Terminal

Abstract

A user device in a radiocommunication system including a base station and the user device, including: a receiving unit configured to receive a plurality of predetermined signals transmitted from the base station by means of a plurality of beams; and a transmitting unit configured to transmit a preamble using a feature that corresponds to at least one beam among the plurality of beams, wherein the receiving unit measures a reception quality for each of the plurality of beams, and the transmitting unit transmits the preamble using a feature that corresponds to a beam of a reception quality that satisfies a predetermined condition.

Description

1 / 44 TERMINAL FIELD OF TECHNIQUE

[001] The present invention relates to a user device and a base station in a radio communication system. BACKGROUND OF THE TECHNIQUE

[002] In LTE (Long Term Evolution), random access (RA: Random Access) is performed when a user device establishes a connection with a base station, or performs resynchronization (Non-Patent Document 1).

[003] In 3GPP (3rd Generation Partnership Project), the study of a radio communication scheme called 5G has progressed to achieve additional system capacity increase, additional data transmission speed increase, and less delay in radio sections and the like. In 5G, in order to meet the requirement to make the radio section delay equal to or less than 1 ms while achieving throughput equal to or greater than 10 Gbps, studies of various radio techniques are progressing. Since there is a high possibility that radio techniques other than LTE will be adopted in 5G, a radio network that supports 5G is called a new radio network (NR: New Radio) so that 5G is differentiated from a radio network that supports LTE in 3GPP. Note that NovoRAT can be called NR.

[004] In 5G, it is assumed that a large frequency range from a low-frequency band similar to LTE to a higher-frequency band than that of LTE will be used. Especially in the high-frequency band, since propagation loss increases, the application of narrow-beamwidth beamforming is being studied in order to compensate for it. Prior Art Document [Non-Patent Document] Petition 870250049867, dated 06 / 13 / 2025, p. 12 / 57 2 / 44

[005] [Non-Patent Document 1] 3GPP TS 36.321 V14.0.0 (2016-09) SUMMARY OF THE INVENTION [PROBLEM TO BE SOLVED BY THE INVENTION]

[006] It is considered that in the case of transmitting a signal using beamforming, the base station or user device determines the direction of a transmission beam (Tx-beam) so that the reception quality becomes good on the communication partner's side by performing beam search (beam sweep) or similar. Similarly, it is considered that in the case of receiving a signal using beamforming, the base station or user device determines the direction of a reception beam (Rx-beam) so that the reception quality on the communication partner's side becomes good.

[007] Here, also in NR, it is assumed that a random access procedure similar to the random access procedure in LTE is performed. However, in NR, the application of beamforming as described above is also being studied in the random access procedure.

[008] However, in the case where beamforming is applied in the random access procedure, for example, when the user device detects a plurality of base station-side transmission beams, it is not clear in the conventional technique which base station-side transmission beam should transmit an RA preamble or similar. In the conventional technique, there is a possibility that the random access procedure cannot be properly executed on the radio communication system to which beamforming is applied.

[009] The present invention is produced with a view to the points described above, and an objective of the present invention is to provide a technique that makes it possible for a radio communication system comprising an apparatus Petition 870250049867, dated 06 / 13 / 2025, page 13 / 57 3 / 44 of a user and a base station properly execute a random access procedure to which beamforming is applied. [WAYS TO SOLVE THE PROBLEM]

[0010] According to a described technique, a user device is provided in a radio communication system including a base station and the user device, including: A receiving unit configured to receive a plurality of predetermined signals transmitted from the base station by a plurality of beams; and a transmitting unit configured to transmit a preamble using a feature corresponding to at least one beam among the plurality of beams, wherein the receiving unit measures a reception quality for each of the plurality of beams, and the transmitting unit transmits the preamble using a feature corresponding to a beam of a reception quality that satisfies a predetermined condition. [ADVANTAGE OF THE INVENTION]

[0011] According to a described technique, a technique is provided that enables a radio communication system having a user device and a base station to properly execute a random access procedure to which beamforming is applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a block diagram of a radio communication system in one embodiment of the present invention; Figure 2 is a diagram to explain an example of a random access procedure; Figure 3 is a diagram to explain beams transmitted from the Petition 870250049867, dated 06 / 13 / 2025, page 14 / 57 4 / 44 base station 20; Figure 4 is a diagram to explain a method of transmitting an AR preamble; Figure 5 is a diagram to explain an example of operation in a case where user device 10 receives a plurality of basic broadcast / SS information; Figure 6 is a diagram to explain modality 1; Figure 7 is a sequence diagram for transmitting a threshold from base station 20 to user device 10; Figure 8 is a diagram to explain a method of applying a threshold; Figure 9 is a diagram to explain an example in the case where a threshold is applied in retransmission; Figure 10 is a diagram to explain an example in the case where the RAR window is split in the time direction in mode 2; Figure 11 is a diagram to explain an example in the case where the RAR window is split in the frequency direction in mode 2; Figure 12 is a diagram to explain the case where a common RAR window is used in mode 2; Figure 13 is a diagram showing an example of a functional configuration of user device 10; Figure 14 is a diagram showing an example of a functional configuration of base station 20; Figure 15 is a diagram showing an example of a hardware configuration of user device 10 and base station 20. MODALITIES OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention (present Petition 870250049867, dated 06 / 13 / 2025, page 15 / 57 5 / 44 embodiment) will be described with reference to the accompanying drawings. The embodiments described below are only examples and the embodiments to which the present invention applies are not limited to the embodiments that follow.

[0014] In actual operation of the radiocommunication system of the present embodiment, existing techniques may be used appropriately. Existing techniques are LTE techniques, for example, but are not limited to LTE. Furthermore, LTE, as used in this descriptive report, has a broad meaning including LTE-Advanced and post-LTE-Advanced schemes (e.g., 5G) unless otherwise specified.

[0015] In the modality described below, the terms RA preamble, RAR, messages 1 to 4, RAR window, SIB, and similar terms used in existing LTE are used, but these terms are only used for convenience of description; signals or functions and similar terms similar to signals or functions indicated by the terms may be referred to by other names.

[0016] Furthermore, in the present embodiment, a random access procedure based on the random access procedure prescribed in LTE is considered as an example. However, the target application of the present invention is not limited to the random access procedure. The present invention is also applicable to communication procedures other than the random access procedure.

[0017] Furthermore, selecting basic diffusion / SS information associated with a beam can be considered synonymous with selecting the beam.

[0018] In the following description, modalities 1 and 2 are described. Before the description of modalities 1 and 2, a basic example of a technology as a premise of modalities 1 and 2 is described. Modalities 1 and 2 are described as improvement measures of the basic example. (Basic example) Petition 870250049867, dated 06 / 13 / 2025, page 16 / 57 6 / 44<Configuração total de sistema>

[0019] Figure 1 shows a block diagram of a radio communication system in the present embodiment. The radio communication system of the present embodiment includes a user device 10 and a base station 20 as shown in Figure 1. In Figure 1, a user device 10 and a base station 20 are shown, but this is an example and a plurality of user devices 10 and a plurality of base stations 20 may exist.

[0020] User device 10 is a communication device that has a radio communication function such as a smartphone, a mobile phone, a tablet, a wearable terminal, a communication module for M2M (Machine to Machine), and the like, and user device 10 connects to base station 20 by radio to use various communication services provided by the radio communication system. Base station 20 is a communication device that provides one or more cells and performs radio communication with user device 10. Both user device 10 and base station 20 can perform beamforming to transmit and receive signals.

