Terminal, wireless communication method, base station and system

Abstract

User equipment according to an aspect of the present disclosure comprises: a control unit that, on the basis of at least one of the identification information of user equipment, the type of the user equipment, user equipment capability information, and information transmitted from a base station, determines at least one of an index and a transmission opportunity at which a random access preamble can be transmitted; and a transmission unit that transmits the random access preamble.

Description

[Technical Field]

[0001] The present disclosure relates to a terminal and a wireless communication method in a next-generation mobile communication system. 、 base station and systems Regarding. [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 future wireless communication systems (e.g., Rel. 17 and later, Beyond 5G / 6G and later), the number of terminals per cell is expected to increase as use cases become more diverse. Alternatively, the number of predetermined signals (e.g., synchronization signals) is expected to increase to support communication control using high frequency bands.

[0007] In this way, an increase in the number of terminals / an increase in synchronization signals (e.g., SSB) may increase collisions (e.g., PRACH collisions) when performing a random access procedure. An increase in collisions in the random access procedure may result in a deterioration of communication quality.

[0008] Therefore, the present disclosure provides a terminal and a wireless communication method that can appropriately control an initial access or random access procedure even when the number of terminals / predetermined signals increases. 、 base station and systems One of the aims is to provide [Means for solving the problem]

[0009] A terminal according to one aspect of the present disclosure includes: a control unit that determines at least one of a transmission opportunity and an index available for transmitting a random access preamble based on at least one of identification information of the terminal, a terminal type, terminal capability information, and information notified from a base station; and a transmission unit that transmits the random access preamble, wherein a subcarrier interval and a sequence length of the random access preamble are set independently. When frequency multiplexing of preamble resources is set, the control unit assumes a sequence length having a number of resource blocks equal to or less than the number of resource blocks of the total frequency-multiplexed preamble resources. do. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to appropriately control the initial access or random access procedure even when the number of terminals / predetermined signals increases. [Brief explanation of the drawings]

[0011] [Figure 1] 1A and 1B are diagrams illustrating an example of an initial access procedure / random access procedure. [Figure 2] FIG. 2 is a diagram illustrating an example of a PRACH format for long sequences. [Figure 3] FIG. 3 is a diagram illustrating an example of a PRACH format for short sequences. [Figure 4] 4A and 4B are diagrams illustrating an example of a transmission opportunity used for transmitting a PRACH preamble according to the first aspect. [Figure 5] 5A and 5B are diagrams illustrating the correspondence between SSBs and PRACH preambles according to the third aspect. [Figure 6] FIG. 6 is a diagram illustrating the correspondence between SSBs and PRACH preambles according to the third aspect. [Figure 7] FIG. 7 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 9]FIG. 9 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 10] FIG. 10 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 / Random Access Procedures) Existing systems (e.g., Rel. 16 and earlier) support random access procedures to establish UL synchronization, including contention-based random access (CBRA) and non-contention-free random access (Non-CBRA, also known as 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] 1A and 1B are diagrams illustrating an example of an initial access procedure. First, a UE receives information (PRACH configuration information) indicating a configuration of a random access channel (PRACH) (PRACH configuration, RACH configuration) in advance through at least one of system information (e.g., a Master Information Block (MIB) or a System Information Block (SIB)) and higher layer signaling (e.g., a Radio Resource Control (RRC) 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 notify the monitoring position of the PDCCH, the PDCCH may notify the resource of the RMSI (RMSI PDSCH), and the RMSI may notify the resource used for the PRACH, etc.

[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] The PRACH may be transmitted at a predetermined transmission opportunity. The predetermined transmission opportunity may be referred to as a PRACH transmission opportunity, a PRACH occasion, or a PRACH transmission occasion. The multiple PRACH transmission opportunities may be configured to have different time domains or may be configured to have different at least one of a frequency domain and a time domain. PRACH may be read as RACH.

[0024] The synchronization signal blocks and the PRACH transmission opportunities may be associated, for example, one or more synchronization signal blocks may be associated with one PRACH transmission opportunity, or one or more PRACH transmission opportunities may be associated with one synchronization signal block.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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. A random access procedure using two steps is also called a two-step random access procedure, two-step RACH, or two-step RACH.

[0031] 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).

[0032] 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.

[0033] 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.

[0034] 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.

