Terminal

Abstract

This terminal comprises a reception unit that repeatedly receives a physical downlink control channel, and a control unit that performs control such that the physical downlink control channel is repeatedly received during a maintenance period in which power consistency and phase continuity are maintained. The control unit uses a plurality of demodulation reference signals in repeated reception of the physical downlink control channel to execute channel estimation with respect to the physical downlink control channel.

Description

Terminal

[0001] The present disclosure relates to a terminal that repeatedly receives a physical downlink channel.

[0002] The 3rd Generation Partnership Project (3GPP) is developing specifications for the 5th generation mobile communication system (5G, also known as New Radio (NR) or Next Generation (NG)), and is also developing specifications for the next generation of mobile communication systems, known as Beyond 5G, 5G Evolution, or 6G.

[0003] 3GPP is currently discussing ways to improve the coverage of non-terrestrial networks (NTNs). NTNs are networks that include relay stations such as satellites, and terminals (User Equipment, UE) can communicate with base stations (next generation NodeB, gNB) via the relay stations.

[0004] In improving NTN coverage, it is necessary to take into account the Power Flux Density (PFD) limitations established by the International Telecommunication Union (ITU) (see Non-Patent Document 1). For example, the ITU PFD limitations have raised concerns about insufficient transmission power for downlink (DL) transmissions such as the Physical Downlink Control Channel (PDCCH).

[0005] “Revised WID: NR NTN (Non-Terrestrial Networks) enhancements”, RP-221819, 3GPP TSG RAN Meeting #96, 3GPP, June 6-9, 2022

[0006] To address these concerns, repeated transmission / reception of the PDCCH (PDCCH repetition) is supported. However, the PDCCH has a higher transmission power than uplink (UL) transmissions such as the Physical Uplink Control Channel (PUCCH), and discussions on PDCCH repetition have not progressed very far.

[0007] For example, in PUCCH repetition, DMRS bundling is adopted, in which demodulation reference signals (DMRSs) arranged at the beginning of each repetition PUCCH are bundled and referred to, and channel estimation is performed collectively. On the other hand, in PDCCH repetition, as with PDCCHs without repetition, the DMRSs arranged at the beginning of each repetition PDCCH are referred to, and channel estimation is performed individually. As such, improving the channel estimation accuracy for PDCCH repetition has not been given much attention until now, due to reasons such as the larger transmission power compared to the above-mentioned UL transmission.

[0008] Therefore, the present disclosure has been made in consideration of such circumstances, and aims to provide a terminal that can improve the accuracy of channel estimation in PDCCH repetition, which has been little considered until now.

[0009] One aspect of the disclosure is a terminal (UE 200) comprising: a receiving unit (radio signal transmitting / receiving unit 210) that repeatedly receives a physical downlink control channel; and a control unit (control unit 270) that controls the physical downlink control channel to be repeatedly received during a maintenance period in which power and phase are maintained, wherein the control unit performs channel estimation for the physical downlink control channel using a plurality of demodulation reference signals in the repeated reception of the physical downlink control channel.

[0010] Fig. 1 is a diagram showing an overall schematic configuration of a wireless communication system. Fig. 2 is a diagram showing frequency ranges used in the wireless communication system. Fig. 3 is a diagram showing example configurations of radio frames, subframes, slots, and symbols used in the wireless communication system. Fig. 4 is a functional block diagram of a terminal. Fig. 5 is a functional block diagram of a base station. Fig. 6 is a diagram showing an example of an initial access procedure. Fig. 7 is a diagram showing an example of DMRS bundling. Fig. 8 is a diagram showing an example of the positional relationship between UE, relay stations, and gNBs. Fig. 9 is a diagram showing an example of the hardware configuration of a base station and a terminal. Fig. 10 is a diagram showing an example of the configuration of a vehicle.

[0011] Hereinafter, embodiments will be described with reference to the drawings. Note that the same or similar reference numerals are used to designate the same functions or configurations, and descriptions thereof will be omitted as appropriate.

[0012] (1) Overall Schematic Configuration of Wireless Communication System The wireless communication system 10 shown in Fig. 1 is a wireless communication system conforming to a method called 5G. Alternatively, the wireless communication system 10 may be a wireless communication system conforming to a method called Beyond 5G, 5G Evolution, or 6G.

[0013] The wireless communication system 10 can support Massive Multiple-Input Multiple-Output (Massive MIMO), which generates more directional beams by controlling wireless signals transmitted from multiple antenna elements, Carrier Aggregation (CA), which uses multiple component carriers (CCs) as a bundle, and Dual Connectivity (DC), which enables simultaneous communication with two base stations.

[0014] As shown in FIG. 1 , the wireless communication system 10 includes a base station (gNodeB, gNB) 100 connected to a Next Generation-Radio Access Network (NG-RAN) 20, and a terminal (User Equipment, UE) 200 that performs wireless communication with the gNB 100. The NG-RAN 20 is connected to a core network (CN) (not shown). The CN is configured by a network function (NF) such as an access and mobility management function (AMF). The NG-RAN 20 and the CN may be simply referred to as a "network," and may or may not be considered to be included in the wireless communication system 10. Note that the specific configuration of the wireless communication system 10, for example, the number of gNBs 100 and UEs 200, is not limited to the example shown in FIG. 1 .