[0021] In this embodiment, the duplexing mode can be TDD (Time Division Duplexing) or FDD (Frequency Division Duplexing).

[0022] In the following description, transmitting a signal using a transmission beam is synonymous with sending a signal multiplied by a pre-encoding vector (pre-encoded with a pre-encoding vector). Similarly, receiving a signal using a reception beam is synonymous with multiplying a received signal by a predetermined weight vector. Furthermore, transmitting a signal using a transmission beam can be expressed as sending a signal using a specific antenna port. Similarly, receiving a signal using a reception beam can be Petition 870250049867, dated 06 / 13 / 2025, page 17 / 57 7 / 44 expressed as receiving a signal using a specific antenna port. Note that an antenna port indicates a logical antenna port defined in the 3GPP standard. Note that the methods for shaping the transmit and receive beams are not limited to those described above. For example, a method for changing the angle of each antenna can be used in a 10 user device / 20 base station that has a plurality of antennas, a method for combining the method using the precoding vector and the method for changing the antenna angle can be used, and other methods can be used.

[0023] Hereafter, a beam used for signal transmission from base station 20 is called a BS transmission beam, a beam used for signal reception by base station 20 is called a BS reception beam, a beam used for signal transmission from user device 10 is called a UE transmission beam, and a beam used for signal reception by user device 10 is called a UE reception beam. <No procedimento de acesso aleatório>

[0024] An example of a random access procedure in the present embodiment is described with reference to Figure 2. In the present embodiment, as an example, a random access procedure similar to the random access procedure in LTE is executed (Non-Patent Document 1). During signal transmission and reception in the random access procedure, each of the user device 10 and the base station 20 applies a transmission beam and a reception beam. It is observed that a portion of signal transmission and reception may be global transmission / reception.

[0025] Base station 20 performs beam scanning and transmits basic broadcast information and a synchronization signal (SS: synchronization signal, Petition 870250049867, dated 06 / 13 / 2025, page 18 / 57 8 / 44 hereinafter referred to as SS) at predetermined intervals respectively for each BS transmission beam (step S101). The transmission periods of the basic broadcast information and the synchronization signal may be the same or different. SIB (System Information Block), described later, is also transmitted at a predetermined interval for each BS transmission beam. SIB may be referred to as “system information”. In the basic example, the transmission period of the SIB is longer than the transmission periods of the basic broadcast information and the synchronization signal, and the size of the SIB is larger than the size of either the basic broadcast information or the synchronization signal.

[0026] Figure 3 shows an image of BS transmission beams. In the example in Figure 3, three transmission beams A, B, and C are shown. In each of the three BS transmission beams, basic broadcast information, an SS, a SIB, and the like are transmitted. In beam scanning, for example, the BS transmission beams are switched for each time (e.g., for each symbol).

[0027] Basic broadcast information is, for example, basic system information (corresponding to MIB in LTE) transmitted on a PBCH. SS includes, for example, two types of signals (code sequences) of P-SS and SSS. P-SS is a signal for the purpose of symbol timing synchronization, for example, and S-SS is a signal for the purpose of radio frame synchronization or similar, for example.

[0028] By receiving basic broadcast information or an SS or “basic broadcast information and SS” via a BS transmission beam, the user device 10 can identify the BS transmission beam. Identifying a BS transmission beam is, for example, detecting an identifier (ID) of the BS transmission beam. An ID of a beam Petition 870250049867, dated 06 / 13 / 2025, page 19 / 57 9 / 44 BS transmission can be an antenna port number. For example, a BS transmission beam ID can be included in the basic broadcast information or can be included in a SS. Additionally, the BS transmission beam ID can be associated with a resource (time and / or frequency resource) through which the basic broadcast information or SS is transmitted, so that the user device can identify the BS transmission beam by the resource with which the basic broadcast information or SS is received.

[0029] A block including any of the P-SS, S-SS, and basic broadcast information may be termed an SS block. User device 10 may assume that receiving an SS block transmitted from base station 20 (to verify the contents of the SS block) is to identify the BS transmission beam associated with the SS block. In this case, for example, user device 10 identifies a BS transmission beam ID from the contents of the received SS block or from the resource with which the SS block is received.

[0030] In the case where a resource of an SS block is associated with a BS transmission beam, it is not necessary that the “BS transmission beam ID” to be identified by user device 10 be an ID assigned to the BS transmission beam (this is referred to as the “beam ID”). For example, a time position (e.g., symbol index) of the SS block above is associated with the BS transmission beam and is associated with a RACH resource subset that is a resource used to transmit an RA preamble. In this case, the time position (e.g., symbol index) can be considered the “BS transmission beam ID”. In this case, it is only necessary that user device 10 recognize the time position (e.g., symbol index) of the SS block. Furthermore, in this case, for example, the beam ID can be included in the basic broadcast information.

[0031] That the SS block feature be associated with the transmission beam Petition 870250049867, dated 06 / 13 / 2025, page 20 / 57 10 / 44 of BS means that, for example, in the case where there is a BS transmission beam A and a BS transmission beam B, the same BS transmission beam A is used in symbol A and the same BS transmission beam B is used in symbol B every time in a period of one unit of time.

[0032] When the SS block resource is not associated with the BS transmission beam, for example, base station 20 includes the beam ID in the basic broadcast information and transmits it, so that user device 10 identifies the BS transmission beam by reading the beam ID transmitted by the basic broadcast information.

[0033] The technique in this mode can be applied to either of the two patterns above. In step S102 of Figure 2, user device 10 transmits an RA preamble (Message 1) using a resource (which is called a RACH resource subset) corresponding to a BS transmission beam of basic broadcast information and / or SS (which are represented as “basic broadcast information / SS”) that can be received in step S101.

[0034] Upon detection of the RA preamble, base station 20 transmits an RA response (RAR, Message 2) as an RA preamble response to user device 10 (step S103). User device 10 receiving the RA response transmits a Message 3 including predetermined information to base station 20 (step S104). Message 3 is, for example, an RRC connection request.

[0035] Base station 20, which receives Message 3, transmits Message 4 (example: RRC connection configuration) to user device 10. After user device 10 confirms that predetermined information is included in Message 4, user device 10 recognizes that Message 4 is a Message 4 corresponding to Message 3 and that it is Petition 870250049867, dated 06 / 13 / 2025, page 21 / 57 11 / 44 addressed to user device 10 itself, then user device 10 completes the random access procedure. On the other hand, when user device 10 cannot identify the predetermined information in Message 4, user device 10 considers this a random access failure, so user device 10 executes the procedure of transmitting an RA preamble again. <No método de transmissão de preâmbulo de RA>

[0036] An example of a method for transmitting an RA preamble in step S102 is described in more detail.

[0037] In this embodiment, the user device 10 selects basic broadcast / SS information that can be received from a plurality of transmitted basic broadcast / SS information by applying beam sweeping from the base station 20. This is the same as selecting a BS transmission beam that transmits the received basic broadcast / SS information. Received here means, for example, that it is received with good reception quality, but the term is not limited to this.

[0038] In this embodiment, a BS transmission beam from base station 20 and a RACH resource subset that is a resource to be used to transmit an RA preamble from user device 10 are associated with each other. User device 10 transmits an RA preamble using a RACH resource subset corresponding to a selected BS transmission beam.

