WO2019216697A1 - Procédé d'émission ou de réception de signal dans un système nr pour une bande sans licence et appareil associé - Google Patents

Procédé d'émission ou de réception de signal dans un système nr pour une bande sans licence et appareil associé Download PDF

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Publication number
WO2019216697A1
WO2019216697A1 PCT/KR2019/005639 KR2019005639W WO2019216697A1 WO 2019216697 A1 WO2019216697 A1 WO 2019216697A1 KR 2019005639 W KR2019005639 W KR 2019005639W WO 2019216697 A1 WO2019216697 A1 WO 2019216697A1
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Prior art keywords
carrier
channel
terminal
random access
case
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PCT/KR2019/005639
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English (en)
Korean (ko)
Inventor
박동현
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주식회사 아이티엘
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Priority claimed from KR1020180095365A external-priority patent/KR20190129660A/ko
Application filed by 주식회사 아이티엘 filed Critical 주식회사 아이티엘
Publication of WO2019216697A1 publication Critical patent/WO2019216697A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/02—Selection of wireless resources by user or terminal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA

Definitions

  • the present invention can provide a method for transmitting a Physical Random Access Channel (PRACH) in a New Radio (NR) system operating in an unlicensed band.
  • PRACH Physical Random Access Channel
  • NR New Radio
  • the International Telecommunication Union (ITU) is developing the International Mobile Telecommunication (IMT) framework and standards, and is currently discussing the 5G (5G) communication through a program called "IMT for 2020 and beyond.” .
  • 3GPP 3rd Generation Partnership Project
  • 3GPP 3rd Generation Partnership Project
  • 3GPP New Radio
  • An object of the present invention is to provide a method for transmitting and receiving signals in an NR system for an unlicensed band.
  • An object of the present invention is to provide a method for transmitting a PRACH in an NR system for an unlicensed band.
  • An object of the present invention is to provide a carrier selection method for PRACH transmission.
  • a terminal may provide a method for performing a random access procedure.
  • the method for performing a random access procedure by the terminal may include triggering an event for the random access procedure, setting information on the random access procedure, and selecting a carrier for performing the random access procedure.
  • the terminal may select at least one or more carriers of the NUL carrier and the SUL carrier, and may perform a random access procedure based on the selected carrier.
  • a method of transmitting and receiving a signal in an NR system for an unlicensed band can be provided.
  • a method of transmitting a PRACH in an NR system for an unlicensed band can be provided.
  • a carrier selection method for PRACH transmission may be provided.
  • FIG. 1 is a diagram showing a frame structure for downlink / uplink transmission to which the present disclosure can be applied.
  • FIG. 2 is a diagram illustrating a resource grid and a resource block to which the present disclosure may be applied.
  • FIG. 3 is a diagram illustrating a random access procedure to which the present disclosure can be applied.
  • FIG. 4 is a diagram illustrating a random access initialization process to which the present disclosure can be applied.
  • FIG. 5 is a diagram illustrating a method of performing LBT to which the present disclosure can be applied.
  • FIG. 6 illustrates a carrier selection method to which the present disclosure can be applied.
  • FIG. 7 is a diagram illustrating a carrier selection method to which the present disclosure can be applied.
  • FIG 8 illustrates a carrier selection method to which the present disclosure can be applied.
  • FIG. 9 illustrates a method of determining a channel accessible period to which the present disclosure can be applied.
  • FIG. 10 is a diagram illustrating a method of performing LBT in parallel to which the present disclosure can be applied.
  • FIG. 11 is a diagram illustrating a method of performing sequential LBT to which the present disclosure can be applied.
  • NDL NUL
  • FIG. 13 is a diagram illustrating a random access procedure when a NUL (NDL) to which the present disclosure is applicable is a licensed carrier and a SUL is an unlicensed carrier.
  • NDL NUL
  • FIG. 14 is a diagram illustrating a method of selecting a carrier by comparing an RSRP value of a DL pathloss reference and a Channel Occupancy Rate (COR) / Received Signal Strength Indicator (RSSI) value.
  • COR Channel Occupancy Rate
  • RSSI Received Signal Strength Indicator
  • 15 is a diagram illustrating a configuration of a base station apparatus and a terminal apparatus to which the present disclosure can be applied.
  • a component when a component is “connected”, “coupled” or “connected” with another component, it is not only a direct connection, but also an indirect connection in which another component exists in the middle. It may also include.
  • a component when a component “includes” or “having” another component, it means that it may further include another component, without excluding the other component unless otherwise stated. .
  • first and second are used only for the purpose of distinguishing one component from other components, and do not limit the order or importance between the components unless specifically mentioned.
  • a first component in one embodiment may be referred to as a second component in another embodiment, and likewise, a second component in one embodiment may be referred to as a first component in another embodiment. It may also be called.
  • components that are distinguished from each other are for clearly describing each feature, and do not necessarily mean that the components are separated. That is, a plurality of components may be integrated into one hardware or software unit, or one component may be distributed and formed into a plurality of hardware or software units. Therefore, even if not mentioned otherwise, such integrated or distributed embodiments are included in the scope of the present disclosure.
  • components described in various embodiments are not necessarily required components, and some may be optional components. Accordingly, embodiments that consist of a subset of the components described in one embodiment are also included in the scope of the present disclosure. In addition, embodiments including other components in addition to the components described in the various embodiments are included in the scope of the present disclosure.
  • the present specification describes a wireless communication network
  • the operation performed in the wireless communication network is performed in the process of controlling the network and transmitting data in the system (for example, the base station) that is in charge of the wireless communication network, or the corresponding wireless Work may be done at the terminal coupled to the network.
  • a 'base station (BS)' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point (AP), and the like.
  • eNB eNode B
  • AP access point
  • the term 'terminal' may be replaced with terms such as user equipment (UE), mobile station (MS), mobile subscriber station (MSS), subscriber station (SS), and non-AP STA. Can be.
  • transmitting or receiving a channel includes transmitting or receiving information or a signal through the channel.
  • transmitting a control channel means transmitting control information or a signal through the control channel.
  • transmitting a data channel means transmitting data information or a signal over the data channel.
  • NR system is used for the purpose of distinguishing a system to which various examples of the present disclosure are applied from an existing system, but the scope of the present disclosure is not limited by the term.
  • NR system is used herein as an example of a wireless communication system capable of supporting various subcarrier spacings (SCS)
  • SCS subcarrier spacings
  • NR system itself is a wireless communication system supporting a plurality of SCSs. It is not limited.
  • FIG. 1 is a diagram illustrating an NR frame structure and a numerology according to an embodiment of the present invention.
  • the base unit of time domain is Can be. At this time, ego, Can be. Also, May be a constant for a multiple relationship between an NR time unit and an LTE time unit. In LTE as a reference time unit , And Can be defined.
  • the time structure of a frame for downlink and uplink (DL / UL) transmission is It can have In this case, one frame It consists of 10 subframes corresponding to time. The number of consecutive OFDM symbols per subframe Can be.
  • each frame is divided into two half frames, and the half frame may include 0 to 4 subframes and 5 to 9 subframes.
  • half frame 1 may include 0 to 4 subframes
  • half frame 2 may include 5 to 9 subframes.
  • the transmission timing of the uplink transmission frame i is determined based on Equation 1 based on the downlink reception timing in the terminal.
  • Equation 1 May be a TA offset value generated due to a duplex mode difference or the like.
  • FDD Frequency Division Duplex
  • TDD Time Division Duplex
  • FIG. 2 is a diagram illustrating a resource grid and a resource block.
  • resource elements in a resource grid may be indexed according to each subcarrier spacing.
  • one resource grid may be generated for each antenna port and each subcarrier spacing.
  • Uplink and downlink transmission and reception may be performed based on a corresponding resource grid.
  • One resource block is composed of 12 resource elements (Resource Element) in the frequency domain, as shown in Equation 2 index for one resource block for each 12 resource elements ( ) Can be configured.
  • the index for the resource block may be utilized within a specific frequency band or system bandwidth.
  • numerology may be defined based on subcarrier spacing (SCS), CP length, and number of OFDM symbols per slot used in an orthogonal frequency division multiplexing (OFDM) system. .
  • SCS subcarrier spacing
  • OFDM orthogonal frequency division multiplexing
  • the above-described values may be provided to the terminal through higher layer parameters DL-BWP-mu and DL-BWP-cp (DL) and UL-BWP-mu and UL-BWP-cp (UL).
  • the normal slot may be defined as a basic time unit used to basically transmit one data and control information in the NR system.
  • the length of a normal slot may basically consist of 14 OFDM symbols.
  • the subframe may have an absolute time length corresponding to 1 ms in the NR system and may be used as a reference time for the length of another time interval.
  • a time interval such as a subframe of LTE may be required for the NR specification for coexistence or backward compatibility of the LTE and NR systems.
  • data may be transmitted based on a transmission time interval (TTI), which is a unit time, and the TTI may be configured by one or more subframe units.
  • TTI transmission time interval
  • one subframe may be set to 1 ms and 14 OFDM symbols (or 12 OFDM symbols) may be included.
  • non-slot may be defined in NR.
  • the nonslot may refer to a slot having a number smaller by at least one symbol than a normal slot.
  • delay time may be reduced through nonslots having a smaller number of symbols than normal slots.
  • the number of OFDM symbols included in the nonslot may be determined in consideration of the frequency range. For example, a nonslot of 1 OFDM symbol length may be considered in a frequency range of 6 GHz or more. As another example, the number of OFDM symbols defining the nonslot may include at least two OFDM symbols.
  • the range of the number of OFDM symbols included in the non-slot may be configured as the length of the mini slot to the normal slot length-1.
  • the number of OFDM symbols may be limited to 2, 4, or 7 symbols as a nonslot standard, but is not limited to the above-described embodiment.