[0015] The wireless communication system 10 of the embodiment includes a relay station 150 that relays communication between the gNB 100 and the UE 200. The relay station 150 is a satellite such as a GEO (Geostationary Earth Orbit) satellite, a MEO (Middle Earth Orbit) satellite, or a LEO (Low Earth Orbit) satellite. The relay station 150 may also be a High Altitude Platform Station (HAPS) mounted on an airship, a balloon, or the like, or may also be an Air to Ground (ATG) commercial aircraft. The relay station 150 of the embodiment is assumed to be an air vehicle as described above, but is not limited thereto.

[0016] The wireless communication system 10 may also support multiple frequency ranges (FR). That is, as shown in Fig. 2, the wireless communication system 10 may support the following FRs: FR1: 410 MHz to 7.125 GHz FR2-1: 24.25 GHz to 52.6 GHz FR2-2: Over 52.6 GHz to 71 GHz

[0017] In FR1, a subcarrier spacing (SCS) of 15, 30, or 60 kHz and a bandwidth (BW) of 5 to 100 MHz may be used, while in FR2-1, an SCS of 60 or 120 kHz (including 240 kHz) and a BW of 50 to 400 MHz may be used.

[0018] In FR2-2, to avoid an increase in phase noise, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) or Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) with a larger SCS may be applied.

[0019] 3, one slot in the wireless communication system 10 is composed of 14 symbols. If this configuration is maintained, the larger (wider) the SCS, the shorter the symbol period (and slot period). Note that the SCS is not limited to the frequencies shown in FIG. 3 and may be, for example, 480 kHz, 960 kHz, or other frequencies.

[0020] Furthermore, the number of symbols constituting one slot does not necessarily have to be 14, but may be, for example, 28 or 56. Furthermore, the number of slots per subframe may differ depending on the SCS.

[0021] (2) Functional Block Configuration of Wireless Communication System (2.1) Functional Block Configuration of Terminal As shown in FIG. 4, the UE 200 includes a wireless signal transmitting / receiving unit 210, an amplifier unit 220, a modulation / demodulation unit 230, a control signal / reference signal processing unit 240, an encoding / decoding unit 250, a data transmitting / receiving unit 260, and a control unit 270.

[0022] The radio signal transmitting / receiving unit 210 transmits and receives radio signals to and from the gNB 100. The radio signal transmitting / receiving unit 210 may be configured as a transmitting unit that transmits radio signals to the gNB 100 and a receiving unit that receives radio signals from the gNB 100. The radio signals include control signals and data.

[0023] The radio signal transceiver 210 of the embodiment can receive a physical downlink control channel (PDCCH) transmitted by the gNB 100. The PDCCH may be repeatedly transmitted by the gNB 100. That is, the radio signal transceiver 210 can repeatedly receive the PDCCH. Note that repeated transmission / reception of the PDCCH may be referred to as PDCCH repetition.

[0024] The PDCCH received by the radio signal transmission / reception unit 210 is not limited to a normal PDCCH, and may be a PDCCH used to receive messages (Msg2 / Msg4) transmitted from the gNB 100 during initial access. The PDCCH used to receive Msg2 / Msg4 is downlink control information (DCI) received via the PDCCH, and may be interpreted as DCI for scheduling Msg2 / Msg4. That is, the radio signal transmission / reception unit 210 can receive Msg2 / Msg4 based on the PDCCH or based on the DCI received via the PDCCH. Such a PDCCH is also referred to as a PDCCH for Msg2 / Msg4 or an Msg2 / Msg4-scheduling PDCCH. Such repeated transmission / reception of the PDCCH is also called PDCCH repetition for Msg2 / Msg4, or Msg2 / Msg4-scheduling PDCCH repetition.

[0025] The radio signal transceiver 210 of the embodiment can transmit a capability (UE capability) related to an operation of controlling the repeated reception of the PDCCH during a maintenance period, which will be described later, to the gNB 100. The UE capability will be described in detail in the section (3.3.2) Operation Example 2.

[0026] The radio signal transceiver 210 of the embodiment can transmit a parameter for advancing the transmission timing to the gNB 100. Such a parameter is also referred to as a Timing Advance (TA) or a TA value. The TA may be used to set a maintenance period for maintaining power and phase, which will be described later. Note that the power and phase (or maintenance thereof) may also be referred to as power consistency and phase continuity.

[0027] The TA involved in the UE 200 is calculated by the following formula, as specified in, for example, 3GPP TS 38.211 V17.3.0: TA = (N TA +N TA,UE-specific +N TA,common +N TA,offset ) × Tc T TA :Timing advance between downlink and uplink N TA :Timing advance between downlink and uplink N TA,UE-specific :UE-derived timing correction N TA,common :Network-controlled timing correction N TA,offset :A fixed offset used to calculate the timing advance Tc:Basic time unit for NR

[0028] N TA is the closed loop TA. N TA is defined as 0 for the Physical Random Access Channel (PRACH). TA is updated based on the TA Command field of msg2 / msgB and the TA command of the control element (MAC CE) of the medium access control layer.

[0029] N TA,UE-specific is the open loop TA. NTA,UE-specific is the TA that the UE 200 self-estimates to compensate for the delay in the service link. TA,UE-specific is calculated based on the location information of UE 200 and the orbit information of relay station 150. Note that the location information of UE 200 may be acquired based on a radio signal from a satellite positioning system (not shown), for example.

[0030] N TA,common is the open loop TA. N TA,common is a common TA controlled by gNB100 (network). TA,common is determined by UE200 based on parameters for determining common TA notified by gNB100.

