRB index #18-#20) starting from CRB index #16+2=#18 as the first sub-RBG (e.g., also expressed as "sub"), and identifies three RBs (CRB index #25-#27) starting from CRB index #25, which is four RBs away from the first sub-RBG (e.g., CRB index #20), as the second sub-RBG.

[0112] Similarly, in FIG. 11, for an RBG including RB indexes #48-63, terminal 200 identifies three RBs (CRB indexes #50-#52) starting from CRB index #48+2=#50 as the first sub-RBG (e.g., also expressed as "sub"), and identifies three RBs (CRB indexes #57-#59) starting from CRB index #57, which is four RBs away from the first sub-RBG (e.g., CRB index #52), as the second sub-RBG.

[0113] In this way, for each RBG, terminal 200 identifies the first sub-RBG based on the offset from the first RB and the size, and identifies the second sub-RBG based on the interval from the first sub-RBG and the size. Note that terminal 200 may similarly repeatedly identify the third and subsequent sub-RBGs based on the interval and size up to the end of the RBG.

[0114] In addition, in FIG. 11, a method of identifying a sub-RBG based on an RB of a low frequency (or a low CRB index) has been described, but this is not limited to this, and for example, a sub-RBG may be identified based on an RB of a high frequency (or a high CRB index).

[0115] According to Operation Example 2-2, the number of RBs and the RB positions within an RBG can be flexibly set, and terminal 200 can receive PDSCH using flexibly set RBs. Furthermore, as shown in FIG. 11 , terminal 200 can receive PDSCH using RBs distributed on the frequency axis, improving reception quality through frequency diversity gain. Furthermore, in Operation Example 2-2, RBs for PDSCH reception are distributed across multiple sub-RBGs within each RBG, and therefore frequency diversity gain can be even greater than in Operation Example 2-1.

[0116] [Operation Example 2-3] In Operation Example 2-3, for example, each RBG may include multiple sub-RBGs. Also, in Operation Example 2-3, for example, terminal 200 identifies RBs for PDSCH reception based on the "number" of sub-RBGs included in each RBG.

[0117] The processing of the base station 100 and the terminal 200 in the operation example 2-3 may be, for example, the same as the processing shown in Fig. 9. In the operation example 2-3, the processing of S201, S202, S204, and S205 is the same as that in the operation example 2-1, but the method of selecting an RB in the processing of S203 is different from that in the operation example 2-1.

[0118] <S203> For each of the multiple RBGs notified in S202, terminal 200 determines (or sets or identifies) sub-RBGs, which are a portion of the RBs included in the RBG, as PDSCH reception resources.

[0119] For example, terminal 200 may identify sub-RBGs of each RBG based on parameters related to the sub-RBGs. The parameters related to the sub-RBGs may include, for example, an "offset," "size," "interval," and "number." The offset may be, for example, a value for identifying the number of RBs from a specified position of each RBG (for example, the edge (or beginning) of the RBG) to the first sub-RBG (for example, the position of the edge of the sub-RBG). The size may be, for example, a value for identifying the number of RBs constituting the sub-RBG. The interval may be, for example, a value for identifying the distance between multiple sub-RBGs within each RBG (for example, the number of RBs). The number may be, for example, a value for identifying the number of sub-RBGs within each RBG.

[0120] FIG. 12 is a diagram showing an example of setting RBs for PDSCH reception.

[0121] 12 , two RBGs including a total of 32 RBs, one including RB index #16-31 and the other including RB index #48-63, are notified to terminal 200. Also, in FIG. 12 , the sub-RBG offset is 2 RBs, the size is 2 RBs, the interval is 2 RBs, and the number is 3.

[0122] 12, terminal 200 identifies three sub-RBGs for an RBG including RB indexes #16-31. For example, terminal 200 identifies two RBs (CRB index #18-#19) starting from CRB index #16+2=#18 as a first sub-RBG (e.g., sub-RBG #0), identifies two RBs (CRB index #22-#23) starting from CRB index #22, which is two RBs away from sub-RBG #0 (e.g., CRB index #19), as a second sub-RBG (e.g., sub-RBG #1), and identifies two RBs (CRB index #26-#27) starting from CRB index #26, which is two RBs away from sub-RBG #1 (e.g., CRB index #23), as a third sub-RBG (e.g., sub-RBG #2).

[0123] 12, terminal 200 identifies three sub-RBGs for an RBG including RB indexes #48-63. For example, terminal 200 identifies two RBs (CRB index #50-#51) starting from CRB index #48+2=#50 as a first sub-RBG (e.g., sub-RBG #0), identifies two RBs (CRB index #54-#55) starting from CRB index #54, which is two RBs away from sub-RBG #0 (e.g., CRB index #51), as a second sub-RBG (e.g., sub-RBG #1), and identifies two RBs (CRB index #58-#59) starting from CRB index #58, which is two RBs away from sub-RBG #1 (e.g., CRB index #55), as a third sub-RBG (e.g., sub-RBG #2).

[0124] According to Operation Example 2-3, the number of RBs and the RB positions within an RBG can be flexibly set, and terminal 200 can receive the PDSCH using flexibly set RBs. Furthermore, as shown in FIG. 12 , terminal 200 can receive the PDSCH using RBs distributed on the frequency axis, improving reception quality through frequency diversity gain. Furthermore, in Operation Example 2-3, the RBs for PDSCH reception are distributed across multiple sub-RBGs within each RBG, so frequency diversity gain can be even greater than in Operation Example 2-1.

[0125] Furthermore, in operation example 2-3, the number of sub-RBGs included in an RBG can be set more finely compared to operation example 2-2, thereby improving the flexibility of resource allocation (RB allocation).

[0126] Note that, in FIG. 12, a method of identifying a sub-RBG based on an RB of a low frequency (or a low CRB index) has been described, but this is not limited to this, and for example, a sub-RBG may be identified based on an RB of a high frequency (or a high CRB index).

[0127] An example of the operation of the base station 100 and the terminal 200 has been described above.

[0128] As described above, in the present embodiment, terminal 200 determines, as PDSCH reception resources, RBs that are distributed on the frequency axis among a plurality of RBs obtained by dividing a frequency band (for example, BWP). At this time, the number of RBs included in the PDSCH reception resources may be equal to or less than a number based on the processing capability of terminal 200, for example. For example, terminal 200 determines, as PDSCH reception resources, some RBs (sub-RBGs) among the RBs included in each of a plurality of RBGs configured in terminal 200. Then, terminal 200 receives a PDSCH signal using the PDSCH reception resources.

[0129] This allows terminal 200 to flexibly set (or identify) RBs for PDSCH reception according to the processing capacity of terminal 200. Furthermore, since non-contiguous RBs can be allocated as RBs for PDSCH reception, reception quality can be improved by frequency diversity gain.