  • Subcarrier spacing equal to 1 and 2 are used, and in unlicensed bands above 6 GHz Subcarrier spacing corresponding to 3 and 4 may be used.
  • SSB Synchronization Siganl Block
  • Table 2 also shows each subcarrier spacing setting in case of normal CP.
  • Number of OFDM symbols per slot Indicates.
  • Table 2 shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe according to each subcarrier spacing value, as provided in Table 1. In this case, Table 2 shows the above values based on the normal slot having 14 OFDM symbols.
  • the extended CP may be applied when the subcarrier spacing is 60 kHz.
  • Table 3 shows the case of extended CP Number of OFDM Symbols Per Slot May represent each value based on a normal slot of 12. In this case, referring to Table 3, in case of an extended CP according to 60 kHz subcarrier spacing, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe may be indicated.
  • the NR base station i.e. gNB
  • the NR base station may periodically transmit signals and channels as shown in Table 4 to the terminals to allow initial cell selection of the terminals (i.e. UEs) in the cell.
  • the SS / PBCH block may be the aforementioned SSB.
  • the UE in order to perform the initial radio access in the NR system, the UE may need to receive a broadcast channel that transmits synchronization signals and important system information transmitted from the radio access system.
  • the terminal can check the reception sensitivity of the synchronization signal (Synchronization Signal) in order to find the optimal cell in the best channel environment.
  • the terminal may perform frequency / time synchronization and cell identification for initial access to an optimal channel among one or more channels in a specific frequency band operated based on the checked reception sensitivity.
  • the UE can check the boundary of the OFDM symbol timing through the above-described operation, and can then start PBCH decoding in the same SSB.
  • the UE may perform PBCH decoding by receiving a PBCH Demodulation Reference Signal (DMRS).
  • DMRS PBCH Demodulation Reference Signal
  • the UE may obtain 2 or 3 LSB bit information of the SSB index information bits through the PBCH DMRS. Thereafter, the UE may acquire information included in the PBCH payload by performing PBCH decoding. Thereafter, the UE may perform a decoding procedure of SIB 1 using the information obtained through the PBCH.
  • DMRS PBCH Demodulation Reference Signal
  • a UE may receive Remaining System Information (RMSI) as a system information not transmitted through a PBCH through a broadcast signal or a channel.
  • RMSI Remaining System Information
  • the terminal may receive other system information (OSI) and paging channel as a broadcast signal or channel as additional system information.
  • OSI system information
  • the system information necessary to perform the random access that is addressed in the present invention is provided to the terminal for initial cell access through the RMSI (SIB1) in the form of broadcast.
  • SIB1 RMSI
  • the RRC CONNECTED mode terminal may be additionally provided to the terminal through dedicated RRC signaling.
  • the terminal may access the base station through a random access channel (RACH) procedure and then perform mobility management.
  • RACH random access channel
  • random access initialization may include beam failure from a PDCCH order, a medium access control (MAC) sublayer, a radio resource control (RRC) sublayer, and a physical layer.
  • MAC medium access control
  • RRC radio resource control
  • BF physical layer.
  • Table 5 below may correspond to a specific cause of starting random access, a cause of triggering a random access procedure according to an event, and a mapping relationship to a layer performing initialization.
  • a regular buffer status report (R-BSR) is derived based on the "RRCConnectionRequest” requesting access to the network. For this purpose, a random access procedure may be performed.
  • R-BSR regular buffer status report
  • a random access procedure may be performed.
  • the transmission of the R-BSR is requested in order to deliver the "RRCConnectionReconfigurationComplete" message to the target base station, for which random access may be performed.
  • random access may be performed based on procedures such as downlink transmission, uplink transmission, positioning, and the like.
  • random access may be performed based on the beam failure indicator.
  • the MAC layer of the terminal may receive an indication of the beam failure from the physical layer of the terminal, and perform a beam failure recovery operation through a random access procedure based on this.
  • the random access procedure may be performed based on a parameter preset through RRC signaling.
  • Table 6 below may be information provided to the terminal in advance through RRC signaling from the base station.
  • the UE may check the PRACH resource, preamble format, period, etc. on the time domain for the preamble transmission based on the “PRACH-CONFIGINDEX” parameter.
  • “Msg.1-SCS” may indicate a subcarrier spacing value of the preamble transmission.
  • the terminal may determine the initial power for the preamble transmitted based on the "RA-PREAMBLEINITIALRECEIVED TARGETPOWER”.
  • the UE may select an associated preamble resource and index based on a reference signal received power (RSRP) value of a sync signal block (SSB) through a parameter “RSRP-THRESHOLDSSB”.
  • RSRP reference signal received power
  • the terminal may select the associated preamble resource and index based on the RSRP value of the CSI-RS based on the "CSIRS-DEDICATEDRACH-THRESHOD" parameter.
  • the terminal may determine the RSRP threshold for the selected SS block and the corresponding PRACH resource based on the “SUL-RSRP-THRESHOLD” parameter.
  • the terminal may determine the power-ramping element based on the “RA-PREAMBLEPOWERRAMPINGSTEP” parameter.
  • the random access preamble index may be determined based on the “RA-PREAMBLEINDEX” parameter.
  • the maximum number of preamble transmissions may be determined based on the “RA-PREAMBLETX-MAX” parameter.
  • Table 6 below is only one embodiment, and other parameters may be configured through RRC signaling.
  • a mapping relationship between each sync signal block (SSB) and the preamble transmission resource / index may be preset.
  • a group of preamble indexes and indexes within the group may be sequentially allocated to each SSB according to whether the mapping between the SSB and the preamble transmission resource / index is preset.
  • the preamble group described above may be utilized by the base station to determine the size of the uplink resource required for msg3 (message 3) transmission. For example, when the preamble groups A and B are configured for the UE, the random access procedure is equal to or larger than the msg3 size (ra-Msg3SizeGroupA) for the group A, and the downlink pathloss value is transmitted to the initial preamble target at the terminal maximum power (PCMAX). preamble initial Target received Power) If less than the value except the power, the UE may perform a random access procedure by selecting a preamble index in the group B.
  • the base station may transmit the random access preamble in the group B including the above-described information in msg2 which is response information about the preamble. That is, the size information of uplink resources required for msg3 transmission may be included in msg2 and transmitted to the terminal.
  • msg 2 may be an RAR
  • msg 3 may be a message transmitted by the terminal based on the RAR.
  • a situation in which SSBs are classified by beams may be considered.
  • the base station when the mapping relationship between the SSB and the preamble transmission resource / index is set in advance, when the UE transmits a random access preamble using a specific preamble transmission resource / index, the base station can determine which beam (or SSB) the terminal prefers. have. That is, the base station can check the received random access preamble to know the preferred beam information of the terminal.
  • the base station may provide information on the random access to the terminal before performing the random access procedure.
  • the base station may provide the terminal with the size information of the random access (RA) window as the number of slots.
  • the RA window may be a time interval in which the UE monitors the RAR reception for the previous preamble transmission. That is, the time interval for the terminal to monitor the RAR reception may be set by the base station.
  • the base station may provide the UE with information on the preamble index set for the SI (System Information) request and the corresponding PRACH resources. For example, based on the “On Demand SI” procedure of Table 6, the UE may perform preamble transmission to the base station to receive necessary SI information. In this case, the RACH resource for performing preamble transmission may be provided by the base station.
  • SI System Information
  • the base station may provide the UE with information about a BFR (Beam Failure Request) response window and a corresponding PRACH resource.
  • the MAC layer of the terminal may receive information about beam failure from the physical layer of the terminal.
  • the MAC layer of the terminal may perform preamble transmission to the base station to perform a beam failure request (Beam Failure Request) procedure.
  • the terminal may receive a RACH resource for performing preamble from the base station.
  • a window may be set as the monitoring interval of the terminal.
  • the base station may provide the terminal with information on the size of the contention resolution window through “RA-CONTENTIONRESOLUTIONWINDOW”, which is not limited to the above-described embodiment.
  • the terminal 100 may transmit a random access preamble to the base station 200.
  • the base station 200 may be an eNodeB, a gNB, and the like, and is not limited to the above-described embodiment.
  • random access initialization and random access resource selection may be performed before the step of transmitting the random access preamble (S310), which will be described later.
  • the terminal may transmit the random access preamble based on the random access initialization and the random access resource selection.
  • the MAC layer of the UE may instruct to perform preamble transmission by providing the selected preamble, the associated RNTI value, the preamble index, and the reception target power to the physical layer. Through this, the UE may perform random access preamble transmission.
  • the base station may receive a random access preamble transmitted by the terminal. Thereafter, the base station may transmit a random access response (RAR) corresponding to the preamble to the terminal. That is, the terminal may receive a random access response from the base station.
  • RAR random access response
  • the preamble may be msg1.
  • the RAR is a message transmitted by the base station after msg1 (preamble), and may be the aforementioned msg2.
  • the UE may start monitoring for reception of msg 2 after a certain symbol (e.g. OFDM symbol).
  • a time interval e.g, defined as the number of slots
  • RA-Window Random Access Window
  • the random access window size may be provided to the terminal by the base station as described in the upper layer parameter, as described above.
  • the terminal may perform monitoring based on a radio network temporary identifier (RA-RNTI) value.
  • RA-RNTI radio network temporary identifier
  • the UE may monitor at least one of PDCCH and PDSCH.
  • the base station may scramble the RA-RNTI value to the CRC bit attached to the downlink control information (DCI) to transmit the PDCCH channel.
  • DCI downlink control information
  • the UE obtains control information for msg.2 reception through PDCCH decoding.
  • the UE may decode the PDSCH including msg.2 based on the obtained scheduling information.
  • the RA-RNTI value may be determined according to the first OFDM symbol index, the first slot index, the frequency resource index, and the carrier index on which the preamble is transmitted. That is, the RA-RNTI value may be determined based on resource related information on which the preamble is transmitted.