[0031] In addition, N TA,common The reference point (RP) that defines N may be set anywhere in the feeder link. That is, the RP may be set to the gNB 100, the relay station 150, or between the gNB 100 and the relay station 150. When the RP is set to the gNB 100, there is an advantage that the burden on the gNB 100 is reduced. When the RP is set to the relay station 150, N TA,common This has the advantage of reducing the burden on UE200.

[0032] The radio signal transceiver unit 210 of the embodiment can transmit various UE capabilities to the gNB 100. Details of the UE capabilities will be described in the section (3.3) Operational Examples.

[0033] The amplifier unit 220 is configured by a power amplifier (PA) / low noise amplifier (LNA), etc. The amplifier unit 220 amplifies the radio signal output from the radio signal transmitting / receiving unit 210. The amplifier unit 220 also amplifies the radio signal output from the modulation / demodulation unit 230.

[0034] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. for each predetermined communication destination (gNB 100 or another gNB). CP-OFDM / DFT-S-OFDM may be applied to the modem unit 230. Furthermore, DFT-S-OFDM may be used not only for the uplink (UL) but also for the downlink (DL).

[0035] The control signal / reference signal processing unit 240 performs processing related to control signals transmitted and received between the gNB 100, such as radio resource control (RRC) signaling.

[0036] The control signal / reference signal processing unit 240 performs processing related to reference signals transmitted and received between the gNB 100, such as Demodulation Reference Signal (DMRS), Phase Tracking Reference Signal (PTRS), Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), and Positioning Reference Signal (PRS).

[0037] The channels include control channels and data channels. The control channels include a physical uplink control channel (PUCCH), a physical downlink control channel (PDCCH), a physical random access channel (PRACH), a physical broadcast channel (PBCH), etc. The data channels include a physical uplink shared channel (PUSCH), a physical downlink shared channel (PDSCH), etc.

[0038] The encoding / decoding unit 250 performs division / concatenation and coding / decoding of data contained in the radio signal for each predetermined communication destination (gNB100 or another gNB).

[0039] Specifically, the encoding / decoding unit 250 decodes the data output from the modem unit 230 and concatenates the decoded data. In addition, the encoding / decoding unit 250 divides the data output from the data transmitter / receiver 260 into pieces of a predetermined size and performs coding on the divided data.

[0040] The data transmitter / receiver 260 transmits and receives data to and from the gNB 100. Specifically, the data transmitter / receiver 260 performs assembly / disassembly of Protocol Data Units (PDUs) / Service Data Units (SDUs) between multiple layers. The multiple layers include a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, etc. The data transmitter / receiver 260 also performs data error correction and retransmission control based on Hybrid Automatic Repeat Request (HARQ).

[0041] The control unit 270 controls the UE 200. The control unit 270 controls, for example, transmission and reception of radio signals by the radio signal transceiver unit 210, amplification by the amplifier unit 220, data modulation / demodulation by the modem unit 230, signal processing by the control signal and reference signal processor 240, coding / decoding by the encoder / decoder unit 250, and transmission and reception of data by the data transceiver unit 260.

[0042] The control unit 270 according to the embodiment can control the radio signal transceiver unit 210 to repeatedly receive the PDCCH during a maintenance period in which power consistency and phase continuity related to transmission / reception of various channels such as the PDCCH are maintained. The maintenance period may be set to the same length as that applied to repeated transmission of the PUCCH, for example. Alternatively, the maintenance period may be set to a length different from that applied to repeated transmission of the PUCCH.

[0043] The control unit 270 of the embodiment can determine the sustain period based on a parameter (or a candidate parameter) transmitted from the gNB 100. The sustain period may be interpreted as a time domain window (TDW), as described below. The parameter may be, for example, the length of the TDW. In this case, the candidate parameter may be interpreted as a candidate TDW length. The length of the TDW or the candidate TDW length may be, for example, the number of slots.

[0044] The control unit 270 of the embodiment can also determine the maintenance period based on NTN-specific factors, such as satellite movement (satellite orbit), an NTN-specific timer, and NTN-specific instructions.

[0045] Specifically, the gNB100 / UE200 determines the actual TDW as a maintenance period for maintaining power consistency and phase continuity. The gNB100 / UE200 performs repeated channel transmission / reception while maintaining power consistency and phase continuity in the actual TDW. The actual TDW is determined to avoid the occurrence of events, as the occurrence of events makes it difficult to maintain power consistency and phase continuity. The TDW and events are described in detail in (3.2.2) DMRS Bundling.

[0046] In the embodiment, the control unit 270 can perform channel estimation for the PDCCH received by the radio signal transceiver unit 210 by referencing the DMRS corresponding to each repeated PDCCH (e.g., the DMRS located at the beginning of the PDCCH). Furthermore, the control unit 270 can perform channel estimation for each PDCCH collectively, rather than individually for each PDCCH repeatedly received by the radio signal transceiver unit 210. Specifically, the control unit 270 can perform channel estimation for the PDCCH by bundling the DMRS corresponding to each repeated PDCCH (i.e., using multiple DMRSs in the repeated reception of the PDCCH, which are located in the time domain as shown in FIG. 7 ). Such channel estimation for the repeated PDCCH may be referred to as DMRS bundling or joint channel estimation. DMRS bundling and joint channel estimation are described in the section (3.2.2) DMRS Bundling.

[0047] The interval between each repeated PDCCH may be longer than the length of the cyclic prefix (CP) or shorter than the length of the CP, as will be described in the section (3.3) Operational Example.

[0048] (2.2) Functional block configuration of base station As shown in Figure 5, the gNB100 includes a radio signal transceiver unit 110 and a control unit 120.

