Terminal, wireless communication method, base station, and system

Abstract

To reduce a payload size related to setting of initial access.SOLUTION: A terminal according to one aspect of the present disclosure includes a receiver configured not to receive, in an initial access procedure, at least one of a broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel (RRMSPDSCH) carrying system information, but to receive, using another channel or signal, at least part of information that has been received using the PBCH, the PDCCH, or the RRMSPDSCH, and a controller configured to perform control in the initial access procedure based on the another channel or signal.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a terminal, a wireless communication method, a base station, and a system in a next-generation mobile communication system. [Background technology]

[0002] In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) was specified with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) was specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

[0003] Successor systems to LTE (e.g., 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 or later) are also being considered.

[0004] In existing LTE systems (e.g., 3GPP Rel. 8-14), a user equipment (UE) transmits uplink control information (UCI) using at least one of an UL data channel (e.g., a Physical Uplink Shared Channel (PUSCH)) and an UL control channel (e.g., a Physical Uplink Control Channel (PUCCH)). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010 Summary of the Invention [Problem to be solved by the invention]

[0006] In NR (5G), it is possible to set designs and parameters more flexibly according to use cases and requirements, and it is also possible to flexibly set channels related to random access (initial access).In future wireless communication systems (e.g., 6G and later / Rel. 17 and later), higher requirements and diverse use cases are expected, and more flexible designs are possible.

[0007] On the other hand, depending on the requirements and use cases, limiting and fixing the design and parameters to a certain extent may lead to improved characteristics. Fixing the initial access design and procedures makes it possible to reduce the payload size for setting up the initial access, improving communication connectivity at the edge of the area (cell) and the availability of Internet of Things (IOT) and limited-function terminals, and enabling ultra-extended coverage and ultra-long-distance communication.

[0008] Therefore, an object of the present disclosure is to provide a terminal, a wireless communication method, a base station, and a system that can reduce the payload size related to the initial access setting. [Means for solving the problem]

[0009] A terminal according to one embodiment of the present disclosure is characterized in that it includes: a receiving unit that does not receive at least one of a broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel (RMSI PDSCH) carrying system information during an initial access procedure, and receives at least a part of information that has been received using the PBCH, the PDCCH, or the RMSI PDSCH using another channel or signal; and a control unit that performs control during the initial access procedure based on the other channel or signal. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, the payload size for setting up initial access can be reduced. [Brief explanation of the drawings]

[0011] [Figure 1] 1A and 1B are diagrams illustrating an example of an initial access procedure. [Figure 2] FIG. 2 is a diagram illustrating another example of the initial access procedure. [Figure 3] FIG. 3 is a diagram illustrating an example of an initial access procedure in which the PBCH is omitted. [Figure 4] FIG. 4 is a diagram illustrating an example of an initial access procedure in which the PDCCH is omitted. [Figure 5] FIG. 5 is a diagram illustrating an example of an initial access procedure in which the RMSI PDSCH is omitted. [Figure 6] FIG. 6 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 9] FIG. 9 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Initial Access Procedures) In the initial access procedure, the random access procedure for establishing uplink (UL) synchronization includes contention-based random access (also called Contention-Based Random Access (CBRA)) and non-contention-based random access (Non-CBRA, also called Contention-Free Random Access (CFRA)).

[0013] In contention-based random access (CBRA), a UE transmits a preamble randomly selected from multiple preambles (also called random access preambles, random access channel (Physical Random Access Channel (PRACH)), RACH preambles, etc.) defined for each cell. Contention-based random access is a UE-initiated random access procedure and can be used, for example, at the time of initial access, the start or restart of UL transmission, etc.

[0014] On the other hand, in contention-free random access (Non-CBRA, CFRA), a network (e.g., a base station) assigns a preamble to a UE on a downlink (DL) control channel (Physical Downlink Control Channel (PDCCH)), and the UE transmits the preamble assigned by the network. Non-contention-free random access is a network-initiated random access procedure, and can be used, for example, at the time of handover, at the start or restart of DL transmission (at the start or restart of UL transmission of DL retransmission instruction information), etc.

[0015] In NR, CBRA includes a four-step CBRA procedure defined in Rel. 15 and a two-step CBRA procedure defined in Rel. 16. The former may be called a four-step RACH, and the latter may be called a two-step RACH.