  • the UE fails to receive the RAR. It may be determined that it is possible to prepare for retransmission of the random access preamble (msg1). That is, the terminal may perform the preamble resource selection procedure again.
  • the terminal may determine that the RAR has been successfully received.
  • the terminal may determine that the RAR reception is successful.
  • the terminal may transmit msg3 to the base station through at least one of scheduling information included in msg2 and parameter information for transmitting msg3. That is, msg 3 may be a message transmitted by a terminal that successfully receives msg2.
  • the base station may transmit a contention resolution message (msg4) to the terminal. Based on the operation as described above, the terminal may perform the initial access.
  • FIG. 4 is a diagram illustrating a procedure required for performing random access.
  • random access initialization and random access resource selection may be performed before performing random access preamble transmission.
  • random access initialization may be performed (S420).
  • random access initialization may be performed by a beam failure indication from a PDCCH order, a MAC sublayer, an RRC sublayer, or a physical layer.
  • random access initialization on the SCell except for the SpCell may be initialized with beam failure indication information from the physical layer or RA preamble index value indicated by the PDCCH order / RRC. Can be.
  • RRC parameter setting and MAC variable setting may be performed.
  • S421, S422 parameters set to the UE through RRC signaling may be as described in Table 6 above. .
  • Table 6 is only one embodiment, it may be possible to set other parameters.
  • a preamble index group may be allocated to each SSB according to whether a mapping relationship between each SSB and the preamble transmission resource and the index is set in advance, and indexes in the group may or may not be sequentially assigned.
  • the preamble group in one preamble transmission resource ie, random access occsion
  • the preamble group may be set to group A or B, but is not limited to the above-described embodiment.
  • the preamble group may be used by the base station to determine the size of the uplink resources required for msg.3 transmission.
  • the UE may perform preamble transmission by selecting a preamble index in group B in a corresponding RA procedure.
  • RA-Msg3SizeGroupA a specific size
  • the base station when the base station determines that the preamble in the group B has been received, the base station includes scheduling information including uplink resource size information necessary for the transmission of msg. 3 in the msg. can do.
  • preamble transmission may be performed on a preamble index, an SSB index, and an associated resource (random access occsion, RO) indicated by a base station.
  • the terminal may receive the information shown in Table 7 from the base station, and is not limited to the above-described embodiment.
  • the UE may flush a buffer including Msg3 to initialize random access.
  • the terminal may set the preamble transmission counter to 1 and the preamble power ramping counter to 1 as well.
  • the UE may set the preamble backoff to 0 ms. That is, an initialization step for random access preamble transmission may be performed.
  • the terminal may perform a carrier selection and PCMAX setting procedure (S423).
  • the terminal may perform a corresponding carrier.
  • a random access procedure can be performed on the. That is, if a carrier for performing random access is determined by the terminal, a random access procedure may be performed through this.
  • a carrier on which a random access procedure is performed is not explicitly signaled, a supplementary uplink cell (SUL cell) for a random access procedure is configured, and a downlink path loss of the corresponding cell is DL path.
  • SUL cell supplementary uplink cell
  • the UE may select the SUL cell as a carrier for performing a random access procedure.
  • the terminal may set a PCMAX value for the SUL to perform a random access procedure on the carrier described above.
  • the SUL may be an extra UL carrier that may additionally be set to a DL carrier or a DL / UL carrier that may constitute one serving cell. Therefore, if the SUL is configured for the UE in addition to one serving cell, the UE may be configured to configure an extra UL carrier in addition to the normal UL carrier (NUL) to configure the serving cell.
  • NUL normal UL carrier
  • the UE may select a normal carrier as a carrier for performing a random access procedure.
  • the general carrier may be the above-described normal uplink carrier (NUL).
  • NUL normal uplink carrier
  • the UE may set a PCMAX value for the NUL and perform a random access procedure through the NUL, which will be described later in more detail.
  • the UE may perform a resource selection procedure (S430).
  • a preamble index value may be set, and the next available PRACH occasion may be determined by an associated PRACH Occasion (RO). .
  • RO PRACH Occasion
  • the PRACH ocean determination may be performed by i) association associations for SSB block indexes and PRACH oceans, ii) association associations for CSI-RS and PRACH oceans, or iii) associations.
  • Settings may be performed based on the case where the settings are not provided to the terminal.
  • the associated PRACH occasion may be determined according to the SSB index or the CSI-RS index selected by the terminal or indicated by the base station.
  • preamble transmission may be performed in the next available PRACH occasion.
  • the UE may perform preamble transmission based on the selected PRACH occasion.
  • the MAC layer of the terminal may instruct the physical layer to perform the selected preamble transmission by providing the selected preamble, the associated RNTI value, the preamble index, and the reception target power to the physical layer of the terminal.
  • the UE may monitor reception of msg. 2 (RAR) information corresponding to the transmitted preamble.
  • the interval monitored by the terminal may be the above-described RA window interval.
  • the start of the RA window section may be determined after a certain number of symbols.
  • the UE may monitor the PDCCH / PDSCH (for msg. 2) for a time corresponding to the RA window interval based on the RA-RNTI or C-RNTI (e.g. BFR (Beam Failure Request)) value.
  • the response information RARID
  • the terminal can successfully receive the RAR.
  • the UE may prepare the aforementioned preamble to prepare for retransmission of the preamble.
  • the resource selection procedure can be performed again.
  • the terminal may perform msg. 3 transmission based on parameter information for scheduling and msg. 3 transmission in the received msg. 2.
  • the terminal may start a contention resolution timer.
  • the UE may perform PDCCH (with C-RNTI) / PDSCH monitoring to receive msg.4 while the above timer is running. If Msg.4 is received, the terminal may determine that contention resolution was successfully performed.
  • the terminal performs an event triggering (S410), random access initialization (S420), and random access resource selection (S430), and then performs a random access procedure by starting the preamble transmission as shown in FIG. 3. Can be.
  • S410 event triggering
  • S420 random access initialization
  • S430 random access resource selection
  • the LBT procedure may refer to a procedure of checking whether the channel is in an idle state and occupying the channel in the idle state.
  • the LBT may be distinguished according to the time occupying the channel.
  • the 25us LBT may determine whether the channel is in the idle state for 25us time, and perform signal transmission when the channel is in the idle state.
  • LAA Licensed Assisted Access
  • DRS Discovery Reference Signal
  • the DRS transmission is transmitted within 1ms or less, and may be configured by a combination of at least one of CRS, SSS, PSS, and CSI-RS.
  • the DRS transmission has a period of 40 ms or more (e.g. 40, 80, 160 ...) and may be transmitted within one subframe.
  • the 25us LBT may determine whether the channel is idle for 25us and perform signal transmission for 1ms if the channel is idle.
  • the aforementioned LBT will be referred to as a short LBT.
  • the short LBT may mean 25us LBT, but is not limited thereto.
  • a reference time for determining whether a channel is idle and a time for performing signal transmission may be different. That is, the following embodiments may be applied to the LBT which is not limited to the 25us LBT described above and determines whether the channel is idle for a short time and transmits a signal for a predetermined time.
  • an operation of occupying a channel to transmit a physical downlink shared channel (PDSCH) for performing downlink data transmission may be performed based on LBT category 4, which will be described with reference to FIG. 5. .
  • PDSCH physical downlink shared channel
  • LBT category 4 is a diagram illustrating a method of performing data transmission based on LBT category 4.
  • LBT category 4 may be configured of an initial CCA (Clear Channel Assessment, ICCA) and an extended CCA (ECCA).
  • ICCA Cerar Channel Assessment
  • ECCA extended CCA
  • the base station may determine whether data transmission is necessary in the ICCA step (S511).
  • the base station may determine whether the slot is idle. (S512) In this case, the defer period (D). During the defer period, if the channel is idle during the defer period, the base station may perform the data burst transmission if necessary. S514) Then, the base station determines whether the transmission is complete (S515), and when the transmission is complete, may enter the ECCA step.
  • the channel is busy (or occupied) during the defer period in step S513, when an energy greater than a certain energy detection threshold (ED) threshold is detected by the node performing the LBT, the ECCA step is performed. You can enter
  • a contention window size may be determined.
  • the contention window size may be updated to a q value between the values of X and Y.
  • the q value may be updated through channel measurement of the ACK / NACK report or the transmitting node (e.g. eNB).
  • the X and Y values are values for determining the maximum contention window size, and as described above, the q value may be updated to a value between the X and Y values.
  • N may be randomly selected from a value between 0 and q-1 as an arbitrary value in the current contention window (S516). At this time, the N value is a random back-off counter.
  • the N value may be used for data transmission by occupying the corresponding unlicensed channel when the channel is idle for N consecutive ECCA slots.
  • the N value may be determined whether the channel is in the idle state during the defer period (S517). In this case, when the channel is busy, it may wait until the channel is switched to the idle state. . In addition, when the channel is idle, it may be determined whether N is 0 (S518). At this time, if N representing a random backoff counter value is 0, data burst transmission may be performed again if necessary. On the other hand, if the N value is not 0, the random backoff counter value N may be changed to N-1 or maintained without performing a specific operation (S519).
  • the ED threshold for which the energy level is described above is maintained. It may be determined whether the value is greater than the value or whether the sensing is not performed (S520). If the energy level is smaller than the ED threshold, it may move to the next slot (S521). If it is greater than hold, it can go back to step S517 to determine if the channel is idle again.
  • LBT may be performed through the procedure as shown in FIG. 5.
  • LBT performed as shown in FIG. 5 is referred to as long LBT below.
  • the long LBT may mean an LBT performed based on the above-described procedure of FIG. 5, but is not limited thereto.
  • the method of determining the idle state of the channel in the long LBT and occupying the channel may be performed based on another method. That is, the following embodiment is equally applicable to the LBT performed for a long time without being limited to the above-described procedure of FIG. 5.
