Terminal, base station, wireless communication system, and wireless communication method

Abstract

The terminal has: a transmitting unit that transmits a random access preamble as a first message during a random access channel procedure; and a receiving unit that receives, during the random access channel procedure, a response message to the first message as a second message. After receiving the second message, the transmitting unit transmits a third message via a physical uplink shared channel during the random access channel procedure, and the transmitting unit performs retransmission of the third message.

Description

Technical Field

[0001] The present disclosure relates to a terminal performing wireless communication, and more particularly to a terminal that transmits a message via a physical uplink shared channel during a random access channel procedure. Background Art

[0002] In the 3rd Generation Partnership Project (3GPP), the fifth-generation mobile communication system (also known as 5G, New Radio (NR), or Next Generation (NG)) has been standardized, and the standardization of the next generation, known as Beyond 5G, 5G Evolution, or 6G, has also been carried out.

[0003] In Releases 15 and 16 (NR) of 3GPP, the operation of a band including multiple frequency ranges, specifically including FR1 (410 MHz to 7.125 GHz) and FR2 (24.25 GHz to 52.6 GHz), has been standardized.

[0004] In Release 17 of 3GPP, coverage enhancement has become an issue in FR1 and FR2 (Non-Patent Document 1). Along with this, improvement in the channel quality of the Physical Uplink Shared Channel (PUSCH), Physical Uplink Shared Channel (PUSCH), Physical Downlink Control Channel (PDCCH), Physical Uplink Control Channel (PUCCH), etc. is desired.

[0005] Prior Art Documents

[0006] Non-Patent Documents

[0007] Non-Patent Document 1: "New SID on NR coverage enhancement", RP-193240, 3GPP TSGRAN Meeting #86, 3GPP, December 2019 Summary of the Invention

[0008] Under such a background, as a message transmitted via PUSCH, the inventors focused on the message (Msg3) used in the random access channel (RACH: Random Access Channel) process. The inventors conducted in-depth research, and as a result, found a method for improving the channel quality of the PUSCH for transmitting such a message (Msg3).

[0009] Therefore, the following disclosure is completed in view of such a situation, and its purpose is to provide a terminal capable of improving channel quality.

[0010] The gist of the present disclosure lies in a terminal having: a transmitting unit that transmits a random access preamble as a first message during a random access channel process; and a receiving unit that receives a response message to the first message as a second message during the random access channel process. After receiving the second message, the transmitting unit transmits a third message via a physical uplink shared channel during the random access channel process, and the transmitting unit performs retransmission of the third message.

[0011] The gist of the present disclosure lies in a terminal having: a transmitting unit that transmits a random access preamble as a first message during a random access channel process; and a receiving unit that receives a response message to the first message as a second message during the random access channel process. After receiving the second message, the transmitting unit transmits a third message via a physical uplink shared channel during the random access channel process. After receiving the second message, the receiving unit receives two or more channel state information reference signals, and the transmitting unit transmits the third message according to the channel state information reference signal selected from the two or more channel state information reference signals.

[0012] The gist of the present disclosure lies in a terminal having: a transmitting unit that transmits a random access preamble as a first message during a random access channel process; and a receiving unit that receives a response message to the first message as a second message during the random access channel process. After receiving the second message, the transmitting unit transmits a third message via a physical uplink shared channel during the random access channel process. The receiving unit performs re-reception of the second message, and the transmitting unit transmits the third message according to the second message selected from the second messages received through the re-reception. Description of the Drawings

[0013] Figure 1 is an overall schematic structural diagram of the wireless communication system 10.

[0014] Figure 2It is a diagram showing the frequency range used in the wireless communication system 10.

[0015] Figure 3 It is a diagram showing an example of the structure of a radio frame, sub-frame, and time slot used in the wireless communication system 10.

[0016] Figure 4 It is a functional block structure diagram of the UE 200.

[0017] Figure 5 It is a diagram for explaining the RACH procedure.

[0018] Figure 6 It is a diagram for explaining the RACH procedure.

[0019] Figure 7 It is a diagram for explaining the method of repeated transmission.

[0020] Figure 8 It is a diagram showing the RAR (Random Access Response).

[0021] Figure 9 It is a diagram showing frequency hopping.

[0022] Figure 10 It is a diagram for explaining the beam pattern of Modification Example 1.

[0023] Figure 11 It is a diagram for explaining the RACH procedure of Modification Example 1.

[0024] Figure 12 It is a diagram for explaining the RACH procedure of Modification Example 1.

[0025] Figure 13 It is a diagram for explaining the RACH procedure of Modification Example 1.

[0026] Figure 14 It is a diagram for explaining the RACH procedure of Modification Example 1.

[0027] Figure 15 It is a diagram showing an example of the hardware structure of the UE 200. Detailed Description of the Invention

[0028] Hereinafter, embodiments will be described with reference to the drawings. In addition, the same or similar reference numerals are given to the same functions and structures, and their descriptions are appropriately omitted.

[0029] [Embodiment]

[0030] (1) Overall Schematic Structure of the Wireless Communication System

[0031] Figure 1This is the overall schematic structure diagram of the wireless communication system 10 of the embodiment. The wireless communication system 10 is a wireless communication system in accordance with the 5G New Radio (NR), and includes a Next Generation - Radio Access Network 20 (hereinafter referred to as the NG - RAN 20) and a terminal 200 (hereinafter referred to as the UE 200).

[0032] In addition, the wireless communication system 10 may also be a wireless communication system in accordance with a manner referred to as Beyond 5G, 5G Evolution or 6G.

[0033] The NG - RAN 20 includes a radio base station 100A (hereinafter referred to as the gNB 100A) and a radio base station 100B (hereinafter referred to as the gNB 100B). In addition, the specific structure of the wireless communication system 10 including the number of gNBs and UEs is not limited to Figure 1 the example shown.

[0034] The NG - RAN 20 actually includes a plurality of NG - RAN nodes, specifically including a plurality of gNBs (or ng - eNBs), and is connected to a 5G - compliant core network (5GC, not shown). In addition, the NG - RAN 20 and the 5GC may be simply referred to as the "network".

[0035] The gNB 100A and the gNB 100B are 5G - compliant radio base stations and perform 5G - compliant wireless communication with the UE 200. The gNB 100A, the gNB 100B, and the UE 200 can support Massive MIMO (Multiple Input Multiple Output) that generates a beam BM with higher directivity by controlling wireless signals transmitted from multiple antenna elements, carrier aggregation (CA) that bundles multiple component carriers (CCs), and dual connectivity (DC) that communicates with two or more transport blocks simultaneously between the UE and two NG - RAN nodes, etc.

[0036] In addition, the wireless communication system 10 supports multiple frequency ranges (FRs). Figure 2 Shows the frequency ranges used in the wireless communication system 10.

[0037] As Figure 2 shown, the wireless communication system 10 supports FR1 and FR2. The frequency bands of each FR are as follows.

[0038] ·FR1: 410 MHz to 7.125 GHz

[0039] ·FR2: 24.25 GHz to 52.6 GHz

[0040] In FR1, a sub-carrier spacing (SCS) of 15, 30, or 60 kHz can be used, and a bandwidth (BW) of 5 to 100 MHz is used. The frequency of FR2 is higher than that of FR1. An SCS of 60 or 120 kHz (240 kHz can also be included) can be used, and a bandwidth (BW) of 50 to 400 MHz is used.

[0041] In addition, the SCS can also be interpreted as a numerology. The numerology is defined in 3GPP TS 38.300 and corresponds to a sub-carrier spacing in the frequency domain.