[0039] As an example, Figure 4 shows A, B, and C as RACH feature subsets on the user device side 10. The RACH feature subsets A, B, C correspond to the BS transmission beams A, B, C, as shown in Figure 3, respectively, for example. In Figure 4, a plurality of RACH feature subsets is Petition 870250049867, dated 06 / 13 / 2025, p. 22 / 57 12 / 44 associated with each BS transmission beam being split in the time direction, but this is just one example. A plurality of RACH feature subsets may be associated with each BS transmission beam being split in the frequency direction, or a plurality of RACH feature subsets may be associated with each BS transmission beam being split in time and frequency units.

[0040] The example in Figure 4 indicates that user device 10 can receive basic broadcast / SS information transmitted with the BS B transmission beam, therefore, user device 10 transmits an RA preamble using the RACH B feature subset corresponding to the BS B transmission beam.

[0041] Based on a received RA preamble feature from user device 10, base station 20 can determine basic broadcast / SS (BS transmission beam) information received by user device 10. In the example in Figure 4, since base station 20 receives an RA preamble via the RACH feature subset B, base station 20 can determine that the BS transmission beam B corresponding to the RACH feature subset B is an appropriate BS transmission beam that user device 10 can receive. For example, base station 20 can use the BS transmission beam B in transmitting the signal to user device 10 afterward. Note that in Figure 4, the beams indicated by E, F, and G on the base station 20 side indicate BS reception beams, and in this example, as shown in the figure, base station 20 is shown to be performing beam scanning on the receiving side.

[0042] Furthermore, Figure 4 shows an RAR window. In the present embodiment, similarly to existing LTE, when the user device 10 transmitting an AR preamble monitors an AR response, but does not Petition 870250049867, dated 06 / 13 / 2025, page 23 / 57 13 / 44 receives the RA response within a predetermined time indicated by the RAR window, it is determined that random access failed. However, this is an example, and processing different from that of existing LTE can be performed as processing to determine if the RA response is successfully received.

[0043] The example in Figure 4 shows a case where user device 10 can receive basic broadcast / SS information using a BS transmission beam. Or the example in Figure 4 shows a case where user device 10 can receive basic broadcast / SS information using a plurality of BS transmission beams, and selects a BS transmission beam that can be received in the best way (example: the reception quality is the best) from the plurality of BS transmission beams.

[0044] When user device 10 receives basic broadcast / SS information via a plurality of BS transmission beams, user device 10 can transmit RA preambles using a plurality of RACH feature subsets corresponding to the plurality of BS transmission beams respectively. By transmitting RA preambles using a plurality of RACH feature subsets, the diversity effect can be achieved.

[0045] For example, when there is a plurality of BS transmission beams through which the basic broadcast / SS information (or the reference signal) can be received with good reception quality to the same degree, the user device 10 selects the plurality of BS transmission beams, and transmits an RA preamble through each of a plurality of RACH feature subsets corresponding to the plurality of BS transmission beams. Consequently, the base station 20 may have Petition 870250049867, dated 06 / 13 / 2025, p. 24 / 57 14 / 44 the ability to detect a truly ideal BS transmission beam. Furthermore, since it can be considered that UE transmission beams and / or BS reception beams may differ between a plurality of RACH feature subsets, base station 20 may have the ability to receive the RA preamble with the ideal beam.

[0046] Figure 5 shows, as an example, a case in which user device 10 transmits RA preambles using RACH feature subsets B and C corresponding to BS transmission beams B and C. It can be observed that, when transmitting an RA preamble in each of a plurality of RACH feature subsets, the content (sequence) of the RA preambles may be the same or different between the plurality of RACH feature subsets. <No método para notificar subconjuntos de recurso de RACH>

[0047] In this embodiment, base station 20 transmits information indicating a RACH feature subset corresponding to a BS transmission beam to user device 10. Based on this information, user device 10 can identify a RACH feature subset corresponding to a BS transmission beam from received basic broadcast / SS information. As an example, if user device 10 receives information from base station 20 indicating a RACH feature subset A as a RACH feature subset corresponding to a BS transmission beam A, and user device 10 selects the BS transmission beam A to transmit an RA preamble, user device 10 transmits the RA preamble using the RACH feature subset A.

[0048] “Information indicating a subset of RACH resource” notified from base station 20 to user device 10 may be Petition 870250049867, dated 06 / 13 / 2025, page 25 / 57 15 / 44 information that indicates a time / frequency feature of the RACH feature subset (example: a feature index), or information that indicates a time feature of the RACH feature subset (time position), or it could be other information.

[0049] For example, the above information is reported, for each BS transmission beam, using a SIB transmitted by the BS transmission beam. In addition, in a SIB transmitted by a BS transmission beam, information from a RACH feature subset corresponding to another BS transmission beam may be included. <Na transmissão de uma pluralidade de preâmbulos de RA>

[0050] From the point of view of quickly connecting to base station 20, it can be considered that user device 10 freely transmits a plurality of RA preambles using the RACH resource subsets associated with each of the plurality of basic broadcast / SS information that can be detected. However, in this case, there is a possibility that user device 10 transmits the RA preamble using the RACH resource subset associated with the basic broadcast / SS information that cannot be received with appropriate reception quality.

[0051] For example, if user device 10 receives two SS and there is a large difference in reception quality between them, the probability that the RA preamble transmitted in the RACH resource subset corresponding to the SS with poor reception quality will be successfully received by base station side 20 is low. Furthermore, the probability of the RA preamble being unusable is high from the point of view of the suitability of the UE transmission beam and the BS reception beam. Additionally, transmitting an unusable RA preamble is considered. Petition 870250049867, dated 06 / 13 / 2025, p. 26 / 57 16 / 44 as described above, this will disperse interference to the surrounding areas. Additionally, if the RA preamble corresponding to the worst reception quality is received by base station 20 and subsequent processing is also continued, the possibility that the BS transmission beam is not appropriate is high, so there is a possibility that the performance of subsequent communication will deteriorate.

[0052] In particular, the effect is more noticeable in cases where there is BS / UE beam matching, i.e., channel reciprocity is available on the BS / UE side. (Overview of the modalities)

[0053] Therefore, in the modes described below, a limit related to the reception quality of the BS transmission beam is provided. Basically, when the reception quality of the BS transmission beam on user device 10 is better than the threshold, an RA preamble is transmitted using the RACH feature subset associated with the BS transmission beam.

[0054] Reception quality is not limited to one particular quality. For example, reception quality is the received power of a desired signal received from base station 20 by user device 10, a ratio between interference and received power (received power / interference, called SNR), or a ratio between “interference + noise” and received power (received power / (interference + noise), called SINR). In addition, received quality may be a path loss related to the BS transmission beam. The desired signal above is, for example, basic broadcast / SS information, a reference signal, or a data signal transmitted by the target BS transmission beam.

[0055] As described above, when using received power or a value Petition 870250049867, dated 06 / 13 / 2025, page 27 / 57 17 / 44, which uses received power as the numerator as a reception quality, if the reception quality value is high, the reception quality is good. On the other hand, when using path loss as the reception quality, if the path loss value is low, the reception quality is good. That is, depending on the type of reception quality being used, there is a case where the higher the reception quality value, the better the reception quality, and a case where the lower the reception quality value, the better the reception quality.