[0049] The radio signal transmitting / receiving unit 110 transmits and receives radio signals to and from the UE 200. The radio signal transmitting / receiving unit 110 may include a transmitting unit that transmits radio signals to the UE 200 and a receiving unit that receives radio signals from the UE 200.

[0050] The radio signal transmitting and receiving unit 110 according to the embodiment can transmit a PDCCH to the UE 200. In this case, the PDCCH may be a PDCCH that is repeatedly transmitted. That is, the radio signal transmitting and receiving unit 110 can repeatedly transmit the PDCCH to the UE 200.

[0051] The control unit 120 controls the gNB 100. The control unit 120 controls, for example, the transmission and reception of radio signals by the radio signal transmission and reception unit 110. The control unit 120 can also perform scheduling for the UE 200.

[0052] The control unit 120 of the embodiment can set a maintenance period for maintaining the power and phase as described above. The maintenance period will be described in the section (3.2.2) DMRS Bundling.

[0053] (3) Operation of Wireless Communication System (3.1) Issues In PDCCH repetition, as with PDCCHs without repetition, the DMRS placed at the beginning of each PDCCH to be repetitive is referenced, and channel estimation is performed individually. As such, improving the channel estimation accuracy for PDCCH repetition has not been given much attention until now due to reasons such as the larger transmission power compared to the above-mentioned UL transmission. However, for example, in initial access in which PDCCH is transmitted to receive Msg2 / Msg4, if the channel estimation accuracy is insufficient, multiple initial access attempts are required, which may cause communication resource congestion.

[0054] (3.2) Prerequisites (3.2.1) Initial Access As shown in Fig. 6, the UE 200 performs initial access to the gNB 100. The initial access may also be referred to as random access. The initial access will be described below with reference to Fig. 6.

[0055] First, the UE 200 transmits a physical random access channel (PRACH) in response to the SS / PBCH block (SSB) received from the gNB 100 (corresponding to Msg1 in the figure). Second, the UE 200 receives a physical downlink shared channel (PDSCH) as a random access response (RAR) (corresponding to Msg2 in the figure). Here, the UE 200 receives a PDCCH used to receive Msg2 prior to receiving Msg2. Note that this PDCCH may also be referred to as Msg2.

[0056] Third, the UE 200 transmits a PUSCH as an RRC connection request message (corresponding to Msg3 in the figure). Fourth, the UE 200 receives a PDSCH as a contention resolution message (corresponding to Msg4 in the figure). Here, prior to receiving Msg4, the UE 200 receives a PDCCH used to receive Msg4. Note that this PDCCH may also be referred to as Msg4.

[0057] Finally, the UE 200 transmits a PUCCH as a Hybrid Automatic Repeat Request (HARQ)-ACK for Msg4 (corresponding to HARQ ACK in the figure), thereby completing the initial access.

[0058] (3.2.2) DMRS Bundling DMRS bundling applied to the wireless communication system 10 of the embodiment will be described with reference to FIG. 7 . DMRS bundling is a technique for collectively estimating channels by bundling and referencing DMRSs corresponding to each channel in repeated transmission / reception of channels (e.g., DMRSs placed at the beginning of each channel). Note that DMRS bundling may be interpreted as joint channel estimation. Furthermore, repeated reception of PDCCHs may mean repeated reception of PDCCHs relating to the same information via different resources. In other words, repeated reception of PDCCHs may not mean repeated reception of multiple PDCCHs relating to different information (PDCCHs containing different information), but may mean repeated reception of multiple PDCCHs relating to the same information (PDCCHs containing the same information). Repeated reception of PDCCHs may be performed within the same search space (SS) or via different SSs. Note that SS and SS set may be interchangeable.

[0059] While conventional channel estimation maintains power consistency and phase continuity for a channel and its corresponding DMRS, DMRS bundling maintains power consistency and phase continuity for multiple channels in repeated transmission / reception and their corresponding DMRS.

[0060] When applying the above-described DMRS bundling, the gNB100 / UE200 need to have a common understanding of the time interval for maintaining power consistency and phase continuity related to channel transmission / reception. Therefore, as shown in Fig. 7, in the actual TDW determined by the gNB100 as the maintenance period for maintaining power consistency and phase continuity, the gNB100 / UE200 performs repeated channel transmission / reception while maintaining power consistency and phase continuity in the actual TDW.

[0061] The actual TDW is determined to avoid the occurrence of an event. The occurrence of an event makes it difficult to maintain power consistency and phase continuity. An example of an event is a TA update. Therefore, the actual TDW can be said to be a maintenance period in which power consistency and phase continuity are maintained, or a maintenance period in which the TA is maintained (the TA is not updated). The actual TDW can also be said to be a cancellation period in which events such as TA updates are canceled, or an application period in which only TA updates that satisfy certain conditions regarding phase continuity can be applied.

[0062] The actual TDW is determined as a period included in a predetermined nominal TDW. Therefore, the nominal TDW can be said to be the maximum period for maintaining the above-mentioned power consistency and phase continuity. Furthermore, the nominal TDW may include one actual TDW or multiple actual TDWs.

[0063] The period for maintaining power consistency and phase continuity may be referred to as the above-mentioned actual / nominal TDW, but may also be referred to as a maintenance period, a cancellation period, an application period, actual / nominal TDW size, bundling size, interval, time duration, time duration for DMRS bundling, or a time duration for avoiding TA (TA pre-compensation) updates that cause phase discontinuity that may violate the required performance of the UE.