[0035] (PRACH preamble) Existing systems (for example, Rel. 16 and earlier) support multiple PRACH formats (also referred to as PRACH preamble formats, preamble formats, etc.).

[0036] The PRACH preamble using each PRACH format includes a RACH OFDM symbol. The PRACH preamble may further include at least one of a cyclic prefix (CP) and a guard period (GP). Figures 2 and 3 show examples of PRACH formats supported in Rel. 15.

[0037] For example, PRACH formats 0 to 3 shown in Fig. 2 indicate cases where a long preamble sequence (here, the preamble sequence length is 839) is used in the RACH OFDM symbol. The preamble sequence may be mapped to frequency resources (e.g., subcarriers) allocated to the PRACH.

[0038] PRACH formats A1 to A3, B1 to B4, C0, and C2 shown in Fig. 3 indicate cases where a short sequence preamble sequence (here, the preamble sequence length is 139) is used in the RACH OFDM symbol. Furthermore, Rel. 16 supports sequence lengths of 571 and 1151.

[0039] In existing systems (e.g., Rel. 16 and earlier), the PRACH preamble is defined by associating a sequence length with a subcarrier spacing. In the PRACH format shown in Figure 2, a preamble sequence length of 839 corresponds to a subcarrier spacing of 1.25 kHz or 5 kHz.

[0040] In the PRACH format shown in Figure 3, subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz (μ=2), and 120 kHz (μ=3) correspond to a preamble sequence length of 839. Also, a subcarrier spacing of 30 kHz (μ=1) corresponds to a preamble sequence length of 571. Also, a subcarrier spacing of 15 kHz (μ=0) corresponds to a preamble sequence length of 1151.

[0041] As described above, in existing systems, only a few types of sequence lengths are defined as applicable to PRACH preambles, and the subcarrier interval (or slot length) that can be set for each sequence length is limited.

[0042] Incidentally, future wireless communication systems (e.g., Rel. 17 and later, Beyond 5G / 6G and later) are expected to further improve communication performance and diversify use cases. For example, in future wireless communication systems, the number of terminals per cell may increase to support environments including a larger number of terminals than ever before (e.g., multi-terminal environments). Furthermore, support for communications using higher frequency bands than ever before may also increase the number of predetermined signals (e.g., synchronization signals, etc.).

[0043] In this way, an increase in the number of terminals / an increase in synchronization signals (e.g., SSB) may increase collisions (e.g., PRACH collisions) when performing a random access procedure. An increase in collisions in the random access procedure may result in a deterioration of communication quality.

[0044] Therefore, the present inventors have focused on the possibility that the number of terminals / synchronization signal blocks may increase in future wireless communication systems, and have studied the initial access / random access procedures in such cases, resulting in the concept of this embodiment.

[0045] 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.

[0046] In the present disclosure, "A / B" may be read as "at least one of A and B," and "A / B / C" may be read as "at least one of A, B, and C."

[0047] 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.

[0048] In this disclosure, fixed, limited, and specified may be read interchangeably. In this disclosure, limited may mean limited to a specific value / parameter / range. Initial access, initial access procedure, random access, and random access procedure may be read interchangeably. Also, specified may mean specified by specifications. In this disclosure, design, configuration, setting, parameter, value, and setting range may be read interchangeably.

[0049] (First aspect) In the first aspect, a case will be described in which an occasion (PRACH transmission opportunity) / preamble index used for transmitting a random access preamble (for example, a PRACH preamble) is set separately for each terminal.

[0050] UEs may be divided into PRACH transmission opportunity units / preamble units. For example, PRACH transmission opportunities / preambles available for the random access procedure (e.g., PRACH transmission) may be configured / defined for each UE (or UE group).

[0051] For example, UE#A (or UE group #A) may be configured to be able to use the first transmission opportunity, and UE#B (or UE group #B) may be configured to be able to use the second transmission opportunity. The first transmission opportunity / second transmission opportunity may each include one or more transmission opportunities. For example, the first transmission opportunity may correspond to a transmission opportunity with an even index, and the second transmission opportunity may correspond to a transmission opportunity with an odd index.

[0052] 4A and 4B show an example of dividing and setting available PRACH transmission opportunities for each UE / UE group. FIG. 4A shows a case where each UE / UE group is divided in the time domain. UE#1-#5 can use (or are limited to) the first transmission opportunity (here, RO#0, RO#2), and UE#6-#10 can use (or are limited to) the second transmission opportunity (here, RO#1, RO#3). Here, the case where the UE / UE group is divided into two is shown, but it may be divided into three or more.