[0056] In this form, greater than or less than can be replaced by greater than or equal to and less than or equal to.

[0057] Henceforth, for the sake of clarity, reception quality is described as improving as the value increases, as does the received power, for example. As for reception quality improving as the value decreases, “greater than” in the following explanation can be replaced by “less than”. Furthermore, in some cases, the expression reception quality is better than the threshold is used as an expression that includes the threshold.

[0058] Several examples using a threshold are described as a 1-mode. In addition, variations related to the RAR window based on 1-mode are described as 2-mode. In the explanation of 1-modes and 2, improvement parts (i.e., modification parts) of the basic example technique described so far are described, and therefore, in the case where the explanation is not specifically provided, the basic example is basically applied. (Modality 1)

[0059] As described above, in the present embodiment, a threshold in the reception quality of the BS transmission beam is provided, and basically, Petition 870250049867, dated 06 / 13 / 2025, page 28 / 57 18 / 44 When the reception quality of the BS transmission beam on user device 10 satisfies a predetermined condition, user device 10 transmits an RA preamble using a RACH feature subset associated with the BS transmission beam (basic broadcast information / SS). Specific examples of the predetermined conditions are described below, but the predetermined conditions are not limited to the following examples.

[0060] As an example, the predetermined condition is that the reception quality is greater than a threshold. For example, in the case where the threshold is TH, if the reception quality X on the BS B transmission beam shown in Figure 5 is above TH and the reception quality Y on the BS C transmission beam is less than TH, the user device 10 transmits an RA preamble using a RACH feature subset associated with the BS B transmission beam.

[0061] For example, user device 10 applies the above threshold to all detected BS transmission beams. Furthermore, user device 10 can apply the threshold only to BS transmission beams of reception quality after the Nth best reception quality, arranging reception qualities of the detected plurality of BS transmission beams in descending order of good reception quality. For example, in the example in Figure 5 described above, if X > Y and N is 2, user device 10 applies the threshold only to BS transmission beam C. That is, user device 10 applies the threshold only to the second best BS transmission beam C.

[0062] Furthermore, the threshold may be different for each BS transmission beam. For example, in the example in Figure 5, TH1 is used for reception quality X in the BS transmission beam B, and TH2 is used for reception quality X. Petition 870250049867, dated 06 / 13 / 2025, page 29 / 57 19 / 44 reception X on the BS C transmission beam. When using different thresholds for each BS transmission beam, for example, the higher the reception quality, the higher the threshold value to use.

[0063] The threshold can be a value (which is called a “direct comparison threshold”) used directly for comparison with the reception quality, as mentioned above, or it can be a relative value (which is called a “relative threshold”). As for the threshold as the relative value, for example, user device 10 compares the relative threshold with a difference that is obtained by subtracting the reception quality in the target BS transmission beam from the highest reception quality in reception qualities of the plurality of BS transmission beams and, when the difference is less than the relative threshold, user device 10 determines that user device 10 can transmit the RA preamble using the RACH feature subset associated with the target BS transmission beam.

[0064] An example of this case is described with reference to Figure 6. In the example in Figure 6, the relative threshold is 3. For example, user device 10 measures the reception quality of basic broadcast / SS information transmitted by the BS B transmission beam as X, and measures the reception quality of basic broadcast / SS information transmitted by the BS C transmission beam as Y. Since X>Y is satisfied, the reception quality of basic broadcast / SS information transmitted by the BS B transmission beam is the best. User device 10 transmits an RA preamble using a RACH feature subset associated with the BS B transmission beam. Furthermore, user device 10 compares (XY) with 3, and if (XY) < 3 is satisfied, user device 10 transmits an RA preamble using the RACH feature subset associated with the BS transmission beam. Petition 870250049867, dated 06 / 13 / 2025, page 30 / 57 20 / 44 W.

[0065] In the example above, the direct comparison limit can be applied to the first preamble of RA.

[0066] An upper threshold value can be set for the number of RA preambles that can be sent simultaneously (i.e., the number of RACH resource subsets available concurrently). Note that concurrent means a time interval that can be considered concurrent.

[0067] For example, in the case where the forward comparison threshold is used, when 3 is provided as an upper threshold value, even if there are four BS transmission beams whose reception quality is greater than the forward comparison threshold, the number of RA preambles that can be transmitted simultaneously is three. In this case, for example, an RA preamble for a BS transmission beam with the worst reception quality among the four is not transmitted.

[0068] Furthermore, for example, in the case of using the relative threshold described with reference to Figure 6, it is assumed that there are N BS transmission beams (which includes the BS transmission beam of the highest reception quality) that have reception quality between the highest reception quality and (highest reception quality - relative threshold). If there is no upper threshold value, or the upper threshold value is greater than N, N RA preambles are transmitted. On the other hand, for example, if the upper threshold value is M( <N), M preâmbulos de RA são transmitidos. <Quanto ao limiar>

[0069] The threshold mentioned above (direct comparison threshold, relative threshold) is, for example, reported by DCI, a MAC signal, an RRC signal and similar signals from base station 20 to user device 10. Or, the threshold may Petition 870250049867, dated 06 / 13 / 2025, p. 31 / 57 21 / 44 to be pre-configured on base station 20 and user device 10.

[0070] Figure 7 shows a sequence diagram for transmitting the threshold from base station 20 to user device 10. As shown in Figure 7, base station 20 transmits the threshold to user device 10 (step S201). User device 10 stores the threshold in a storage unit such as memory. Additionally, user device 10 determines the availability of RA preamble transmission for basic broadcast / SS information (BS transmission beam) that can be received using reception quality on the BS transmission beam and the threshold, and if transmission is available, user device 10 performs the transmission (step S202). <Aplicação de limiar em retransmissão>

[0071] In this embodiment, as in existing LTE, a RAR (time window) is provided. After transmitting an RA preamble, user device 10 monitors a RAR (RACH response) within the RAR window. More specifically, user device 10 performs blind decoding using an RA-RNTI. After transmitting an RA preamble, if user device 10 does not receive a RAR corresponding to the RA preamble within the RAR window, user device 10 retransmits the RA preamble.

[0072] Regarding the threshold already described, the same can be applied by the same method for initial transmission and retransmission (including retransmission on or after the second retransmission) of an RA preamble. User device 10 can transmit an RA preamble without applying a threshold on the initial transmission, and can apply the threshold on the retransmission. Furthermore, user device 10 can not apply the threshold for RA preambles up to and including the Nth transmission (N is an integer equal to or greater than 1). Petition 870250049867, dated 06 / 13 / 2025, page 32 / 57 22 / 44 the initial transmission, and may apply a threshold when determining the transmission of the RA preamble after the (N+1)-th transmission (including the (N+1)-th transmission). Furthermore, user device 10 may apply the threshold to RA preambles up to the N-th transmission (N is an integer equal to or greater than 1) including the initial transmission, and may not apply a threshold when determining the transmission of the RA preamble after the (N+1)-th transmission (including the (N+1)-th transmission). For example, when N=1, the threshold is applied to the initial transmission, and the threshold is not applied to retransmissions after that.

[0073] ON above is, for example, notified by DCI, a MAC signal, an RRC signal and the like from base station 20 to user device 10. Or, N can be pre-configured on base station 20 and user device 10.