[0016] 1 is a diagram showing an example of an initial access procedure. First, a UE receives in advance information (PRACH configuration information) indicating a configuration of a random access channel (PRACH) (PRACH configuration, RACH configuration) through system information (e.g., at least one of MIB (Material Information Block) or SIB (System Information Block)) or higher layer signaling (e.g., RRC (Radio Resource Control) signaling).

[0017] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and the like, or a combination thereof.

[0018] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0019] In the example of FIG. 1A, first, the UE receives PRACH configuration information and Remaining Minimum System Information (RMSI) through a Synchronization Signal Block (SSB). The SSB is a signal block that includes at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). The SSB may also be referred to as an SS / PBCH block.

[0020] The PRACH configuration information may include, for example, a plurality of physical cell IDs (PCIs) defined for each cell, a plurality of preambles (e.g., preamble formats) defined for each cell, time resources (e.g., system frame numbers, subframe numbers) and frequency resources (e.g., an offset (prach-FrequencyOffset) indicating the start position of 6 resource blocks (PRBs: Physical Resource Blocks)) used for PRACH transmission, etc.

[0021] The PBCH may be used to notify the monitoring position of the PDCCH, the PDCCH may be used to notify the resource of the RMSI (RMSI PDSCH), and the RMSI may be used to notify the resource used for the PRACH.

[0022] As shown in FIG. 1A, when the UE transitions from an idle (RRC_IDLE) state to an RRC connected (RRC_CONNECTED) state (e.g., at the time of initial access), or when the UE is in an RRC connected state but UL synchronization is not established (e.g., at the start or restart of UL transmission), the UE randomly selects one of multiple preambles indicated by the PRACH configuration information and transmits the selected preamble via PRACH (Message 1).

[0023] When the base station detects the preamble, it transmits a Random Access Response (RAR) in response (Message 2). If the UE fails to receive the RAR within a predetermined period (RAR window) after transmitting the preamble, it increases the transmission power of the PRACH and transmits (resends) the preamble again. Note that increasing the transmission power during retransmission is also called power ramping.

[0024] Upon receiving the RAR, the UE adjusts the UL transmission timing based on the timing advance (TA) included in the RAR to establish UL synchronization. The UE also transmits a control message (Message 3) of higher layers (L2 / L3: Layer 2 / Layer 3) using the UL resources specified by the UL grant included in the RAR. The control message includes the UE identifier (UE-ID). The UE identifier may be, for example, a Cell-Radio Network Temporary Identifier (C-RNTI) if the UE is in an RRC connected state, or a UE-ID of a higher layer such as a System Architecture Evolution-Temporary Mobile Subscriber Identity (S-TMSI) if the UE is in an idle state.

[0025] The base station transmits a collision resolution message in response to the control message from the higher layer (message 4). The collision resolution message is transmitted based on the user equipment identifier included in the control message. A user equipment that successfully detects the collision resolution message transmits an acknowledgement (ACK) in Hybrid Automatic Repeat reQuest (HARQ) to the network. This transitions the UE from idle state to an RRC connected state.

[0026] On the other hand, if a UE fails to detect the collision resolution message, it determines that a collision has occurred, reselects a preamble, and repeats the random access procedure of messages 1 to 4. When the radio base station detects that the collision has been resolved by an ACK from the user terminal, it transmits an UL grant to the UE. The UE starts transmitting UL data using the UL resources allocated by the UL grant.

[0027] In the above-described contention-based random access, when a UE desires to transmit UL data, it can autonomously initiate a random access procedure. Furthermore, after UL synchronization is established, UL data is transmitted using UL resources allocated specifically to the user terminal by an UL grant, enabling highly reliable UL transmission. Messages 1 to 4 of the initial access procedure may be referred to as a random access procedure.

[0028] In NR Rel. 16, a random access procedure using fewer steps than the existing four steps is being considered. One example is a random access procedure using two steps. The random access procedure using two steps is also called a two-step random access procedure, a two-step RACH, or a two-step RACH.

[0029] A two-step RACH may consist of a first step of transmission from the UE to the network and a second step of transmission from the network to the UE (see FIG. 1B).

