Apparatus and method for setting power of prach repeative transmission in wireless communication system

Abstract

According to various embodiments of the present disclosure, an operation method of a user equipment (UE) in a wireless communication system is provided, comprising the steps of: receiving, from a base station (BS), radio resource control (RRC) information related to a maximum number of repetitions of a random access (RA) preamble corresponding to a first number of times; performing, for the first RA procedure, a first repeat transmission of an RA preamble to the BS based on a first number of times; if the first repeated transmission of the RA preamble is performed based on a first number of times and the first RA process is not completed, determining a number of repeated transmissions of the RA preamble based on a second number of times greater than the first number of times; and performing a second repeat transmission of the RA preamble to the base station based on a second number of times for the second RA procedure.

Description

Technical Field

[0001] This disclosure relates to wireless communication systems. More specifically, this disclosure relates to apparatus and methods for configuring the power of PRACH repetitive transmissions in a wireless communication system. Background Technology

[0002] NR supports multiple parameter sets (or subcarrier spacing (SCS)) to support diverse 5G services. For example, if the SCS is 15kHz, NR supports wide areas of traditional cellular bands; if the SCS is 30kHz / 60kHz, NR supports dense urban areas, low latency, and wider carrier bandwidth; and if the SCS is 60kHz or higher, NR supports bandwidths greater than 24.25GHz to overcome phase noise.

[0003] A variety of RAN1 work items are defined to differentiate User Equipment (UE) / base station operations based on RACH resources (e.g., PRACH preamble indexes). For example, a UE associated with RedCap, small data transmission, Msg.3PUSCH repetition is defined as selecting a specific preamble index in the PRACH preamble transmission step and requesting the base station whether to use the corresponding function. However, defining separate operations for each work item in the specification could complicate UE / base station operations.

[0004] Therefore, in the RAN2 Rel-17 RACH partitioning work item, the concept of "function combination" has been introduced to efficiently support the differentiated UE / base station operations using RACH resources (e.g., PRACH preamble index, etc.). That is, the base station can configure specific PRACH resources (e.g., preamble start index and total count indication) and notify the UE to support a specific function or a combination of specific functions. When performing the RACH procedure, a UE intending to use / request a specific function and / or a combination of specific functions can select one of the preamble indices assigned to the region of the desired specific function and / or combination of specific functions, and can send a PRACH preamble.

[0005] The key feature is that multiple parameters "FeatureCombinationPreambles" can be configured in RACH-ConfigCommon, and the preamble index duration corresponding to each region needs to be configured to be non-overlapping. Furthermore, the functions and / or function combinations configured in each region need to be configured to be non-overlapping.

[0006] In addition to the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon, the base station can also additionally assign RACH configuration via AdditionalRACH-Config-r17. Therefore, a Rel-16 UE that cannot read AdditionalRACH-Config-r17 performs the RACH procedure based on the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon. However, a Rel-17 UE that can read AdditionalRACH-Config-r17 checks both the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon and the RACH-ConfigCommon assigned to AdditionalRACH-Config-r17, and performs the RACH procedure. Furthermore, one or more of the aforementioned FeatureCombinationPreambles can also be configured to the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon. One or more of the aforementioned FeatureCombinationPreambles can also be configured to the RACH-ConfigCommon assigned to AdditionalRACH-Config-r17. The RRC parameters related to RACH allocation can be as follows: Figure 3 -0 is shown.

[0007] To enhance UL coverage in existing NR systems, the introduction of PRACH preamble retransmission is being considered. Therefore, to support PRACH retransmission, it is necessary to define how to configure PRACH resources with different retransmission counts. As a simple approach, a method for allocating PRACH resources could be considered to differentiate multiple PRACH retransmission resources with different retransmission counts based on either the preamble level or the RO level. Summary of the Invention

[0008] Technical issues

[0009] To address the aforementioned problems, this disclosure provides apparatus and methods for configuring PRACH repetitive transmission power in a wireless communication system.

[0010] This disclosure provides apparatus and methods for performing operations in a wireless communication system related to the assignment of the same number of repetitions to multiple PRACH repetition resources.

[0011] The technical objectives to be achieved by this disclosure are not limited to those described above by way of example only, and other technical objectives not mentioned will be clearly understood by those skilled in the art to which this disclosure pertains from the following description.

[0012] Technical solution

[0013] According to various embodiments of this disclosure, a method for operating a user equipment (UE) in a wireless communication system is provided. The method includes: receiving radio resource control (RRC) information from a base station related to a maximum number of repetitions of a random access (RA) preamble corresponding to a first number; for a first RA process, performing a first repetition transmission of the RA preamble to the base station based on the first number; determining a number of repetitions of the RA preamble based on a second number greater than the first number, since the first repetition transmission of the RA preamble was performed based on the first number and the first RA process was not yet completed; and for a second RA process, performing a second repetition transmission of the RA preamble to the base station based on the second number.

[0014] According to various embodiments of this disclosure, a method for operating a base station in a wireless communication system is provided. The method includes: sending radio resource control (RRC) information to a user equipment (UE) relating to a maximum number of repetitions of a random access (RA) preamble corresponding to a first number; receiving a first repetition of the RA preamble from the UE based on the first number for a first RA process; and receiving a second repetition of the RA preamble from the UE based on a second number for a second RA process, where the first repetition of the RA preamble is performed based on the first number and the first RA process is not yet completed, and the second number is a number of repetitions of the RA preamble greater than the first number.