[0074] Regarding reception quality, a reception quality measured at a time when an RA preamble is transmitted (immediately before the actual transmission) can be used, or, when the time interval between initial transmission (or previous retransmission) and retransmission is short, a reception quality measured at the initial transmission (or previous retransmission) can be used for retransmission determination.

[0075] The example shown in Figure 8 illustrates the case where N=1. As shown in Figure 8, user device 10 applies the threshold when performing the first retransmission without applying the threshold in the initial transmission.

[0076] When performing a retransmission, there is a case where user device 10 transmits an RA preamble using a different RACH feature subset than the RACH feature subset used for the initial transmission (or previous retransmission). For example, at the time of initial transmission, user device 10 transmits the RA preamble using a Petition 870250049867, dated 06 / 13 / 2025, page 33 / 57 23 / 44 RACH resource subset corresponding to BS transmission beam A as one of the detected BS transmission beams; however, since RAR cannot be received, user device 10 transmits an RA preamble using a RACH resource subset corresponding to BS transmission beam B, which is another beam among the plurality of detected BS transmission beams in retransmission. In such a case, user device 10 can determine, using a threshold, the possibility of changing RACH resource subsets between RA preamble transmission and the next RA preamble transmission as a retransmission for the RA preamble transmission.

[0077] A specific example is described with reference to Figure 9. First, a case is described in which the direct comparison threshold TH is used. For example, detecting that a reception quality in the transmission beam of BS B is greater than TH, the user device 10 transmits (initial transmission) an RA preamble using the RACH feature subset B associated with the transmission beam of BS B (initial transmission).

[0078] User device 10 decides to retransmit an RA preamble using a different RACH feature subset because it sent an RA preamble using RACH feature subset B but did not receive the RAR in the RAR window. In this case, for example, user device 10 detects the BS C transmission beam as a BS transmission beam with a reception quality above TH, unlike the BS B transmission beam. More specifically, for example, user device 10 detects that basic broadcast / SS associated with the BS C transmission beam can be received with a reception quality higher than TH. Therefore, user device 10 retransmits an RA preamble using the RACH C feature subset associated with the BS C transmission beam. Petition 870250049867, dated 06 / 13 / 2025, p. 34 / 57 24 / 44

[0079] The following case describes a situation where the relative RTH limit is used. User device 10 decides to retransmit the RA preamble using a different RACH resource subset because it sent the RA preamble using the RACH resource subset B corresponding to the BS transmission beam B but did not receive the RAR in the RAR window.

[0080] In this document, it is assumed that the reception quality on the BS B transmission beam is B. For example, user device 10 detects the BS C transmission beam as a BS transmission beam whose reception quality is greater than (B-RTH). Then, user device 10 retransmits an RA preamble using the RACH C feature subset associated with the BS C transmission beam.

[0081] As described above, in this mode, since the transmission of the RA preamble is limited using the threshold, the possibility of inappropriate beam selection that can occur when transmitting an RA preamble using a RACH feature subset corresponding to a BS transmission beam whose reception quality is not good can be reduced, and interference in the vicinity can be reduced. (Modality 2)

[0082] Next, a modality 2 is described. Modality 2 is based on the premise of modality 1 (RA preamble transmission restriction using thresholding). However, it is not necessary to assume that modality 1 is a prerequisite, and only the basic example can be assumed. In modality 2, an example of RAR window definition is described. Next, a 2-1 modality and a 2-2 modality are described. <Modalidade 2-1>

[0083] In the 2-1 mode, a RAR window is configured for each of a plurality of RACH feature subsets corresponding to Petition 870250049867, dated 06 / 13 / 2025, page 35 / 57 25 / 44 different BS transmission beams.

[0084] Figure 10 shows an example of a case where RAR windows for each of a plurality of RACH feature subsets are configured by splitting a RAR window in the time direction. In the case of Figure 10, a RAR window B is configured for the RACH feature subset B through which an RA preamble is transmitted, and a RAR window C is configured for the RACH feature subset C through which an RA preamble is transmitted.

[0085] For example, by defining, on user device 10, a time duration (to be called offset for convenience) from the timing (time) at which the RA preamble is transmitted to an initial timing (time) of the RAR window corresponding to the RACH feature subset through which the RA preamble is transmitted, and a time duration (to be called window time duration for convenience) of the RAR window, user device 10 can determine the RAR window corresponding to the RA preamble based on the offset and window time duration. Furthermore, base station 20 maintains the offset and window time duration, so that base station 20 can specify the RAR window that is used by user device 10 based on the timing at which the RA preamble is received.

[0086] The offset and window time duration mentioned above can be notified by DCI, a MAC signal, an RRC signal and the like from base station 20 to user device 10, or they can be pre-configured on base station 20 and user device 10.

[0087] Figure 11 shows an example of a case where the RAR windows for each of a plurality of RACH feature subsets are configured by splitting a RAR window in the frequency direction. In the case Petition 870250049867, dated 06 / 13 / 2025, page 36 / 57 26 / 44 of Figure 11, a RAR window B is configured for the RACH B feature subset through which an RA preamble is transmitted, and a RAR window C is configured for the RACH C feature subset through which an RA preamble is transmitted.

[0088] For example, by defining, in user device 10, a correspondence relationship between the RA preamble transmission timer and a frequency position (example: width and center frequency), user device 10 can determine the RAR window based on the timing when transmitting the RA preamble and the correspondence relationship. Regarding the position (initial timing and time duration) of the RAR window in the time direction, for example, an initial timing and time duration in relation to a predetermined number of RACH feature subsets (example: three RACH feature subsets A, B and C shown in Figure 11) are fixed for the predetermined number of RACH feature subsets as common values, so that they are used. Or, the method described with reference to Figure 10 can be applied to the time direction in the method shown in Figure 11.

[0089] Information indicating the correspondence relationship between the RA preamble transmission timer and the frequency position can be notified by DCI, a MAC signal, an RRC signal and the like from base station 20 to user device 10, or can be pre-configured on base station 20 and user device 10.

[0090] In the 2-1 mode, for example, a plurality of RAR windows corresponding to a plurality of RA preamble transmissions is configured so that they do not overlap. Consequently, the user device 10 can determine which RACH feature subset (i.e., which BS transmission beam) the received RAR corresponds to based on Petition 870250049867, dated 06 / 13 / 2025, pp. 37 / 57 27 / 44 in the RAR window where the RAR is received. As described above, by configuring the plurality of RAR windows to correspond to the plurality of RA preamble transmissions so that they do not overlap, the identifier transmission mentioned later is unnecessary, thus reducing the amount of signaling.

[0091] In the 2-1 mode, it is possible to allow the plurality of RAR windows corresponding to the plurality of RA preamble transmissions to overlap. In this case, for example, base station 20 includes, within the RAR or RA-RNTI (identifier indicating that the transmission signal is a RAR), an identifier to identify which RACH feature subset (i.e., which BS transmission beam) the RAR corresponds to. The identifier is, for example, an index to identify basic broadcast / SS information, or an index to identify the RACH feature subset. For example, when there is an overlap time width between a RAR-A window and a RAR-B window, even if user device 10 receives a RAR within the overlap time width, user device 10 can determine which RACH feature subset the RAR corresponds to by the identifier above.By allowing overlap in this way, the entire duration of the RAR window can be shortened, so that the delay can be reduced. <Modalidade 2-2>

[0092] As shown in Figure 12, in the 2-2 mode, a RAR window is commonly configured for a plurality of RACH feature subsets corresponding to different BS transmission beams. For example, a RAR window is commonly configured for N (N is an integer equal to or greater than 1) RACH feature subsets. The value of N can be reported by DCI, a MAC signal, an RRC signal, and similar signals from base station 20 to user device 10, and can be pre-configured in Petition 870250049867, dated 06 / 13 / 2025, page 38 / 57 28 / 44 base station 20 and in the user device 10, or a value equal to a value can be determined (example: the number of BS transmission beams).