[0130] As described above, according to this embodiment, downlink resource allocation can be appropriately set.

[0131] (Note on the second embodiment) In the present embodiment, the same values ​​(or common values) may be applied to all RBGs included in the BWP for each of the sub-RBG parameters "offset," "size," "interval," and "number." This reduces the overhead of control signals that notify the parameters.

[0132] Alternatively, different values ​​may be applied to each of the sub-RBG parameters "offset," "size," "interval," and "number" among multiple (e.g., some or all) RBGs included in the BWP, which allows the terminal 200 to use RBs more flexibly.

[0133] Furthermore, in this embodiment, each parameter of the sub-RBG may be identified based on the processing capability of terminal 200 or the identification number of terminal 200, or may be defined in advance, or may be notified (or set) to terminal 200 by a control signal (for example, RRC, MAC, DCI, or the like). Alternatively, each parameter of the sub-RBG may be identified by a combination of these methods.

[0134] For example, sub-RBG parameters may be set to individual values ​​for terminals 200 (for example, different values ​​between terminals 200). This makes it possible to avoid collisions of PDSCH resources between terminals 200.

[0135] Furthermore, in this embodiment, if the total number of RBs included in a sub-RBG identified by terminal 200 exceeds a threshold (for example, a value based on the processing capacity of terminal 200), terminal 200 may further identify a partial RB group from among the RBs included in the identified sub-RBG, as in embodiment 1. In this case, the total number of RBs included in the identified RB group is set to a value equal to or less than the threshold. This allows terminal 200 to use the number of RBs that can be appropriately processed according to, for example, the processing capacity of terminal 200.

[0136] Furthermore, in this embodiment, the same value may be applied to a certain combination (or group) of parameters related to sub-RBGs. For example, the values ​​of both "offset" and "interval" may be set to the same value. This makes it possible to reduce the overhead of control signals, etc., that notify parameters related to sub-RBGs.

[0137] (Note on embodiments 1 and 2) Among the RBGs notified to a certain terminal 200, other RBs (for example, RBs that are not resources for PDSCH reception) that are different from the RB group identified by the terminal 200 for receiving PDSCH may be reused for purposes other than PDSCH reception by the terminal 200.

[0138] For example, the other RBs may be reused for the following purposes: - Transmission and reception of electromagnetic waves for wireless power supply (for example, for devices equipped with small-capacity batteries, battery-less devices, Ambient IoT devices, etc.) - Transmission and reception of downlink or uplink reference signals - Transmission and reception of a Physical Broadcast Channel (PBCH) or PDCCH - Transmission and reception of an uplink channel (for example, PUSCH, PUCCH, PRACH) - Muting (for example, not transmitting on that resource, for example, to perform interference measurement, etc.) - Transmission and reception by other terminals different from the terminal 200 (for example, a wake-up signal, etc.)

[0139] Furthermore, in each of the above embodiments, at least one of the start RB index and size of the RBG with the lowest frequency (or the RBG with the highest frequency) among the BWPs may be notified to terminal 200 by a control signal or the like. For example, as shown in Fig. 13, at least one of the start RB index = 14 and RBG size = 10 of the first RBG (e.g., the RBG with the lowest frequency) among the BWPs (e.g., the active BWP) may be notified (or set) to terminal 200. This enables more flexible use of RBs or RBGs.

[0140] Here, RBs (RBs #12-13 in the example of FIG. 13 ) that do not belong to an RBG in the BWP may be reused for purposes other than PDSCH reception by terminal 200. Examples of reuse of RBs that do not belong to an RBG may be the same as the examples described above.

[0141] (Third Embodiment) The base station 100 and the terminal 200 according to this embodiment may be the same as those in the first embodiment.

[0142] In the present embodiment, for the RBG with the lowest frequency (or the RBG with the highest frequency) among the BWPs, at least one of the start RB index and the RBG size is notified (or set) to terminal 200. For example, terminal 200 may determine the PDSCH reception resource based on at least one of the start RB position and the RBG size of one of the RBGs with the lowest frequency and the RBG with the highest frequency (for example, a first RBG) among the BWPs set in terminal 200.

[0143] In addition, at this time, the total number of RBs included in the first RBG and other RBGs different from the first RBG set in the terminal 200 is equal to or less than a specified number. The specified number may be a value according to the processing capacity of the terminal 200, for example.

[0144] As a result, by notifying at least one of the starting RB index and RBG size of an RBG, and notifying other RBGs, the number of RBs of the PDSCH that the terminal 200 uses to receive the PDSCH can match a specified number (e.g., a number corresponding to the processing capacity of the eRedCap terminal).

[0145] [Operation Example 3-1] In operation example 3-1, at least one of the start RB index and the RBG size is notified (or set) to terminal 200 for the RBG with the lowest frequency in the BWP.

[0146] For example, as shown in FIG. 14, the starting RB index=15 and the RBG size=9 of the RBG (CRB index#15-#23) with the lowest frequency among the BWPs (for example, active BWPs) may be set in terminal 200.

[0147] Also, at this time, as shown in FIG. 14, the total number of RBs included in the RBG to which the starting RB index and RBG size are set for terminal 200 and in each of the other RBGs is set to a specified number (for example, a number according to the processing capacity of terminal 200, for example, 25).

[0148] For example, terminal 200 may be notified of two allocations: the RBG with the lowest frequency among the BWPs, and another RBG. As a result, terminal 200 identifies 25 RB groups as PDSCH reception resources. Terminal 200 receives the PDSCH using the identified RB groups.

[0149] According to this embodiment, the total number of RBs in the RBG in which at least one of the start RB index and the RBG size is set and in the other RBGs is set to match a specified value. This allows terminal 200 to receive the PDCSH using a number of RBs appropriate for the processing capability of terminal 200.

[0150] Note that sub-RBGs may be set within an RBG, as in embodiment 2. This allows for more flexible use of RBs.

[0151] Furthermore, for the RBG with the lowest frequency (or the RBG with the highest frequency) among the BWPs, at least one of the starting RB index and the RBG size may be identified based on the processing capability of the terminal 200 or the identification number of the terminal 200, or may be specified in advance, or may be notified to the terminal 200 by a control signal (e.g., RRC, MAC, or DCI, etc.).

[0152] Furthermore, RBs (RBs #12-14 in the example of FIG. 14 ) that do not belong to an RBG in the BWP may be reused for purposes other than PDSCH reception by terminal 200. Examples of reuse of RBs that do not belong to an RBG may be the same as the examples described above.

[0153] Furthermore, the RBG for which at least one of the start RB index and the RBG size is notified (or set) to the terminal 200 is not limited to the RBG with the lowest frequency or the RBG with the highest frequency among the BWPs, and may be another RBG. Which RBG among the BWP is the RBG for which at least one of the start RB index and the RBG size is notified (or set) to the terminal 200 may be identified based on the processing capability of the terminal 200 or the identification number of the terminal 200, or may be specified in advance, or may be notified to the terminal 200 by a control signal (for example, RRC, MAC, DCI, or the like).