[0015] According to various embodiments of the present disclosure, a user equipment (UE) in a wireless communication system is provided, the UE including a transceiver, at least one processor, and at least one memory, the at least one memory being operatively connectable to the at least one processor and storing instructions for performing operations based on execution by the at least one processor, and the operations including all steps of a method for operating the UE according to various embodiments of the present disclosure.

[0016] According to various embodiments of the present disclosure, a base station in a wireless communication system is provided, the base station including a transceiver, at least one processor, and at least one memory, the at least one memory being operatively connectable to the at least one processor and storing instructions for performing operations based on execution by the at least one processor, and the operations including all steps of a method for operating the base station according to various embodiments of the present disclosure.

[0017] According to various embodiments of the present disclosure, a control device for controlling a user equipment in a wireless communication system is provided. The control device includes at least one processor and at least one memory operatively connected to the at least one processor, wherein the at least one memory stores instructions for performing operations based on execution by the at least one processor, and the operations include all steps of a method for operating a user equipment according to various embodiments of the present disclosure.

[0018] According to various embodiments of the present disclosure, a control device for controlling a base station in a wireless communication system is provided. The control device includes at least one processor and at least one memory operatively connected to the at least one processor, wherein the at least one memory stores instructions for performing operations based on execution by the at least one processor, and the operations include all steps of a method for operating a base station according to various embodiments of the present disclosure.

[0019] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media are provided that store one or more instructions, which, when executed by one or more processors, perform operations including all steps of a method for operating a user equipment according to various embodiments of the present disclosure.

[0020] According to various embodiments of the present disclosure, one or more non-transitory computer-readable media are provided that store one or more instructions that, when executed by one or more processors, perform operations including all steps of a method for operating a base station according to various embodiments of the present disclosure.

[0021] Beneficial effects

[0022] To address the aforementioned problems, this disclosure provides apparatus and methods for configuring PRACH repetitive transmission power in a wireless communication system.

[0023] This disclosure provides apparatus and methods for performing operations in a wireless communication system related to assigning the same number of repetitions to multiple PRACH repetition resources. Attached Figure Description

[0024] The accompanying drawings are included to provide a further understanding of the present disclosure and form part of the detailed description. The drawings illustrate embodiments of the present disclosure and, together with the description, serve to explain the technical features of the present disclosure. The technical features of the present disclosure are not limited to the specific drawings, and the features disclosed in each drawing can be combined with each other to form new embodiments. Reference numerals in each drawing may denote structural elements.

[0025] Figure 1Examples of physical channels used in systems applicable to this disclosure and general signal transmission methods using physical channels are shown.

[0026] Figure 2 An example of the structure of a radio frame used in the system applicable to this disclosure is shown.

[0027] Figure 3 An example of a time slot structure used in a system applicable to this disclosure is shown.

[0028] Figure 4 An example of a time slot structure for a radio frame used in a system applicable to this disclosure is shown.

[0029] Figure 5 An example of RRC parameters related to RACH partitioning is shown in the system applicable to this disclosure.

[0030] Figure 6 An example of the operation procedure of a user equipment (UE) in a system applicable to this disclosure is shown.

[0031] Figure 7 An example of the operation procedure of a base station in a system applicable to this disclosure is shown.

[0032] Figure 8 Examples of the structures of the first and second devices applicable to the system of this disclosure are shown. Detailed Implementation

[0033] In various embodiments of this disclosure, "A or B" can mean "A only", "B only", or "both A and B". In other words, in various embodiments of this disclosure, "A or B" can be interpreted as "A and / or B". For example, in various embodiments of this disclosure, "A, B or C" can mean "A only", "B only", "C only", or "any combination of A, B and C".

[0034] In various embodiments of this disclosure, the forward slash ( / ) or comma used can represent "and / or". For example, "A / B" can mean "A and / or B". Thus, "A / B" can mean "A only", "B only", or "both A and B". For example, "A, B, C" can mean "A, B, or C".

[0035] In various embodiments of this disclosure, "at least one of A and B" can mean "only A", "only B" or "both A and B". Furthermore, in various embodiments of this disclosure, the expression "at least one of A or B" or "at least one of A and / or B" can be interpreted as having the same meaning as "at least one of A and B".

[0036] Furthermore, in various embodiments of this disclosure, "at least one of A, B, and C" can mean "A only", "B only", "C only" or "any combination of A, B, and C". Additionally, "at least one of A, B, or C" or "at least one of A, B, and / or C" can mean "at least one of A, B, and C".

[0037] Furthermore, the parentheses used in the various embodiments of this disclosure can denote "for example". Specifically, when describing "control information (PDCCH)", "PDCCH" can be cited as an example of "control information". In other words, "control information" in the various embodiments of this disclosure is not limited to "PDCCH", and "PDDCH" can be cited as an example of "control information". Moreover, even when describing "control information (i.e., PDCCH)", "PDCCH" can be cited as an example of "control information".

[0038] In various embodiments of this disclosure, the technical features described individually in a single drawing may be implemented individually or simultaneously.

[0039] General signal transmission methods in 3GPP

[0040] Physical channels and general signal transmission

[0041] Figure 1 Examples of physical channels used in systems applicable to this disclosure and general signal transmission methods using physical channels are shown. More specifically, Figure 1 The physical channels and general signal transmissions used in the 3GPP system are shown.

[0042] Figure 1 This illustrates the physical channels and general signal transmission used in a 3GPP system. In a wireless communication system, the UE receives information from the eNB via the downlink (DL) and transmits information to the eNB via the uplink (UL). The information transmitted and received by the eNB and UE includes data and various control information, and various physical channels exist depending on the type / purpose of the information transmitted and received by the eNB and UE.