[0030] For example, in the first step, at least one of an UL signal and an UL channel including a preamble and a message may be transmitted from the UE to the network (base station). The preamble may be configured to play a role similar to that of message 1 (PRACH) in the existing random access procedure. The message may be configured to play a role similar to that of message 3 (PUSCH) in the existing random access procedure. Note that the preamble and the message transmitted in the first step may be referred to as message A (Msg. A) or a first message.

[0031] In the second step, at least one of a DL signal and a DL channel including a response and contention-resolution may be transmitted from the network (base station) to the UE. The response may be configured to play a role similar to that of message 2 (random access response (RAR) transmitted by PDSCH) in the existing random access procedure. The contention resolution may be configured to play a role similar to that of message 4 (PDSCH) in the existing random access procedure. Note that the message transmitted in the second step may be referred to as message B (Msg. B) or a second message.

[0032] Figure 2 is a diagram showing another example of the initial access procedure. Figure 2 shows the allocation of each channel / information in time / frequency resources. The processing flow is the same as in Figure 1A, so a detailed description will be omitted. The upper and lower diagrams in Figure 2 are connected at part (A). The example in Figure 2 shows that each signal / channel is received by one of four beams. Blank blocks indicate blocks corresponding to other beams.

[0033] RMSI may be a PDSCH carrying RMSI (RMSI PDSCH). Message 2 may be a PDSCH carrying Message 2 (Message 2 PDSCH). Message 3 may be a PUSCH carrying Message 3 (Message 3 PUSCH). Message 4 may be a PDSCH carrying Message 4 (Message 4 PDSCH). The PDSCHs carrying RMSI / Message 2 / Message 4 may be scheduled by the PDCCH.

[0034] (PBCH) The MIB (Master Information Block) of the MSI (Minimum System Information) read by the UE at initial access is transmitted by the PBCH. The remaining MSI is the RMSI (Remaining Minimum System Information), which corresponds to SIB (System Information Block) 1 and SIB2 in LTE. The RMSI is scheduled by the PDCCH specified by the MIB (or the PDCCH transmitted in the CORESET specified by the MIB).

[0035] For example, MIB contents (information elements) include SystemFrameNumber, subCarrierSpacingCommon, Ssb-subcarrierOffset, Dmrs-TypeA-Position, pdcchConfigSIB1, cellBarred, intraFreqReselection, etc.

[0036] SystemFrameNumber indicates the upper 6 bits of the system frame number (SFN). subCarrierSpacingCommon indicates the subcarrier spacing (SCS, numerology) for RMSI reception. Ssb-subcarrierOffset indicates the PRB (Physical Resource Block) grid offset for RMSI reception. Dmrs-TypeA-Position indicates the symbol position of the DMRS for PDSCH (whether it is the third or fourth symbol in a slot). pdcchConfigSIB1 (which may be called RMSI-PDCCH-Config) indicates the parameter set (PDCCH parameter set) of the PDCCH (or CORESET (Control Resource Set) including the PDCCH, RMSI CORESET) for RMSI reception. cellBarred indicates whether camping on this cell is prohibited (Barred / notBarred). The intraFreqReselection notifies whether or not there is a cell that can be camped on within the same frequency (carrier band) (allowed / not allowed).

[0037] Incidentally, in NR (5G), it is possible to set designs / parameters more flexibly according to use cases / requirements, and it is also possible to flexibly set channels related to random access (initial access). In future wireless communication systems (e.g., 6G and later / Rel. 17 and later), higher requirements and more diverse use cases are expected, and more flexible designs are possible.

[0038] On the other hand, depending on the requirements / use cases, limiting / fixing the design / parameters to a certain extent may lead to improved characteristics. Fixing the initial access design / procedures makes it possible to reduce the payload size for setting up the initial access, improving communication connectivity at the edge of the area (cell) and the availability of IoT / limited-function terminals, and enabling ultra-extended coverage and ultra-long-distance communication.

[0039] Therefore, the present inventors have conceived a terminal that can reduce the payload size related to the initial access setting.

[0040] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The wireless communication methods according to the embodiments may be applied independently or in combination. For example, the following example may be applied in combination with either the four-step random access procedure or the two-step random access procedure described above.

[0041] In the present disclosure, "A / B" may be read as "at least one of A and B."