[0154] (Fourth Embodiment) The base station 100 and the terminal 200 according to this embodiment may be the same as those in the first embodiment.

[0155] In this embodiment, at least one of the RBG size and the number of RBGs is notified (or set) to the terminal 200. For example, the terminal 200 identifies multiple RBGs in the BWP based on information regarding at least one of the number of RBGs and the RBG size. In this case, the total number of RBs included in the multiple RBGs is smaller than the total number of RBs included in the BWP. According to this embodiment, since the number of RBs included in the RBGs is smaller than the total number of RBs in the BWP, the overhead of the control signal used to notify the RBGs can be reduced.

[0156] [Operation Example 4-1] In Operation Example 4-1, information regarding at least one of the RBG size and the number of RBGs is notified (or set) to the terminal 200. At this time, the total number of RBs included in the multiple RBGs identified by the information is smaller than the total number of RBs included in the BWP.

[0157] FIG. 15 shows an example of RBG settings according to operation example 4-1.

[0158] In Fig. 15 , the total number of RBs included in the BWP is 106. In Fig. 15 , an RBG size of 5 and an RBG count of 8 are signaled (or set). In the example of Fig. 15 , the total number of RBs included in all RBGs is 40, which is less than the total number of RBs included in the BWP, 106.

[0159] In the example of FIG. 15, the multiple RBGs are set without any offset or spacing, that is, consecutively in frequency.

[0160] RBGs may be notified to terminal 200 based on the above settings. For example, if the RBGs to be set in terminal 200 are notified by a bitmap in RBG units, the bitmap information will be 8 bits in the example of FIG. 15. As an example, five RBGs (e.g., 25 RBs) out of the eight RBGs shown in FIG. 15 may be set in terminal 200. Terminal 200 identifies an RB group included in the notified RBG as an RB for PDSCH reception. Terminal 200 receives the PDSCH using the identified RB group. Note that the method of identifying the RB for PDSCH reception may be either of the first and second embodiments.

[0161] As a result, the amount of information (e.g., the number of bits) used for notifying the RBG can be reduced compared to when the RBG is set for the entire BWP, thereby suppressing the overhead of the control signal used for notifying the RBG and enabling flexible use of the RBG. Furthermore, in operation example 4-1, the overhead of the control signal can be reduced by the amount that offset and spacing settings are not required.

[0162] [Operation Example 4-2] Operation example 4-2 differs from operation example 4-1 in that at least one of offset and spacing is set for a plurality of RBGs.

[0163] FIG. 16 shows an example of RBG settings according to operation example 4-2.

[0164] In Fig. 16, the total number of RBs included in the BWP is 106. As shown in Fig. 16, an RBG size of 5 and an RBG number of 8 (partially not shown) are notified (or set). Also, in Fig. 16, an offset of 5 and a spacing of 5 may be notified (or set) to terminal 200.

[0165] In the example of FIG. 16, the total number of RBs included in all RBGs set in terminal 200 is 40, which is less than the total number of RBs included in BWPs, 106.

[0166] 16, eight RBGs with an RBG size of 5 RBs are set with a spacing of 5 RBs from an RB (CRB index #21) shifted by an offset of 5 RBs from the end of the BWP. That is, multiple RBGs are set discontinuously in frequency.

[0167] RBGs may be notified to terminal 200 based on the above settings. For example, if the RBGs to be set in terminal 200 are notified by a bitmap in RBG units, the bitmap information will be 8 bits in the example of FIG. 16. As an example, five RBGs (e.g., 25 RBs) out of the eight RBGs shown in FIG. 16 may be set in terminal 200. Terminal 200 identifies an RB group included in the notified RBG as an RB for PDSCH reception. Terminal 200 also receives the PDSCH using the identified RB group. Note that the method of identifying the RBs for PDSCH reception may be either of the first and second embodiments.

[0168] As a result, the amount of information (e.g., the number of bits) used for notifying the RBG can be reduced compared to when the RBG is set over the entire BWP, thereby suppressing the overhead of the control signal used for notifying the RBG and enabling flexible use of the RBG. Furthermore, in Operation Example 4-2, by setting the offset or spacing, more flexible RBG setting is possible compared to Operation Example 4-1, and since the RBG is distributed on the frequency axis, the frequency diversity gain is increased.

[0169] (Note on the fourth embodiment) Note that sub-RBGs may be set within an RBG, as in the second embodiment, which allows for more flexible use of RBs.

[0170] In addition, at least one of the RBG size, number, offset and spacing may be determined based on the processing capability of the terminal 200 or an identification number of the terminal 200, or may be predefined, or may be notified to the terminal 200 by a control signal (e.g., RRC, MAC or DCI, etc.).

[0171] Furthermore, RBs in the BWP that do not belong to an RBG (RBs corresponding to "unused" in the examples of FIGS. 15 and 16 ) may be reused for purposes other than PDSCH reception by terminal 200. Examples of reuse of RBs that do not belong to an RBG may be the same as the examples described above.

[0172] Fifth Embodiment The base station 100 and the terminal 200 according to this embodiment may be the same as those in the first embodiment.

[0173] In this embodiment, multiple Resource Indication Values ​​(RIVs) are notified to terminal 200. Terminal 200 determines PDSCH reception resources, for example, based on the multiple RIVs notified to terminal 200. This makes it possible to set RBGs in a distributed manner on the frequency axis, thereby improving the PDSCH reception quality due to frequency diversity gain.

[0174] [Operation Example 5-1] A plurality of RIVs may be notified to terminal 200. For example, as shown in Fig. 17 , three RIVs may be notified to terminal 200: RIV#0 indicating RB#20-29, RIV#1 indicating RB#36-41, and RIV#2 indicating RB#48-56.

[0175] Terminal 200 identifies RBs (for example, 25 RBs) to be used for PDSCH reception based on the notified RIV, and receives the PDSCH.

[0176] The RIV settings shown in FIG. 17 are merely an example, and the number of RIVs is not limited to three, but may be two or four or more.

[0177] Setting multiple RIVs allows flexible setting or use of the number of RBs, and also increases frequency diversity gain.

[0178] The number and value of RIVs may be determined based on the processing capability of terminal 200 or the identification number of terminal 200, or may be specified in advance, or may be notified to terminal 200 via a control signal (RRC, MAC, DCI, etc.).

[0179] The embodiments of the present disclosure have been described above.

[0180] (Other Embodiments) Note that the RBs allocated to terminal 200 are not limited to RBs distributed on the frequency axis, and may be RBs (for example, consecutive RBs) that are not distributed on the frequency axis. Terminal 200 may, for example, determine RBs that are not distributed on the frequency axis as PDSCH reception resources.