[0043] In S11, the UE, upon power-up after a power outage or entering a new cell, performs an initial cell search operation, such as synchronizing with the base station (BS). To do this, the UE receives the primary synchronization channel (PSCH) and secondary synchronization channel (SSCH) from the base station to synchronize with it and obtains information such as the cell identifier (ID). Additionally, the UE can receive the physical broadcast channel (PBCH) from the base station and obtain intra-cell broadcast information. The UE can also receive a downlink reference signal (DL RS) during the initial cell search step to check the downlink channel status.

[0044] In S12, the UE that has completed the initial cell search can receive the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH) corresponding to the PDCCH to obtain more detailed system information.

[0045] Next, in S13 to S16, the UE can perform a random access procedure to complete access to the base station. Specifically, in S13, the UE can transmit a preamble on the Physical Random Access Channel (PRACH), and in S14, it can receive a Random Access Response (RAR) for the preamble on the PDCCH and the corresponding PDSCH. Subsequently, in S15, the UE can use the scheduling information within the RAR to transmit the Physical Uplink Shared Channel (PUSCH), and in S16, it performs contention resolution procedures such as those for the PDCCH and the corresponding PDSCH.

[0046] Next, the UE performing the above process can execute PDCCH / PDSCH reception S17 and PUSCH / Physical Uplink Control Channel (PUCCH) transmission S18, as a general uplink / downlink signal transmission process. The control information sent by the UE to the base station is called uplink control information (UCI). UCI includes Hybrid Automatic Repeat Request (HARQ) acknowledgment / negation ACK (ACK / NACK), scheduling request (SR), channel state information (CSI), etc. CSI includes channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), etc. UCI is usually transmitted on PUCCH, but if control information and data need to be transmitted simultaneously, it can also be transmitted on PUSCH. The UE can transmit UCI on PUSCH aperiodically based on network requests / indications.

[0047] Orthogonal Frequency Division Multiplexing (OFDM) Parameter Set

[0048] The new RAT system uses an OFDM transmission scheme or a similar one. The new RAT system can follow OFDM parameters different from those of LTE. Alternatively, the new RAT system can follow the existing LTE / LTE-A parameter set as is, but with a larger system bandwidth (e.g., 100MHz). Alternatively, a single cell can support multiple parameter sets. In other words, UEs operating with different parameter sets can coexist in a single cell.

[0049] Radio frame structure

[0050] Figure 2 An example of the structure of a wireless frame used in a system applicable to this disclosure is shown.

[0051] In NR, uplink and downlink transmissions consist of frames. A radio frame is 10 ms long and is defined as two 5 ms half-frames (HF). A half-frame is defined as five 1 ms subframes (SF). Subframes are divided into one or more time slots, and the number of time slots in a subframe depends on the subcarrier spacing (SCS). Depending on the cyclic prefix (CP), each time slot includes 12 or 14 OFDM(A) symbols. When using normal CP, each time slot includes 14 symbols. When using extended CP, each time slot includes 12 symbols. Symbols can include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or DFT-s-OFDM symbols).

[0052] Table 1 shows how the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS when using normal CP.

[0053] [Table 1]

[0054] <![CDATA[SCS(15*2 u )]]> <![CDATA[N slot symb ]]> <![CDATA[N frame，u slot ]]> <![CDATA[N subframe,u slot ]]> 15kHz (u=0) 14 10 1 30kHz (u=1) 14 20 2 60kHz (u=2) 14 40 4 120kHz (u=3) 14 80 8 240kHz (u=4) 14 160 16

[0055] N slot symb N is the number of symbols in the time slot. frame,u slot N is the number of time slots in a frame. subframe,u slot It is the number of time slots in the subframe.

[0056] Table 2 shows how the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS when using extended CP.

[0057] [Table 2]

[0058] <![CDATA[SCS(15*2 u )]]> <![CDATA[N slot symb ]]> <![CDATA[N frame,u s lot ]]> <![CDATA[N subframe,u slot ]]> 60kHz (u=2) 12 40 4

[0059] NR supports multiple sets of parameters (or subcarrier spacing (SCS)) to support various 5G services. For example, a 15kHz SCS supports wide-area coverage in traditional cellular bands, a 30kHz / 60kHz SCS supports dense urban areas, lower latency, and wider carrier bandwidth, and a 60kHz or higher SCS supports bandwidths greater than 24.25GHz to overcome phase noise.

[0060] NR bands can be defined as two types of frequency ranges (FR1 and FR2). The values ​​of the frequency ranges can be changed; for example, the two frequency ranges (FR1 and FR2) can be shown in Table 3 below. For ease of description, in the frequency ranges used in NR systems, FR1 can represent "below 6 GHz" and FR2 can represent "above 6 GHz," and can be referred to as millimeter wave (mmW).

[0061] [Table 3]

[0062] Frequency range name Corresponding frequency range Subcarrier spacing FR1 450MHz-6000MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0063] As mentioned above, the frequency range of the NR system can be changed. For example, FR1 can include a frequency band from 410MHz to 7125MHz, as shown in Table 4 below. That is, FR1 can include a frequency band of 6GHz (or 5850, 5900, 5925MHz, etc.) or higher. For example, the 6GHz (or 5850, 5900, 5925MHz, etc.) or higher frequency band included in FR1 can include unlicensed frequency bands. Unlicensed frequency bands can be used for various purposes, such as for vehicle communications (e.g., autonomous driving).

[0064] [Table 4]

[0065]

[0066]

[0067] In NR systems, OFDM(A) parameter sets (e.g., SCS, CP length, etc.) can be configured differently across multiple cells merged into a single UE. Therefore, the (absolute time) duration of time resources (e.g., SF, time slots, or TTI) consisting of the same number of symbols (collectively referred to as Time Units (TUs) for convenience) can be configured differently across merged cells.