  • the above-described defer period may be defined as having the same period for coexistence with WiFi.
  • the defer period may be as shown in Equation 3 below.
  • the channel must be at least guaranteed that the channel is idle for a time such as a Distributed Inter Frame Space (DIFS) or Arbitration Inter Frame Space (AIFS) of WiFi.
  • DIFS Distributed Inter Frame Space
  • AIFS Arbitration Inter Frame Space
  • the length of the defer period may vary according to an access class, and the determining may be an n value.
  • the n value may be set to a small value for faster channel occupation of access classes such as VoIP or video traffic.
  • an embodiment in which the defer period is set differently may be possible, and is not limited to the above-described embodiment.
  • a method of operating an unlicensed band is described.
  • LTE a method of using an unlicensed band based on a primary CC (PCell) assistance of a licensed band, such as LAA
  • PCell primary CC
  • LAA licensed band
  • this has been introduced as a 3GPP standard specification and is continuously evolving.
  • RAT radio access technology
  • the standalone method performs initial access in the control plane as well as initial cell access without the assistance of the PCell in the licensed band, and operates in the unlicensed band. ) May be necessary.
  • spectrum characteristics and regulations may be applied in the unlicensed band. That is, because of the unlicensed band, restrictions such as uncertainty of channel availability or the Occupied Channel Bandwidth (OCB) requirement may be applied.
  • OBC Occupied Channel Bandwidth
  • other regulations may be applied by the unlicensed band, but are not limited to the above-described embodiment. In order to perform an initial cell access as well as to perform a transmission / reception procedure between various base stations and terminals while complying with the regulations to be considered in order to use the unlicensed band, an effective radio access technology is required for the unlicensed band.
  • a problem may occur in that transmission of a common broadcast signal (ie SS / PBCH block, SIB1, RACH etc.) cannot always be guaranteed, and similar signals may be transmitted. At this time, it is necessary to study how the channel occupancy bandwidth will be satisfied and how much transmission power should be performed based on the amount of transmission power.
  • a common broadcast signal ie SS / PBCH block, SIB1, RACH etc.
  • the unlicensed band may not always guarantee channel use due to channel access related regulations (ie, LBT) as described above. Therefore, the receiving end and the transmitting end cannot perform soft-combining on the signals transmitted at all times. That is, in the unlicensed band, it may be difficult to meet the performance requirements (reliability / delay aspect) as in the licensed band.
  • LBT channel access related regulations
  • the NR system may consider scenarios as shown in Table 8 below.
  • Table 8 below.
  • Table 8 a method for supporting the initial connection in the standalone NR system, but is not limited to this, it may be applicable to the scenario of Table 8.
  • Table 8 shows the dual connectivity of licensed band LTE (PCell) and unlicensed band NR-U (PSCell) when carrier aggregation of licensed band NR (PCell) and unlicensed band NR-U (SCell) is applied.
  • PCell licensed band LTE
  • PCell unlicensed band NR-U
  • SCell unlicensed band NR-U
  • the downlink uses the unlicensed band in the NR system
  • the uplink uses the licensed band and the case where the dual connectivity of the licensed band NR (PCell) and unlicensed band NR-U (PSCell) is applied.
  • the following embodiments may be applied to the above-described scenario, but are not limited to the above-described embodiment.
  • the above-described short LBT and long LBT operations may be applied.
  • the base station when the base station performs SSB transmission together with SSB / RACH transmission or nonslot-based PDSCH / PDCCH at the time of transmission, the base station may occupy a channel through a short LBT procedure and perform transmission.
  • the base station when the base station performs transmission based on the Short LBT, the base station may transmit a signal by occupying the channel only for a relatively short time period.
  • LAA DRS Discovery RS
  • the base station is at least LAA DRS can be transmitted for less than 1ms only when the channel is idle.
  • the base station may perform a Short LBT (hereinafter, S-LBT) procedure for SSB / RACH transmission. Also, the base station may perform long LBT for SSB / RACH transmission. In this case, the following will be referred to as LBT for convenience of description, but may be the above-described short LBT or Long LBT, it is not limited to the above-described embodiment.
  • S-LBT Short LBT
  • LBT Long LBT
  • the NR system may define an NR DRS (Discovery Reference Signal) for the purpose of cell identification and cell measurement. That is, NR DRS may be defined as a new reference signal associated with cell search.
  • the NR DRS may be configured of at least one of SSB and CSI-RS. That is, the SSB described below may be considered as one transmission signal and channel constituting the NR DRS, and is not limited to the above-described embodiment.
  • a RAT Radio Access Technology
  • a method of performing initial access may be required. That is, the initial connection may be a radio access technology that is required for operation even in standalone NR-U.
  • the unlicensed band unlike an unlicensed band, there may be spectrum characteristics and regulatory requirements (e.g. uncertainty of channel availability, the Occupied Channel Bandwidth (OCB) requirement). Therefore, there may be a problem that transmission of a common broadcast signal (ie SS / PBCH block, SIB1, RACH etc.) necessary when performing initial access in a standalone NR-U may not always be guaranteed. . More specifically, since the unlicensed band is used, constant use of the channel may not be guaranteed. In this case, since the receiving end cannot perform soft-combining on the signals that can be transmitted by the transmitting end, there may be a problem in that the operation is performed while satisfying the performance requirements (e.g. reliability / delay side) in the licensed band. In particular, since the random access procedure takes a large part of the control plane latency, it is necessary to terminate the random access procedure by occupying the channel as soon as possible.
  • a common broadcast signal ie SS / PBCH block, SIB1, RACH etc.
  • random access initialization may be performed before performing a random access procedure.
  • carrier selection may be performed in a random access initialization procedure.
  • carrier selection may be performed by a MAC entity in the terminal.
  • the terminal when the terminal receives explicit signaling for using a specific carrier, the terminal may perform a random access procedure on the indicated carrier based on the signaling. That is, the terminal may perform carrier selection for performing a random access procedure through explicit signaling by the base station.
  • the UE may implicitly perform carrier selection without explicit signaling.
  • the SUL carrier in one serving cell is additionally configured to the NUL for the random access procedure to the terminal, and the RSRP value of the DL pathloss reference of the serving cell is smaller than the RSRP-ThresholdSSB-SUL value, the MAC entity of the terminal is A SUL carrier may be selected as a carrier for performing random access, and a PCMAX value for the corresponding SUL may be set based on a parameter provided by a base station.
  • the RSRP value of the DL pathloss reference of the serving cell is larger than the RSRP-ThresholdSSB-SUL value
  • the NUL may be selected and the corresponding PCMAX value for the NUL may be set similarly.
  • a single serving cell may select an SUL carrier or a NUL carrier in the serving cell by comparing the RSRP value of the DL pathloss reference on the DL carrier with the RSRP-ThresholdSSB-SUL.
  • the UE may estimate an uplink state through DL pathloss for downlink, and may operate as described above based on this.
  • the UE may determine a RACH occasion (RACH occasion, RO) available for transmission of a preamble (ie, msg. 1) on the determined carrier and perform preamble transmission in the corresponding RO.
  • RACH occasion RACH occasion
  • a SUL carrier may be configured in a terminal for one serving cell for performing random access.
  • the UE may determine which carrier of the NUL carrier and the SUL carrier should perform a random access procedure.
  • the SUL carrier can usually be set in a low frequency band.
  • the SUL carrier may be set to ensure the stability of the RACH procedure, and is not limited to the above-described embodiment.
  • an operation may be performed by occupying a channel based on the LBT. In relation to the random access procedure, random access delay due to LBT failure in the unlicensed band and thus performance degradation may occur. Therefore, methods for preventing this may be necessary and will be described.
  • the following description will be based on msg.1 preamble transmission, but is not limited thereto.
  • the msg.1 preamble transmission may be multiplexed with another channel (e.g. PUSCH / msg. 3, PUCCH, SRS or etc.) and transmitted.
  • another channel e.g. PUSCH / msg. 3, PUCCH, SRS or etc.
  • the ETSI regulation in the 5 GHz band there is a regulation for Occupied Channel BW in which 99% of the power of the signal must be occupied between 100% and 80% of the nominal channel BW.
  • the basic LBT grid (20MHz) it may be effective to multiplex msg.1 preamble transmissions with other channels (e.g.
  • PUSCH / msg.3, PUCCH, SRS or etc. may be equally applied to a signal multiplexed and transmitted as described above. However, hereinafter, for convenience of explanation, the description will be based on msg.1 transmission, but is not limited thereto.
  • At least one of the proposed methods may be applied to the NR-U system and used for performing random access.
  • the above-described bar may be set through dedicated signaling for the RRC CONNECTED mode terminal.
  • Embodiment 1 Performance of Parallel LBT Operation for Each of SUL and NUL in One Serving Cell
  • the MAC entity of the terminal may configure an additional SUL in one serving cell based on higher layer signaling of the base station. Through this, the terminal can increase the channel occupancy probability and can ensure the stability of performing the random access procedure.
  • the terminal may select a carrier in a random access procedure through the following procedure.
  • the UE may determine the RO based on the selected carrier, perform LBT (channel access procedure) for preamble transmission on the RO, and then perform random access procedure according to channel occupation.
  • LBT channel access procedure
  • the terminal can perform uplink msg.1 transmission on the NR-U serving cell.
  • msg.1 may be multiplexed with another channel, as described above.
  • the random access procedure may be performed when an event is triggered as described above.
  • the event triggering cause may be as described in Table 6 above, but is not limited to the above-described embodiment.
  • random access initialization may be performed as shown in FIG. 4.
  • the RRC parameter setting (S610) and the MAC variable setting (S620) may be performed, as shown in FIG.
  • the UE may first set random access-related RRC parameters on both UL carriers.
  • the terminal may initialize the MAC variable values and select a carrier for performing random access (S630). That is, the carrier selection process may be performed in FIG.