[0181] (DCI for eRedCap terminal) In each of the above embodiments, the eRedCap terminal may determine that the payload size of the RIV included in the DCI notified exclusively to the eRedCap terminal is smaller than the payload size of the RIV included in other DCI.

[0182] For example, when the SCS is 15 kHz and the total number of RBs included in the BWP is 106, it is desirable that the RIV in DCI notified commonly to all terminals (e.g., DCI carried in Common Search Space) corresponds to all cases where the number of RBs is 1 to 106. On the other hand, the RIV in DCI notified exclusively to eRedCap terminals (e.g., DCI carried in UE-specific Search Space) only needs to correspond to cases where the number of RBs is 1 to 25. Therefore, the RIV included in DCI notified exclusively to eRedCap terminals has a smaller payload size than the RIV included in DCI notified commonly to all terminals.

[0183] The eRedCap terminal may receive the PDCCH, taking into account that the payload size of the RIV included in the DCI notified exclusively to the eRedCap terminal is relatively small. After receiving the RIV, the eRedCap terminal may identify RBs for receiving the PDSCH and receive the PDSCH.

[0184] In this way, since the payload size of the RIV in the DCI notified only to the eRedCap terminal is relatively small, the overhead of the control signal can be reduced.

[0185] This setting of the RIV payload size is not limited to cases where the resources for PDSCH reception of an eRedCap terminal are RBs that are distributed on the frequency axis, but may also be applied to cases where the resources are RBs that are not distributed on the frequency axis (e.g., consecutive RBs).

[0186] Furthermore, this setting of the payload size of the RIV may be applied whether the number of RIVs set in the terminal 200 (for example, an eRedCap terminal) is one or more.

[0187] (Notification of RBG and RIV) In the above embodiments, an example has been described in which the RBG or RIV of the PDSCH is notified by DCI, but the present invention is not limited to this, and the RBG or RIV may be set by a higher layer signal, etc. In this case, the resource notified by the RBG or RIV may be activated or deactivated by at least one of the DCI and the higher layer signal.

[0188] (RB and RB index) Although the RB (RB index) used in each of the above embodiments has been described as a Common Resource Block (CRB), this is not limited thereto, and for example, a Physical RB (PRB), a Virtual RB (VRB), or other types of RB may also be used.

[0189] (BWP) Each of the above embodiments may be applied when the total number of RBs included in a BWP (configured BWP) configured in a terminal or an activated BWP (active BWP) is greater than a threshold (for example, the number of RBs of PDSCH that can be processed by the terminal). For example, each of the above embodiments may be applied when a BWP consisting of more than 25 or 12 RBs is configured or activated in a terminal. This makes it possible to appropriately allocate PDSCHs and utilize the wide bandwidth to achieve a large frequency diversity gain, even when a BWP with a wide bandwidth is configured or activated.

[0190] Note that the frequency bands (e.g., RBs) shown in Figures 6 to 8, 10 to 12, and 14 to 17 may be RBs that make up the entire BWP, or may be some of the RBs included in the BWP (i.e., other RBs are not shown).

[0191] (Parameter setting) The parameters related to the processing capacity of the eRedCap terminal mentioned above (e.g., the number of RBs that can be processed per slot), the threshold for the number of RBs, SCS, parameters related to sub-RBGs (e.g., size, number, offset and interval), and parameters related to RBGs (e.g., size, number, offset and spacing) are examples, and other values ​​may also be used.

[0192] (Type, Classification, and Identification of Terminal) The above embodiment is assumed to be applied to, for example, an "eRedCap terminal," but may be applied to other types of terminals. For example, the above embodiment may be applied to a RedCap terminal.

[0193] In the above embodiment, an "eRedCap terminal" or a "RedCap terminal" may be, for example, a terminal having at least one of the following characteristics (for example, characteristics, attributes, or capabilities): (1) A terminal that notifies (for example, reports) the base station 100 that it is a "RedCap terminal," an "eRedCap terminal," or a "terminal that is a target of coverage extension." Or, a terminal that notifies (for example, reports) the base station 100 of information corresponding to RedCap or eRedCap (for example, a UE feature or capability report). For the above notification (report), for example, uplink channels such as PRACH and PUSCH, or uplink signals such as Sounding Reference Signal (SRS), may be used. (2) A terminal that corresponds to at least one of the following capabilities, or a terminal that reports at least one of the following capabilities to the base station 100. For the above report, for example, uplink channels such as PRACH and PUSCH, or uplink signals such as UCI or SRS may be used. - A terminal whose transmittable / receiveable frequency bandwidth (e.g., maximum value) is below a threshold (e.g., 20 MHz or less for RedCap terminals, 5 MHz or less for eRedCap terminals). - A terminal whose transmittable / receiveable number of resource blocks (e.g., maximum number) is below a threshold (e.g., 106 / 51 or less for 15 / 30 kHz SCS for RedCap terminals, 25 / 12 or less for 15 / 30 kHz SCS for eRedCap terminals). - A terminal whose implemented number of receive antennas or number of receive blocks is below a threshold (e.g., threshold = 1). - A terminal whose supportable number of downlink ports (e.g., number of receive antenna ports) is below a threshold (e.g., threshold = 2). - A terminal whose supportable number of transmission ranks (e.g., maximum number of Multiple-Input Multiple-Output (MIMO) layers (or rank number)) is below a threshold (e.g., threshold = 2). - A terminal that can transmit and receive signals in a frequency band below a threshold (e.g., Frequency Range 1 (FR1) for eRedCap or a band below 6 GHz). - Terminals whose processing time is greater than the threshold.- A terminal whose usable transport block size (TBS) is equal to or less than a threshold. - A terminal whose usable peak data rate is the same as or less than a threshold (for example, a terminal whose threshold is 10 Mbps or less for eRedCap). - A terminal whose usable number of transmission ranks (for example, the number of MIMO transmission layers) is equal to or less than a threshold. - A terminal whose usable modulation order is equal to or less than a threshold. - A terminal whose usable number of Hybrid Automatic Repeat reQuest (HARQ) processes is equal to or less than a threshold. - A terminal that supports Rel-17 or later in the case of RedCap terminals, and a terminal that supports Rel-18 or later in the case of eRedCap terminals. (3) A terminal to which parameters corresponding to a RedCap terminal or eRedCap terminal are notified by base station 100. Note that the parameters corresponding to a RedCap terminal or eRedCap terminal may include, for example, a parameter such as a Subscriber Profile ID for RAT / Frequency Priority (SPID).

[0194] Furthermore, the above-described embodiments may be applied to terminals of other types than eRedCap and RedCap. For example, similar embodiments may be applied to battery-less or extremely small battery capacity terminals (e.g., Ambient IoT terminals) that are expected to be standardized in Rel-19 or later. For example, it is expected that Ambient IoT terminals will be able to process even fewer PDSCH RBs than eRedCap terminals.