[0042] In the present disclosure, PDSCH, RMSI, RMSI PDSCH, message 2, message 2 PDSCH, message 4, and message 4 PDSCH may be interchangeable. PUSCH, message 3, and message 3 PUSCH may be interchangeable. RACH, PRACH, message 1, random access preamble, and RACH preamble may be interchangeable.

[0043] In the present disclosure, fixation, limitation, and definition may be read interchangeably with each other. In the present disclosure, being limited may mean being limited to a specific value / parameter / range. Initial access, initial access procedure, random access, and random access procedure may be read interchangeably with each other. Also, being defined may mean being defined in the specification. In the present disclosure, design, configuration, setting, parameter, value, and setting range may be read interchangeably with each other. Omitting A may indicate omitting a part of A. Omitting A may indicate that the UE does not receive A.

[0044] (Wireless communication method) <Omission of PBCH> The UE may not receive the PBCH and receive at least a part of the information that was received using the conventional PBCH (e.g., the information within the above-mentioned MIB content) using other channels / signals (see FIG. 3). Alternatively, the UE may receive the PBCH, but at least a part of the information transmitted by the PBCH may be omitted.

[0045] The UE may receive the information that was received using the conventional PBCH using the PSS / SSS. For example, the UE may receive information regarding the cell (cellBarred, intraFreqReselection), the SSB index using the PSS / SSS. By increasing the number of signal sequences / symbols of the PSS / SSS, the information that was received using the conventional PBCH may be included. A tertiary SS may be set, and the information that was received by the PBCH may be included in that SS.

[0046] When omitting the PBCH, a configuration in which the PBCH is removed from the SS / PBCH block of the existing system may be applied. Alternatively, a configuration in which the PBCH is removed from the SS / PBCH block of the existing system and, in addition, the positional relationship between the PSS and the SSS, the assigned position in the frequency domain, and the assigned position in the time domain are changed may be applied. Alternatively, the arrangement of the PSS / SSS may be determined separately from the SS / PBCH block of the existing system.

[0047] When a part of the PBCH is omitted, a configuration in which a part of the PBCH is removed from the SS / PBCH block of the existing system may be applied. For example, a configuration in which one symbol of the PBCH included in the two-symbol PBCH in the SS / PBCH block is omitted may be applied. The symbol of the PBCH to be omitted may be the PBCH of the symbol arranged first in the time direction or the PBCH of the symbol arranged second.

[0048] By restricting or uniquely defining the settings of RMSI / PDCCH (e.g., monitoring position, resources), the information regarding RMSI / PDCCH / CORESET included in the PBCH may be omitted. For example, it may be specified that the PDCCH / CORESET is transmitted / set in the same slot as the SSB. The relative relationship between the start RB / RB number (start symbol / symbol number) of the RMSI / PDCCH / CORESET and the SSB or PSS / SSS may be specified. With these specifications, the information of the PBCH can be omitted.

[0049] The UE may receive the information (e.g., System Frame Number) that was received by the conventional PBCH by RMSI. The UE may receive, for example, the information that was received by the conventional PBCH within the configuration information (RACH-ConfigCommon, rach-ConfigGeneric) regarding RACH transmitted by RRC.

[0050] <Omission of PDCCH> The UE may not receive the PDCCH, but may receive at least a portion of the information that it has received using the conventional PDCCH, using another channel / signal (see FIG. 4). The PDCCH may be at least one of the PDCCH used to schedule the RMSI PDSCH, the PDCCH used to schedule message 2, and the PDCCH used to schedule message 4. The information may be, for example, information related to the scheduling of the PDSCH (such as Time Domain Resource Assignment / Allocation (TDRA) and Frequency Domain Resource Assignment / Allocation (FDRA) of DCI). Alternatively, the UE may receive the PDCCH, but omit at least a portion of the information transmitted by the PDCCH. The PDCCH may be interpreted as CORESET or DCI.

[0051] [Information about RMSI PDSCH] The UE may receive, for example, information about frequency / time resources of the RMSI PDSCH (RMSI) using the PBCH (see (1) in FIG. 4). For example, information about monitoring the PDCCH may be removed from the PBCH, and instead, configuration information about the RMSI PDSCH (TDRA / FDRA / Modulation and Coding Scheme (MCS)) may be included in the PBCH.