[0042] Moreover, the wireless communication system 10 also supports a frequency band higher than the FR2 band. Specifically, the wireless communication system 10 supports a frequency band exceeding 52.6 GHz up to 114.25 GHz. For convenience, such a high-frequency band can also be referred to as "FR2x".

[0043] To solve such a problem, in the case of using a band exceeding 52.6 GHz, cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) / discrete Fourier transform-spread OFDM (DFT-S-OFDM) with a larger sub-carrier spacing (SCS) can be applied.

[0044] Figure 3 An example of the structure of a radio frame, sub-frame, and time slot used in the wireless communication system 10 is shown.

[0045] As Figure 3 shown, one time slot consists of 14 symbols. The larger (wider) the SCS, the shorter the symbol period (and the time slot period). The SCS is not limited to Figure 3 the intervals (frequencies) shown. For example, 480 kHz, 960 kHz, etc. can be used.

[0046] In addition, the number of symbols constituting one time slot does not necessarily have to be 14 symbols (for example, 28, 56 symbols). Also, the number of time slots in each sub-frame can vary according to the SCS.

[0047] In addition, Figure 3The time direction (t) shown can also be referred to as the time domain, symbol period, symbol time, etc. In addition, the frequency direction can also be referred to as the frequency domain, resource block, subcarrier, bandwidth part (BWP), etc.

[0048] DMRS is a type of reference signal and is prepared for various channels. Here, unless otherwise specified, it can mean the downlink data channel. Specifically, it can mean the DMRS for PDSCH (Physical Downlink Shared Channel). However, the DMRS for the uplink data channel, specifically the PUSCH (Physical Uplink Shared Channel), can be interpreted in the same way as the DMRS for PDSCH.

[0049] DMRS can be used for channel estimation in UE 200 as part of a device, for example, as part of coherent demodulation. DMRS can exist only in the resource blocks (RBs) used for PDSCH transmission.

[0050] DMRS can have multiple mapping types. Specifically, DMRS has mapping type A and mapping type B. In mapping type A, the first DMRS is configured in the second or third symbol of the time slot. In mapping type A, DMRS can be mapped based on the time slot boundary regardless of where the actual data transmission starts in the time slot. The reason for configuring the first DMRS in the second or third symbol of the time slot can also be interpreted as being due to configuring the first DMRS in the control resource sets (CORESETs).

[0051] In mapping type B, the first DMRS can be configured in the first symbol of the data allocation. That is, the position of DMRS can be given relatively with respect to the location where data is configured, rather than with respect to the time slot boundary.

[0052] In addition, DMRS can have multiple types. Specifically, DMRS has type 1 and type 2. Regarding type 1 and type 2, the mapping in the frequency domain and the maximum number of orthogonal reference signals are different. Type 1 can output up to 4 orthogonal signals in a single-symbol DMRS, and type 2 can output up to 8 orthogonal signals in a double-symbol DMRS.

[0053] (2) Functional block structure of the wireless communication system

[0054] Next, the functional block structure of the wireless communication system 10 will be described. Specifically, the functional block structure of the UE 200 will be described.

[0055] Figure 4 It is a functional block structure diagram of the UE 200. As Figure 4 shown, the UE 200 includes a radio signal transceiver unit 210, an amplifier unit 220, a modulation / demodulation unit 230, a control signal / reference signal processing unit 240, an encoding / decoding unit 250, a data transceiver unit 260, and a control unit 270.

[0056] The radio signal transceiver unit 210 transmits and receives radio signals in accordance with NR. The radio signal transceiver unit 210 supports massive MIMO (Massive Multiple-Input Multiple-Output), CA (Carrier Aggregation) that bundles multiple CCs (Component Carriers), and DC (Dual Connectivity) in which the UE communicates with two NG-RAN nodes simultaneously.

[0057] In an embodiment, the radio signal transceiver unit 210 is configured as a transmission unit that transmits a random access preamble as the first message (hereinafter referred to as Msg1) in a random access process (hereinafter referred to as the RACH (Random Access Channel) process). The radio signal transceiver unit 210 is configured as a reception unit that receives the second message (hereinafter referred to as Msg2) as a response message to Msg1 in the RACH process. After receiving Msg2, the radio signal transceiver unit 210 transmits the third message (hereinafter referred to as Msg3) via the PUSCH in the RACH process. The radio signal transceiver unit 210 receives the fourth message (hereinafter referred to as Msg4) as a response message to Msg3 in the RACH process (3GPP TS38.321 V16.2.1 §5.1 "Random Access procedure").

[0058] For example, Msg1 may be transmitted via the PRACH (Physical Random Access Channel). Msg1 may also be referred to as a PRACH preamble (PRACH Preamble). Msg2 may be transmitted via the PDSCH. Msg2 may also be referred to as an RAR (Random Access Response). Msg3 may also be referred to as an RRC connection request (RRC Connection Request). Msg4 may also be referred to as an RRC connection setup (RRC ConnectionSetup).

[0059] In this context, the wireless signal transceiver unit 210 repeatedly transmits Msg3. Details of the repeated transmission of Msg3 will be described later (see Figure 5 and Figure 6 ).

[0060] The amplification unit 220 is composed of a PA (Power Amplifier) / LNA (Low Noise Amplifier), etc. The amplification unit 220 amplifies the signal output from the modulation and demodulation unit 230 to a predetermined power level. In addition, the amplification unit 220 amplifies the RF signal output from the wireless signal transceiver unit 210.

[0061] The modulation and demodulation unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. for each predetermined communication target (gNB 100 or other gNBs). In the modulation and demodulation unit 230, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform-Spread OFDM (DFT-S-OFDM) can be applied. In addition, DFT-S-OFDM can be used not only for the uplink (UL) but also for the downlink (DL).

[0062] The control signal / reference signal processing unit 240 performs processing related to various control signals transmitted and received by the UE 200, as well as processing related to various reference signals transmitted and received by the UE 200.

[0063] Specifically, the control signal / reference signal processing unit 240 receives various control signals transmitted from the gNB 100 via a predetermined control channel, such as receiving control signals of the radio resource control layer (RRC). In addition, the control signal / reference signal processing unit 240 transmits various control signals to the gNB 100 via a predetermined control channel.

[0064] The control signal / reference signal processing unit 240 performs processing using reference signals (RS) such as Demodulation Reference Signal (DMRS) and Phase Tracking Reference Signal (PTRS).

[0065] DMRS is a terminal-specific reference signal (pilot signal) known between the base station and the terminal, which is used to estimate the fading channel used in data demodulation. PTRS is a terminal-specific reference signal for the purpose of estimating phase noise, which becomes an issue in the high frequency band.

[0066] In addition, among the reference signals, in addition to DMRS and PTRS, it may also include a channel state information reference signal (CSI-RS: Channel State Information-Reference Signal), a sounding reference signal (SRS: Sounding Reference Signal), and a positioning reference signal for position information (PRS: Positioning Reference Signal).

[0067] In addition, the channel includes a control channel and a data channel. The control channel includes a PDCCH (Physical Downlink Control Channel), a PUCCH (Physical Uplink Control Channel), a RACH (including a random access channel (Random Access Channel), a downlink control information (DCI: Downlink Control Information) of a random access radio network temporary identifier (RA-RNTI: Random Access Radio Network Temporary Identifier)), and a physical broadcast channel (PBCH: Physical Broadcast Channel), etc.

[0068] In addition, the data channel includes a PDSCH (Physical Downlink Shared Channel) and a PUSCH (Physical Uplink Shared Channel), etc. Data means the data transmitted via the data channel. The data channel may also be replaced with a shared channel.