[0195] (Application to Sub-Band Full-Duplex) The above-described embodiments assume a case where a PDSCH is allocated to a slot and a symbol in which all RBs are set to be used for downlink transmission and reception. However, the above-described embodiments may also be applied to a case where a PDSCH is allocated to another type of slot or symbol. For example, the above-described embodiments may be applied to a slot or a symbol in which some RBs of a frequency resource (e.g., a BWP) are used for downlink transmission and reception. For example, the above-described embodiments may be applied to PDSCH allocation in an SBFD (Sub-Band Full-Duplex) slot or symbol. In an SBFD slot or symbol, a frequency resource is divided into multiple frequency bands (e.g., subbands, RB sets, sub-bands, or sub-BWPs). The base station 100 may simultaneously transmit and receive downlink signals in one or multiple frequency bands and uplink signals in the remaining frequency band. The terminal 200 may receive downlink signals in the downlink frequency band and may transmit and receive nothing in the uplink frequency band, or may simultaneously transmit uplink signals. Alternatively, the terminal 200 may transmit an uplink in the uplink frequency band and transmit or receive nothing in the downlink frequency band, or may simultaneously receive a downlink. Information such as the use of a certain slot or symbol for SBFD, the position, bandwidth, and transmission direction (uplink or downlink) of each frequency band may be notified to the terminal 200 by a control signal or the like.

[0196] For example, the RBs or RBGs of the PDSCH notified in the SBFD slot may exist in both the downlink frequency band and another frequency band different from the downlink frequency band. In this case, for example, the terminal 200 may identify the RBs to be used for PDSCH reception from among the RBs included in the downlink frequency band among the RBs notified to the terminal 200. At this time, the number of RBs identified by the terminal 200 may be set to a threshold value (for example, a maximum value depending on the processing capability of the eRedCap terminal) or less.

[0197] (Application to Unlicensed Bands and Shared Spectrum) The above-described embodiments assume a case where it is not necessary to perform a channel access procedure (or Listen Before Talk (LBT), carrier sense, or Channel Clear Assessment (CCA)) before downlink transmission. However, the above-described embodiments may also be applied to a case where it is necessary to perform a channel access procedure before downlink transmission, such as in operation in shared spectrum (e.g., unlicensed band). For example, a frequency resource (e.g., BWP) may be divided into multiple frequency bands (e.g., RB sets), and the channel access procedure may be performed for each RB set. Terminal 200 may receive downlink in an RB set that is determined to be available from the result of the channel access procedure among the RB sets.

[0198] For example, the RBs or RBGs of the PDSCH notified to terminal 200 may be present in both the available RB set and the unavailable RB set based on the result of the channel access procedure. In this case, for example, terminal 200 may identify RBs to be used for PDSCH reception from among the RBs included in the RB set determined to be available based on the result of the channel access procedure, among the RBs notified to terminal 200. At this time, the number of RBs identified by terminal 200 may be set to a threshold value (for example, a maximum value based on the processing capability of the eRedCap terminal) or less. Furthermore, at this time, terminal 200 may determine, for example, RBs that are distributed on the frequency axis or RBs that are not distributed, as PDSCH reception resources.

[0199] (Application to Broadcast, Groupcast, and Multicast) In the above-described embodiments, it is assumed that a PDSCH is allocated exclusively to a certain terminal 200. However, the above-described embodiments may also be applied to cases in which the same PDSCH resource is allocated to multiple terminals, such as in broadcast, groupcast, and multicast. For example, in cases such as broadcast, groupcast, and multicast, the total number of RBs of the PDSCH to be notified may be greater than a threshold (e.g., a maximum value depending on the processing capability of the eRedCap terminal). In this case, for example, terminal 200 may identify RBs to be used for PDSCH reception from among the RBs notified to terminal 200. At this time, the number of RBs identified by terminal 200 may be set to be equal to or less than a threshold (e.g., a maximum value depending on the processing capability of the eRedCap terminal). Furthermore, at this time, terminal 200 may determine, for example, RBs that are distributed on the frequency axis or RBs that are not distributed, as PDSCH reception resources.

[0200] Note that Broadcast, Groupcast, and Multicast may be, for example, SI (System Information), paging, Message 2 (Msg2), Random Access Response (RAR), Message 4 (Msg4), Contention Resolution, Message B (MsgB), fallbackRAR, successRAR, or a Multicast PDSCH or Broadcast PDSCH in Multicast-Broadcast Services (MBS).Furthermore, the frequency resources of these PDSCHs may be notified by, for example, a PDCCH scrambled with SI-RNTI, P-RNTI, RA-RNTI, TC-RNTI, MsgB-RNTI, G-RNTI, G-CS-RNTI, or MCCH-RNTI.

[0201] (Supplementary Note) Information indicating whether the terminal 200 supports the functions, operations, or processes described in the above-described embodiments may be transmitted (or notified) from the terminal 200 to the base station 100, for example, as capability information or capability parameters of the terminal 200.

[0202] The capability information may include an information element (IE) that individually indicates whether or not the terminal 200 supports at least one of the functions, operations, or processes described in the above-described embodiments. Alternatively, the capability information may include an information element that indicates whether or not the terminal 200 supports a combination of any two or more of the functions, operations, or processes described in the above-described embodiments, modifications, and supplements.

[0203] For example, the base station 100 may determine (or decide or assume) the functions, operations, or processes that the terminal 200 that transmitted the capability information supports (or does not support) based on the capability information received from the terminal 200. The base station 100 may perform operations, processes, or controls according to the determination result based on the capability information. For example, the base station 100 may control downlink resources based on the capability information received from the terminal 200.

[0204] Note that the fact that terminal 200 does not support some of the functions, operations, or processes described in the above-described embodiments may be interpreted as meaning that such some of the functions, operations, or processes are restricted in terminal 200. For example, information or a request regarding such restrictions may be notified to base station 100.

[0205] Information regarding the capabilities or limitations of terminal 200 may, for example, be defined in a standard, or may be implicitly notified to base station 100 in association with information known at base station 100 or information transmitted to base station 100.

[0206] (Control Signal) In the present disclosure, a downlink control signal (or downlink control information) related to an embodiment of the present disclosure may be, for example, a signal (or information) transmitted in a Physical Downlink Control Channel (PDCCH) of a physical layer, or a signal (or information) transmitted in a Medium Access Control Control Element (MAC CE) or Radio Resource Control (RRC) of a higher layer. Furthermore, the signal (or information) is not limited to being notified by a downlink control signal, but may be predefined in a specification (or standard) or preconfigured in a base station and a terminal.