[0093] Furthermore, for example, when user device 10 transmits an RA preamble using at least one RACH feature subset in N consecutive RACH feature subsets, user device 10 monitors a RAR in the RAR (common) window corresponding to the N RACH feature subsets.

[0094] For example, regarding an RA window for N RACH feature subsets, defining, on user device 10, a time duration (to be called offset for convenience) from the end of the N RACH feature subsets in the time direction to an initial timing (time) of the RAR window, and a time duration (to be called window time duration for convenience) of the RAR window, user device 10 can determine the RAR window based on the offset and window time duration. Furthermore, base station 20 maintains the offset and window time duration, so that base station 20 can specify the RAR window that is used by user device 10 based on the timing at which the RA preamble is received.

[0095] The offset and window time duration mentioned above can be notified by DCI, a MAC signal, an RRC signal and the like from base station 20 to user device 10, or they can be pre-configured on base station 20 and user device 10.

[0096] In the 2-2 mode, a common RAR window for a plurality of RACH feature subsets is used, therefore, for example, base station 20 includes, within the RAR or RA-RNTI, an identifier to identify which RACH feature subset (i.e., which BS transmission beam) the RAR corresponds to. The identifier is, for example, an index to identify Petition 870250049867, dated 06 / 13 / 2025, page 39 / 57 29 / 44 basic broadcast information / SS, or an index to identify the RACH feature subset. For example, even when user device 10 receives a RAR in a RAR window common to a plurality of RACH feature subsets, user device 10 can determine which RACH feature subset the RAR corresponds to.

[0097] Furthermore, the order of RACH resource subsets can be associated with the RAR order within the RA window. For example, as shown in Figure 12, in the case where user device 10 transmits an RA preamble using RACH resource subset B and then transmits an RA preamble using RACH resource subset C, user device 10 determines that a RAR received first in the RAR window common to these RACH resource subsets is the RAR corresponding to RACH resource subset B, and determines that a RAR received subsequently is a RAR corresponding to RACH resource subset C.

[0098] In the example above, a RAR window is commonly configured for a plurality of RACH resource subsets. However, the technique is not limited to this. A common RAR window can be configured for a plurality of RACH resources used for RA preamble transmission by the user device 10 between individual RACH resources included in a RACH resource subset. This is explained with reference to Figure 12. For example, in a case where the transmission of two RA preambles is performed using two RACH resources between a plurality of individual RACH resources included in the RACH resource subset indicated by B, a common RAR window is commonly configured for the transmission of the two RA preambles.

[0099] Furthermore, in a case where a common RAR window is Petition 870250049867, dated 06 / 13 / 2025, pp. 40 / 57 30 / 44 configured for a plurality of RACH resources used for RA preamble transmission, for example, base station 20 includes an identifier in a RAR or an RA-RNTI, to identify which RACH resource the RAR corresponds to.

[00100] Just like the 2-2 mode, by using the common RAR window for a plurality of RACH feature subsets, the entire duration of the RAR window can be reduced, so that latency can be eliminated. (Device Setup)

[00101] Below is an example of the functional configurations of user device 10 and base station 20 that perform the operations described above. Each of user device 10 and base station 20 includes at least functions to implement modes 1 and 2. However, each of user device 10 and base station 20 may include only a portion of the functions in modes 1 and 2. <Aparelho de Usuário>

[00102] Figure 13 is a diagram illustrating an example of a functional configuration of the user device 10. As illustrated in Figure 13, the user device 10 includes a signal transmission unit 101, a signal reception unit 102, a configuration information management unit 103, and an AR control unit 104. The signal reception unit 102 includes a measurement unit 112 configured to measure reception quality. The functional configuration illustrated in Figure 13 is only an example. The functional subdivision and names of the functional units are not particularly limited as long as the operations associated with the mode can be performed. The signal transmission unit 101 and the signal reception unit 102 can be designated as a Petition 870250049867, dated 06 / 13 / 2025, pp. 41 / 57 31 / 44 transmitter and one receiver, respectively.

[00103] Signal transmission unit 101 generates a transmission signal from transmission data to transmit the transmission signal by radio. Signal reception unit 102 receives various signals by radio, and obtains a higher layer signal from a signal received from the physical layer. Furthermore, signal transmission unit 101 is configured to perform beamforming on the transmission side, and signal reception unit 102 is configured to perform beamforming on the reception side.

[00104] The configuration information management unit 103 stores various configuration information received from the base station 20 by the signal receiving unit 102. The content of the configuration information includes, for example, threshold information, beam matching information, and subsets of RACH features and similar information described so far. In addition, the configuration information management unit 103 stores the configuration information pre-configured in the user device 10.

[00105] The RA control unit 104 performs the random access procedure processing on the user device 10 described in the basic example and in embodiments 1 and 2. Note that a functional unit related to signal transmission in the RA control unit 104 can be included in the signal transmission unit 101 and a functional unit related to signal reception in the RA control unit 104 can be included in the signal reception unit 102.

[00106] In addition, for example, signal receiving unit 102 is configured to receive a plurality of predetermined signals transmitted from the base station by a plurality of beams; and the unit Petition 870250049867, dated 06 / 13 / 2025, pp. 42 / 57 Signal transmission unit 101 is configured to transmit a preamble using a resource corresponding to at least one beam among a plurality of beams, and signal reception unit 102 is configured to measure a reception quality for each of the plurality of beams, and signal transmission unit 101 is configured to transmit the preamble using a resource corresponding to a beam of a reception quality that satisfies a predetermined condition.

[00107] The predetermined condition is, for example, that: the reception quality is better than a predetermined threshold, or a difference between the reception quality and the best reception quality among the reception qualities among the plurality of beams is less than a predetermined relative threshold.

[00108] The signal transmission unit 101 can be configured to use resources corresponding to a predetermined upper threshold number of beams from all beams whose reception quality satisfies the predetermined condition in order to transmit the upper threshold number of preambles.

[00109] The signal transmission unit 101 can be configured to perform retransmission for a preamble transmitted by a first resource using a second resource corresponding to a beam whose reception quality satisfies the predetermined condition.

[00110] Signal receiving unit 102 can be configured to monitor a response to a preamble within a time window corresponding to a resource used to transmit the preamble by signal transmitting unit 101, or signal receiving unit 102 can be configured to monitor a response to the preamble within a time window common to a plurality of resources including a resource Petition 870250049867, dated 06 / 13 / 2025, pp. 43 / 57 33 / 44 used to transmit the preamble via signal transmission unit 101. <Estação base 20>

[00111] Figure 14 is a diagram illustrating an example of a functional configuration of base station 20. As illustrated in Figure 14, base station 20 includes a signal transmission unit 201, a signal reception unit 202, a configuration information management unit 203, and an RA control unit 204. The functional configuration illustrated in Figure 14 is only an example. The functional subdivision and names of the functional units are not particularly limited as long as the operations associated with the mode can be performed. The signal transmission unit 201 and the signal reception unit 202 can be referred to as a transmitter and a receiver, respectively.