[0052] For example, it may be specified that the RMSI is transmitted in the same slot as the SSB. The allocation / setting conditions of the RMSI PDSCH may be specified. The allocation / setting conditions of the RMSI PDSCH may be, for example, at least one of the number of symbols of the PDSCH, the starting RB, and the number of RBs. Furthermore, the allocation / setting conditions of the RMSI PDSCH may be the relative relationship between the RMSI PDSCH and the SSB.

[0053] [Message 2 PDSCH / Message 4 PDSCH information] The UE may receive monitoring information (information about frequency / time resources) of the message 2 PDSCH / message 4 PDSCH (hereinafter referred to as message 2 / 4) using the RMSI (RMSI PDSCH) (see (2) in FIG. 4). For example, the UE may monitor the corresponding PDSCH within a window after receiving the RACH / message 3.

[0054] The resources for message 2 / 4 may be restricted. For example, the resources for message 2 / 4 may be set (restricted) to a specific slot after the transmission slot of RACH / message 3. To reduce the amount of information for message 2, information related to the scheduling of message 3 (e.g., TDRA / FDRA) may be restricted / limited. UE identification may be performed using the RA-RNTI / TC-RNTI used for scrambling the CRC of message 2 / 4.

[0055] Information about message 2 / 4 that was included in the PDCCH may be omitted by restricting or uniquely defining the configuration of message 2 / 4 (e.g., monitoring position, resource). Allocation / configuration conditions for message 2 / 4 may be specified. The allocation / configuration conditions for message 2 / 4 may be, for example, at least one of the number of slots / number of symbols, the starting RB, and the number of RBs for message 2 / 4. Furthermore, the allocation / configuration conditions for message 2 / 4 may be the relative relationship between message 2 / 4 and SSB. These specifications make it possible to omit information about the PDCCH.

[0056] [others] A dedicated signal / channel may be defined for transmitting information related to at least one of RMSI and message 2 / 4. Since the payload size of message 2 / 4 is somewhat fixed, a procedure may be performed in which the setting of time / frequency resources is defined and a channel is generated, such as a Physical Sidelink Control Channel (PSCCH).

[0057] <Omission of RMSI PDSCH> The UE may not receive the RMSI PDSCH (PDSCH carrying RMSI), and at least a part of the information that was previously received using the conventional RMSI PDSCH may be received using other channels / signals (see Figure 5). Alternatively, the UE may receive the RMSI PDSCH, but at least a part of the information transmitted by the RMSI PDSCH may be omitted. When the RMSI PDSCH is omitted, the PDCCH that schedules the RMSI PDSCH may also be omitted.

[0058] [Notification by PBCH] The UE may receive information (e.g., resource information) regarding RACH (PRACH) transmission using the PBCH. In this case, in order to reduce the amount of information in the PBCH, the RACH settings may be restricted / limited.

[0059] Regarding the frequency resources of the RACH, at least one of the start position of the RACH (start PRB (msg1 - FrequencyStart)) and the number of PRBs may be limited to a specific value. Alternatively, RACH grouping (RBG) may be defined. For example, a predetermined number of PRBs (e.g., 4 PRBs) may be regarded as one group, and resource settings may be performed in group units.

[0060] Regarding the time resources of the RACH, for example, the period of the RACH opportunity may be limited (e.g., in Equation (1), x = 16, y = 1). n SFN is the system frame number. n SFN mod x = y (1) Also, the number of sub - frames / slots may be limited (e.g., number of sub - frames = 3, number of slots = 7).

[0061] [Notification by PDCCH] The UE may receive information (e.g., resource information) related to RACH transmission using the PDCCH. That is, the RACH transmission may be notified and scheduled by the PDCCH. To reduce the amount of information in the PDCCH (DCI), the frequency / time resources of the RACH may be limited, as in the case of notification by the PBCH.

[0062] A new DCI format including settings related to RACH transmission such as a PRACH configuration index (prach-ConfigurationIndex) may be defined, and information related to RACH transmission may be reported using the new DCI format.

[0063] [RACH setting restrictions / regulations] By restricting or uniquely specifying the RACH configuration (e.g., monitoring location, resource), the information about the RACH included in the RMSI PDSCH may be omitted. The relative positions (slot / symbol / PRB) of the RACH and the SSB / PDCCH may be specified.