[0064] (3.3) Operational Examples (3.3.1) Operational Example 1 The following describes operational example 1 in which DMRS bundling is applied to PDCCH repetition in NTN. Note that DMRS bundling applied to PDCCH repetition is also referred to as DMRS bundling for PDCCH.

[0065] DMRS bundling for PDCCH may be read as joint channel estimation for PDCCH. DMRS bundling for PDCCH may be applied to repeated transmission / reception of PDCCH related to DCI corresponding to a single Transport Block (TB), i.e., PDCCH repetition, or may be applied to PDCCHs including multiple different pieces of information.

[0066] (3.3.1.1) Operational Example 1-1 Under the assumption that power consistency and phase continuity are maintained, the time domain window (TDW) in which DMRSs are aggregated will be described in detail. The TDW described in this operational example is a nominal TDW.

[0067] The TDW length (window length) may be defined and configured by the network (gNB 100). The TDW length is indicated, for example, by an information element (IE) such as PDCCH-TimeDomainWindowLength. Opt 1: The candidate TDW lengths for PDCCH DMRS bundling may be defined as the same as the candidate TDW lengths for PUCCH DMRS bundling or PDSCH DMRS bundling. That is, they may be defined as 2 to 8 slots. Opt 2: The candidate TDW lengths for PDCCH DMRS bundling may be newly defined for the PDCCH in the NTN. For example, they may be defined as 2 to 16 slots. Note that the same TDW length (value) may always be configured for the PUCCH or PDSCH and the PDCCH, or different TDW lengths (values) may be configured.

[0068] The start / end of a TDW may be defined as follows: Example: The start of the first nominal TDW may be defined as, for example, the first symbol / slot of the first PDCCH reception. Example: The end of the last nominal TDW may be defined as, for example, the last symbol / slot of the last PDCCH reception. Example: The start of another nominal TDW may be defined as, for example, the first symbol / slot of the first PDCCH reception that comes after the last symbol / slot of the last PDCCH reception in the previous nominal TDW.

[0069] If the length or start / end of the TDW is not configured, the TDW may be determined based on the UE capability.

[0070] (3.3.1.2) Operation Example 1-2 Details of the actual TDW will be described. The actual TDW may be determined separately from the nominal TDW described in Operation Example 1.

[0071] The start of the first actual TDW may be defined as the first symbol / slot of the first PDCCH reception, for example, in the symbols / slots determined for PDCCH reception within the nominal TDW mentioned above.

[0072] The end of the last actual TDW may be defined as follows: Example: When the actual TDW reaches the end of the last PDCCH reception in the above-mentioned nominal TDW, the last symbol / slot of the last PDCCH reception in the slot determined for PDCCH reception in the above-mentioned nominal TDW Example: When an event occurs in PDCCH reception in the above-mentioned nominal TDW that disturbs the maintenance of power consistency and phase continuity, and the PDCCH reception is in the symbol / slot determined for PDCCH reception, the last symbol of PDCCH reception before the event

[0073] The following may be defined as events that disrupt the maintenance of power consistency and phase continuity. Note that the term "event" may be replaced with "triggering event."

[0074] Opt 1: The same events as those in DMRS bundling for PUSCH may be defined. For example, the gap between two consecutive PDCCHs (e.g., PDCCHs in linked search spaces) in PDCCH reception may exceed a predetermined symbol (symbol length) for CP. Note that the CP may be a normal CP or an extended CP. For example, the gap between two consecutive PDCCHs (e.g., PDCCHs in linked search spaces) in PDCCH reception is equal to or less than a predetermined symbol (symbol length) for CP, and another DL reception may be scheduled in this gap. For example, dropping or canceling PDCCH transmission. For example, for a Reduced Capability (RedCap) UE in half-duplex communication, dropping or canceling PDCCH transmission, or overlapping of the gap between two consecutive PDCCHs (e.g., PDCCHs in linked search spaces) with DL reception symbols.

[0075] Opt 2: New NTN-specific events may be defined, e.g., satellite movement (satellite orbit), NTN-specific timers, NTN-specific instructions.

[0076] Opt 3: Events may not be defined. For example, power consistency and phase continuity may be maintained by the implementation of the gNB100.

[0077] (3.3.1.3) Operation Example 1-3 Details of assistance information will be described. It may be considered that at least one of the following assistance information is reported from the UE 200 to the gNB 100 via Uplink Control Information (UCI) / MAC Control Element (MAC CE) / RRC IE. In other words, by reporting the assistance information from the UE 200 to the gNB 100, it is possible to assist in maintaining power consistency and phase continuity in the TDW.

[0078] Alt 1: Timestamp of the assistance information report Alt 2: UE-specific TA Alt 2': Change in UE-specific TA over a given period Note that this period may be predefined or may be set by the network (gNB100) via System Information Block (SIB) / Downlink Control Information (DCI) / RRC.

[0079] Alt 3: Elevation angle of UE 200 at NTN. The elevation angle of UE 200 is the angle between the horizon as seen from UE 200 and relay station 150. Hereinafter, the elevation angle of UE 200 is also referred to as the UE elevation angle. Alt 3': Amount of change in UE elevation angle at NTN over a predetermined period. This period may be predefined or may be set by the network (gNB 100) via SIB / DCI / RRC. This period may be set to the same length as the period of Alt 2' or may be set to a different length.

[0080] Alt 4: The speed of UE200. Alt 4': The amount of change in the speed of UE200 over a predetermined period. This period may be predefined or may be set by the network (gNB100) via SIB / DCI / RRC. This period may be set to the same length as the period of Alt 2' or Alt 3', or may be set to a different length. Alt 5: The movement trajectory of UE200.