[0069] Here, the control signal / reference signal processing unit 240 constitutes a receiving unit that receives downlink control information (DCI). The DCI includes fields storing DCI formats (DCI Formats), carrier indicators (CI: Carrier indicator), BWP indicators (BWP indicator), FDRA (Frequency Domain Resource Allocation), TDRA (Time Domain Resource Allocation), MCS (Modulation and Coding Scheme), HPN (HARQ Process Number), NDI (New Data Indicator), RV (Redundancy Version), etc., as existing fields.

[0070] The value stored in the DCI format field is an information element that specifies the format of the DCI. The value stored in the CI field is an information element that specifies the CC to which the DCI is applied. The value stored in the BWP indicator field is an information element that specifies the BWP to which the DCI is applied. The BWP that can be specified by the BWP indicator is set by the information element (BandwidthPart-Config) included in the RRC message. The value stored in the FDRA field is an information element that specifies the frequency domain resources to which the DCI is applied. The frequency domain resources are determined by the value stored in the FDRA field and the information element (RA Type: RA type) included in the RRC message. The value stored in the TDRA field is an information element that specifies the time domain resources to which the DCI is applied. The time domain resources are determined by the value stored in the TDRA field and the information elements (pdsch-TimeDomainAllocationList, pusch-TimeDomainAllocationList) included in the RRC message. The time domain resources can also be determined by the value stored in the TDRA field and the default table. The value stored in the MCS field is an information element that specifies the MCS to which the DCI is applied. The MCS is determined by the value stored in the MCS and the MCS table. The MCS table can be specified by the RRC message or determined by RNTI scrambling. The value stored in the HPN field is an information element that specifies the HARQ process (HARQ Process) to which the DCI is applied. The value stored in the NDI is an information element used to determine whether the data to which the DCI is applied is the initially transmitted data. The value stored in the RV field is an information element that specifies the redundancy of the data to which the DCI is applied.

[0071] In an embodiment, the DCI includes time domain resource allocation (TDRA) of an uplink channel (PUSCH). The DCI including the TDRA of the PUSCH may be DCI of Format 0_0, Format 0_1, or Format 0_2.

[0072] The encoding / decoding unit 250 performs data segmentation / concatenation, channel encoding / decoding, etc. for each predetermined communication target (gNB 100 or other gNB).

[0073] Specifically, the encoding / decoding unit 250 segments the data output from the data transceiver unit 260 into a predetermined size and performs channel encoding on the segmented data. In addition, the encoding / decoding unit 250 decodes the data output from the modulation / demodulation unit 230 and concatenates the decoded data.

[0074] The data transceiver unit 260 performs the transmission and reception of protocol data units (PDUs) and service data units (SDUs). Specifically, the data transceiver unit 260 performs the assembly / disassembly of PDUs / SDUs in multiple layers (such as the media access control layer (MAC), radio link control layer (RLC), and packet data convergence protocol layer (PDCP)). In addition, the data transceiver unit 260 performs error correction and retransmission control of data according to hybrid automatic repeat request (HARQ).

[0075] The control unit 270 controls each functional block constituting the UE 200. For example, in the embodiment, the control unit 270 controls the above-mentioned RACH procedure.

[0076] (3) Retransmission of the third message

[0077] Hereinafter, the retransmission of the third message (Msg3) will be described. The retransmission of Msg3 may include the first retransmission and the second retransmission shown below.

[0078] (3.1) The first retransmission

[0079] As Figure 5As shown, in the first retransmission, UE 200 performs retransmission of Msg1. The retransmission of Msg1 is performed regardless of whether Msg2 is received from NG RAN 20 (e.g., gNB 100). Therefore, the retransmission of Msg1 is a different concept from "retransmission of Msg1 accompanied by an increase in transmission power (Power ramping)". UE 200 receives Msg2 corresponding to each Msg1 from NGRAN 20. UE 200 sends Msg3 corresponding to each Msg2 to NG RAN 20. UE 200 receives Msg4 for any one of Msg3 from NG RAN 20. UE 200 sends an acknowledgement (HARQ-ACK) for Msg4 to NG RAN 20.

[0080] In this way, in the first retransmission, by performing retransmission of Msg1, UE 200 performs re-reception of Msg2 corresponding to each Msg1. By sending Msg3 corresponding to each Msg2, UE 200 performs retransmission of Msg3.

[0081] In the first retransmission, UE 200 can calculate the RA-RNTI based on the RACH occasion (RACH occasion). UE200 can also use a different RA-RNTI for each Msg2 to decode the PDCCH corresponding to each Msg2. NG RAN20 can set a different TC-RNTI (Temporary Cell Radio Network Temporary Identifier) for each Msg1. UE 200 can use a different RA-RNTI for each Msg2 to send Msg3 corresponding to each Msg2. On the other hand, UE 200 can use the same UE id to send Msg3 corresponding to each Msg2. NG RAN 20 can determine two or more Msg3 received from the same UE 200 based on the UE id included in each Msg3, and use the TC-RNTI selected from the TC-RNTIs of the two or more determined Msg3 as one C-RNTI (Cell Radio Network Temporary Identifier) to send Msg4. NG RAN 20 can select the Msg3 with the best reception quality from two or more Msg3 received from the same UE 200 and send Msg4 for the selected Msg3.

[0082] In the first retransmission, even considering the impact of fading and the like, since the probability of Msg3 reaching the NG RAN 20 is increased due to the retransmission of Msg3, the channel quality of the PUSCH used for the transmission of Msg3 can also be improved.

[0083] In addition, in Figure 5 an example is given of allocating resources for Msg2 and Msg3 through a number of PDCCHs corresponding to the number of retransmissions of Msg1. However, the first retransmission is not limited to this. The resources for the re-reception of Msg2 and the retransmission of Msg3 can also be allocated through at least one of one PDCCH and one RAR PDSCH. In such a case, for one Msg1 selected from each Msg1, the NG RAN 20 can allocate the resources for the retransmission of Msg2 and Msg3 through one PDCCH. For two or more Msg1s selected from each Msg1, the NG RAN 20 can allocate the resources for the retransmission of Msg2 and Msg3 through one PDCCH. According to such a structure, since the resources for the retransmission of Msg3 are known in the NG RAN 20, the channel quality of the PUSCH can be improved through the combined reception of Msg3.

[0084] (3.2) Second retransmission

[0085] As Figure 6 shown, in the second retransmission, the UE 200 does not perform the retransmission of Msg1 and sends Msg1 to the NG RAN 20 (for example, gNB 100). In the transmission of Msg1, a retransmission of Msg1 with an increase in transmission power (Power ramping) can be performed. The UE 200 receives Msg2 corresponding to Msg1 from the NG RAN 20. The UE 200 sends Msg3 corresponding to Msg2 to the NG RAN 20. The UE 200 receives Msg4 for any one of Msg3 from the NG RAN 20. The UE 200 sends an acknowledgement (HARQ-ACK) for Msg4 to the NG RAN 20.

[0086] In this way, in the second retransmission, the UE 200 does not perform the retransmission of Msg1 but performs the retransmission of Msg3. That is, the second retransmission is different from the first retransmission in that it does not perform the retransmission of Msg1 and the re-reception of Msg2.

[0087] In the second retransmission, the NG RAN 20 can allocate the resources for the retransmission of Msg3 through one PDCCH. That is, the resources for the retransmission of Msg3 are known in the NG RAN 20. Therefore, the NG RAN 20 can determine two or more Msg3s received from the same UE 200 before decoding Msg3 (in other words, without using the UE id). According to such a structure, the NGRAN 20 can perform the combined reception of Msg3.

[0088] According to the second retransmission, even considering the influence of fading and the like, the channel quality of the PUSCH can be improved through the combined reception of Msg3.