[0068] Figure 3 An example of a time slot structure used in a system applicable to this disclosure is shown.

[0069] A time slot comprises multiple symbols in the time domain. For example, a time slot includes 7 symbols under normal CP, while a time slot includes 6 symbols under extended CP. A carrier comprises multiple subcarriers in the frequency domain. A resource block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth portion (BWP) is defined as multiple consecutive (P) RBs in the frequency domain and may correspond to a set of parameters (e.g., SCS, CP length, etc.). A carrier may include up to N (e.g., 5) BWPs. Data communication can be performed through active BWPs, and only one BWP can be active in a UE. In the resource grid, each element is called a resource element (RE), and a complex symbol can be mapped to each RE.

[0070] Figure 4 An example of a time slot structure for a radio frame used in a system applicable to this disclosure is shown.

[0071] More specifically, Figure 4The time slot structure of a frame in an NR system, which serves as an example system, is shown.

[0072] like Figure 4 As shown, the frame structure of NR is characterized by its self-contained structure, where the DL control channel, DL or UL data, and UL control channel can all be included in a single time slot. In this case, DL data scheduling information and UL data scheduling information can be transmitted on the DL control channel, and ACK / NACK information, CSI information (modulation and coding scheme information, MIMO transmission-related information, etc.), and scheduling requests for DL ​​data can be transmitted on the UL control channel. Figure 4 In this context, the time slot used for DL ​​to UL or UL to DL switching can exist between the control area and the data area. Furthermore, a portion of the DL control channel / DL data / UL data / UL control channel may not be configured within a single time slot. Alternatively, the order of the channels constituting a time slot can vary (e.g., DL control / DL data / UL control / UL data or UL control / UL data / DL control / DL data, etc.).

[0073] Structure and method of the present invention

[0074] NR supports multiple parameter sets (or subcarrier spacing (SCS)) to support diverse 5G services. For example, if the SCS is 15kHz, NR supports wide areas of traditional cellular bands; if the SCS is 30kHz / 60kHz, NR supports dense urban areas, low latency, and wider carrier bandwidth; if the SCS is 60kHz or higher, NR supports bandwidths greater than 24.25GHz to overcome phase noise.

[0075] Several RAN1 work items are defined to differentiate User Equipment (UE) / base station operations based on RACH resources (e.g., PRACH preamble indexes). For example, a UE associated with RedCap, small data transmission, or Msg.3PUSCH repetition is defined as selecting a specific preamble index in the PRACH preamble transmission step and requesting the base station whether to use the corresponding function. However, if the 3GPP standard specification defines operations separately for each work item, UE / base station operations may become complex.

[0076] Therefore, in the RAN2 Rel-17 RACH partitioning work item, the concept of "feature combination" has been introduced to efficiently support differentiated UE / base station operations using RACH resources (e.g., PRACH preamble indexes, etc.). That is, the base station can configure specific PRACH resources (e.g., preamble start indexes and total counts) and notify the UE to support a specific function or a combination of specific functions. When performing the RACH procedure, a UE intending to use / request a specific function and / or a combination of specific functions can select one of the preamble indices assigned to the region of the desired specific function and / or combination of specific functions, and can send a PRACH preamble. The RRC parameters used for this operation are defined in "Feature Combination Preambles" and "Feature Combination" of 3GPP Technical Specification (TS) 38.331.

[0077] Table 5 below shows the "Feature Combination Preambles" in 3GPP TS 38.331. Table 6 below shows the "Feature Combination" in 3GPP TS 38.331.

[0078] [Table 5]

[0079]

[0080] [Table 6]

[0081]

[0082] The key feature is that multiple parameters "FeatureCombinationPreambles" can be configured in RACH-ConfigCommon, and the preamble index duration corresponding to each region needs to be configured to be non-overlapping. Furthermore, the functions and / or function combinations configured in each region need to be configured to be non-overlapping.

[0083] Figure 5 An example of RRC parameters related to RACH partitioning is shown in the system applicable to this disclosure.

[0084] In addition to the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon, the base station can also additionally assign RACH configuration via AdditionalRACH-Config-r17. Therefore, a Rel-16 UE that cannot read AdditionalRACH-Config-r17 performs the RACH procedure based on the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon. However, a UE that can read AdditionalRACH-Config-r17 checks both the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon and the RACH-ConfigCommon assigned to AdditionalRACH-Config-r17, and performs the RACH procedure. Furthermore, one or more of the aforementioned FeatureCombinationPreambles can also be configured for the RACH-ConfigCommon assigned to the existing BWP-UplinkCommon. Similarly, one or more of the aforementioned FeatureCombinationPreambles can also be configured for the RACH-ConfigCommon assigned to AdditionalRACH-Config-r17. Figure 5 An example of RRC parameters related to RACH partitioning is shown.

[0085] To enhance UL coverage in existing NR systems, the introduction of PRACH preamble retransmission is being considered. Therefore, to support PRACH retransmission, it is necessary to define how to allocate PRACH resources with different retransmission numbers. As a simple approach, a method for allocating PRACH resources can be considered to differentiate multiple PRACH retransmission resources with different retransmission numbers based on preamble level or RO level. This disclosure proposes UE operations and / or base station operations related to the scenario where multiple PRACH retransmission resources are assigned the same retransmission number.