[0207] Furthermore, the PDCCH may be transmitted, for example, in either a Common Search Space (CSS) or a UE Specific Search Space (USS).

[0208] (Base Station) In an embodiment of the present disclosure, the base station may be a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a Base Station (BS), a Base Transceiver Station (BTS), a parent device, a gateway, or the like. In sidelink communication, a terminal may play the role of a base station. Instead of a base station, a relay device that relays communication between an upper node and a terminal may be used. Alternatively, a roadside unit may be used.

[0209] (Uplink / Downlink / Sidelink) An embodiment of the present disclosure may be applied to, for example, any of the uplink, downlink, and sidelink. For example, an embodiment of the present disclosure may be applied to a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), or a Physical Random Access Channel (PRACH) in the uplink, a Physical Downlink Shared Channel (PDSCH), a PDCCH, or a Physical Broadcast Channel (PBCH) in the downlink, or a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Control Channel (PSCCH), or a Physical Sidelink Broadcast Channel (PSBCH) in the sidelink.

[0210] The PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel. The PBCH and PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0211] (Data Channel / Control Channel) An embodiment of the present disclosure may be applied to, for example, either a data channel or a control channel. For example, the channel in an embodiment of the present disclosure may be replaced with any of the data channels PDSCH, PUSCH, and PSSCH, or the control channels PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0212] (Reference Signal) In one embodiment of the present disclosure, the reference signal is, for example, a signal known by both the base station and the terminal, and may also be called a Reference Signal (RS) or a pilot signal. The reference signal may be any of a Demodulation Reference Signal (DMRS), a Channel State Information - Reference Signal (CSI-RS), a Tracking Reference Signal (TRS), a Phase Tracking Reference Signal (PTRS), a Cell-specific Reference Signal (CRS), or a Sounding Reference Signal (SRS).

[0213] (Time Interval) In one embodiment of the present disclosure, the unit of time resource is not limited to one or a combination of slots and symbols, but may be, for example, a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot, a subslot, a minislot, a symbol, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier-Frequency Division Multiplexing Access (SC-FDMA) symbol, or another time resource unit. Furthermore, the number of symbols included in one slot is not limited to the number of symbols exemplified in the above-mentioned embodiment, and may be another number of symbols.

[0214] (Frequency Band) An embodiment of the present disclosure may be applied to either a licensed band or an unlicensed band (unlicensed spectrum, shared spectrum). In the case of an unlicensed band, a channel access procedure (or Listen Before Talk (LBT), carrier sense, or Channel Clear Assessment (CCA)) may be performed before each signal transmission.

[0215] (Communication) An embodiment of the present disclosure may be applied to communication between a base station and a terminal (Uu link communication), communication between terminals (Sidelink communication), or Vehicle to Everything (V2X) communication. For example, in an embodiment of the present disclosure, the PDCCH may be replaced with a PSCCH, the PUSCH / PDSCH may be replaced with a PSSCH, the PUCCH may be replaced with a Physical Sidelink Feedback Channel (PSFCH), and the PBCH may be replaced with a PSBCH.

[0216] An embodiment of the present disclosure may be applied to a terrestrial network, a non-terrestrial network (NTN) using a satellite or a high altitude pseudo satellite (HAPS), or a terrestrial network in which transmission delay is large compared to the symbol length or slot length, such as a network with a large cell size or an ultra-wideband transmission network.

[0217] (Antenna Port) In one embodiment of the present disclosure, an antenna port refers to a logical antenna (antenna group) consisting of one or more physical antennas. For example, an antenna port does not necessarily refer to a single physical antenna, but may refer to an array antenna consisting of multiple antennas. For example, the number of physical antennas that an antenna port is composed of is not specified, and the antenna port may be specified as the smallest unit by which a terminal station can transmit a reference signal. Furthermore, an antenna port may also be specified as the smallest unit by which a weighting of a precoding vector is multiplied.

[0218] 5G NR System Architecture and Protocol Stack 3GPP continues work on the next release of fifth-generation cellular technology (also referred to simply as "5G"), which includes the development of new radio access technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, allowing for the prototyping and commercial deployment of 5G NR-compliant devices (e.g., smartphones).

[0219] For example, the system architecture generally assumes a Next Generation - Radio Access Network (NG-RAN) comprising gNBs. The gNBs provide UE-side termination of NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are connected to each other via an Xn interface. The gNBs are also connected to a Next Generation Core (NGC) via a Next Generation (NG) interface, more specifically to an Access and Mobility Management Function (AMF) (e.g., a specific core entity performing AMF) via an NG-C interface, and to a User Plane Function (UPF) (e.g., a specific core entity performing UPF) via an NG-U interface. The NG-RAN architecture is shown in Figure 18 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0220] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes a PDCP (Packet Data Convergence Protocol (see, for example, TS 38.300, section 6.4)) sublayer, a RLC (Radio Link Control (see, for example, TS 38.300, section 6.3)) sublayer, and a MAC (Medium Access Control (see, for example, TS 38.300, section 6.2)) sublayer, which are terminated on the network side in the gNB. A new access stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) has also been introduced above PDCP (see, for example, 3GPP TS 38.300, section 6.5). A control plane protocol stack has also been defined for the NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functions is described in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in clauses 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in clause 7 of TS 38.300.

[0221] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0222] For example, the physical layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include the Physical Random Access Channel (PRACH), the Physical Uplink Shared Channel (PUSCH), and the Physical Uplink Control Channel (PUCCH) as uplink physical channels, and the Physical Downlink Shared Channel (PDSCH), the Physical Downlink Control Channel (PDCCH), and the Physical Broadcast Channel (PBCH) as downlink physical channels.

[0223] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communication (mMTC), which have diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps in the downlink and 10 Gbps in the uplink) and effective (user-experienced) data rates approximately three times higher than those offered by IMT-Advanced. On the other hand, URLLC imposes stricter requirements on ultra-low latency (0.5 ms for user plane latency in both UL and DL) and high reliability (1-10-5 within 1 ms). Finally, mMTC preferably requires high connection density (1,000,000 devices / km in urban environments).２ ), wide coverage in adverse environments, and extremely long battery life (15 years) for a low-cost device may be desired.

[0224] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be valid for another use case. For example, low-latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with short delay spreads. The subcarrier spacing may be optimized accordingly to maintain similar CP overhead. NR may support one or more subcarrier spacing values. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, etc. are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related by the formula 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.

[0225] In the new radio system 5G-NR, for each numerology and each carrier, a resource grid of subcarriers and OFDM symbols is defined for each uplink and downlink. Each element of the resource grid is called a resource element and is specified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0226] <Functional Separation Between NG-RAN and 5GC in 5G NR> Figure 19 shows the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0227] For example, gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, ciphering and integrity protection of data; - AMF selection at UE attach time if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data towards the UPF; - Routing of control plane information towards the AMF; - Connection setup and release; - Scheduling and transmission of paging messages; - Scheduling and transmission of system broadcast information (sourced from the AMF or Operation, Admission, Maintenance (OAM)); - Configuration of measurements and measurement reports for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; Support for network slicing; - QoS flow management and mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - NAS message delivery function; - Radio access network sharing; - Dual connectivity; - Close coordination between NR and E-UTRA.