[0089] (4) Method of retransmission

[0090] Hereinafter, the method of retransmitting the third message (Msg3) will be described. As the method of retransmitting Msg3, the methods shown below are considered.

[0091] As described above, Msg3 is transmitted via the PUSCH. Therefore, the existing PUSCH mapping type can be used as the resource for the retransmission of Msg3.

[0092] The PUSCH mapping type determines the starting position (S) of the symbols that can be allocated to the PUSCH and the number of symbols (L) that can be allocated to the PUSCH. The PUSCH mapping type can be determined by S+L. The values of S, L, and S+L can be determined according to each CP (Cyclic Prefix) length. The values of S, L, and S+L can also be determined according to each repetition type of the PUSCH.

[0093] As the existing PUSCH mapping types, there are Type A and Type B. Type A is only used for repetition type A, and Type B is used in both repetition type A and repetition type A. In the existing Type A and Type B, since the allocation in units of time slots is assumed, the value of L does not exceed "14" (refer to §6.1.2 of 3GPP TS38.214 V16.2.0).

[0094] Against such a background, as Figure 7 shown, the case where the TDD mode is "DDDSU" will be described. "D" means a time slot of a symbol used only for the downlink (hereinafter referred to as a D time slot), "U" means a time slot of a symbol used only for the uplink (hereinafter referred to as a U time slot), and "S" means a time slot of a symbol used for both the downlink and the uplink (hereinafter referred to as an S time slot).

[0095] In addition, the case where one time slot contains 14 symbols is described. "D" means a symbol for the downlink (hereinafter referred to as a D symbol), "U" means a symbol for the uplink (hereinafter referred to as a U symbol), and "G" means a guard symbol (hereinafter referred to as a G symbol).

[0096] First, in the case of using Type A as the resource for the retransmission of Msg3, the NG RAN 20 may specify the interval of time slots for the retransmission of Msg3. For example, in the case where the TDD mode is "DDDSU", the D time slots and S time slots are discarded, so "0" can be specified as the interval of time slots for the retransmission of Msg3. In addition, in Type A, the values of S, L, and S+L are common in each time slot.

[0097] Second, in the case of using Type B as the resource for the retransmission of Msg3, the NG RAN 20 may specify the U symbols (2) at the end of the S time slot and the U symbols ( ) of the U time slot as one resource unit. In other words, the NG RAN 20 may specify the values of S, L, and S+L to specify 16 consecutive U symbols. In such a case, the range of values that L can take may include a value larger than the number of symbols contained in one time slot (here, "14") (for example, "16"). According to such a structure, when assuming the case where the number of symbols of Msg3 is 8, it is possible to perform two retransmissions of Msg3 using 16 consecutive U symbols.

[0098] (5) Feasibility of retransmission

[0099] Regarding whether to perform the retransmission of Msg3, it can be notified by the method shown below.

[0100] First, the UE 200 may receive broadcast information from the NG RAN 20 that includes an information element indicating whether to perform the retransmission of Msg3. Such an information element may include an information element indicating the number of retransmissions. The broadcast information may be an SIB (System Information Block). The information element may be RACH-ConfigCommon included in SIB1. RACH-ConfigCommon may be included in BWP-UplinkCommon (TS38.331 V16.2.0 §6.3.2 "Radio resource control Information element").

[0101] Here, the information element indicating whether to perform the retransmission of Msg3 can be an example of the information element related to retransmission. That is, the UE 200 can receive the broadcast information containing the information element related to retransmission. According to such a structure, it is possible to implement the retransmission of Msg3 without accompanying the extension of the message related to the RACH procedure (for example, Msg2).

[0102] Second, the UE 200 can receive Msg2 from the NG RAN 20 containing the information element indicating whether to perform the retransmission of Msg3. Such an information element can include the information element indicating the number of retransmissions. As Figure 8 shown, Msg2 (RAR) contains UL grant, and the information element can be UL Grant. In such a case, similar to the TPC (Transmission Power control) command included in the RAR, the NG RAN 20 can determine the number of retransmissions according to the received power of Msg1.

[0103] Here, the information element indicating whether to perform the retransmission of Msg3 can be an example of the information element related to retransmission. That is, the UE 200 can receive Msg2 containing the information element related to retransmission. According to such a structure, it is possible to flexibly set the number of retransmissions of Msg3 for each UE 200.

[0104] (6) Resources for retransmission

[0105] Regarding the resources for the retransmission of Msg3, it can be notified by the method shown below.

[0106] First, the UE 200 can receive the broadcast information from the NG RAN 20 containing the information element indicating the repetition type. The UE 200 can also receive Msg2 from the NG RAN 20 containing the information element indicating the repetition type. In the case where the repetition type is Type A, the information element can include the information element indicating the time slot interval for the retransmission of Msg3. In the case where the repetition type is Type B, the information element can include the information element indicating the values of S, L, and S + L for the retransmission of Msg3.

[0107] Here, the information element indicating the repetition type can be an example of the information element related to retransmission. That is, the UE 200 can receive the broadcast information containing the information element related to retransmission. The UE 200 can also receive Msg2 containing the information element related to retransmission.

[0108] Second, the RV (Redundancy Version) used in the retransmission of Msg3 can be predetermined. The UE 200 can receive broadcast information from the NG RAN 20 that includes an information element indicating the RV used in the retransmission of Msg3. The UE 200 can also receive Msg2 from the NG RAN 20 that includes an information element indicating the RV used in the retransmission of Msg3. For example, the RV can be defined according to the number of retransmissions.

[0109] Here, the information element indicating the RV used in the retransmission of Msg3 can be an example of the information element related to retransmission. That is, the UE 200 can receive broadcast information that includes an information element related to retransmission. The UE 200 can also receive Msg2 that includes an information element related to retransmission.

[0110] Second, as Figure 9 shown, frequency hopping can be applied in the retransmission of Msg3. In Figure 9 , the case of performing two retransmissions in 16 consecutive U symbols is illustrated. The UE 200 can receive broadcast information from the NG RAN 20 that includes an information element indicating the frequency hopping pattern. The UE 200 can also receive Msg2 from the NG RAN 20 that includes an information element indicating the frequency hopping pattern.

[0111] For example, in the case where the repetition type is type A, inter-slot hopping can be applied. In inter-slot hopping, frequency hopping with a specified offset is performed for each retransmission (time slot). In the case where the repetition type is type A, intra-slot hopping can be applied. In intra-slot hopping, the same frequency hopping pattern is used for each retransmission (time slot).

[0112] Similarly, in the case where the repetition type is type B, inter-slot hopping can be applied. In inter-slot hopping, frequency hopping with a specified offset is performed for each retransmission (time slot). In the case where the repetition type is type B, intra-slot hopping can be applied. In intra-slot hopping, the same frequency hopping pattern is used for each retransmission (time slot).

[0113] Here, the information element indicating the frequency hopping pattern may include an information element specifying the repetition type for repeated transmission. Such an information element may also be referred to as pusch-RepTypeIndicator. The information element indicating the frequency hopping pattern may include an information element specifying frequency hopping within a time slot or frequency hopping between time slots. Such an information element can be specified for each repetition type and may also be referred to as frequencyHoppingMsg3-RepTypeA and frequencyHoppingMsg3-RepTypeB. pusch-RepTypeIndicator, frequencyHoppingMsg3-RepTypeA, and frequencyHoppingMsg3-RepTypeB may be included in RACH-Config Common.

[0114] The information element indicating the frequency hopping pattern may include an information element specifying a specified offset used in frequency hopping. Such an information element may also be referred to as frequencyHoppingOffset. frequencyHoppingOffset may be included in RACH-Config Common. frequencyHoppingOffset may also be included in Msg2. Additionally, the specified offset may be predefined by the bandwidth used in the transmission of Msg3.