[0086] 1. Controlling PRACH issuance when multiple RACH configurations (and / or multiple RACH partitions) are assigned the same number of repetitions. Methods of power delivery

[0087] Among various methods for allocating PRACH repetition resources with different repetition counts, one approach can be considered to differentiate multiple PRACH repetition resources with different repetition counts based on preamble level or RO level. In this case, if multiple PRACH repetition resources are assigned the same repetition count, the UE can perform the RACH procedure using the PRACH resource corresponding to a specific RACH configuration, and then perform the RACH procedure using the PRACH resource corresponding to another RACH configuration at a pre-arranged time. The following proposes a scheme regarding when to set this pre-arranged time and / or how to set the PRACH transmission power to be used by the UE at that time.

[0088] As the first proposed method, it can be stipulated that the UE cannot select a PRACH repeat resource corresponding to another RACH configuration (or another RACH partition) before the UE has selected a PRACH repeat resource corresponding to a specific RACH configuration (and / or a specific RACH partition) and has completed all RACH attempt transmissions. More specifically, if the UE fails to receive RAR from the base station after performing all RACH attempt transmissions, the UE can be allowed to select any RACH configuration (and / or any RACH partition), regardless of the information of the previously selected RACH configuration.

[0089] In this case, the time when all RACH attempts have been completed refers to the time when the value of the higher-level parameter "PREAMBLE_TRANSMISSION_COUNTER", which counts the number of RACH attempts, is greater than the value of the higher-level parameter "preambleTransMax", which indicates the maximum number of RACH attempts. In other words, this time can be the time when all RACH attempts have been completed when the value of "PREAMBLE_TRANSMISSION_COUNTER", which increments by 1 for each RACH attempt, is greater than the value of "preambleTransMax" (in 38.321, i.e., when PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax + 1).

[0090] Furthermore, the repetition count can be reconfigured at the time when the UE has completed all RACH attempts. That is, the UE can remeasure RSRP at this time to reconfigure the repetition count, or the UE can increase the repetition count if it fails to receive RAR after performing all RACH attempts.

[0091] If the number of repetitions to be used by the UE does not increase, the RACH procedure can be performed in a newly selected RACH configuration by reusing the most recently used PRACH transmit power value from a previous RACH procedure. In this case, since the UE uses and transmits the maximum transmit power from the first RACH attempt, it can be configured not to perform power ramp-ups between RACH attempts.

[0092] On the other hand, if the number of repetitions to be used by the UE increases, the RACH procedure can be performed in a newly selected RACH configuration based on the PRACH transmit power used in the previous RACH procedure (with the corresponding value set to the PRACH transmit power of the first RACH attempt). In this case, the UE can be configured to perform power ramp-up between RACH attempts as before.

[0093] As a second proposed method, it can be defined that when the UE has already selected a PRACH repeating resource corresponding to a specific RACH configuration (or a specific RACH partition) but has not completed all RACH attempts (i.e., when "PREAMBLE_TRANSMISSION_COUNTER" is not greater than "preambleTransMax"), the UE selects a PRACH repeating resource corresponding to another RACH configuration (and / or another RACH partition). In this case, the number of RACH attempts allowed to select different RACH configurations (or different RACH partitions) can be configured / indicated by the base station via higher-layer signaling (e.g., SIB1, etc.), or can be predefined as a specific value (e.g., can be reselected at each RACH attempt). More specifically, if the UE fails to receive RAR from the base station after performing a predefined / pre-indicated number of RACH attempts, the UE can be allowed to select one of the RACH configurations (and / or specific RACH partitions) with the same number of repeats, regardless of the previously selected RACH configuration. In the above UE operation, the method for configuring the UE's PRACH transmission power can be as follows.

[0094] First, it can be configured such that the UE performs the RACH procedure without changing the parameter values ​​used in previous RACH procedures for counting RACH attempts and / or counting power climbs. That is, the UE can perform the RACH procedure in a newly selected RACH configuration (and / or RACH partition) while maintaining PREAMBLE_POWER_RAMPING_COUNTER, PREAMBLE_TRANSMISSION_COUNTER, etc., without changing them. In this case, the UE can use a PRACH transmit power that is one order higher than the PRACH transmit power transmitted in the previous RACH attempt to perform the RACH procedure in the newly selected RACH configuration. In this case, the PREAMBLE_POWER_RAMPING_STEP value for the higher power climb can be configured to apply the value of the newly selected RACH configuration (and / or RACH partition).

[0095] Second, the UE can be configured to initialize the parameter values ​​used in previous RACH procedures for counting RACH attempts and / or counting power climbs to 0, and then execute the RACH procedure. That is, the UE can execute the RACH procedure in a newly selected RACH configuration (and / or RACH partition) by initializing PREAMBLE_POWER_RAMPING_COUNTER, PREAMBLE_TRANSMISSION_COUNTER, etc., to 0. In this case, the UE can execute the RACH procedure using the initial PRACH transmit power defined in the newly selected RACH configuration, regardless of the PRACH transmit power values ​​transmitted in previous RACH attempts.

[0096] Third, the configuration can be as follows: the UE reduces the parameter values ​​used in previous RACH procedures for counting RACH attempts and / or counting power ramps by X and Y, respectively, and then performs the RACH procedure. In this case, the X and Y values ​​can be independently set / indicated by the base station via higher-layer signaling (e.g., SIB1), or they can be predefined values ​​(e.g., X=1, Y=1). In this case, the base station can set the remaining parameter values ​​to be equal to the indicated parameter values ​​by indicating only the X value or only the Y value. That is, the UE can reduce PREAMBLE_TRANSMISSION_COUNTER, PREAMBLE_POWER_RAMPING_COUNTER, etc., by X and Y from their existing values, respectively, and then perform the RACH procedure in the newly selected RACH configuration (and / or RACH partition). For example, if X=1 and Y=1, the UE can use the same PRACH transmit power value as the one transmitted in the previous RACH attempt to perform the RACH procedure in the newly selected RACH configuration (and / or RACH partition).