[0228] The Access and Mobility Management Function (AMF) hosts the following main functions: - Termination of Non-Access Stratum (NAS) signaling; - Security of NAS signaling; - Security control of Access Stratum (AS); - Signaling between Core Network (CN) nodes for mobility between 3GPP access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Registration area management; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including checking of roaming rights; - Mobility management control (subscription and policy); - Support for network slicing; - Selection of Session Management Function (SMF).

[0229] Furthermore, the User Plane Function (UPF) hosts the following main functions: - anchor point for intra-RAT / inter-RAT mobility (if applicable); - external PDU (Protocol Data Unit) session point for interconnection with data networks; - packet routing and forwarding; - packet inspection and policy rule enforcement for the user plane part; - traffic usage reporting; - uplink classifier to support routing of traffic flows to the data network; - branching point to support multi-homed PDU sessions; - QoS processing for the user plane (e.g. packet filtering, gating, UL / DL rate enforcement); - uplink traffic validation (mapping of SDF to QoS flows); - downlink packet buffering and triggering of downlink data notifications.

[0230] Finally, the Session Management Function (SMF) hosts the following main functions: session management; allocation and management of IP addresses for UEs; selection and control of UPF; configuration of traffic steering in the User Plane Function (UPF) to route traffic to the appropriate destination; policy enforcement and QoS of the control part; downlink data notification.

[0231] <RRC connection setup and reconfiguration procedure> Figure 20 shows some of the interactions between the UE, gNB, and AMF (5GC entities) when the UE transitions from RRC_IDLE to RRC_CONNECTED in the NAS part (see TS 38.300 v15.6.0).

[0232] RRC is a higher layer signaling (protocol) used to configure the UE and gNB. With this transition, the AMF prepares UE context data (including, for example, PDU session context, security keys, UE radio capabilities, 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, and the UE responding with a SecurityModeComplete message to the gNB. The gNB then sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB performs reconfiguration to set up Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, the steps related to RRCReconfiguration are omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0233] Accordingly, the present disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) that includes: a control circuit that, upon operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that, upon operation, transmits an initial context setup message to the gNodeB via the NG connection so that a signaling radio bearer between the gNodeB and a user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling, including a resource allocation configuration information element (IE), to the UE via the signaling radio bearer. The UE then transmits in uplink or receives in downlink based on the resource allocation configuration.

[0234] <IMT Usage Scenarios Beyond 2020> Figure 21 shows some use cases for 5G NR. The 3rd Generation Partnership Project New Radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC), in addition to expanding support for eMBB. Figure 21 shows some examples of envisioned usage scenarios for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0235] The URLLC use case has stringent performance requirements for throughput, latency, and availability. It is envisioned as one of the enabling technologies for future applications such as wireless control of industrial production or manufacturing processes, remote medical surgery, automated power transmission and distribution in smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913. Key requirements for NR URLLC in Release 15 include a target user plane latency of 0.5 ms on the uplink (UL) and 0.5 ms on the downlink (DL). The overall URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size with a user plane latency of 1 ms.

[0236] From a physical layer perspective, reliability can be improved in many possible ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and developed. Specific use cases for NR URLLC in Release 15 include Augmented Reality / Virtual Reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0237] Additionally, the technology enhancements targeted by NR URLLC aim to improve latency and reliability. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition in the data channel, and preemption in the downlink. Preemption means that a transmission with already allocated resources is stopped and the already allocated resources are used for another transmission with a later requested lower latency / higher priority. Therefore, a previously allowed transmission is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for reliability improvement include a dedicated CQI / MCS table for a target BLER of 1E-5.

[0238] The use case of mMTC (massive machine type communication) is characterized by a very large number of connected devices that typically transmit relatively small amounts of data that are not sensitive to delays. These devices are required to be low-cost and have very long battery life. From the NR perspective, utilizing very narrow bandwidth portions is one solution that saves power and extends battery life from the UE's perspective.

[0239] As mentioned above, the scope of reliability improvement in NR is expected to be broader. One of the key requirements for all cases, for example, URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can improve reliability from a radio perspective and a network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, repetition of data channels / control channels, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0240] For NR URLLC, further use cases with more stringent requirements are envisaged, such as factory automation, transportation, and power distribution, with high reliability (up to 10-6 level reliability), high availability, packet size up to 256 bytes, time synchronization down to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and low latency in the order of 0.5 ms to 1 ms (e.g., 0.5 ms latency on the targeted user plane)).

[0241] Furthermore, for NR URLLC, there may be several technical enhancements from the physical layer perspective. These technical enhancements include PDCCH (Physical Downlink Control Channel) enhancements for compact DCI, PDCCH repetition, and increased PDCCH monitoring. Also, UCI (Uplink Control Information) enhancements relate to enhanced Hybrid Automatic Repeat Request (HARQ) and CSI feedback enhancements. There may also be PUSCH enhancements related to minislot-level hopping and retransmission / repetition enhancements. The term "minislot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot comprises 14 symbols).

[0242] <QoS Control> The 5G Quality of Service (QoS) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (Guaranteed Bit Rate QoS flows (GBR)) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Thus, at the NAS level, a QoS flow is the finest granularity of QoS classification in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI) carried in an encapsulation header over the NG-U interface.

[0243] For each UE, 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for each PDU session, e.g., as shown above with reference to Figure 20. Additional DRBs for the QoS flows of that PDU session can be configured later (when this is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and 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.

[0244] Figure 22 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (e.g., an external application server hosting 5G services, as illustrated in Figure 21) interacts with the 3GPP core network to provide services. For example, it accesses the Network Exposure Function (NEF) to support applications that affect traffic routing, or interacts with a 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 associated Network Functions. Application Functions not permitted by the operator to directly access Network Functions interact with the associated Network Functions using an external exposure framework via the NEF.

[0245] Figure 22 further illustrates further functional units of the 5G architecture, namely, Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN, e.g., operator-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0246] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of 5GC functions (e.g., an NEF, an AMF, an SMF, a PCF, an UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0247] Furthermore, the notation "... section" in the above-described embodiments may be replaced with other notations such as "... circuitry," "... device," "... unit," or "... module."

[0248] Furthermore, in the above-described embodiments, the values ​​of parameters such as the number of RBs, frequency bandwidth, and SCS are merely examples and other values ​​may be used.