[0053] 4B shows a case where UE / UE groups are divided in the frequency domain. UE#1-#5 can use (or are limited to) the first transmission opportunity (here, RO#0, RO#2, RO#4, RO#6), and UE#6-#10 can use (or are limited to) the second transmission opportunity (here, RO#1, RO#3, RO#5, RO#7). Here, the case where UE / UE groups are divided into two is shown, but they may also be divided into three or more.

[0054] Note that UEs / UE groups may be classified by taking both the frequency domain and the time domain into consideration. For example, in FIG. 4B, the first transmission opportunity may be composed of RO#0, RO#3, RO#4, and RO#7, and the second transmission opportunity may be composed of RO#1, RO#2, RO#5, and RO#6.

[0055] Alternatively, the UEs / UE groups may be divided based on other parameters (e.g., preamble index domain), or the UEs / UE groups may be divided based on a combination of the preamble index domain and the time domain / frequency domain.

[0056] As a UE division method, at least one of the following options 1-1 to 1-3 may be applied.

[0057] <Option 1-1> The available transmission opportunity / preamble index may be determined based on a UE identifier, which may be any index used to identify a UE, such as a UE ID.

[0058] Information regarding the correspondence between a UE identifier and a transmission opportunity / preamble index may be specified in advance (e.g., defined in a specification), or may be notified / configured to the UE from a network (e.g., a base station). For example, the base station may notify the UE of information regarding the transmission opportunity / preamble index corresponding to the UE identifier by including it in system information (e.g., MIB / SIB) or RRC.

[0059] <Option 1-2> Available transmission opportunities / preamble indexes may be determined based on the type / capability of the UE. The type / capability of the UE may be, for example, at least one of a UE type, a UE capability, a UE class, and a category. The UE type may be interpreted as a traffic type, a service type, or a communication type.

[0060] For example, available transmission opportunities / preamble indexes may be configured separately for an Internet of Things (IoT) UE and a URLLC / eMBB UE, in which case more transmission opportunities may be configured for the URLLC / eMBB UE than for the Internet of Things (IoT) UE.

[0061] Information regarding the correspondence between the UE type / capability and the transmission opportunity / preamble index may be specified in advance (e.g., defined in a specification), or may be notified / configured to the UE from a network (e.g., a base station). For example, the base station may notify the UE of information regarding the transmission opportunity / preamble index corresponding to the UE type / capability by including it in system information (e.g., MIB / SIB) or RRC.

[0062] <Options 1-3> Information about transmission opportunities / preamble indexes available to each UE may be notified / configured in advance by the base station for each terminal. For example, the base station may notify / configure information about transmission opportunities / preamble indexes for each UE using higher layer signaling (e.g., RRC signaling, RRC release message, etc.).

[0063] The UE may determine the transmission opportunity to be used for transmitting the PRACH preamble based on the information notified / configured by the base station. Note that the UE in the inactive mode may determine the transmission opportunity to be used for transmitting the PRACH preamble based on the configuration information last notified by the base station (or the configuration information held by the UE).

[0064] In this way, in the first aspect, a transmission opportunity / preamble index is set separately for each UE / UE group. In existing systems (e.g., before Rel. 16), terminals in a cell share the same PRACH transmission opportunity, and therefore, for example, when there are a large number of terminals that access / activate at the same time, there is a risk that collisions of PRACH transmissions may occur. In contrast, by applying the first aspect, it is possible to suppress cases where collisions occur in the random access procedure (e.g., PRACH transmission) even when the number of terminals in a cell increases.

[0065] (Second aspect) In the second aspect, the setting of the sequence length (for example, sequence length) / subcarrier spacing / slot length of the PRACH preamble will be described.

[0066] In existing systems, values ​​that can be used as the sequence length of the PRACH preamble are predefined and are limited to some values ​​(e.g., 139, 571, 839, 1151, etc.) (see FIGS. 2 and 3). In this embodiment, the sequence length of the PRACH preamble may be flexibly settable.

[0067] In addition, in existing systems, the correspondence relationship between the sequence length of the PRACH preamble and the subcarrier spacing is predefined in a fixed manner. In this embodiment, the subcarrier spacing and the sequence length of the PRACH preamble may be set independently.