[0097] The key feature is that, to prevent the UE from frequently and excessively changing the RACH configuration, a method can be considered that maintains PREMBLE_TRANSMISSION_COUNTER while only decreasing PREMBLE_POWER_RAMPING_COUNTER. That is, in the example above, X can be set to 0 (X = 0) and Y can be set to 1 (Y = 1). If this is set, each time the UE changes the RACH configuration, the PRACH transmission power will use the same value as the previously transmitted PRACH transmission power (i.e., no transmission power ramp-up is performed), and only the RACH attempt counter will increase, making it difficult to reach the maximum PRACH transmission power. This will lead to an increased probability of RACH process failure for UEs that excessively reselect the RACH configuration.

[0098] The proposed method can be configured / applied to other UL signals / channels (such as MSG3 PUSCH, MSGA preamble / PUSCH, and / or PUSCH / PUCCH). Its key feature is that the proposed UE / base station operation for PRACH repetition can also be configured / applied to UE / base station operation for other newly introduced functions (e.g., the repetition function of Msg.4HARQ ACK PUCCH). For example, the PUCCH repetition function (e.g., pucch-Repetitions-r18) can be configured / applied to replace the proposed PRACH repetition function, and the PUCCH repetition function can also be used in the proposed combination method as well as methods not anticipated by the UE. Furthermore, when UE / base station operation for both PRACH repetition and / or PUCCH repetition is supported simultaneously, the proposed method can be configured / applied to both channels.

[0099] Since examples of the proposed methods described above can also be included as embodiments of this disclosure, they can obviously be considered as a proposed method. Furthermore, the proposed methods described above can be performed independently, but also in combination (or merged) of some proposed methods. Information regarding whether a proposed method is applied (or information regarding the rules governing the proposed method) can be defined as a rule so that the base station notifies the UE via predefined signals (e.g., physical layer signals or higher-layer signals). For example, higher layers may include one or more of the following functional layers: MAC, RLC, PDCP, RRC, and SDAP.

[0100] The methods, implementations, or descriptions used to implement the methods proposed in this disclosure may be applied individually, or one or more methods (or implementations or descriptions) may be applied in combination.

[0101] [Description of the claims related to the UE]

[0102] Below, we will refer to Figure 6 The implementation methods described above are described in detail from the perspective of user equipment (UE) operation. The methods described below are distinguished only for ease of explanation. Therefore, as long as these methods are not mutually exclusive, it is obvious that a portion of the configuration of any method can be replaced by a portion of the configuration of another method or combined with a portion of the configuration of another method.

[0103] Figure 6 An example of the operation procedure of a UE that can be applied to the system of this disclosure is illustrated.

[0104] In step S610, the UE receives radio resource control (RRC) information from the base station related to the maximum number of repetitions of the random access (RA) preamble corresponding to the first number.

[0105] In step S620, the UE performs a first retransmission of the RA preamble to the base station based on the first number for the first RA process.

[0106] In step S630, when the first retransmission of the RA preamble is performed based on the first number and the first RA process is not completed, the UE determines the number of retransmissions of the RA preamble based on the second number, which is greater than the first number.

[0107] In step S640, the UE performs a second retransmission of the RA preamble to the base station based on the second number for the second RA process.

[0108] According to various embodiments of this disclosure, the first RA process can be successfully completed when the first retransmission of the RA preamble associated with the first number is performed and a random access response (RAR) is received from the base station.

[0109] According to various embodiments of this disclosure Figure 6 The implementation may also include determining random access (RA) resources associated with a second retransmission of the RA preamble based on the second number.

[0110] According to various embodiments of this disclosure, a second RA process can be performed based on the RA resource.

[0111] According to various embodiments of this disclosure, the information of PREAMBLE_TRANSMISSION_COUNTER can be incremented by one each time the RA preamble is sent to the base station.

[0112] According to various embodiments of this disclosure, the number of times the RA preamble is repeatedly transmitted can be changed by the UE from the first count to the second count.

[0113] According to various embodiments of this disclosure, when the information of PREAMBLE_TRANSMISSION_COUNTER is related to preambleTransMax+1, all random access channels (RACH) attempts of the full configured number can be performed.

[0114] According to various embodiments of this disclosure, preambleTransMax can be correlated with the maximum number of RACH attempts.

[0115] According to various embodiments of this disclosure, a second number can be determined based on a measurement of the reference signal received power (RSRP).

[0116] According to various embodiments of this disclosure, a user equipment (UE) is provided in a wireless communication system. The UE may include a transceiver and at least one processor, and the at least one processor may be configured to perform operations based on… Figure 6 The operation method of UE.

[0117] According to various embodiments of this disclosure, an apparatus for controlling a user equipment (UE) in a wireless communication system is provided. The apparatus may include at least one processor and at least one memory operatively connected to the at least one processor. The at least one memory may be configured to store data based on actions executed by the at least one processor. Figure 6 Instructions for the operation methods of the UE.

[0118] According to various embodiments of this disclosure, one or more non-transitory computer-readable media (CRMs) storing one or more instructions are provided. The one or more instructions may be configured to perform operations based on execution by one or more processors, and the operations may include operations based on... Figure 6 The operation method of UE.

[0119] [Description of claims related to base stations]

[0120] Below, for reference Figure 7 The above implementation methods are described in detail from the perspective of base station operation. The methods described below are distinguished only for ease of explanation. Therefore, it is obvious that, as long as the methods are not mutually exclusive, a portion of the configuration of any method can be replaced or combined with a portion of the configuration of another method.