[0115] Here, the information element indicating the frequency hopping pattern may be an example of an information element related to repeated transmission. That is, UE200 may receive broadcast information including an information element related to repeated transmission. UE 200 may also receive Msg2 including an information element related to repeated transmission.

[0116] (7) Functions and effects

[0117] In the embodiment, when UE 200 transmits Msg3 via PUSCH during the RACH procedure, repeated transmission of Msg3 is performed. According to such a structure, the channel quality of the PUSCH used for the transmission of Msg3 can be improved.

[0118] [Modification Example 1]

[0119] Hereinafter, Modification Example 1 of the embodiment will be described. Hereinafter, mainly the differences from the embodiment will be described.

[0120] In Variation 1, the beam pattern of gNB 100 will be described. Specifically, the relationship between the beam for receiving Msg1 and transmitting Msg2 and the beam for receiving Msg3 will be described. The beam for receiving Msg1 and transmitting Msg2 can be the beam for transmitting SSB (Synchronization Signal Block) (hereinafter referred to as SSB Beam). The beam for receiving Msg3 can be the beam for transmitting CSI-RS (hereinafter referred to as CSI-RS Beam). Here, the above-mentioned second repeated transmission ( Figure 6 ) will be taken as an example for description.

[0121] As Figure 10 shown, on the premise that the CSI-RS Beam is narrower than the SSB Beam, the beam pattern of gNB 100 is switched as follows.

[0122] gNB 100 uses the SSB Beam to receive Msg1. gNB 100 uses the SSB Beam to transmit Msg2. On the other hand, gNB 100 uses the CSI-RS Beam to receive Msg3. In such a case, gNB 100 switches the orientation of the CSI-RS Beam for each repeated transmission of Msg3. The orientation of the CSI-RS Beam can be the same as the orientation of the SSB Beam used in receiving Msg1 or transmitting Msg2. In other words, gNB 100 can switch the orientation of the CSI-RS Beam within the range of the SSB Beam used in receiving Msg1 or transmitting Msg2 for each repeated transmission of Msg3. gNB 100 uses the CSI-RS Beam used in receiving the selected Msg3 from each Msg3 to transmit Msg4. The selected Msg3 from each Msg3 can be the Msg3 with the best reception quality.

[0123] With such a structure, gNB 100 switches the orientation of the CSI-RS Beam for each repeated transmission of Msg3. Therefore, the reception of Msg3 is attempted by the CSI-RS Beam which is narrower (higher directivity) than the SSB Beam. As a result, the possibility of receiving Msg3 with better reception quality increases, and the channel quality of the PUSCH used for transmitting Msg3 is improved.

[0124] Against this background, consider the following beam as the beam used when UE 200 transmits Msg3.

[0125] First, the UE 200 can use the same beam as that for Msg1 to send Msg3. For example, as Figure 11 shown, take the case where the indexes of each CSI-RS (CSI-RS-1 to CSI-RS-4) are associated with the indexes of the SSB (SSB index 1 (SSBindex1), SSB index 2 (SSBindex2)) as an example. Specifically, CSI-RS-1 and CSI-RS-2 are associated with SSB index1, and the orientations of the CSI-RS Beams of CSI-RS-1 and CSI-RS-2 are the same as the orientation of the SSB Beam of SSB index1. Similarly, CSI-RS-3 and CSI-RS-4 are associated with SSB index2, and the orientations of the CSI-RS Beams of CSI-RS-3 and CSI-RS-4 are the same as the orientation of the SSB Beam of SSB index2.

[0126] In such a case, the gNB 100 uses the SSB Beams corresponding to SSB index1 and SSB index2 to receive Msg1 and send Msg2. On the other hand, the gNB 100 uses the CSI-RS Beams corresponding to CSI-RS-1 and CSI-RS3 to receive Msg#1, and uses the CSI-RS Beams corresponding to CSI-RS-2 and CSI-RS4 to receive Msg#2. In addition, the UE 200 uses the same beam as that for Msg1 to send Msg3.

[0127] According to such a structure, it is possible to improve the channel quality of the PUSCH for sending Msg3 without changing the specifications of the UE 200.

[0128] Second, the UE 200 can select the beam for sending Msg3 according to the CSI-RS received from the gNB 100, and use the selected beam to send Msg3. For example, as Figure 12 and Figure 13 shown, after sending Msg2, the gNB 100 sends two or more CSI-RS. The orientations of the CSI-RS Beams for sending two or more CSI-RS can be different. When the UE 200 receives CSI-RS#1, it uses the beam (CSI-RS Beam) adjusted to the orientation of CSI-RS#1 to send Msg3#1. Similarly, when the UE 200 receives CSI-RS#2, it uses the beam (CSI-RSBeam) adjusted to the orientation of CSI-RS#2 to send Msg3#2.

[0129] In addition, in Figure 12illustrates a case where the resources of CSI-RS#2 are allocated after the resource time of Msg3#1 corresponding to CSI-RS#1. That is, in Figure 12 the resources of CSI-RS and the resources of Msg3 are alternately allocated.

[0130] On the other hand, in Figure 13 illustrates a case where the resources of CSI-RS#2 are allocated before the resource time of Msg3#1 corresponding to CSI-RS#1. That is, in Figure 13 after the resources of CSI-RS are continuously allocated, the resources of Msg3 are continuously allocated.

[0131] As described using Figure 12 and Figure 13 after receiving the second message (Msg2), the UE 200 receives two or more channel state information reference signals (CSI-RS). The UE 200 transmits the third message (Msg3) according to the CSI-RS selected from two or more CSI-RS. The UE 200 can transmit Msg3 using a beam (CSI-RSBeam) adjusted to the orientation of the selected CSI-RS.

[0132] Here, in the case shown in Figure 12 since the resources of CSI-RS and the resources of Msg3 are alternately allocated, two or more CSI-RS can be compared before transmitting Msg3. Therefore, it can be considered that the CSI-RS selected from two or more CSI-RS are all CSI-RS. In other words, the UE 200 transmits the same number of Msg3 as the number of CSI-RS. According to such a structure, after establishing an RRC connection, the UE 200 can use the measurement results of the CSI-RS obtained in the RACH procedure as a CSI report (CSI Report). In addition, in the case shown in Figure 12 since Msg3 is transmitted according to each CSI-RS, it can be considered that such a method also includes the repeated transmission of Msg3.

[0133] On the other hand, in Figure 13In the case shown, since the resources for continuously transmitting Msg3 are allocated after the resources for continuously allocating CSI-RS, it is possible to compare two or more CSI-RS before transmitting Msg3. Therefore, the CSI-RS selected from two or more CSI-RS can be the CSI-RS with the best reception quality. In other words, UE 200 can transmit one Msg3 corresponding to the CSI-RS with the best reception quality. According to such a structure, UE 200 can use the measurement results of the CSI-RS obtained during the RACH procedure as a CSI report after establishing an RRC connection. And it is possible to reduce the number of transmissions of Msg3 based on UE200. In addition, even when the same Msg1 resources are shared among UE 200s when transmitting Msg1, it is possible to avoid conflicts when each UE 200 transmits Msg3 through different resources. Additionally, in Figure 13 the case shown, it is also possible not to transmit Msg3 for each CSI-RS, and it can be considered that such a method does not include repeated transmissions of Msg3.

[0134] Here, the resources of the CSI-RS transmitted during the RACH procedure can be notified to UE 200 through broadcast information (e.g., RACH-ConfigCommon), or can be notified to UE 200 through Msg2.