[0064] [others] The PBCH / DCI may be extended to accommodate additional settings for RMSI and the like due to functional enhancement of the terminal. For example, reserved bits (R) of a size corresponding to the functional enhancement may be set in the payload of the PBCH / PDCCH. PBCH resources may also be extended. For example, a terminal with enhanced functionality may also decode resources resulting from the extension of PBCH symbols / RBs. When the PDCCH is used to notify information omitted from the RMSI PDSCH, a new DCI format may be defined as the terminal functionality is enhanced, and this information may be notified using this DCI format.

[0065] The above-described communication control in which the PBCH / PDCCH / RMSI is omitted during initial access may not be applied after RRC connection. For example, communication control in which the PBCH / PDCCH / RMSI is omitted may be applied during initial access, and communication control in which the PBCH / PDCCH / RMSI is not omitted may be applied after RRC connection. Alternatively, communication control in which the PBCH / PDCCH / RMSI is omitted may be applied after RRC connection, as in the case of initial access. Whether or not communication control in which the PBCH / PDCCH / RMSI is omitted after RRC connection may be configured in the UE by higher layer signaling.

[0066] (wireless communication system) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0067] 6 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0068] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0069] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the secondary node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0070] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and the SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0071] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0072] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0073] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may be a frequency band higher than FR2.

[0074] Furthermore, the user terminal 20 may perform communication using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

[0075] The multiple base stations 10 may be connected by wire (for example, optical fiber conforming to the Common Public Radio Interface (CPRI), an X2 interface, or the like) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0076] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0077] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0078] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the radio communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0079] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0080] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0081] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. may be used as an uplink channel.

[0082] The PDSCH transmits user data, higher layer control information, System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit Master Information Block (MIB).

[0083] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0084] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as an UL grant, a UL DCI, etc. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

[0085] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources to search for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor a CORESET associated with a certain search space based on the search space configuration.

[0086] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be called a search space set. Note that the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," "CORESET setting," etc. in the present disclosure may be read interchangeably.

[0087] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), acknowledgement information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0088] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0089] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted as DL-RS.

[0090] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including the SS (PSS, SSS) and the PBCH (and DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as reference signals.

[0091] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0092] (base station) 7 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0093] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0094] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0095] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0096] The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0097] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiving unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0098] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0099] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0100] The transceiver 120 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0101] The transceiver 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0102] The transceiver 120 (transmission processor 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0103] The transmitting / receiving unit 120 (RF unit 122) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna .

[0104] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna .

[0105] The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

[0106] The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0107] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0108] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0109] In addition, during the initial access procedure, the transceiver unit 120 may not transmit at least one of the broadcast channel (PBCH), the physical downlink control channel (PDCCH), and the physical downlink shared channel (RMSI PDSCH) that carries system information, and may instead transmit other channels or signals.

[0110] The control unit 110 may perform control in the initial access procedure based on the other channels or signals.

[0111] (user terminal) 8 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0112] Note that this example mainly shows functional blocks of the characteristic parts of the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0113] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0114] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 220.

[0115] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured from a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0116] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0117] The transmitting / receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0118] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0119] The transceiver 220 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0120] The transceiver 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0121] The transceiver 220 (transmission processor 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0122] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and when transform precoding is not enabled, the transceiver unit 220 may not perform DFT processing as the transmission processing.

[0123] The transmitting / receiving unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna 230.

[0124] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0125] The transceiver 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

[0126] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0127] The transmitting section and receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220 and the transmitting / receiving antenna 230.

[0128] In addition, during the initial access procedure, the transceiver unit 220 may not receive at least one of the broadcast channel (PBCH), the physical downlink control channel (PDCCH), and the physical downlink shared channel (RMSI PDSCH) that carries system information, but may instead receive other channels or signals.

[0129] In the initial access procedure, the transceiver unit 220 may not receive the PBCH, but may receive the other channel or signal including at least one of information about a cell, a synchronization signal block (SSB) index, and a system frame number.

[0130] In the initial access procedure, the transceiver unit 220 may not receive the PDCCH, but may receive information about the resource of the RMSI PDSCH using the PBCH, and may receive information about the resource of the message 2 PDSCH and the message 4 PDSCH using the RMSI PDSCH.

[0131] The transceiver 220 may receive information related to random access channel (RACH) transmission using the PBCH or the PDCCH without receiving the RMSI PDSCH.