[0121] Figure 7 An example of the operation procedure of a base station applicable to the system of this disclosure is shown.

[0122] In step S710, the base station sends radio resource control (RRC) information to the user equipment (UE) related to the maximum number of repetitions of the random access (RA) preamble corresponding to the first number.

[0123] In step S720, the base station receives the first repeated transmission of the RA preamble from the UE based on the first number for the first RA process.

[0124] In step S730, when the first retransmission of the RA preamble is performed based on the first count and the first RA process is not completed, the base station receives the second retransmission of the RA preamble from the UE based on the second count for the second RA process.

[0125] According to various embodiments of this disclosure, the second number is the number of times the RA preamble is repeatedly transmitted, which is greater than the first number.

[0126] According to various embodiments of this disclosure, the first RA procedure can be successfully completed when the first retransmission of the RA preamble associated with the first number is performed and the UE receives a random access response (RAR) from the base station.

[0127] According to various embodiments of this disclosure, the information of PREAMBLE_TRANSMISSION_COUNTER can be incremented by one each time the UE sends the RA preamble to the base station.

[0128] According to various embodiments of this disclosure, the number of times the RA preamble is repeatedly transmitted can be changed by the UE from the first count to the second count.

[0129] According to various embodiments of this disclosure, when the information of PREAMBLE_TRANSMISSION_COUNTER corresponds to preambleTransMax+1, the full number of configured random access channel (RACH) attempts can be performed.

[0130] According to various embodiments of this disclosure, preambleTransMax can be correlated with the maximum number of RACH attempts.

[0131] According to various embodiments of this disclosure, a second number can be determined based on a measurement of the reference signal received power (RSRP).

[0132] According to various embodiments of this disclosure, a base station in a wireless communication system is provided. The base station may include a transceiver and at least one processor, and the at least one processor may be configured to perform operations based on… Figure 7 Base station operation methods.

[0133] According to various embodiments of the present disclosure, an apparatus for controlling a base station in a wireless communication system is provided. The apparatus may include at least one processor and at least one memory operatively connected to the at least one processor. The at least one memory may be configured to store instructions that, when executed by the at least one processor, perform actions based on… Figure 7 Base station operation methods.

[0134] According to various embodiments of this disclosure, one or more non-transitory computer-readable media (CRMs) storing one or more instructions are provided. The one or more instructions may be configured to perform operations based on execution by one or more processors, the operations including... Figure 7 The operation method of the base station.

[0135] Wireless devices applicable to this disclosure

[0136] Examples of wireless devices that apply various embodiments of the present disclosure are described below.

[0137] Figure 8 Examples of the structures of the first and second devices applicable to the system of this disclosure are shown.

[0138] The first device 1600 may include a processor 1610, an antenna unit 1620, a transceiver 1630, and a memory 1640.

[0139] Processor 1610 can perform baseband-related signal processing and includes a higher-layer processing unit 1611 and a physical layer processing unit 1615. Higher-layer processing unit 1611 can handle operations at the MAC layer, RRC layer, or higher layers. Physical layer processing unit 1615 can handle PHY layer operations. For example, if the first device 1600 is a base station (BS) device in BS-UE communication, physical layer processing unit 1615 can perform uplink receive signal processing, downlink transmit signal processing, etc. For example, if the first device 1600 is a first UE device in UE-to-UE communication, physical layer processing unit 1615 can perform downlink receive signal processing, uplink transmit signal processing, sidelink transmit signal processing, etc. In addition to performing baseband-related signal processing, processor 1610 can also control the overall operation of the first device 1600.

[0140] Antenna unit 1620 may include one or more physical antennas, and if antenna unit 1620 includes multiple antennas, MIMO transmission / reception is supported. Transceiver 1630 may include a radio frequency (RF) transmitter and an RF receiver. Memory 1640 may store information processed by processor 1610, as well as software, operating system, and applications related to the operation of first device 1600. Memory 1640 may also include components such as buffers.

[0141] In the embodiments described in this disclosure, the processor 1610 of the first device 1600 may be configured to implement the operation of the BS in BS-UE communication (or the operation of the first UE device in UE-to-UE communication).

[0142] The second device 1650 may include a processor 1660, an antenna unit 1670, a transceiver 1680, and a memory 1690.

[0143] Processor 1660 can perform baseband-related signal processing and includes a higher-layer processing unit 1661 and a physical layer processing unit 1665. Higher-layer processing unit 1661 can handle operations at the MAC layer, RRC layer, or higher layers. Physical layer processing unit 1665 can handle PHY layer operations. For example, if the second device 1650 is a UE device in BS-UE communication, physical layer processing unit 1665 can perform downlink receive signal processing, uplink transmit signal processing, etc. For example, if the second device 1650 is a second UE device in inter-UE communication, physical layer processing unit 1665 can perform downlink receive signal processing, uplink transmit signal processing, sidelink receive signal processing, etc. In addition to performing baseband-related signal processing, processor 1660 can also control the overall operation of the second device 1660.

[0144] Antenna unit 1670 may include one or more physical antennas, and if antenna unit 1670 includes multiple antennas, MIMO transmission / reception is supported. Transceiver 1680 may include an RF transmitter and an RF receiver. Memory 1690 may store information processed by processor 1660, as well as software, operating system, and applications related to the operation of second device 1650. Memory 1690 may also include components such as buffers.

[0145] In the embodiments described in this disclosure, the processor 1660 of the second device 1650 may be configured to implement the operation of the UE in BS-UE communication (or the operation of the second UE device in inter-UE communication).