[0135] [Modification Example 2]

[0136] Hereinafter, a second modification example of the embodiment will be described. Hereinafter, mainly the differences from the embodiment will be described.

[0137] In the embodiment, repeated transmission of Msg3 was mainly described. In contrast, in the second modification example, a case where UE 200 does not perform repeated transmission of Msg3 but UE 200 performs repeated reception of Msg2 will be described.

[0138] As Figure 14 shown, UE 200 transmits Msg1 to NG RAN 20. Repeated transmission of Msg1 can be not performed. NG RAN20 performs repeated transmission of Msg2. In other words, UE 200 performs repeated reception of Msg2. UE 200 can select the Msg2 with the best reception quality from two or more Msg2 received from NG RAN 20 and transmit Msg3 for the selected Msg2. NG RAN20 transmits Msg4 for Msg3.

[0139] In this way, the UE 200 performs repeated reception of the second message (Msg2), and based on the Msg2 selected from the Msg2 received through repeated reception, sends the third message (Msg3). The Msg2 selected from the Msg2 can be the Msg2 with the best reception quality.

[0140] Here, the resources of the repeatedly sent Msg2 applied in the RACH procedure can be notified to the UE 200 through broadcast information (e.g., RACH-ConfigCommon).

[0141] [Other Embodiments]

[0142] As described above, the content of the present invention has been described according to the embodiments, but the present invention is not limited to these descriptions. It is obvious that various modifications and improvements can be made by those skilled in the art.

[0143] Although not specifically mentioned in the above disclosure, the information related to the repeated transmission of Msg3 can be included in both the broadcast information (e.g., RACH-ConfigCommon) and Msg2. In such a case, the candidates for the parameters used for the repeated transmission of Msg3 can be specified by the information elements included in the broadcast information, and the parameters actually used in the repeated transmission of Msg3 can be specified by the information elements included in Msg2. The information elements included in Msg2 can be indices associated with the parameters. For example, the candidates for the number of repeated transmissions of Msg3 can be specified by the information elements included in the broadcast information, and the number actually used in the repeated transmission of Msg3 can be specified by the information elements included in Msg2. Similarly, the candidates for the frequency hopping (e.g., specifying the offset) used in the repeated transmission of Msg3 can be specified by the information elements included in the broadcast information, and the frequency hopping (e.g., specifying the offset) actually used in the repeated transmission of Msg3 can be specified by the information elements included in Msg2.

[0144] Although not specifically mentioned in the above disclosure, the resources of the CSI-RS transmitted in the RACH procedure can be included in both the broadcast information (e.g., RACH-ConfigCommon) and Msg2. In such a case, the candidates for the resources of the CSI-RS can be specified by the information elements included in the broadcast information, and the resources of the CSI-RS can be specified by the information elements included in Msg2.

[0145] The block diagrams used in the description of the above embodiments ( Figure 4shows blocks in terms of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using a single device physically or logically combined, or two or more physically or logically separated devices can be directly or indirectly (e.g., using wired, wireless, etc.) connected and these multiple devices can be used for implementation. A functional block can also be implemented by combining software with the above-mentioned single device or the above-mentioned multiple devices.

[0146] Functionally, it has judgment, decision-making, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, regarded as, broadcasting, notification, communication, forwarding, configuration, reconfiguration, allocation (allocating, mapping), assignment, etc., but not limited to this. For example, a functional block (structural part) that enables transmission to function is called a transmitting unit or a transmitter. In short, as described above, there is no particular limitation on the implementation method.

[0147] Moreover, the above-mentioned UE 200 (this device) can function as a computer that processes the wireless communication method of the present disclosure. Figure 15 is a diagram showing an example of the hardware structure of this device. As Figure 15 shown, this device can also be configured as a computer device including a processor 1001, a memory 1002 (memory), a storage 1003 (storage), a communication device 1004, an input device 1005, an output device 1006, and a bus 1007, etc.

[0148] In addition, in the following description, the term "device" can be replaced with "circuit", "equipment (device)", "unit", etc. The hardware structure of this device can be configured to include one or more of each of the devices shown, or can be configured not to include some of the devices.

[0149] Each functional block of this device (refer to Figure 4 ) is implemented by any hardware element or combination of hardware elements in this computer device.

[0150] In addition, the functions in this device are implemented by the following method: a predetermined software (program) is read into hardware such as the processor 1001 and the memory 1002, so that the processor 1001 performs operations and controls at least one of the communication of the communication device 1004 or the reading and writing of data in the memory 1002 and the storage 1003.

[0151] The processor 1001, for example, operates the operating system to control the entire computer. The processor 1001 may also be composed of a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, registers, etc.

[0152] In addition, the processor 1001 reads a program (program code), software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and performs various processes accordingly. As the program, a program that causes the computer to execute at least a part of the operations described in the above embodiments is used. And regarding the above various processes, although it is described that the above various processes are executed by one processor 1001, the above various processes may also be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may also be installed on one or more chips. In addition, the program may also be sent from a network via a telecommunication line.

[0153] The memory 1002 is a computer-readable recording medium and may, for example, be composed of at least one of a read-only memory (ROM: Read Only Memory), an erasable programmable read-only memory (EPROM: Erasable Programmable ROM), an electrically erasable programmable read-only memory (EEPROM: Electrically Erasable Programmable ROM), a random access memory (RAM: Random Access Memory), etc. The memory 1002 may also be referred to as a register, a cache, a main memory (main storage device), etc. The memory 1002 can store a program (program code), software module, etc. that can execute the method according to an embodiment of the present disclosure.

[0154] The memory 1003 is a computer-readable recording medium, which can be constituted by at least one of optical discs such as a compact disc ROM (CD-ROM), hard disk drives, floppy disks, magneto-optical discs (e.g., compact discs, digital versatile discs, Blu-ray (registered trademark) discs), smart cards, flash memories (e.g., cards, sticks, key drives), Floppy (registered trademark) disks, magnetic strips, etc. The memory 1003 can also be referred to as an auxiliary storage device. The above-mentioned recording medium can be, for example, a database, a server, and other appropriate media including at least one of the memory 1002 and the memory 1003.

[0155] The communication device 1004 is hardware (a transceiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, etc.

[0156] The communication device 1004 can be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. for implementing at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0157] The input device 1005 is an input device that accepts input from the outside (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.). The output device 1006 is an output device that performs output to the outside (e.g., a display, a speaker, an LED lamp, etc.). In addition, the input device 1005 and the output device 1006 can also be integrally constituted (e.g., a touch panel).

[0158] In addition, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 can be constituted by a single bus, or different buses can be used between devices.

[0159] Moreover, the apparatus 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 a part or all of the functional blocks may be implemented by this hardware. For example, the processor 1001 may also be implemented using at least one of these hardware components.

[0160] In addition, the notification of information is not limited to the forms / embodiments described in the present disclosure, and other methods may also be used. For example, the notification of information may be implemented by physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI)), high layer signaling (e.g., RRC signaling, medium access control (MAC) signaling, broadcast information (master information block (MIB), system information block (SIB))), other signals, or a combination thereof. In addition, the RRC signaling may also be referred to as an RRC message, and may be, for example, an RRC connection setup message, an RRC connection reconfiguration message, etc.

[0161] Each form / embodiment described in the present disclosure can also be applied to at least one of Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, the 4th generation mobile communication system (4G), the 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), systems using other appropriate systems, and next-generation systems extended therefrom. In addition, multiple systems (for example, a combination of at least one of LTE and LTE-A and 5G, etc.) can be combined and applied.

[0162] For the processing procedures, timings, flows, etc. of each form / embodiment described in the present disclosure, the order can be changed without contradiction. For example, for the methods described in the present disclosure, the exemplified order indicates the elements of various steps, but is not limited to the specific order indicated.