[0249] The present disclosure can be realized by software, hardware, or software integrated with hardware. Each functional block described in the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit. Each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data inputs and outputs. Depending on the level of integration, an LSI may be referred to as an IC, system LSI, super LSI, or ultra LSI. The integrated circuit implementation is not limited to LSIs, and may be realized using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, a field programmable gate array (FPGA), which can be programmed after LSI fabrication, or a reconfigurable processor, which allows the connections and settings of circuit cells within an LSI to be reconfigured, may also be used. The present disclosure may be realized as digital or analog processing. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology, etc. is also a possibility.

[0250] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0251] The communication devices are not limited to portable or mobile devices, but also include any kind of non-portable or fixed equipment, devices, and systems, such as smart home devices (such as home appliances, lighting equipment, smart meters or measuring devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0252] Communications include data communications via cellular systems, wireless LAN systems, communication satellite systems, and the like, as well as data communications via combinations of these.

[0253] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0254] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0255] A terminal according to a non-limiting example of the present disclosure includes: a control circuit that determines, from among a plurality of resource blocks obtained by dividing a frequency band, resource blocks that are distributed on a frequency axis as reception resources for a downlink signal, and the number of resource blocks included in the reception resources is equal to or less than a specified value; and a reception circuit that receives the downlink signal using the reception resources.

[0256] In a non-limiting example of the present disclosure, when the total number of resource blocks included in multiple resource block groups (RBGs) configured for the terminal is greater than the specified value, the control circuit determines resource blocks in the multiple RBGs that are equal to or less than the specified value as the reception resources.

[0257] In a non-limiting example of the present disclosure, the control circuit determines, for each of a plurality of resource block groups (RBGs) configured in the terminal, some of the resource blocks included in the RBG as the receiving resources.

[0258] In a non-limiting example of the present disclosure, parameters related to the portion of resource blocks are signaled to the terminal.

[0259] In a non-limiting embodiment of the present disclosure, the control circuit determines the receiving resource based on at least one of the starting resource block position of a first RBG, either the lowest frequency resource block group (RBG) or the highest frequency RBG in a bandwidth part (BWP), and the size of the first RBG, and the total number of resource blocks included in the multiple RBGs including the first RBG is less than or equal to the specified value.

[0260] In a non-limiting example of the present disclosure, the control circuit identifies multiple resource block groups (RBGs) in a bandwidth part (BWP) based on information regarding at least one of the number and size of the RBGs, and the total number of resource blocks included in the multiple RBGs is less than the number of resource blocks included in the BWP.

[0261] In a non-limiting example of the present disclosure, the control circuit determines the reception resource based on a plurality of Resource Indication Values ​​(RIVs) notified to the terminal.

[0262] A base station according to a non-limiting example of the present disclosure includes: a control circuit that determines, from among a plurality of resource blocks obtained by dividing a frequency band, resource blocks that are distributed on a frequency axis as transmission resources for a downlink signal, and the number of resource blocks included in the transmission resources is equal to or less than a specified value; and a transmission circuit that transmits the downlink signal using the transmission resources.

[0263] In a communication method according to a non-limiting example of the present disclosure, a terminal determines, as a receiving resource for a downlink signal, resource blocks that are distributed on a frequency axis among a plurality of resource blocks obtained by dividing a frequency band, and the number of resource blocks included in the receiving resource is equal to or less than a specified value, and receives the downlink signal using the receiving resource.

[0264] In a communication method according to a non-limiting example of the present disclosure, a base station determines resource blocks, which are distributed on a frequency axis among a plurality of resource blocks obtained by dividing a frequency band, as transmission resources for a downlink signal, and transmits the downlink signal using the transmission resources, when the number of resource blocks included in the transmission resources is equal to or less than a specified value.

[0265] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2023-107284, filed on June 29, 2023, are incorporated herein by reference in their entirety.

[0266] One embodiment of the present disclosure is useful in wireless communication systems.

[0267] 100 Base station 101, 206 Control unit 102 DCI generation unit 103 Upper layer signal generation unit 104, 207 Coding and modulation unit 105, 208 Signal mapping unit 106, 209 Transmission unit 107, 201 Antenna 108, 202 Reception unit 109, 203 Signal separation unit 110, 205 Demodulation and decoding unit 200 Terminal 204 DCI detection unit

Claims

1. A terminal comprising: a control circuit that determines, from among a plurality of resource blocks obtained by dividing a frequency band, resource blocks that are distributed on a frequency axis as receiving resources for a downlink signal, and the number of resource blocks included in the receiving resources is equal to or less than a specified value; and a receiving circuit that receives the downlink signal using the receiving resources.

2. The terminal according to claim 1, wherein, when the total number of resource blocks included in a plurality of resource block groups (RBGs) set in the terminal is greater than the specified value, the control circuit determines, as the receiving resource, a resource block in the plurality of RBGs that is equal to or less than the specified value.

3. The terminal according to claim 1, wherein the control circuit determines, for each of a plurality of resource block groups (RBGs) set in the terminal, a portion of the resource blocks included in the RBG as the receiving resources.

4. The terminal according to claim 3, wherein parameters relating to the part of resource blocks are notified to the terminal.

5. The terminal according to claim 1, wherein the control circuit determines the receiving resource based on at least one of the starting resource block position of a first RBG, which is one of the resource block group (RBG) with the lowest frequency and the RBG with the highest frequency in a bandwidth part (BWP), and the size of the first RBG, and the total number of the resource blocks included in the multiple RBGs including the first RBG is less than or equal to the specified value.

6. The terminal according to claim 1, wherein the control circuit identifies a plurality of resource block groups (RBGs) in a bandwidth part (BWP) based on information regarding at least one of the number and size of the RBGs, and the total number of resource blocks included in the plurality of RBGs is less than the number of resource blocks included in the BWP.

7. The terminal according to claim 1, wherein the control circuit determines the receiving resource based on a plurality of Resource Indication Values ​​(RIVs) notified to the terminal.

8. A base station comprising: a control circuit that determines, from among a plurality of resource blocks obtained by dividing a frequency band, resource blocks that are distributed on a frequency axis as transmission resources for a downlink signal, and the number of resource blocks included in the transmission resources is equal to or less than a specified value; and a transmission circuit that transmits the downlink signal using the transmission resources.

9. A communication method in which a terminal determines resource blocks that are distributed on a frequency axis from among multiple resource blocks obtained by dividing a frequency band as receiving resources for a downlink signal, the number of resource blocks included in the receiving resources is equal to or less than a specified value, and the terminal receives the downlink signal using the receiving resources.

10. A communication method, in which a base station determines resource blocks that are distributed on a frequency axis from among a plurality of resource blocks obtained by dividing a frequency band as transmission resources for a downlink signal, the number of resource blocks included in the transmission resources is equal to or less than a specified value, and the downlink signal is transmitted using the transmission resources.

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