  • a first carrier selection may be performed in a carrier selection process (S631).
  • the first carrier selection may be performed by the MAC entity of the terminal in the RSRP of the DL pathloss reference of the NR-U serving cell. This can be done by comparing the value with the RSRP-ThresholdSSB-SUL value.
  • the terminal may select the SUL based on the comparison result described above.
  • the terminal may select the NUL and SUL based on the above-described comparison result, which will be described later.
  • the UE may perform random access resource selection (S632).
  • the UE may determine ROs available for msg.1 preamble transmission in the random access resource selection process.
  • the above-described process may be performed in the SUL as the selected carrier.
  • the terminal may perform channel access (S633).
  • the terminal is an unlicensed band, and the terminal may perform an LBT procedure. That is, the UE may perform an LBT procedure for performing preamble transmission in each determined RO.
  • the terminal may access the channel and perform preamble transmission in each determined RO.
  • the following procedure may be the same as the random access procedure described above. On the contrary, if the channel occupancy of the terminal is impossible as a result of performing LBT, the terminal may perform the first carrier selection procedure again.
  • the UE may perform random access resource selection (S634). Then, the UE may perform a channel access procedure (S635). For example, since both NUL and SUL are selected in the first carrier selection, the random access resource selection and the channel access procedure may be performed in the NUL and the SUL, respectively. That is, the above-described procedure may be performed in parallel in each carrier. That is, in the random access resource selection process, an RO for preamble transmission is determined for each of NUL and SUL, and an LBT procedure for channel access in each carrier may be performed.
  • the parallel channel access referred to herein may not mean that they always perform in parallel at the same time at the same time.
  • this may mean that channel access operations for two carriers are performed in parallel within a time interval in which determination of whether channel access is successful is performed. That is, it also means that channel access operations for two carriers are respectively performed within a time interval in which a determination of whether channel access is successful or not is performed.
  • the second carrier selection may be performed based on the parallel channel access procedure. (S636) If the channel occupancy is successful in either the SUL carrier or the NUL carrier based on the second carrier selection process, the terminal accesses the channel. The channel may be accessed based on the procedure S633, and preamble transmission may be performed at each determined RO. The following procedure may be the same as the random access procedure described above.
  • the UE may perform a new procedure for random access by performing the above-described first carrier selection S631.
  • the terminal does not perform the above-described first carrier selection procedure (S631) and is random again in the SUL carrier and the NUL carrier.
  • An access resource selection procedure S634 and a parallel channel selection procedure S635 may be performed. That is, if the second carrier selection fails, the terminal may try again from the first carrier selection or perform parallel operations on each carrier without the first carrier selection, but is not limited to the above-described embodiment.
  • Example 1-1 carrier selection method by comparing RSRP value of DL pathloss reference
  • FIG. 7 is a diagram illustrating a first carrier selection procedure.
  • the terminal may perform the first carrier selection (S710).
  • the MAC entity of the terminal may compare the RSRP value and the RSRP-ThresholdSSB-SUL value of the downlink pathloss reference of the corresponding NR-U serving cell.
  • the RSRP-ThresholdSSB-SUL value may be a value compared with the RSRP value of the channel measured by the UE through SSB (SS / PBCH block).
  • the above-described value may be a parameter provided through a base station higher layer signaling as a threshold for selecting an uplink carrier configured in one serving cell.
  • the MAC entity of the terminal may perform a random access procedure by preparing LBT in the NR-U serving cell based on a plurality of carrier selection methods, which will be described later.
  • the UE selects a SUL carrier (S730), and selects the random access resource and the channel described above in the SUL carrier. (S740) That is, the UE may check channel occupancy by performing LBT before the RO determined for msg.1 preamble transmission on the SUL carrier.
  • the SUL carrier may be operated in a lower frequency band band than the NUL carrier.
  • SUL carriers may consider lower signal attenuation and system loading and interference than NUL carriers.
  • SUL generally has a better channel environment than NUL.
  • the channel environment of the NUL carrier is poor (that is, a situation where a low RSRP value is measured in the NUL)
  • the preamble transmission is successful. May not be performed.
  • the base station may not successfully receive a signal. Therefore, in the above situation, it may be efficient to instruct the physical layer to perform LBT only in the SUL carrier of the MAC layer of the terminal.
  • a NUL having a good channel state among the respective NULs may correspond to the above-described SUL. That is, only the NUL having a good channel state among the plurality of NULs may be preferentially performed after performing LBT, and channel access may be performed. As another example, when there are more than two carriers, channel access may be performed after performing LBT only for the carrier having the best channel state, and the present invention is not limited to the above-described embodiment.
  • the UE selects the SUL carrier and the NUL carrier (S750), and the above-described SUL carrier and NUL carrier are described above.
  • Random access resource selection and channel access may be performed (S760). This may be an operation for selecting a second carrier, which will be described later.
  • random access resource selection and channel access may be performed in parallel in each NUL. Also, for example, when two or more carriers exist, the above-described random access resource selection and channel access may be performed on all carriers.
  • FIG. 8 is a diagram illustrating a second carrier selection procedure.
  • the UE may select the SUL carrier and the NUL carrier.
  • the second carrier selection may be performed.
  • the MAC layer of the UE is physically prepared to perform LBT on both the NUL carrier and the SUL carrier for the NR-U serving cell. Instruct the hierarchy. That is, the UE determines that the NUL channel environment can compete with the SUL channel environment, and can perform a procedure for random access in each carrier.
  • the physical layer of the terminal determines the other available UL channel and RO for signal transmission including at least one of msg.1 and / or msg.3 / data / control information in the indicated NUL carrier and the SUL carrier. And prepare to perform LBT.
  • the terminal may perform Case 1 to Case 4 operations according to whether channel occupancy of the two UL carriers is successful.
  • Case 1 When the UE succeeds in channel occupancy only on the NUL carrier, the UE may then perform a random access procedure on the NUL carrier.
  • msg.1 may be multiplexed with another uplink channel and signal including at least one of msg.3 / data / control information, and information about this may be transmitted through a NUL carrier. , As described above.
  • Case 2 When the UE succeeds in channel occupancy only on the SUL carrier, the UE may then perform a random access procedure on the SUL carrier. The procedure is as described above.
  • Case 3 When the UE succeeds in channel occupancy on both the NUL carrier and the SUL carrier, the UE may perform a random access procedure later using at least one of the NUL carrier and the SUL carrier. For example, the terminal may perform a random access procedure based on the advance indication information. In this case, when there is no information previously indicated by the base station, the terminal may perform uplink transmission on one predetermined UL carrier (NUL or SUL) and proceed with the remaining random access procedure. That is, the terminal may predetermine information about the preferred UL carrier.
  • NUL or SUL predetermined UL carrier
  • the terminal may perform uplink transmission on the UL carrier previously indicated by the base station, and then proceed with a random access procedure. That is, the terminal may select the UL carrier based on the indication received from the base station.
  • the terminal may perform uplink transmission on both the NUL carrier and the SUL carrier, and then proceed with the remaining random access procedure.
  • Case 4 If both channel occupancy for the NUL carrier and the SUL carrier fails, the UE may wait for the next available physical resource of the two carriers through a random access resource selection procedure. As another example, the UE may return to the aforementioned first carrier selection procedure and perform a new carrier selection operation. In addition, as an example, it may be possible to operate differently based on the count of the LBT failure and the maximum threshold value (e.g. MAX LBT counter), which will be described later.
  • MAX LBT counter e.g. MAX LBT counter
  • FIG. 8 may be referred to.
  • the terminal may determine whether the random access selection and the channel access succeed in at least one of the NUL carrier and the SUL carrier based on the second carrier selection (S820).
  • the LBT procedure may be performed to check whether the channel is occupied, and the procedure for accessing the channel may be performed.
  • the terminal may perform a new carrier selection procedure based on the aforementioned first carrier selection procedure.
  • the terminal may perform the random access resource selection and channel access procedure on each of the NUL carrier and the SUL carrier again based on the second carrier selection procedure (S830). That is, the operation based on Case 4 described above is performed. Can be.
  • the UE may operate differently depending on whether the channel occupancy is successful (S840). For example, if channel occupancy succeeds in only one of the NUL carrier and the SUL carrier, the UE may perform uplink transmission on the UL carrier on which the channel occupancy is successful and then perform a random access procedure (S850). An operation based on Case 1 or Case 2 may be performed.
  • the terminal may perform uplink transmission based on whether there is signaling from the base station or whether there is predetermined information, and then perform a random access procedure.
  • the terminal may perform uplink transmission on both the NUL carrier and the SUL carrier, and then proceed with the remaining random access procedure. That is, the operation based on Case 3 described above may be performed, as described above.
  • FIG. 9 is a diagram illustrating a method of determining a section for determining whether to occupy a channel through channel access.
  • the UE may perform a time domain determination on whether channel RO of the RO determined for msg.1 transmission on the NUL carrier and the SUL carrier is successful based on the respective “SSB-RO mapping period”. More specifically, referring to FIG. 9, the "SSB-RO mapping period" in the NUL carrier and the “SSB-RO mapping period” in the SUL carrier may be set differently.
  • one serving cell A may be set as shown in Table 9 below.
  • Table 9 below.
  • more higher layer information may be provided to the terminal through common higher layer signaling or terminal specific higher layer signaling, and is not limited to the following embodiments.
  • different periods may be set in the NUL carrier and the SUL carrier.
  • the determination of channel occupancy on the NUL carrier and the SUL carrier may be performed based on the longer SSB-RO mapping time interval (e.g. NUL SSB-RO mapping period in FIG. 9) among the two UL carriers. That is, the NUL SSB-RO mapping period may be a determination period for determining channel occupancy.
  • the determination of channel occupancy may be performed based on at least one SSB-RO mapping period or SSB-RO mapping period pattern time (e.g. 160ms).