[0163] In the present disclosure, specific actions performed by the base station may sometimes be performed by its upper node according to circumstances. In a network composed of one or more network nodes having a base station, it is obvious that various actions performed for communicating with the terminal can be performed by at least one of the base station and other network nodes other than the base station (for example, MME or S-GW is considered, but not limited thereto). In the above, the case where there is one other network node other than the base station is exemplified, but the other network nodes may also be a combination of multiple other network nodes (for example, MME and S-GW).

[0164] Information, signals (such as information) can be output from a higher layer (or a lower layer) to a lower layer (or a higher layer). It can also be input or output via multiple network nodes.

[0165] The input or output information can be stored in a specific location (e.g., memory), or can be managed using a management table. The input or output information can be rewritten, updated, or appended. The output information can also be deleted. The input information can also be sent to other devices.

[0166] The determination can be made by a value represented by 1 bit (0 or 1), can also be made by a Boolean value (true or false), and can also be made by a numerical comparison (e.g., comparison with a predetermined value).

[0167] Each form / embodiment described in the present disclosure can be used alone, can be used in combination, or can be switched according to the execution. In addition, the notification of predetermined information is not limited to being explicit (e.g., notification of "it is X"), and can also be implicit (e.g., not notifying the predetermined information).

[0168] For software, regardless of whether it is called software, firmware, middleware, microcode, hardware description language, or any other name, it should be broadly interpreted as referring to commands, command sets, codes, code segments, program codes, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc.

[0169] In addition, software, commands, information, etc. can be transmitted and received via a transmission medium. For example, when using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and wireless technologies (infrared, microwave, etc.) to send software from a website, server, or other remote source, at least one of these wired technologies and wireless technologies is included in the definition of the transmission medium.

[0170] The information, signals, etc. described in the present disclosure can also be represented using any one of various different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be involved in the above description as a whole can be represented by voltage, current, electromagnetic wave, magnetic field or magnetic particles, optical field or photons, or any combination of these.

[0171] In addition, terms described in this disclosure and terms required to understand this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may also be a signal (signaling). In addition, a signal may also be a message. In addition, a component carrier (CC) may also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0172] Terms such as "system" and "network" used in this disclosure may be used interchangeably.

[0173] In addition, information, parameters, etc. described in this disclosure may be represented by absolute values, may be represented by relative values with respect to a predetermined value, or may be represented by corresponding other information. For example, radio resources may also be indicated by an index.

[0174] The names used for the above parameters are non - restrictive in any aspect. Furthermore, mathematical expressions using these parameters are sometimes different from the content explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by all appropriate names, the various names assigned to these various channels and information elements are non - restrictive in any aspect.

[0175] In this disclosure, terms such as "Base Station (BS)", "radio base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. Sometimes, terms such as macro cell, small cell, femto cell, pico cell, etc. are also used to refer to a base station.

[0176] A base station can accommodate one or more (e.g., 3) cells (also referred to as sectors). When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))).

[0177] Terms such as "cell" or "sector" refer to a part or the whole of the coverage area of at least one of a base station and a base station subsystem that provides communication services within that coverage range.

[0178] In the present disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", and "terminal" can be used interchangeably.

[0179] Regarding the mobile station, those skilled in the art sometimes also refer to it using the following terms: subscriber station, mobile unit, subscriber unit, radio 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 appropriate terms.

[0180] At least one of the base station and the mobile station can be referred to as a transmitting device, a receiving device, a communication device, etc. Additionally, at least one of the base station and the mobile station can also be a device mounted on a moving body, the moving body itself, etc. The moving body can be a vehicle (e.g., a car, an airplane, etc.), a moving body that moves in an unmanned manner (e.g., a drone, a self-driving car, etc.), or a robot (humanoid or non-humanoid). Additionally, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station can be an Internet of Things (IoT) device such as a sensor.

[0181] Furthermore, the base station in the present disclosure can also be replaced with a mobile station (user terminal, the same hereinafter). For example, regarding a structure in which communication between the base station and the mobile station is replaced with communication between multiple mobile stations (e.g., which can also be referred to as Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.), various forms / embodiments of the present disclosure can also be applied. In this case, it can also be configured such that the mobile station has the functions of the base station. Additionally, terms such as "uplink" and "downlink" can also be replaced with terms corresponding to inter-terminal communication (e.g., "side"). For example, an uplink channel, a downlink channel, etc. can also be replaced with a side channel.

[0182] Similarly, the mobile station in the present disclosure can be replaced with the base station. In this case, it can also be configured such that the base station has the functions of the mobile station.

[0183] A radio frame can be composed of one or more frames in the time domain. In the time domain, each of the one or more frames can be referred to as a subframe.

[0184] A subframe can be further composed of one or more time slots in the time domain. A subframe can also be a fixed time length independent of numerology (e.g., 1 ms).

[0185] Numerology can also be communication parameters applied to at least one of transmission and reception of a certain signal or channel. Numerology can represent, for example, at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering processing performed by a transceiver in the frequency domain, specific windowing processing performed by a transceiver in the time domain, etc.

[0186] A time slot can be composed of one or more symbols (orthogonal frequency division multiplexing (OFDM) symbols, single carrier frequency division multiple access (SC-FDMA) symbols, etc.) in the time domain. A time slot can be a time unit based on numerology.

[0187] A time slot can contain multiple mini-slots. Each mini-slot can be composed of one or more symbols in the time domain. In addition, a mini-slot can also be referred to as a sub-slot. A mini-slot can be composed of a smaller number of symbols than a time slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-slot can be referred to as PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot can be referred to as PDSCH (or PUSCH) mapping type B.

[0188] A radio frame, a subframe, a time slot, a mini-slot, and a symbol all represent time units for transmitting signals. A radio frame, a subframe, a time slot, a mini-slot, and a symbol can be respectively referred to by corresponding other names.

[0189] For example, 1 subframe can also be referred to as a transmission time interval (TTI), multiple consecutive subframes can also be referred to as a TTI, 1 time slot or 1 mini-slot can also be referred to as a TTI. That is, at least one of a subframe and a TTI can be a subframe (1 ms) in existing LTE, can also be a period shorter than 1 ms (e.g., 1 - 13 symbols), and can also be a period longer than 1 ms. In addition, the unit representing a TTI can be referred to not as a subframe, but as a time slot, a mini-slot, etc.

[0190] Here, the TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling to allocate radio resources (such as the bandwidth and transmission power that can be used in each user terminal) to each user terminal in units of TTI. Additionally, the definition of the TTI is not limited to this.

[0191] The TTI can be the transmission time unit for data packets (transport blocks), code blocks, codewords, etc. after channel coding, or can also be the processing unit for scheduling, link adaptation, etc. Additionally, when the TTI is given, the actual time interval (such as the number of symbols) to which the transport block, code block, codeword, etc. are mapped can be shorter than the TTI.

[0192] In addition, when 1 time slot or 1 mini time slot is referred to as the TTI, one or more TTIs (i.e., one or more time slots or one or more mini time slots) can constitute the minimum time unit for scheduling. Furthermore, the number of time slots (number of mini time slots) that constitute the minimum time unit for scheduling can be controlled.

[0193] The TTI with a time length of 1 ms can also be referred to as the normal TTI (TTI in LTE Rel.8 - 12), normal TTI, long TTI, normal subframe, long subframe, time slot, etc. The TTI shorter than the normal TTI can also be referred to as the shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini time slot, sub - time slot, time slot, etc.