[0081] Assistance information may be reported according to predefined rules or NW indications.

[0082] (3.3.2) Operation Example 2 The following describes the reporting of UE capabilities in the above-described operation example 1.

[0083] (3.3.2.1) Operation Example 2-1 The UE 200 may report at least one of the following as its own capability information:

[0084] Alt 1: Whether DMRS bundling for PDCCH is supported. Alt 2: Maximum supported TDW length. Alt 3: Maximum supported DMRS bundling period. Alt 4: Maximum supported allowable frequency offset.

[0085] That is, if power consistency and phase continuity are not maintained by the gNB100, the UE200 may report the maximum value of the supportable DMRS bundling period (Alt 3) or the maximum value of the supportable allowable frequency offset (Alt 4).

[0086] When reporting the content of Alt1 / 2 / 3 / 4 for PDCCH DMRS bundling, UE 200 may always report support for PUCCH DMRS bundling or PDSCH DMRS bundling. That is, a UE that reports support for PUCCH DMRS bundling or PDSCH DMRS bundling may also report the content of Alt1 / 2 / 3 / 4 for PDCCH DMRS bundling.

[0087] The values ​​reported in Alt 2 / 3 / 4 above may be affected by various satellite parameters (e.g., altitude, velocity of relay station 150) and / or may be affected by various UE elevation angles, as shown in FIG. 8.

[0088] UE 200 may report the maximum value of the DMRS bundling period (Alt 3) or the maximum value of the allowed frequency offset (Alt 4) in a specific format related to various satellite parameters and / or UE elevation angle. The maximum value of the DMRS bundling period to be reported will be specifically described below. In the following description, the maximum value of the DMRS bundling period is T_max. T_max is determined by UE 200 based on at least one of the UE elevation angle and the satellite parameters.

[0089] Opt 1: Report T_max corresponding to one UE elevation angle X / satellite parameter Y (e.g., X = 30 deg / Y = 1200 km).

[0090] Opt 1': Reports T_max corresponding to multiple UE elevation angles X (X1 to X3) / satellite parameters Y (Y1 to Y3). Opt 1'-1: Reports T_max corresponding to multiple UE elevation angles X / satellite parameters Y (e.g., {X1, X2, X3} = {30 deg, 60 deg, 90 deg} / {Y1, Y2, Y3} = 600 km, 1200 km, 2000 km}). Opt 1'-2: Reports T_max corresponding to multiple UE elevation angles X / satellite parameters Y (e.g., 30 deg <= X1 < 60 deg, 60 deg <= X2 <= 90 deg / 600 km <= X1 < 1200 km, 1200 km <= X2 <= 2000 km).

[0091] Opt 1'': Set multiple period sets consisting of T_max for multiple UE elevation angles X / satellite parameters Y, and report one of the multiple period sets. For example, report one index (e.g., Series#5) from the indexes of each period set (Series#0 to Series#9) in the list shown below. Note that A to J_max_10 to 90 deg in the list refer to the T_max corresponding to the UE elevation angle of 10 to 90 deg in multiple period sets (Series#0 to Series#9). Series#0: {A_max_10 deg, A_max_20 deg, … A_max_90 deg} Series#1: {B_max_10 deg, B_max_20 deg, … B_max_90 deg} … Series#9: {J_max_10 deg, J_max_20 deg, … J_max_90 deg}

[0092] In the above-mentioned Opt 1 / 1' / 1'', the UE elevation angle X / satellite parameter Y may be defined in the specification or may be set via an SIB such as an NTN-specific SIB. The NTN-specific SIB may be an SIB in which parameters for the NTN are transmitted, or may be SIB19.

[0093] Opt 2: Report satellite orbit information and T_max corresponding to one validity period T_valid (e.g., T_valid = s10) related to the common TA parameters. Note that the satellite orbit information may be replaced with the orbit information of the relay station 150. The common TA parameters are parameters for determining the common TA notified by the gNB 100.

[0094] Opt 2': Report T_max corresponding to each of multiple valid periods T_valid (e.g., {T_valid_1, T_valid_2, T_valid_3} = {s10, s20, s30}).

[0095] Opt 2'': Set multiple period sets consisting of T_max for each valid period T_valid, and report one of the multiple period sets. For example, report one index (for example, Series#5) from the indexes of each period set (Series#0 to Series#9) in the list shown below. Note that A to J_max_s5 to s240 in the list refer to the T_max corresponding to the valid period T_valid of s5 to s240 in multiple period sets (Series#0 to Series#9). Series#0: {A_max_s5, A_max_s10, ... A_max_s240} Series#1: {B_max_s5, B_max_s10, ... B_max_s240} ... Series#9: {J_max_s5, J_max_s10, ... J_max_s240}

[0096] In the above-mentioned Opt 2 / 2' / 2'', the validity period T_valid may be defined in the specification or may be set via a SIB such as an NTN-specific SIB. The NTN-specific SIB may be a SIB in which parameters for the NTN are transmitted, or may be SIB19.

[0097] (3.3.2.2) Operation Example 2-2 The timing of reporting the UE capability in the above-described operation example 2-1 may be any of the following. Alt 1: Any time. Alt 2: When a UE capability report is requested by the gNB100. Alt 3: May follow the implementation of the UE200, such as when the UE200 detects the need for DMRS bundling for PDCCH. Note that if the PDCCH is an Msg2 / Msg4-scheduling PDCCH, the UE200 may report the UE capability via Msg1 / Msg3.