[00112] Signal transmission unit 201 includes a function configured to generate a signal to be transmitted to the user device side 10, and to transmit the signal by radio. Signal reception unit 202 includes a function configured to receive various signals transmitted from user device 10, and to obtain upper-layer information from the received signal. Furthermore, signal transmission unit 201 is configured to perform beamforming on the transmit side, and signal reception unit 202 is configured to perform beamforming on the receive side.

[00113] The configuration information management unit 203 stores various configuration information to be transmitted to the user device 10. The content of the configuration information includes, for example, threshold information, matching information described so far. In addition, the configuration information management unit 203 stores pre-configured configuration information in Petition 870250049867, dated 06 / 13 / 2025, pp. 44 / 57 34 / 44 base station 20.

[00114] The RA 204 control unit performs the random access procedure processing on base station 20 described in embodiments 1 and 2. Note that a functional unit related to signal transmission in the RA 204 control unit may be included in signal transmission unit 201 and a functional unit related to signal reception in the RA 204 control unit may be included in signal reception unit 202. <Configuração de Hardware >

[00115] The block diagrams (Figures 13 and 14), which are used above to describe the embodiments, illustrate blocks in the function units. The function blocks (constituent units) are incorporated into an arbitrary combination of hardware and / or software. The means of incorporating the function blocks is not particularly limited. That is, the function blocks can be incorporated by a unit in which a plurality of components are coupled physically and / or logically, or they can be incorporated by two or more devices that are physically and / or logically separated and that are connected directly and / or indirectly (e.g., in a wired and / or wireless manner).

[00116] For example, user device 10 and base station 20, according to this embodiment, can function as computers that perform processes according to this embodiment. Figure 15 is a diagram illustrating an example of a hardware configuration of user device 10 and base station 20 according to this embodiment. User device 10 and base station 20 can 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, and a bus 1007. Petition 870250049867, dated 06 / 13 / 2025, pp. 45 / 57 35 / 44

[00117] In the following description, a device word may refer to a circuit, a device, a unit, or similar. The hardware configurations of user device 10 and base station 20 may include one or more devices indicated by numerical references 1001 to 1006 in the drawings, or may not include some devices in them.

[00118] The functions of the user device 10 and the base station 20 are performed by having hardware such as the processor 1001 and memory 1002 read predetermined software (a program) and having the processor 1001 perform calculations and control the communication of the communication device 1004 and read and / or record data in memory 1002 and storage 1003.

[00119] The 1001 processor controls the computer as a whole, for example, by activating an operating system. The 1001 processor may consist of a central processing unit (CPU) including an interface with peripherals, a control device, a calculation device, a register, and the like.

[00120] Processor 1001 reads a program (program codes), a software module, or data from storage 1003 and / or communication device 1004 into memory 1002 and performs various processes accordingly. As for the program, a program is used that causes a computer to perform at least some of the operations described above in the embodiment. For example, the signal transmission unit 101, the signal reception unit 102, the configuration information management unit 103, and the AR control unit 104 of the user device 10 shown in Figure 13 may incorporate a control program that is stored in memory 1002 and operated by processor 1001. The signal transmission unit 201, the signal reception unit 202, Petition 870250049867, dated 06 / 13 / 2025, pp. 46 / 57 36 / 44 The configuration information management unit 203 and the RA control unit 204 of base station 20 shown in Figure 14 can be incorporated by a control program that is stored in memory 1002 and operated by processor 1001. Several processes described above were described to be performed by a single processor 1001, but can be performed simultaneously or sequentially by two or more processors 1001. Processor 1001 can be mounted as one or more chips. The program can be transmitted from a network via an electrical communication line.

[00121] Memory 1002 is a computer-readable record medium and may consist, for example, of at least one of a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), and a random access memory (RAM). Memory 1002 may be referred to as a register, a cache, or main memory (a primary storage device). Memory 1002 may store a program (program codes), a software module, or similar items that can be executed to perform processes according to the modality.

[00122] Storage 1003 is a computer-readable recording medium and may consist, for example, of at least one of an optical disc such as a compact disc ROM (CD-ROM), a hard disk drive, a floppy disk, a magneto-optical disc (such as a compact disc, a digital versatile disc, or a Blu-ray disc (trademark)), a smart card, a flash memory (such as a card, a stick, or a key drive), a floppy disk (trademark), and a magnetic strip. Storage 1003 may be referred to as an auxiliary storage device. Examples of recording media may include a database including memory 1002 Petition 870250049867, dated 06 / 13 / 2025, pages 47 / 57 37 / 44 and / or storage 1003, a server, and other appropriate media.

[00123] Communication device 1004 is hardware (a transceiver device) that enables communication between computers via a wired and / or wireless network and is referred to, for example, as a network device, a network controller, a network card, or a communication module. For example, the signal transmission unit 101 and the signal reception unit 102 of user device 10 can be incorporated by communication device 1004. The signal transmission unit 201 and the signal reception unit 202 of base station 20 can be incorporated by communication device 1004.

[00124] Input device 1005 is an input device (such as a keyboard, mouse, microphone, switch, button, or sensor) that receives an input from the outside. Output device 1006 is an output device (such as a display, speaker, or LED lamp) that outputs to the outside. Input device 1005 and output device 1006 can be configured as a unified unit (such as a touch panel).

[00125] Devices such as processor 1001 and memory 1002 are connected to each other via bus 1007 to transmit and receive information. Bus 1007 may consist of a single bus or may be configured with different buses for the devices.

[00126] The user device 10 and the base station 20 can 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), or part or all of the blocks Petition 870250049867, dated 06 / 13 / 2025, pages 48 / 57 38 / 44 functional modules can be incorporated into the hardware. For example, the 1001 processor can be implemented by at least one of these hardware modules. (Summary of Modalities)

[00127] As described above, according to the present embodiment, a user apparatus is provided in a radiocommunication system including a base station and the user apparatus, including: a receiving unit configured to receive a plurality of predetermined signals transmitted from the base station by a plurality of beams; and a transmitting unit configured to transmit a preamble using a feature corresponding to at least one beam among the plurality of beams, wherein the receiving unit measures a reception quality for each of the plurality of beams, and the transmitting unit transmits the preamble using a feature corresponding to a beam of a reception quality that satisfies a predetermined condition.

[00128] According to the configuration above, a random access procedure to which beamforming is applied can be executed properly while avoiding performance deterioration and preventing interference.

[00129] The predetermined condition is, for example, that: the reception quality is better than a predetermined threshold, or a difference between the reception quality and the best reception quality among the reception qualities within the plurality of beams is less than a predetermined relative threshold. According to this configuration with the use of a threshold, accurate processing can be performed quickly.

[00130] The transmission unit can use resources corresponding to a predetermined upper threshold number of beams from all beams whose Petition 870250049867, dated 06 / 13 / 2025, pp. 49 / 57 39 / 44 reception quality satisfies the predetermined condition in order to transmit the upper threshold number of preambles. According to this configuration, since the number of preambles can be restricted, for example, use of unnecessary resources can be suppressed.

[00131] The transmission unit can retransmit a preamble transmitted by a first resource using a second resource corresponding to a beam whose reception quality satisfies the predetermined condition. According to this configuration, the retransmission can be performed using appropriate resources.