[0068] As the parameters of the PRACH preamble (for example, sequence length / subcarrier spacing / slot length), at least one of the following options 2-1 to 2-2 may be applied.

[0069] <Option 2-1> The sequence length value may be notified / configured to the UE from the network (e.g., a base station). For example, a predetermined value may be configurable for the UE. The predetermined value may be selected from a first range (e.g., a value from 1 to 839), a second range (e.g., a value from 1 to 1151), or another range.

[0070] Also, all values ​​within the first range / second range / other range may be settable, or only some values ​​within the range may be settable. When all values ​​are settable, for example, (1, 2, 3, ..., 839) may be set. When only some values ​​are settable, for example, (1, 3, 5, 7, 11, 13, ...), (71, 139, ...), etc. may be set.

[0071] If some values ​​can be set as the sequence length of the PRACH preamble, the some values ​​may be notified / set to the UE, or the some values ​​may be associated with a predetermined format and information about the format may be notified / set to the UE.

[0072] The base station may notify / configure the subcarrier spacing and sequence length of the PRACH preamble separately to the UE, which allows for flexible configuration of the subcarrier spacing and sequence length of the PRACH preamble.

[0073] <Option 2-2> The sequence length setting value may be set in a predetermined unit. The predetermined value may be a frequency domain unit, such as a resource block (RB / PRB / VRB). In other words, instead of directly setting the sequence length value, the number of RBs may be set, and the UE may determine / recognize the sequence length based on the set number of RBs.

[0074] When 1 RB is configured for the sequence length, the UE may recognize / assume the sequence length to be a preamble frequency resource corresponding to 1 RB. When 6 RBs are configured, the UE may recognize / assume the sequence length to be a preamble frequency resource corresponding to 6 RBs.

[0075] Even when the same RBs are configured, the sequence length may differ depending on the subcarrier spacing of the preamble (or the CP length / guard interval, etc.). For this reason, the UE may determine the sequence length taking into account the number of RBs configured and the subcarrier spacing.

[0076] Furthermore, the relationship between the number of RBs and the sequence length may be specified / defined. Alternatively, the relationship between the number of RBs, the sequence length, and the subcarrier spacing may be specified / defined. Information regarding the correspondence between the number of RBs and the sequence length (or the correspondence between the number of RBs, the sequence length, and the subcarrier spacing) may be notified / configured from the base station to the UE.

[0077] Also, frequency division multiplexing (e.g., FDM) of preamble resources may be configured. When the frequency division multiplexing (FDM) number of preamble resources is configured, the UE may recognize / assume a sequence length such that the amount of total FDM-multiplexed preamble frequency resources is equal to (or less than) the configured number of RBs.

[0078] For example, when 1 RB and 2 FDM numbers are set, the sequence length may be set so that the total of two FDMed preamble resources is 1 RB (one preamble frequency resource corresponds to 0.5 RB).

[0079] Also, the maximum configurable amount of preamble frequency resources may be defined (for example, defined in specifications), or information regarding the maximum configurable amount of preamble frequency resources may be notified / configured from the base station to the UE.

[0080] The maximum amount of preamble frequency resources may be the maximum value for all FDM-modulated preamble frequency resources or the maximum value for a single preamble frequency resource. The preamble frequency resources are determined based on the sequence length, subcarrier spacing, and number of FDMs. Therefore, the range of configurable preamble frequency resource values ​​may be determined / controlled in consideration of the set values ​​of the sequence length, subcarrier spacing, and number of FDMs.

[0081] In the PRACH preamble of the existing system, the types of available sequence lengths are limited, and the subcarrier spacing (or slot length) that can be set for each sequence length is also limited. In contrast, as shown in the second aspect, the sequence length of the PRACH preamble can be flexibly set, and the subcarrier spacing and sequence length of the PRACH preamble can be set independently, thereby enabling flexible setting of the PRACH preamble. This makes it possible to suppress collisions in the random access procedure (e.g., PRACH transmission) even when the number of terminals in a cell increases.

[0082] The second aspect may be selectively applied in a specific frequency range (for example, high frequency band / FR2), or may be applied regardless of the frequency range.

[0083] (Third aspect) In the third aspect, a case is described in which it is possible (or supported / allowed) to associate (or link) multiple synchronization signal blocks (e.g., SSBs) with the same preamble index in the same PRACH transmission opportunity. The synchronization signal block may be read as a synchronization signal.