[0098] (3.4) Actions and Effects Although not previously considered, applying DMRS bundling to PDCCH repetition can improve the accuracy of channel estimation for the PDCCH. In particular, when the PDCCH is a PDCCH used to receive Msg2 / Msg4 in initial access, the success rate of initial access can be dramatically improved, thereby avoiding a shortage of communication resources.

[0099] (4) Other Embodiments The contents of the present invention have been described above in accordance with the embodiments, but it will be obvious to those skilled in the art that the present invention is not limited to these descriptions and that various modifications and improvements are possible.

[0100] In the above disclosure, the UE elevation angle may be read as the gNB elevation angle (see FIG. 8). The gNB elevation angle is the angle between the horizon as seen from the gNB 100 and the relay station 150.

[0101] In the above disclosure, it is assumed that the UE 200 of the embodiment is applied to an NTN, but this is not limited thereto. It may also be applied to a TN (Terrestrial Network) without being limited to an NTN. In this case, the UE capability may be reported by different parameters for the NTN and the TN, or may be reported by the same parameters, but is signaled for each band.

[0102] The above-described operation examples may be combined and applied in a composite manner, as long as no contradiction occurs.

[0103] In the above disclosure, configure, activate, update, indicate, enable, specify, and select may be interchangeable. Similarly, link, associate, correspond, and map may be interchangeable, and allocate, assign, monitor, and map may be interchangeable.

[0104] Furthermore, specific, dedicated, UE-specific, and UE-dedicated may be interchangeable. Similarly, common, shared, group-common, UE-common, and UE-shared may be interchangeable.

[0105] The block diagrams (FIGS. 4 and 5) used to explain the above-described embodiments show functional blocks. These functional blocks (components) are realized by any combination of hardware and / or software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (e.g., wired, wireless, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or multiple devices.

[0106] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, regard, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how each is implemented.

[0107] Furthermore, the above-described gNB100 and UE200 (the devices) may function as a computer that performs processing of the wireless communication method of the present disclosure. Figure 9 is a diagram showing an example of the hardware configuration of the devices. As shown in Figure 9, the devices may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0108] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the apparatus may be configured to include one or more of the apparatuses shown in the drawings, or may be configured to exclude some of the apparatuses.

[0109] Each functional block of the device (FIGS. 4 and 5) is realized by any hardware element of the computer device or a combination of the hardware elements.

[0110] In addition, each function of the device is realized by loading specified software (programs) onto hardware such as processor 1001 and memory 1002, causing processor 1001 to perform calculations, control communication via communication device 1004, and control at least one of reading and writing data in memory 1002 and storage 1003.

[0111] The processor 1001 controls the entire computer by running, for example, an operating system, and may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, and registers.

[0112] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. Furthermore, the various processes described above may be executed by a single processor 1001, or may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The programs may be transmitted from a network via a telecommunications line.

[0113] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The memory 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The memory 1002 may store a program (program code), a software module, etc., capable of executing a method according to an embodiment of the present disclosure.

[0114] Storage 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. Storage 1003 may also be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, a database, a server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0115] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, or a communication module.

[0116] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize, for example, at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD).

[0117] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0118] Furthermore, each device such as the processor 1001 and the memory 1002 is connected to a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0119] Furthermore, the device may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0120] Furthermore, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination thereof. Furthermore, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0121] Each aspect / embodiment described in the present disclosure may be applied to at least one of a system using Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, a 4th generation mobile communication system (4G), a 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable system, and a next-generation system enhanced based on these. Furthermore, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G) may also be applied.

[0122] The order of the procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless it is consistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0123] In the present disclosure, a specific operation described as being performed by a base station may be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal may be performed by at least one of the base station and another network node other than the base station (for example, an MME or an S-GW, etc., but are not limited to these). Although the above example illustrates a case where there is one other network node other than the base station, a combination of multiple other network nodes (for example, an MME and an S-GW) may also be used.

[0124] Information, signals (information, etc.) may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0125] The input and output information may be stored in a specific location (for example, a memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added. The output information may be deleted. The input information may be transmitted to another device.

[0126] The determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0127] The aspects / embodiments described in this disclosure may be used alone, in combination, or switched depending on the implementation. Notification of predetermined information (e.g., notification that "X is true") is not limited to explicit notification, but may be implicit (e.g., not notifying the predetermined information).

[0128] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0129] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0130] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0131] Note that terms described in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0132] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0133] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0134] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0135] In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0136] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0137] The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication services within that coverage area.

[0138] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0139] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0140] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, the mobile object itself, etc. The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0141] Furthermore, a base station in the present disclosure may be read as a mobile station (user terminal, the same applies hereinafter). For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between multiple mobile stations (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the mobile station may be configured to have the functions of a base station. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, terms such as an uplink channel and a downlink channel may be read as a side channel.

[0142] Similarly, a mobile station in the present disclosure may be interpreted as a base station, in which case the base station may have the functions of a mobile station.

[0143] A radio frame may be made up of one or more frames in the time domain, each of which may be called a subframe.

[0144] A subframe may further be composed of one or more slots in the time domain, and may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0145] Numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering operations performed by the transceiver in the frequency domain, and specific windowing operations performed by the transceiver in the time domain.

[0146] A slot may consist of one or more symbols in the time domain (such as Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) A slot may be a time unit based on numerology.

[0147] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0148] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0149] For example, one subframe may be referred to as a transmission time interval (TTI), multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be referred to as a slot, minislot, etc. instead of a subframe.