[0132] The control unit 210 may perform control in the initial access procedure based on the other channels or signals.

[0133] (Hardware configuration) The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method 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 (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or multiple devices with software.

[0134] Here, the 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, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As mentioned above, the implementation method of each is not particularly limited.

[0135] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 9 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically 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.

[0136] In this disclosure, terms such as apparatus, circuit, device, section, unit, etc. may be read interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0137] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0138] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0139] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0140] 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. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be realized in a similar manner.

[0141] 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 read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, a cache, a main memory, or the like. The memory 1002 may store executable programs (program codes), software modules, and the like for implementing a wireless communication method according to an embodiment of the present disclosure.

[0142] Storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as a secondary storage device.

[0143] 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 referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0144] The input device 1005 is an input device (for example, 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 (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0145] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0146] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using such hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0147] (Variation) Note that terms explained in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0148] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0149] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, and a specific windowing process performed by a transceiver in the time domain.

[0150] A slot may be composed of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol), and may be a time unit based on numerology.

[0151] 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 (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0152] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0153] For example, one subframe may be referred to as a TTI, or 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 a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0154] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0155] 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.

[0156] 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. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0157] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP 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.

[0158] 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.

[0159] 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 also be determined based on numerology.

[0160] In addition, an RB may include one or more symbols in the time domain 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] The BWP may include an UL BWP (a BWP for UL) and a DL BWP (a BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0165] 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."

[0166] 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 changed in various ways.

[0167] 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 a predetermined index.

[0168] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (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.

[0169] 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.

[0170] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0171] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0172] Notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0173] Note that the physical layer signaling may be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be called an RRC message, such as an RRC connection setup message or an RRC connection reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0174] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0175] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0176] 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.

[0177] 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.

[0178] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0179] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0180] In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0181] A base station can accommodate one or more (e.g., three) cells. 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 service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0182] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0183] A mobile station may also be referred to 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.

[0184] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile object, or the mobile object itself. 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.

[0185] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as uplink channel and downlink channel may be read as sidelink channel.

[0186] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0187] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) and a Serving-Gateway (S-GW)), or a combination thereof.

[0188] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the specific order presented.

[0189] Each aspect / embodiment described in the present disclosure may be related to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or a decimal)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE The present invention may be applied to systems that use 802.20, Ultra-Wide Band (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, or to next-generation systems that are based on and extend these systems. Furthermore, the present invention may be applied to a combination of multiple systems (for example, a combination of LTE or LTE-A and 5G).

[0190] 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."

[0191] The term "determining," as used in this disclosure, may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0192] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0193] Also, "decision" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "decision" may be considered to be "deciding" on some action.

[0194] Furthermore, "judgment (decision)" may be interpreted as "assuming," "expecting," "considering," or the like.

[0195] As used in this disclosure, 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."

[0196] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0197] 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."

[0198] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0199] 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.

[0200] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. a receiving unit that does not receive at least one of a broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel (RMSI PDSCH) carrying system information during an initial access procedure, and receives at least a part of information that has been received using the PBCH, the PDCCH, or the RMSI PDSCH using another channel or signal; a control unit that performs control in the initial access procedure based on the other channel or signal; A terminal having:

2. In an initial access procedure, not receiving at least one of a broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel carrying system information (RMSI PDSCH), and receiving at least a part of information that has been received using the PBCH, the PDCCH, or the RMSI PDSCH using another channel or signal; controlling the initial access procedure based on the other channel or signal; A wireless communication method for a terminal having the above configuration.

3. a transmitter that does not transmit at least one of a broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel (RMSI PDSCH) carrying system information in an initial access procedure, and transmits at least a part of information that has been transmitted using the PBCH, the PDCCH, or the RMSI PDSCH using another channel or signal; a control unit that performs control in the initial access procedure based on the other channel or signal; A base station having

4. A system including a terminal and a base station, The terminal a receiving unit that does not receive at least one of a broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel (RMSI PDSCH) carrying system information during an initial access procedure, and receives at least a part of information that has been received using the PBCH, the PDCCH, or the RMSI PDSCH using another channel or signal; a control unit that performs control in the initial access procedure based on the other channel or signal, The base station a control unit that performs control in the initial access procedure based on the other channel or signal; system.

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