[0084] As the configuration of SSB / PRACH, at least one of the following options 3-1 and 3-2 may be applied.

[0085] <Option 3-1> The correspondence between multiple SSB indices and the PRACH transmission opportunities and preamble indices may be specified (e.g., defined in a specification) or may be notified / configured by the base station to the UE. For example, for a certain transmission opportunity, a common preamble index may be associated with multiple SSB indices, and information regarding the association may be notified / configured to the UE.

[0086] For example, multiple SSB indices corresponding to spatially separable beams (or spatial domain filters, TCI states, or QCLs) may be associated with the same preamble index within the same transmission opportunity (see FIG. 5A). In FIG. 5A, multiple SSBs #0, #2, #4, and #6 corresponding to beams #0, #2, #4, and #6, respectively, may correspond to the same preamble index #Y within the same transmission opportunity #X.

[0087] For example, when the base station receives a PRACH preamble (e.g., #Y) from the UE at transmission opportunity #X, the base station may determine / distinguish which SSB the preamble corresponds to and then control subsequent procedures (e.g., random access procedures).The base station may determine / distinguish a specific SSB from multiple SSBs corresponding to the same preamble index based on the direction of the PRACH preamble transmitted from the UE (or the direction from which the beam of the PRACH preamble was received).

[0088] When the base station receives the PRACH preamble, the base station may notify the UE of information about the SSB corresponding to the PRACH preamble. The information about the SSB may be included in a DL transmission of message 2, message 4, message B, or message 4 or later and notified to the UE.

[0089] Alternatively, multiple SSB indices corresponding to adjacent beams may be associated with the same preamble index within the same transmission opportunity (see Figure 5B). In Figure 5B, multiple SSB indices #0, #1, and #2 corresponding to beams #0, #1, and #2, respectively, may correspond to the same preamble index #Y at the same transmission opportunity #X.

[0090] When the base station receives PRACH preamble index #Y, it may assume that the UE has received one of SSBs #0, #1, or #2 (e.g., with maximum received power) and control the subsequent procedures, allowing the base station / UE to select a beam with good quality, even if it is not the best beam.

[0091] In this way, by supporting / allowing multiple SSBs to be associated with the same preamble index within the same transmission opportunity, it is possible to prevent an increase in unused SSBs (or transmission opportunities corresponding to the SSBs) even when the number of SSBs (e.g., SSB indices) used in communication increases, thereby enabling efficient resource utilization in the random access procedure (e.g., PRACH transmission).

[0092] <Option 3-2> An SSB with the same index may be transmitted multiple times within a predetermined period (for example, one SSB period).

[0093] In this case, multiple signals (including SSBs with the same index) transmitted within the same period set for the SSB may be transmitted using different beams (see FIG. 6). FIG. 6 shows a case where SSB #0 to SSB #3 are each transmitted twice in different time domains within a predetermined period (for example, the same period). The number of times the same SSB is transmitted, the range of SSBs, and the order in which the SSBs are transmitted are not limited to this.

[0094] FIG. 6 shows a case where different beams are applied to SSB#0 and SSB#1, SSB#2 and SSB#3, respectively.

[0095] In this case, only one SSB index may be associated with the same PRACH preamble within the same transmission opportunity. For example, SSB#0 and SSB#1 may be associated with a transmission opportunity, and different preamble indices may be associated with SSB#0 and SSB#1.

[0096] When a single SSB index is transmitted multiple times using different beams, the SSB#0 associated with a certain preamble index includes multiple SSB#0s transmitted using different beams. Therefore, as with Option 3-1, it is possible to associate SSBs using different beams (multiple SSBs with the same index) with the same transmission opportunity / same preamble index. This makes it possible to prevent an increase in unused SSBs (or transmission opportunities corresponding to those SSBs) even if the number of SSBs used in communication (e.g., SSB indexes) increases.

[0097] Information about the synchronization signal / SSB to be transmitted multiple times (e.g., resource location / number of transmissions / cycle of SSB, etc.) may be specified in advance (e.g., defined in specifications), or may be notified / configured from the base station to the UE. Notification from the base station to the UE may be made using system information (e.g., MIB / SIB) or RRC.