[0146] The descriptions of the BS and UE (or the first UE device and the second UE device in inter-UE communication) in the examples of this disclosure can be applied equivalently to the operation of the first device 1600 and the second device 1650, and redundant descriptions are omitted.

[0147] The wireless communication technologies implemented in devices 1600 and 1650 according to this disclosure may include LTE, NR and 6G, as well as various other wireless communication technologies.

[0148] The claims described in the various embodiments of this disclosure can be combined in various ways. For example, the technical features of the method claims in the various embodiments of this disclosure can be combined and implemented as an apparatus, and the technical features of the apparatus claims in the various embodiments of this disclosure can be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the apparatus claims in the various embodiments of this disclosure can be combined and implemented as an apparatus, and the technical features of the method claims and the technical features of the apparatus claims in the various embodiments of this disclosure can be combined and implemented as a method.

Claims

1. A method for operating a user equipment (UE) in a wireless communication system, the method comprising: Receive radio resource control (RRC) information from the base station related to the maximum number of repetitions of the random access (RA) preamble corresponding to the first number; For the first RA process, the first retransmission of the RA preamble is performed to the base station based on the first number of times; The first repeated transmission based on the RA preamble is performed based on the first number of times and the first RA process is not completed. The number of repeated transmissions of the RA preamble is determined based on a second number of times greater than the first number of times. as well as For the second RA process, the RA preamble is retransmitted to the base station a second time based on the second number of times.

2. The method according to claim 1, wherein, The first repeated transmission based on the RA preamble associated with the first number of times is executed and a random access response (RAR) is received from the base station, thus the first RA procedure is successfully completed.

3. The method of claim 1, further comprising determining random access (RA) resources associated with the second retransmission of the RA preamble based on the second number of times. in, The second RA process is executed based on the RA resources.

4. The method according to claim 1, wherein, Each time the RA preamble is sent to the base station, the PREAMBLE_TRANSMISSION_COUNTER information is incremented by one.

5. The method according to claim 1, wherein, The number of repeated transmissions of the RA preamble is changed by the UE from the first number to the second number.

6. The method according to claim 4, wherein, Based on the information in PREAMBLE_TRANSMISSION_COUNTER related to preambleTransMax+1, perform all configured random access channel (RACH) attempts, and The preambleTransMax is related to the maximum number of RACH attempts.

7. The method according to claim 1, wherein, The second number is determined based on the measurement of the reference signal received power (RSRP).

8. A method for operating a base station in a wireless communication system, the method comprising: Send radio resource control (RRC) information to the user equipment (UE) related to the maximum number of repetitions of the random access (RA) preamble corresponding to the first number; For the first RA process, a first retransmission of the RA preamble is received from the UE based on the first number of times; as well as The first retransmission based on the RA preamble is performed based on the first number of times and the first RA process is not completed. For the second RA process, a second retransmission of the RA preamble is received from the UE based on the second number of times. Wherein, the second number is the number of times the RA preamble is repeatedly transmitted, which is greater than the first number.

9. The method according to claim 8, wherein, The first repeated transmission based on the RA preamble associated with the first number of times is performed and the UE receives a Random Access Response (RAR) from the base station, thus the first RA procedure is successfully completed.

10. The method according to claim 8, wherein, The second RA process is performed based on random access (RA) resources associated with the second repeated transmission of the RA preamble based on the second number of times.

11. The method according to claim 8, wherein, Each time the RA preamble is sent from the UE to the base station, the PREAMBLE_TRANSMISSION_COUNTER information is incremented by one.

12. The method according to claim 8, wherein, The number of repeated transmissions of the RA preamble is changed by the UE from the first number to the second number.

13. The method according to claim 11, wherein, Based on the information in PREAMBLE_TRANSMISSION_COUNTER related to preambleTransMax+1, perform all configured random access channel (RACH) attempts, and The preambleTransMax is related to the maximum number of RACH attempts.

14. The method according to claim 8, wherein, The second number is determined based on the measurement of the reference signal received power (RSRP).

15. A user equipment (UE) in a wireless communication system, the UE comprising: transceiver; At least one processor; as well as At least one memory, operatively connectable to the at least one processor and storing instructions for performing operations based on execution by the at least one processor. The operation includes all the steps of the method according to any one of claims 1 to 7.

16. A base station in a wireless communication system, the base station comprising: transceiver; At least one processor; as well as At least one memory, operatively connectable to the at least one processor and storing instructions for performing operations based on execution by the at least one processor. The operation includes all the steps of the method according to any one of claims 8 to 14.

17. A control device that controls user equipment in a wireless communication system, the control device comprising: At least one processor; as well as At least one memory, said at least one memory being operatively connected to said at least one processor, Wherein, the at least one memory stores instructions for operations performed based on the execution of the at least one processor, and The operation includes all the steps of the method according to any one of claims 1 to 7.

18. A control device that controls a base station in a wireless communication system, the control device comprising: At least one processor; as well as At least one memory, said at least one memory being operatively connected to said at least one processor, Wherein, the at least one memory stores instructions for operations performed based on the execution of the at least one processor, and The operation includes all the steps of the method according to any one of claims 8 to 14.

19. One or more non-transitory computer-readable media storing one or more instructions. in, The one or more instructions perform operations based on being executed by one or more processors, and The operation includes all the steps of the method according to any one of claims 1 to 7.

20. One or more non-transitory computer-readable media storing one or more instructions. in, The one or more instructions perform operations based on being executed by one or more processors, and The operation includes all the steps of the method according to any one of claims 8 to 14.

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