  • the above-described SSB-RO mapping period pattern may consist of SSB-RO mapping periods of various time lengths in a specific fixed time interval (e.g. 160ms).
  • each time period corresponding to the SSB-RO mapping period pattern may be composed of repetitive SSB-RO mapping periods.
  • the terminal has an advantage that the terminal implementation can be easily assuming that at least the same SSB-RO mapping pattern is repeated every specific time (e.g. 160ms).
  • the determination of whether to occupy the channel may be performed based on a time interval corresponding to the number of specific ROs.
  • the above-described time interval may be regarded as a minimum time period for determining channel occupancy through performing LBT on the NUL carrier and the SUL carrier.
  • the UE may attempt msg.1 preamble transmission by performing LBT on the selectable (or available) RO of the NUL carrier and the SUL carrier based on the above-described time period.
  • the above-described time period may be the number of PRACH configuration periods, the number of radio frames (SFN), the number of slot / OFDM symbols, or any specific time, and the like. That is, the terminal may set a specific time for fitting the time interval to determine channel occupancy on the plurality of UL carriers, and other time intervals may be possible.
  • the time period described above may be applicable to both the NUL carrier and the embodiment performed in the SUL carrier performing the above-described parallel LBT operation.
  • performing channel access in parallel may not mean that the parallel channel access is always performed in parallel at the same time at the same time.
  • FIG. 9 it may mean that channel access operations for two carriers are performed in parallel within a time interval in which a determination on whether channel access is successful is performed.
  • parallel channel access may also mean that determination of whether channel access is successful in each of two carriers is performed within a time interval for determining whether channel access is successful as shown in FIG. 9.
  • the present invention is not limited to the above-described embodiment.
  • Example 1-2 carrier selection method without RSRP value comparison of DL pathloss reference
  • the DL reference RSRP value and the RSRP-ThresholdSSB-SUL value are compared to determine whether to perform a random access procedure on the SUL carrier or to perform a random access procedure on both the NUL carrier and the SUL carrier.
  • LBT may be performed on both the NUL carrier and the SUL carrier without a comparison procedure between the DL pathloss reference RSRP value and the RSRP-ThresholdSSB-SUL (ie, without a 1st carrier selection block). That is, the terminal may perform random access resource selection and channel access procedures on all UL carriers. This allows the active LBT on the NUL carrier compared to the above-described method, thereby increasing the channel occupancy probability and the corresponding msg.1 transmission probability.
  • the increase of interference and the possibility of potential base station reception failure probability may be selectively applied, which will be described later.
  • a method of performing LBT on all UL carriers may be effective.
  • an RRC parameter setting (S1020) and a MAC variable setting (S1030) may be performed, as described above.
  • the UE may perform random access resource selection on the NUL carrier and the SUL carrier, respectively (S1040). That is, the UE may determine available ROs for msg.1 preamble transmission on the NUL carrier and the SUL carrier, respectively. .
  • the UE may perform an LBT procedure for preamble transmission in each RO determined on the NUL carrier and the SUL carrier. (S1050, S1060) That is, the UE may determine whether to occupy a channel in each UL carrier. .
  • the UE may perform carrier selection and PCMax setting.
  • S1070 For example, a channel access operation may be performed in parallel on the NUL carrier and the SUL carrier.
  • the above-described operations of Cases 1 to 4 may be applied in the same manner, and are not limited to the above-described embodiment. That is, the carrier selection procedure may be performed similarly to the operations of Case 1 to Case 4.
  • the UE may transmit the msg.1 preamble on the carrier determined by the successful channel occupancy and the RO (S1080).
  • the msg.1 preamble may be multiplexed with the above-described other information and transmitted. This is as described above.
  • the terminal may perform the remaining random access procedure, as described above (S1090).
  • the terminal uses the common RACH configuration information (ie RACH-ConfigCommon) in PBCH or RMSI (SIB1), which is a broadcast channel, in the above-described embodiments 1-1 or 1-2 Which method may be used may be indicated.
  • the common RACH configuration information may include information indicating whether to select a carrier by comparing the RSRP value of the DL pathloss reference or without comparison.
  • the common RACH configuration information may include information such as “totalNumberOfRA-Preambles”, “ssb-perRACH-OccasionAndCB-PreamblesPerSSB”, “groupBconfigured”, and the like.
  • the common RACH configuration information may include other information related to the RACH procedure, but is not limited to the above-described embodiment.
  • Table 10 below may be information included in common RACH configuration information, but this is merely an example and the present invention is not limited thereto.
  • the RRC CONNECTED mode UE performs a random access procedure, which of the above-described embodiments 1-1 or 1-2 is to be used through UE-specific RACH configuration information (ie RACH-configDedicated) It can indicate whether or not. That is, the common RACH configuration information may include information indicating whether to select a carrier by comparing the RSRP value of the DL pathloss reference or without comparison.
  • Table 11 may be information included in the UE-specific RACH configuration information. However, Table 11 is only one embodiment and may also include other information.
  • the UE may be instructed on the carrier selection and the LBT execution scheme for preamble transmission. That is, the base station may provide a terminal with a more efficient method of performing LBT for msg.1 preamble transmission by reflecting the cell deployment environment and the regulation of the NR-U frequency band through signaling.
  • the information indicating Embodiments 1-1 and 1-2 described above in Table 10 or Table 11 may be configured as 1-bit information.
  • the above-described indication information may be described as "Carrier Selection Mode” in Table 10 or Table 11.
  • “Carrier Selection Mode” in Table 10 and Table 11 may indicate Mode 1, Mode 2, or All.
  • Mode 1 and Mode 2 may indicate Embodiment 1-1 and Embodiment 1-2 described above, respectively.
  • Mode 1 corresponds to Embodiment 1-1
  • Mode 2 may correspond to Embodiment 1-2.
  • Mode 1 corresponds to Embodiment 1-2
  • Mode 2 may correspond to Embodiment 1-1.
  • All may mean that the embodiments 1-1 and 1-2 are possible.
  • the "Carrier Selection Mode" of Table 10 and Table 11 described above may be one embodiment, and is not limited to the above-described embodiment.
  • information on carrier selection may be included in the common RACH configuration information or the UE-specific RACH configuration information, but is not limited to the above-described embodiment.
  • the present invention is not limited to the above-described name, and may be equally applied to information performing the same indication.
  • the terminal assumes that the terminal that is not set to the "Carrier Selection Mode" performs a conventional operation (see Figure 4).
  • Example 1-4 carrier selection method by comparing RSRP value and COR / RSSI value of DL pathloss reference
  • FIG. 14 is a diagram illustrating a method of selecting a carrier by comparing an RSRP value of a DL pathloss reference and a Channel Occupancy Rate (COR) / Received Signal Strength Indicator (RSSI) value.
  • COR Channel Occupancy Rate
  • RSSI Received Signal Strength Indicator
  • the terminal may perform carrier selection as described above.
  • FIG. 14 may be a method for the terminal to perform carrier selection.
  • the terminal may perform carrier selection.
  • S1400 the terminal may perform carrier selection.
  • the MAC entity of the terminal is a corresponding NR-U serving.
  • the RSRP value and the RSRP-ThresholdSSB-SUL value of the downlink pathloss reference of the cell may be compared. It can be the value being compared.
  • the above-described value may be a parameter provided through a base station higher layer signaling as a threshold for selecting an uplink carrier configured in one serving cell.
  • a Channel Occupancy Rate (COR) and / or a Received Signal Strength Indicator (RSSI) value may be measured by the terminal on an unlicensed carrier.
  • the UE may further consider the COR and / or RSSI values measured in the RACH carrier selection.
  • the COR value may indicate the rate at which the channel is occupied by neighboring nodes for a period of time.
  • the RSSI value is a measure of all signal strengths (interference + noise + desired signal) of neighboring nodes and can be considered together with COR as an index for estimating the use degree of the corresponding unlicensed carrier.
  • the MAC entity of the UE may perform a random access procedure by preparing LBT in the NR-U serving cell based on a plurality of carrier selection methods, which will be described later.
  • the DL pathloss reference RSRP value of the NR-U serving cell and the RSRP-ThresholdSSB-SUL value may be compared.
  • the UE may select a SUL carrier.
  • the DL COR / RSSI value is set by a base station (eg COR / RSSI-Threshold-SUL).
  • the UE may select a SUL carrier. If the terminal selects the SUL carrier, the terminal may perform the above-described random access resource selection and channel access in the SUL carrier.
  • the UE may select a NUL carrier.
  • the terminal may perform the above-described random access resource selection and channel access on the NUL carrier.
  • COR and / or RSSI values may be considered further.
  • the newly considered COR and RSSI values are measured values of the UE reporting the occupancy rate of the corresponding carrier and the strength of the neighboring signal in the unlicensed carrier (NDL / NUL).
  • the terminal can be used to determine the current unlicensed channel environment. That is, in the embodiment 1-4, the case where the COR and RSSI values are larger than the threshold may mean that both of the corresponding NUL / NDL are in use by neighboring nodes. Thus, it can be expected that there are many competing nodes to occupy the channel. Therefore, in terms of performing RACH carrier selection, selecting the SUL rather than selecting the NUL carrier may increase the RACH success rate.
  • the UE may check channel occupancy by performing LBT before the RO determined for msg.1 preamble transmission on the SUL carrier.
  • the SUL carrier may be operated in a lower frequency band band than the NUL carrier.
  • SUL carriers may consider lower signal attenuation and system loading and interference than NUL carriers. That is, it can be assumed that SUL generally has a better channel environment than NUL.
  • the channel environment of the NUL carrier is poor (that is, a situation where a low RSRP value is measured in the NUL), even though the LBT is occupied by the NUL, the preamble transmission is successful. May not be performed.
  • the base station may not successfully receive a signal. Therefore, in the above situation, it may be efficient to instruct the physical layer to perform LBT only in the SUL carrier of the MAC layer of the terminal.