[0194] In addition, for the long TTI (such as the normal TTI, subframe, etc.), it can be replaced with a TTI having a time length exceeding 1 ms, and for the short TTI (such as the shortened TTI, etc.), it can be replaced with a TTI having a TTI length less than that of the long TTI and having a TTI length of 1 ms or more.

[0195] The resource block (RB) is the resource allocation unit in the time domain and the frequency domain. In the frequency domain, it can contain one or more consecutive subcarriers. The number of subcarriers contained in the RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers contained in the RB can also be determined according to the parameter set.

[0196] In addition, the time domain of an RB may include one or more symbols, or may be the length of 1 time slot, 1 mini-slot, 1 sub-frame, or 1 TTI. 1 TTI, 1 sub-frame, etc. may each be composed of one or more resource blocks.

[0197] In addition, one or more RBs may also be referred to as Physical Resource Blocks (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0198] In addition, a resource block may also be composed of one or more Resource Elements (REs). For example, 1 RE may be a radio resource area of 1 sub-carrier and 1 symbol.

[0199] A Bandwidth Part (BWP) (which may also be referred to as partial bandwidth, etc.) may represent a subset of consecutive common resource blocks (common RBs) used for a certain parameter set in a certain carrier. Here, the common RBs can be determined by the indices of the RBs based on the common reference point of the carrier. PRBs can be defined in a certain BWP and numbered within that BWP.

[0200] A BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs can be set for a UE within 1 carrier.

[0201] At least one of the set BWPs can be active, and it can be assumed that the UE does not transmit or receive a predetermined signal / channel outside the active BWP. In addition, "cell", "carrier", etc. in the present disclosure can be replaced by "BWP".

[0202] The structures of the above-mentioned radio frames, sub-frames, time slots, mini-slots, symbols, etc. are only examples. For example, the number of sub-frames included in a radio frame, the number of time slots in each sub-frame or radio frame, the number of mini-slots included in a time slot, the symbols and the number of RBs included in a time slot or mini-slot, the number of sub-carriers included in an RB, the number of symbols within a TTI, the symbol length, the Cyclic Prefix (CP) length, etc. can be variously changed.

[0203] Terms such as "connected" and "coupled", or any variations of these terms, are intended to represent all direct or indirect connections or couplings between two or more elements, and may include cases where there is one or more intermediate elements between the two elements that are "connected" or "coupled" to each other. The coupling or connection between elements can be a physical coupling or connection, a logical coupling or connection, or a combination of these. For example, "access" can also be used to replace "connected". In the context of the present disclosure, it can be considered that two elements are "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, and, as some non-limiting and non-inclusive examples, using electromagnetic energy having wavelengths in the radio frequency domain, microwave region, and optical (both visible and invisible) regions, etc. to "connect" or "couple" to each other.

[0204] The reference signal can be abbreviated as Reference Signal (RS), or can also be referred to as a Pilot according to the applied standard.

[0205] The description "in accordance with" used in the present disclosure does not mean "only in accordance with" unless otherwise clearly stated. In other words, the description "in accordance with" means both "only in accordance with" and "at least in accordance with".

[0206] The "unit" in the structure of each of the above devices can also be replaced with a "section", "circuit", "equipment", etc.

[0207] Any reference to elements using designations such as "first", "second", etc. used in the present disclosure does not entirely limit the quantity or order of these elements. These designations can be used in the present disclosure as a convenient method for distinguishing between two or more elements. Therefore, a reference to a first element and a second element does not mean that only two elements can be involved or that the first element must precede the second element in any form.

[0208] When the terms "include", "including", and their variations are used in the present disclosure, these terms mean inclusive in the same way as the term "comprising". Also, the term "or" used in the present disclosure does not mean exclusive or.

[0209] In the present disclosure, for example, in cases where articles are added through translation such as a, an, and the in English, the present disclosure can also include cases where the noun following these articles is in the plural form.

[0210] As used in this disclosure, terms such as "determining" may sometimes include a variety of actions. For example, "determining" may include considering something that has been judged, calculated, computed, processed, derived, investigated, looked up / search / inquired (e.g., search in a table, database, or other data structure), or ascertained as having been "determined". In addition, "determining" may include considering something that has been received (e.g., receiving information), transmitted (e.g., transmitting information), input, output, accessed (e.g., accessing data in memory), etc. as having been "determined". Further, "determining" may include considering something that has been resolved, selected, chosen, established, compared, etc. as having been "determined". That is, "determining" may include anything that is considered to have "determined" any action. In addition, "determining" may also be replaced by "assuming", "expecting", "considering", etc.

[0211] In this disclosure, the phrase "A is different from B" may also mean that "A and B are distinct from each other". Additionally, this phrase may also mean that "A and B are each different from C". Terms such as "separating" and "combining" may be interpreted in the same way as "different".

[0212] As described above, this disclosure has been explained in detail. However, for those skilled in the art, it should be clear that this disclosure is not limited to the embodiments described in this disclosure. This disclosure can be implemented in the form of modifications and changes without departing from the gist and scope of this disclosure determined by the claims. Therefore, the purpose of the description of this disclosure is for illustrative purposes and has no restrictive meaning for this disclosure.

[0213] Reference Numeral Explanation

[0214] 10: Wireless communication system;

[0215] 20: NG-RAN;

[0216] 100: gNB;

[0217] 200: UE;

[0218] 210: Radio signal transceiver unit;

[0219] 220: Amplification unit;

[0220] 230: Modulation / demodulation unit;

[0221] 240: Control signal and reference signal processing unit;

[0222] 250: Encoding / decoding unit;

[0223] 260: Data transceiver unit;

[0224] 270: Control unit;

[0225] 1001: Processor;

[0226] 1002: Memory;

[0227] 1003: Storage;

[0228] 1004: Communication device;

[0229] 1005: Input device;

[0230] 1006: Output device;

[0231] 1007: Bus.

Claims

1. A terminal, comprising: a transmitting unit that transmits a random access preamble as a first message; and a receiving unit that receives a response message to the first message as a second message, after receiving the second message, the transmitting unit transmits a third message via a physical uplink shared channel, the transmitting unit performs retransmission of the third message according to downlink control information, the transmitting unit applies inter-slot frequency hopping during the retransmission of the third message.

2. The terminal according to claim 1, wherein, the transmitting unit performs retransmission of the third message according to broadcast information including an information element related to the retransmission and the downlink control information.

3. The terminal according to claim 1 or 2, wherein, the transmitting unit performs retransmission of the third message according to the second message.

4. The terminal according to claim 3, wherein, the transmitting unit performs retransmission of the third message according to broadcast information including an information element related to the retransmission and the second message.

5. A base station, wherein, the base station has: a receiving unit that receives a random access preamble as a first message; and a transmitting unit that transmits a response message to the first message as a second message, after transmitting the second message, the receiving unit receives a third message via a physical uplink shared channel, the receiving unit performs re-reception of the third message according to downlink control information, the receiving unit applies inter-slot frequency hopping during the re-reception of the third message.

6. A wireless communication system, comprising a terminal and a base station, wherein, the terminal transmits a random access preamble as a first message, the base station transmits a response message to the first message as a second message, after receiving the second message, the terminal transmits a third message via a physical uplink shared channel, the terminal performs retransmission of the third message according to downlink control information, the terminal applies inter-slot frequency hopping during the retransmission of the third message.

7. A wireless communication method, wherein, the wireless communication method includes the following steps: Step A, transmitting a random access preamble as a first message; Step B, receiving a response message to the first message as a second message; and Step C, after receiving the second message, transmitting a third message via a physical uplink shared channel, Step C includes a step of performing retransmission of the third message according to downlink control information, Step C includes a step of applying inter-slot frequency hopping during the retransmission of the third message.

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