[0098] In Option 3-1 / 3-2, if the base station can distinguish between preamble transmissions at a certain transmission opportunity corresponding to different SSBs, information about the SSB corresponding to the PRACH preamble received by the base station (e.g., information about the SSB index / SSB resource location, etc.) may be notified to the UE. The information about the SSB may be included in at least one of a random access response (RAR), a PDCCH, and an RMSI. The information about the SSB may be index information for the entire SSB, or index information within SSBs that share the same preamble index for the same transmission opportunity.

[0099] In existing systems, only one SSB index can be associated with the same preamble index at the same transmission opportunity. In contrast, this embodiment supports / allows association of multiple SSB indexes (or SSBs with the same index but different beams) with the same preamble index at the same transmission opportunity. This makes it possible to prevent an increase in unused SSBs (or transmission opportunities corresponding to the SSBs) even when the number of SSBs increases.

[0100] (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.

[0101] 7 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).

[0102] 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.

[0103] 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.

[0104] 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))).

[0105] 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.

[0106] 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).

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0112] 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).

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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).

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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).

[0126] (base station) 8 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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 .

[0138] 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 .

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] The transceiver 120 may receive a random access preamble.

[0144] The control unit 110 may determine at least one of a transmission opportunity and an index to be used for transmitting a random access preamble from each terminal based on at least one of the terminal identification information, the terminal type, the terminal capability information, and information notified to the terminal.

[0145] (user terminal) 9 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] The transceiver 220 may transmit a random access preamble, and may receive information about a synchronization signal block corresponding to the transmitted random access preamble.

[0163] The control unit 210 may determine at least one of a transmission opportunity and an index available for transmitting a random access preamble based on at least one of the terminal identification information, the terminal type, the terminal capability information, and information notified from the base station.

[0164] The random access preamble may have a subcarrier spacing and a sequence length that are set separately. When multiple synchronization signal blocks are associated with a random access preamble transmission opportunity, association of the same random access preamble index with multiple synchronization signal blocks may be supported.

[0165] (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.

[0166] 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.

[0167] 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. 10 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.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] 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).

[0177] 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.

[0178] 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.

[0179] (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.

[0180] 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.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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."

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] 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).

[0206] 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).

[0207] 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).

[0208] 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.

[0209] 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.

[0210] 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).

[0211] 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.

[0212] 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.

[0213] 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.

[0214] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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).

[0222] 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."

[0223] 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.

[0224] 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.

[0225] 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.

[0226] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0227] 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."

[0228] 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.

[0229] 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."

[0230] 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.

[0231] 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.

[0232] 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 control unit that determines at least one of a transmission opportunity and an index available for transmitting a random access preamble based on at least one of identification information of the terminal, a terminal type, terminal capability information, and information notified from the base station; a transmitter that transmits the random access preamble; a subcarrier interval and a sequence length of the random access preamble are set independently; When frequency multiplexing of preamble resources is set, the control unit assumes a sequence length having a number of resource blocks equal to or less than the number of resource blocks of the total frequency-multiplexed preamble resources.

2. The terminal of claim 1 , wherein when multiple synchronization signal blocks are associated with the transmission opportunity for the random access preamble, association of the same random access preamble index to the multiple synchronization signal blocks is supported.

3. 3. The terminal according to claim 1, further comprising a receiving unit that receives information about a synchronization signal block corresponding to a transmitted random access preamble.

4. determining at least one of an available transmission opportunity and an index for transmitting a random access preamble based on at least one of terminal identification information, terminal type, terminal capability information, and information notified by the base station; transmitting the random access preamble; a subcarrier interval and a sequence length of the random access preamble are set independently; A wireless communication method for a terminal, in which, when frequency multiplexing of preamble resources is set, a sequence length is assumed in which the number of resource blocks is equal to or less than the number of resource blocks of the total frequency-multiplexed preamble resources.

5. a control unit that determines at least one of a transmission opportunity and an index to be used for transmitting a random access preamble from each terminal based on at least one of terminal identification information, terminal type, terminal capability information, and information notified to the terminal; a receiving unit for receiving the random access preamble, a subcarrier interval and a sequence length of the random access preamble are set independently; When frequency multiplexing of preamble resources is set, the control unit assumes a sequence length having a number of resource blocks equal to or less than the number of resource blocks of the total frequency-multiplexed preamble resources.

6. A system comprising the terminal according to claim 1 and a base station, The base station includes a receiver for receiving the random access preamble.

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