  • the RSRP value of the DL pathloss reference of the NR-U serving cell is larger than the RSRP-ThresholdSSB-SUL value, and the channel occupancy rate and / or RSSI (Received Signal Strength Indicator) are set by the base station.
  • the UE may select a NUL carrier (S1404) and perform the above-described random access resource selection and channel access in the SUL carrier. In this case, it may be determined that the NUL channel environment of the UE is good through comparison of the RSRP value and that the channel occupancy degree of the corresponding NUL unlicensed carrier is low. Therefore, the UE selects the NUL carrier, which is an unlicensed carrier, as a carrier for the RACH procedure.
  • the UE selects the SUL carrier (S1403), and selects the random access resource and the channel described above in the SUL carrier. Access can be performed. In this case, it may be determined that the NUL channel environment of the UE is not good through comparison of RSRP values. Therefore, regardless of considering channel occupancy information (e.g. COR / RSSI) of the NUL carrier, the UE selects the SUL carrier as a carrier for the RACH procedure.
  • channel occupancy information e.g. COR / RSSI
  • a NUL having a good channel state among each NUL and having a low or low channel occupancy rate may correspond to the above-described SUL. That is, only the NUL having a good channel state among the plurality of NULs may be preferentially performed after performing LBT, and channel access may be performed. As another example, when there are more than two carriers, channel access may be performed after performing LBT only for the carrier having the best channel state, and the present invention is not limited to the above-described embodiment.
  • the terminal may sequentially perform channel sensing on two UL carriers. That is, the terminal may perform channel sensing for each carrier sequentially without requiring a channel sensing operation (ie, LBT) on the NUL carrier and the SUL carrier at the same time.
  • the UE may perform a method of switching preamble transmission between two UL carriers according to a situation.
  • 11 is a diagram illustrating a method of performing sequential LBT.
  • an RRC parameter setting (S1120) and a MAC variable setting (S1130) may be performed, as described above.
  • uplink msg.1 (with other channels) transmission on the NR-U serving cell may be performed, as described above.
  • the UE may perform carrier selection.
  • the MAC entity of the UE may compare the RSRP value and the RSRP-ThresholdSSB-SUL value of the DL pathloss reference of the corresponding NR-U serving cell.
  • the terminal may determine whether to select the SUL carrier or the NUL carrier based on the comparison result.
  • the terminal may perform random access resource selection. That is, as described above, the UE may determine an available RO for msg.1 preamble transmission on one selected carrier.
  • the terminal may perform channel access on the selected UL carrier (S1160). That is, the terminal performs an LBT procedure to perform preamble transmission on the determined RO, and checks whether the channel is occupied based on this. Can be.
  • the terminal msg. 1 preamble transmission may be performed (S1180), and then a random access procedure may be performed (S1190).
  • the LBT counter LC parameter may be newly defined and is not limited to the above-described embodiment. That is, the LBT counter parameter can be used to determine the carrier and RO to perform the next LBT.
  • the LBT counter value may be increased by one.
  • the UE may prepare to perform the next LBT by selecting the next available RO of the previously selected UL carrier.
  • the UE may determine that the channel state of the selected UL carrier is busy and attempt to change to another UL carrier.
  • the carrier change may be changed between the NUL carrier and the SUL carrier.
  • the carrier change may be changed between NUL carriers. More specifically, as described above, in the case of performing a random access initialization process through any one of the UL carrier or the NUL carrier and SUL carrier, if the LBT failure is confirmed as described above through the other UL carrier The random access initialization process may be performed.
  • the carrier change determination (S1170) may be performed through at least one of an LBT counter, channel measurement information of the terminal, and a downlink channel access procedure.
  • channel measurement information of the terminal may be used to determine whether to change the carrier.
  • the channel occupancy rate information of the uplink unlicensed carrier by the terminal may be used to determine whether the carrier is changed as measurement information on how many hours the carrier is used by the transmitting nodes.
  • the RSSI value is greater than a specific threshold as the strength of the signal and the interference of the corresponding carrier
  • the random access may be changed to another carrier.
  • the channel occupancy is sensed by the channel whether or not the channel is occupied for each time interval corresponding to the number of OFDM symbols, the number of slots, etc. based on a new time interval (eg, subcarrier spacing).
  • Each measured sample value and its average value can be generated.
  • the generated average value may also be generated as an additional weighted average value in future higher layers and reported to the base station later.
  • the determination of whether to change the carrier may be performed based on whether the uplink channel is shared through the downlink channel access procedure by the base station.
  • the shared uplink may mean whether a part of the occupied time interval may be used for uplink transmission of the terminal by the base station signaling in the channel time interval occupied by the base station.
  • the determination of whether to change the carrier may be performed using any one of an LBT counter, channel measurement information of the terminal, and downlink channel access procedures.
  • the determination of whether to change the carrier may be performed by determining some or all of the above-mentioned information in a complex manner, and is not limited to the above-described embodiment.
  • the above-described situation may be equally applied between NUL carriers of each of the plurality of serving cells.
  • a NUL carrier to perform LBT may be selected in consideration of channel states between NUL carriers.
  • the LBT procedure may be retried in another NUL carrier. That is, even in an environment where a plurality of NUL carriers exist, the LBT procedure may be sequentially performed.
  • the above-described situation may be equally applied between UL BWPs of each of a plurality of bandwidth parts (BWPs).
  • the UL BWP to preferentially perform the LBT may be selected in consideration of channel conditions between specific UL BWPs.
  • another UL BWP may try the LBT procedure again. That is, the LBT procedure may be sequentially performed even in an environment in which a plurality of UL BWPs exist.
  • the channel measurement information of the UE such as channel occupancy rate information and / or received signal strength information measurement information, may be used to determine whether to change the UL BWP.
  • the channel occupancy rate information of the UL BWP by the UE may be used to determine whether the UL BWP is changed as measurement information on how much time the corresponding UL BWP is used by the transmitting nodes.
  • the RSSI value is greater than a specific threshold due to the strength of the signal and the interference of the corresponding UL BWP, the random access may be changed to another UL BWP.
  • the determination of whether to change the UL BWP may be performed based on whether uplink channel access shared through the downlink channel access procedure.
  • the shared uplink may mean whether a part of the occupied time interval may be used for uplink transmission of the terminal by the base station signaling in the channel time interval occupied by the base station.
  • the determination of whether to change the UL BWP may be performed by using any one of an LBT counter, channel measurement information of the terminal, and downlink channel access procedures.
  • the determination of whether to change the UL BWP may be performed by determining some or all of the above-described information in combination, and is not limited to the above-described embodiment.
  • the NUL or SUL carrier based on the RSRP value of the DL pathloss reference when changing a UL carrier (or a plurality of NUL carrier change or a plurality of UL BWP change), the NUL or SUL carrier based on the RSRP value of the DL pathloss reference once again in the middle of attempting the change
  • the selection may be considered once more. That is, when it is determined that the LBT procedure has failed, the comparison of the RSRP value of the DL pathloss reference may be performed once more.
  • the RSRP value comparison procedure of the above-described DL pathloss reference may be unnecessary and may be omitted. That is, the terminal may perform the LBT procedure on another UL carrier.
  • Example 3 (Signaling for Selecting Example 1 and Example 2)
  • Operations for the first and second embodiments described above may be selectively performed.
  • the terminal may be signaled by the base station about which method of the first embodiment or the second embodiment to perform.
  • Embodiment 1 described above may require more capabilities from the terminal because monitoring of the carrier is required as compared with Embodiment 2.
  • a plurality of channels are considered together, so that the channel occupancy can be performed more quickly.
  • the second embodiment is performed sequentially, the implementation may be easy and the cost may be reduced.
  • the base station may selectively use any of the above-described methods based on the characteristics of the band in which two UL carriers are operated, the channel environment and traffic loading information of the current NR-U system, and the like.
  • the base station may provide the above-described information to the terminal through signaling.
  • the terminal may perform a random access procedure based on the signaled information.
  • the information indicating the method of Embodiment 1 and Embodiment 2 described above is also included in common RACH configuration information (ie RACH-ConfigCommon) or UE specific RACH configuration information based on Table 10 or Table 11 described above. It may be indicated, which may be the same as the method described above.
  • RACH-ConfigCommon common RACH configuration information
  • UE specific RACH configuration information based on Table 10 or Table 11 described above. It may be indicated, which may be the same as the method described above.
  • the random access operation is described based on the fact that all UL carriers are operated on an unlicensed band.
  • Table 12 below may be applied to the NR-U system based on the configuration of the base station and the NR-U deployment scenario.
  • Table 12 below does not describe the case of SDL, but may be applied in a similar manner.
  • NDL NUL
  • SUL SUL
  • a situation may be considered in which NUL (NDL) is a licensed band carrier and SUL is an unlicensed band carrier.
  • NDL NUL
  • SUL is an unlicensed band carrier
  • Example 4-1 NUL (NDL): Unlicensed Carrier, SUL: Licensed Carrier
  • one NR-U serving cell may be configured as a normal carrier on an unlicensed carrier. That is, both DL / UL can be set on an unlicensed carrier as a normal carrier.
  • the SUL carrier may be additionally set up if necessary by the base station to the corresponding terminal. At this time, the SUL carrier may be set on the license carrier. That is, in one NR-U serving cell, NUL (NDL) may be set as an unlicensed carrier and SUL may be set as a licensed carrier.
  • NDL NUL
  • the normal carrier of the unlicensed band is located in a high unlicensed frequency band (eg 60 GHz) corresponding to the mmWave band, while the SUL is set to be located in a lower frequency band (eg 2 GHz) corresponding to the licensed band. It may be possible. In the above situation, additional fallback operation for uplink transmission may be performed in the SUL licensed carrier. Thus, reliability in NR-U system operation can be improved.