[00132] The receiving unit can monitor a response to a preamble within a time window corresponding to a resource used to transmit the preamble through the transmitting unit, or the receiving unit can monitor a response to the preamble within a time window common to a plurality of resources including a resource used to transmit the preamble through the transmitting unit. According to this configuration, the response to the preamble can be monitored in an appropriate time window. (Complement to the Modality)

[00133] Although embodiments of the invention have been described above, the invention disclosed in this document is not limited to embodiments and it will be understood by those skilled in the art that various modifications, corrections, alternatives, substitutions, and the like may be made. Although the description has been made using specific numerical value examples for the purpose of promoting understanding of the invention, such numerical values ​​are only simple examples and arbitrary appropriate values ​​may be used unless otherwise specified. The separation of items in the description above is not essential to the invention, the details described in two or more Petition 870250049867, dated 06 / 13 / 2025, pages 50 / 57 40 / 44 items can be combined for use, if necessary, or the details described in a given item can be applied to details described in another item (unless incompatible). It cannot be said that the boundaries between functional units or processing units in functional block diagrams necessarily correspond to the boundaries of physical components. The operations of a plurality of functional units can be physically performed by a single component, or an operation of a functional unit can be physically performed by a plurality of components. The processing sequences described above can be modified in order as long as they are not incompatible with each other.For the sake of descriptive convenience, although a user device 10 and a base station 20 have been described above with reference to functional block diagrams, such devices may be incorporated by hardware, by software, or by a combination thereof. Each of the software that is executed by means of a processor of the user device 10 and software that is executed by means of a processor of the base station 20 in the embodiments of the invention may be stored in an appropriate storage medium, such as a random access memory (RAM), a flash memory, a read-only memory (ROM), an EPROM, an EEPROM, a register, a hard disk drive (HDD), a removable disk, a CD-ROM, a database, or a server.

[00134] Information reporting is not limited to the aspects / modalities described in this descriptive report, but may be performed using other methods. For example, information reporting may be performed by physical layer signaling (such as downlink control information (DCI) or uplink control information (UCI)), upper layer signaling (such as Petition 870250049867, dated 06 / 13 / 2025, pages 51 / 57 41 / 44 Radio Resource Control (RRC) signal, Medium Access Control (MAC) signaling, or broadcast information (Master Information Block (MIB) and System Information Block (SIB))), other signals, or combinations thereof. RRC signaling may be referred to as an RRC message and may be, for example, an RRC connection configuration message or an RRC connection reconfiguration message.

[00135] The aspects / modalities described in this descriptive report may be applied to systems employing Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G, 5G, Future Radio Access (FRA), W-CDMA (trademark), GSM (trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra Wideband (UWB), Bluetooth (trademark), or other appropriate systems and / or next-generation systems to which the systems are extended.

[00136] The processing sequences, sequences, flowcharts and similar aspects / modalities described above in this descriptive report may have their order modified as long as they are not incompatible with each other. For example, in the methods described in this descriptive report, several steps as elements are described in an illustrative order and the methods are not limited to the order described.

[00137] The specific operations performed by base station 20 in this descriptive report may, in some cases, be performed by a higher-level node of the same. In a network including one or more network nodes that include base station 20, various operations performed to communicate with a user device 10 may apparently be performed by base station 20 and / or different network nodes (e.g., an MME or an S-GW may be considered, but network nodes are not limited to them). Petition 870250049867, dated 06 / 13 / 2025, pages 52 / 57 42 / 44 from base station 20. A case where the number of network nodes different from base station 20 is one was described above, but a combination of different plural network nodes (e.g., an MME and an S-GW) can be used.

[00138] The aspects described in this descriptive report can be used alone, can be used in combination, or can be switched with the deployment of the same.

[00139] The user device 10 may also be referred to as a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a telephone apparatus, a user agent, a mobile client, a client, or various terms appropriate to those skilled in the art.

[00140] Base station 20 may be referred to as a B-node (NB), an enhanced B-node (eNB), a gNB, a base station, or some other terms appropriate to those skilled in the art.

[00141] The terms determination (determine) and decision (determine) used in this descriptive report can include various types of operations. For example, determination and decision can include considering that performing judgment, calculation, computation, processing, derivation, investigation, consultation (e.g., searching a table, a database, or other data structure), or verification is performing determination or decision. Furthermore, determination and decision can include considering that performing receipt (e.g., receiving information), transmission (e.g., transmitting information), input, output, or access (e.g., accessing data in memory) is performing determination or decision. Additionally, Petition 870250049867, dated 06 / 13 / 2025, pp. 53 / 57 43 / 44 Determination and decision may include considering that performing a resolution, selection, choice, establishment, or comparison is performing a determination or decision. Namely, determination and decision may include considering that some operation is performing a determination or decision.

[00142] An expression based on ~, which is used in this descriptive report, does not refer only to based solely on ~, unless clearly stated. In other words, the expression “based on ~” refers both to based solely on ~ and to based on at least ~”.

[00143] Since the terms include and including and modifications thereof are used in this descriptive report or in the appended claims, the terms are intended to have a broad meaning similar to a term comprising. A term or, which is used in this descriptive report or in the claims, is not intended to mean an exclusive “or”.

[00144] In every invention, for example, when an article, such as a, an, the, or the is added in the translation into Portuguese, such article refers to the inclusion of the plural unless otherwise recognized from the context.

[00145] Although the invention has been described above in detail, it is evident to those skilled in the art that the invention is not limited to the embodiments described in the descriptive report. The invention can be produced as modified and altered embodiments without departing from the concept and scope of the invention as defined by the appended claims. Consequently, the description in this descriptive report is made for illustrative purposes only and has no restrictive meaning.

[00146] This patent application is based on and claims the benefit of priority of Patent Application No. JP2017-019142, filed on February 3, 2017, and the entire content of Patent Application No. JP2017019142 is incorporated herein by reference. Petition 870250049867, dated 06 / 13 / 2025, pages 54 / 57 44 / 44 LIST OF NUMERICAL REFERENCES user device 101 signal transmission unit 102 signal reception unit 112 unit of measurement 103 Configuration Information Management Unit 104 AR control unit base station 201 signal transmission unit 202 signal reception unit 203 Configuration Information Management Unit 204 AR control unit 1001 processor 1002 memory 1003 storage 1004 communication device 1005 input device 1006 output device Petition 870250049867, dated 06 / 13 / 2025, pages 55 / 57

Claims

1 / 1 CLAIMS 1. Terminal (10) characterized in that it comprises: a receiving unit (102) configured to measure the received power of at least one synchronization signal block from a plurality of synchronization signal blocks, each synchronization signal block being transmitted by a beam, received from a base station (20);and a transmitting unit (101) configured to select a synchronization signal block with received power above a threshold, determine a resource corresponding to the selected synchronization signal block, and transmit a random access preamble using the resource, wherein the transmitting unit (101) is configured, when the reception of a random access response by the receiving unit (102) for a random access preamble transmitted using a first resource is unsuccessful, to perform random access preamble transmission using a second resource corresponding to a synchronization signal block with received power above the threshold.

2. Terminal (10), according to claim 1, characterized in that the receiving unit (102) is configured to receive the threshold from the base station (20).

3. Terminal (10), according to claim 1 or 2, characterized in that the synchronization signal block includes a synchronization signal and a broadcast channel. Petition 870250049867, dated 06 / 13 / 2025, pp. 56 / 57

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