[0150] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station schedules each user terminal to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) in TTI units. Note that the definition of TTI is not limited to this.

[0151] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0152] In addition, when one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Furthermore, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0153] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0154] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0155] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0156] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0157] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0158] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0159] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0160] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0161] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0162] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be variously changed.

[0163] The terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0164] The reference signal may also be abbreviated as Reference Signal (RS) and may be called a pilot depending on the applicable standard.

[0165] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0166] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0167] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way.

[0168] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0169] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0170] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like, all of which are considered to be "determining." "Determining" and "determining" may also include resolving, selecting, choosing, establishing, comparing, and the like, all of which are considered to be "determining." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Also, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0171] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0172] 10 shows an example of the configuration of a vehicle 2001. As shown in Fig. 10, the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013.

[0173] The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor.

[0174] The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

[0175] The electronic control unit 2010 is composed of a microprocessor 2031, a memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2027 provided in the vehicle. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0176] The signals from the various sensors 2021 to 2028 include a current signal from a current sensor 2021 that senses the current of the motor, a rotation speed signal of the front and rear wheels obtained by a rotation speed sensor 2022, an air pressure signal of the front and rear wheels obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

[0177] The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing various types of information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information obtained from external devices via the communication module 2013, etc., to provide various types of multimedia information and multimedia services to the occupants of the vehicle 1.

[0178] The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS, etc.), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps, etc.), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driving assistance functions or autonomous driving functions.

[0179] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 1 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 to and from a driving unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, an axle 2009, a microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 2028, which are provided in the vehicle 2001.

[0180] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, or the like.

[0181] The communication module 2013 transmits, via wireless communication to an external device, a current signal from the current sensor that is input to the electronic control unit 2010. The communication module 2013 also transmits, via wireless communication to an external device, the rotation speed signals of the front and rear wheels acquired by a rotation speed sensor 2022, the air pressure signals of the front and rear wheels acquired by an air pressure sensor 2023, the vehicle speed signal acquired by a vehicle speed sensor 2024, the acceleration signal acquired by an acceleration sensor 2025, the accelerator pedal depression amount signal acquired by an accelerator pedal sensor 2029, the brake pedal depression amount signal acquired by a brake pedal sensor 2026, the shift lever operation signal acquired by a shift lever sensor 2027, and the detection signals for detecting obstacles, vehicles, pedestrians, etc. acquired by an object detection sensor 2028, all of which are input to the electronic control unit 2010.

[0182] The communication module 2013 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on an information service unit 2012 provided in the vehicle. The communication module 2013 also stores the various information received from the external devices in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, axle 2009, sensors 2021 to 2028, and the like provided in the vehicle 2001.

[0183] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0184] (Additional Note) The above disclosure may be expressed as follows.

[0185] A first feature is a terminal including: a receiving unit that repeatedly receives a physical downlink control channel; and a control unit that controls the repeated reception of the physical downlink control channel during a maintenance period in which power and phase are maintained, wherein the control unit performs channel estimation on the physical downlink control channel by using a plurality of demodulation reference signals in the repeated reception of the physical downlink control channel.

[0186] A second feature is the terminal based on the first feature, wherein the receiver receives a message transmitted from a base station in initial access, based on the physical downlink control channel.

[0187] A third feature is the terminal according to the first or second feature, wherein the control unit determines the maintenance period based on a parameter set by a base station.

[0188] A fourth feature is the terminal according to the third feature, wherein the parameter candidates set by the base station are the same as the parameter candidates applied to repeated reception of a physical downlink shared channel.

[0189] A fifth feature is the terminal according to any one of the first to fourth features, wherein the control unit determines the maintenance period based on a factor specific to a non-terrestrial network.

[0190] A sixth feature is the terminal according to any one of the first to fifth features, further comprising a transmitter that transmits, to a base station, capability related to an operation of controlling to repeatedly receive the physical downlink control channel during the maintenance period.

[0191] 10 Wireless communication system 20 NG-RAN 100 gNB 110 Wireless signal transceiver 120 Control unit 150 Relay station 200 UE 210 Wireless signal transceiver 220 Amplifier 230 Modulation / demodulation unit 240 Control signal / reference signal processing unit 250 Encoding / decoding unit 260 Data transceiver 270 Control unit 1001 Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Left and right front wheels 2008 Left and right rear wheels 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 RPM sensor 2023 Air pressure sensor 2024 Vehicle speed sensor 2025 Acceleration sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030 Driving assistance system unit 2031 Microprocessor 2032 Memory (ROM, RAM) 2033 Communication port

Claims

1. A terminal comprising: a receiving unit that repeatedly receives a physical downlink control channel; and a control unit that controls the repeated reception of the physical downlink control channel during a maintenance period in which power and phase are maintained, wherein the control unit performs channel estimation for the physical downlink control channel using a plurality of demodulation reference signals in the repeated reception of the physical downlink control channel.

2. The terminal according to claim 1, wherein the receiving unit receives a message transmitted from a base station in initial access based on the physical downlink control channel.

3. The terminal according to claim 1, wherein the control unit determines the maintenance period based on a parameter set by a base station.

4. The terminal according to claim 3, wherein the parameter candidates set by the base station are the same as the parameter candidates applied to repeated reception of the physical downlink shared channel.

5. The terminal according to claim 1, wherein the control unit determines the maintenance period based on factors specific to a non-terrestrial network.

6. The terminal according to claim 1, further comprising: a transmitter configured to transmit, to a base station, a capability relating to an operation of controlling the repeated reception of the physical downlink control channel during the sustainment period.

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