  • a high unlicensed frequency band eg 60 GHz
  • the SUL is set to be located in a lower frequency band (eg 2 GHz) corresponding to the licensed band.
  • the random access procedure may be performed in consideration of the above-described situation.
  • NDL NUL
  • an RRC parameter setting (S1202) and a MAC variable setting (S1203) may be performed.
  • the first carrier selection may be performed.
  • the MAC entity of the terminal may first select the NUL carrier of the NR-U serving cell.
  • the NUL is an unlicensed carrier, and the system side has an advantage of offloading the uplink transmission to the unlicensed carrier first.
  • the MAC entity of the UE may compare the RSRP value and the RSRP-ThresholdSSB-SUL value of the DL pathloss reference of the corresponding NR-U serving cell. At this time, it is possible to determine whether to select the SUL or NUL based on the comparison result.
  • the method of comparing RSRP values of DL pathloss references may first compare the NUL channel environment and determine whether to select a SUL carrier as a licensed carrier, thereby improving reliability of uplink transmission.
  • the terminal may determine the RO resource based on the random access resource selection procedure (S1209) and perform msg.1 preamble transmission. (S1210) Then, perform an additional random access procedure. It can be done (S1211).
  • NUL NUL
  • the NUL carrier is selected first, when the NUL carrier is selected based on the comparison of the RSRP values of the DL pathloss references or when the NUL carrier is selected, based on the comparison of the RSRP values of the DL pathloss references, This may be the case when all of the NUL carriers are selected and are not limited to the above-described embodiment.
  • the terminal may perform random access resource selection. That is, as described above, the UE may determine an available RO for msg.1 preamble transmission on one selected carrier. Next, the UE may perform channel access on the selected UL carrier (S1206). That is, the UE performs an LBT procedure to perform preamble transmission on the determined RO, and checks whether the channel is occupied based on this. Can be.
  • the terminal may perform msg. 1 preamble transmission may be performed (S1210), and then a random access procedure may be performed (S1211).
  • the LBT counter LC parameter may be newly defined and is not limited to the above-described embodiment. That is, the LBT counter parameter can be used to determine the carrier and RO to perform the next LBT.
  • the LBT counter value may be increased by one.
  • the UE may prepare to perform the next LBT by selecting the next available RO of the selected UL carrier.
  • the UE may determine that the channel state of the selected UL carrier is busy and attempt to change to another UL carrier (S1208).
  • determining whether to change the carrier may be performed through at least one of an LBT counter, channel measurement information of the terminal, and a downlink channel access procedure.
  • channel measurement information of the terminal such as channel occupancy measurement information and / or RSSI measurement information, may be used to determine whether to change the carrier.
  • the determination of whether to change the carrier may be performed based on whether the uplink channel is shared through the downlink channel access procedure, as described above.
  • the determination of whether to change the carrier may be performed using any one of an LBT counter, channel measurement information of the terminal, and downlink channel access procedures.
  • the determination of whether to change the carrier may be performed by determining some or all of the above-mentioned information in a complex manner, and is not limited to the above-described embodiment.
  • the carrier change may be changed between the NUL carrier and the SUL carrier.
  • the carrier change may be changed between NUL carriers.
  • the above-described situation may be equally applied between UL BWPs of each of a plurality of bandwidth parts (BWPs).
  • the UL BWP to preferentially perform the LBT may be selected in consideration of channel conditions between specific UL BWPs.
  • another UL BWP may try the LBT procedure again. That is, the LBT procedure may be sequentially performed even in an environment in which a plurality of UL BWPs exist. For example, when determining whether to change the UL BWP as described above, at least one or more of an LBT counter, channel measurement information of the UE, and a downlink channel access procedure may be utilized, as described above.
  • the switched UL carrier is a SUL
  • the SUL since the SUL is in a licensed band, the LBT procedure is not necessary, and thus msg.1 preamble transmission may be performed immediately after the determined RO.
  • UL carrier switching may be immediately performed, and the present invention is not limited thereto.
  • NDL NUL
  • an RRC parameter setting (S1302) and a MAC variable setting (S1303) may be performed.
  • the first carrier selection may be performed (S1304).
  • the MAC entity of the UE may first select the NUL carrier of the NR-U serving cell.
  • the MAC entity of the UE may compare the RSRP value and the RSRP-ThresholdSSB-SUL value of the DL pathloss reference of the corresponding NR-U serving cell. At this time, it is possible to determine whether to select the SUL or NUL based on the comparison result.
  • NUL NUL
  • the UE may determine the RO resource based on the random access resource selection procedure (S1305) and perform msg.1 preamble transmission. (S1310) Then, an additional random access procedure may be performed. (S1311).
  • a case where SUL is selected may be considered.
  • the SUL may be determined by comparing RSRP values of DL pathloss references.
  • the terminal may perform random access resource selection. That is, as described above, the UE may determine an available RO for msg.1 preamble transmission on one selected carrier. Next, the UE may perform channel access on the selected UL carrier (S1307). That is, the UE performs an LBT procedure to perform preamble transmission on the determined RO, and checks whether the channel is occupied based on this. Can be.
  • the terminal msg. 1 preamble transmission may be performed (S1309), and then a random access procedure may be performed (S1310).
  • the LBT counter LC parameter may be newly defined and is not limited to the above-described embodiment. That is, the LBT counter parameter can be used to determine the carrier and RO to perform the next LBT.
  • the LBT counter value may be increased by one.
  • the UE may prepare to perform the next LBT by selecting the next available RO of the selected UL carrier.
  • the UE may determine that the channel state of the selected UL carrier is busy, and may attempt to change to another UL carrier (S1304).
  • determining whether to change the carrier may be performed through at least one of an LBT counter, channel measurement information of the terminal, and a downlink channel access procedure.
  • channel measurement information of the terminal such as channel occupancy measurement information and / or RSSI measurement information, may be used to determine whether to change the carrier.
  • the determination of whether to change the carrier may be performed based on whether the uplink channel is shared through the downlink channel access procedure, as described above.
  • the determination of whether to change the carrier may be performed using any one of an LBT counter, channel measurement information of the terminal, and downlink channel access procedures.
  • the determination of whether to change the carrier may be performed by determining some or all of the above-mentioned information in a complex manner, and is not limited to the above-described embodiment.
  • the carrier change may be changed between the NUL carrier and the SUL carrier.
  • the carrier change may be changed between NUL carriers.
  • the above-described situation may be equally applied between UL BWPs of each of a plurality of bandwidth parts (BWPs).
  • the UL BWP to preferentially perform the LBT may be selected in consideration of channel conditions between specific UL BWPs.
  • another UL BWP may try the LBT procedure again. That is, the LBT procedure may be sequentially performed even in an environment in which a plurality of UL BWPs exist. For example, when determining whether to change the UL BWP as described above, at least one or more of an LBT counter, channel measurement information of the UE, and a downlink channel access procedure may be utilized, as described above.
  • the switched UL carrier is a SUL
  • the SUL since the SUL is in a licensed band, the LBT procedure is not necessary, and thus msg.1 preamble transmission may be performed immediately after the determined RO.
  • UL carrier switching may be immediately performed, and the present invention is not limited thereto.
  • the RACH carrier selection method using the COR / RSSI value further considered in the above-described embodiments 1-4 is applicable to the methods existing in all the embodiments proposed in the present invention.
  • the RACH carrier selection method in the “carrier selection and PCMAX setting block” present in the methods proposed in FIGS. 11, 12, and 13 may be applied in place of the RACH carrier selection method considered in the above-described embodiments 1-4.
  • the RACH carrier selection method in the “carrier selection and PCMAX setting block” of FIGS. 6 and 10 may be applied instead of the RACH carrier selection method of the above-described embodiments 1-4.
  • the LBT operation performed in the channel access block is performed in the physical layer
  • the result performed in the physical (PHY) layer may be provided to the MAC layer and applied to the proposed methods. It is not limited to.
  • 15 is a diagram illustrating the configuration of a base station apparatus and a terminal apparatus according to the present disclosure.
  • the base station apparatus 1500 may include a processor 1510, an antenna unit 1520, a transceiver 1530, and a memory 1540.
  • the processor 1510 performs baseband related signal processing and may include an upper layer processor 1511 and a physical layer processor 1512.
  • the upper layer processor 1511 may process operations of a medium access control (MAC) layer, a radio resource control (RRC) layer, or more upper layers.
  • the physical layer processor 1512 may process operations (eg, uplink reception signal processing and downlink transmission signal processing) of a physical (PHY) layer.
  • the processor 1510 may control the overall operation of the base station apparatus 1500.
  • the antenna unit 1520 may include one or more physical antennas, and may include multiple input multiple output (MIMO) transmission and reception when a plurality of antennas are included.
  • the transceiver 1530 may include a radio frequency (RF) transmitter and an RF receiver.
  • the memory 1540 may store arithmetic processed information of the processor 1510, software, an operating system, an application, and the like related to the operation of the base station apparatus 1500, and may include components such as a buffer.
  • the processor 1510 may be configured to implement the operation of the base station in the embodiments described herein.
  • the terminal device 1550 may include a processor 1560, an antenna unit 1570, a transceiver 1580, and a memory 1590.
  • the processor 1460 performs baseband related signal processing and may include an upper layer processor 1561 and a physical layer processor 1562.
  • the upper layer processor 1561 may process operations of the MAC layer, the RRC layer, or more upper layers.
  • the physical layer processor 1562 may process an operation of the PHY layer (for example, downlink reception signal processing and uplink transmission signal processing).
  • the processor 1560 may control the overall operation of the terminal device 1550.
  • the antenna unit 1570 may include one or more physical antennas, and may support MIMO transmission / reception if the antenna unit includes a plurality of antennas.
  • the transceiver 1580 may include an RF transmitter and an RF receiver.
  • the memory 1590 may store computationally processed information of the processor 1460, software, an operating system, an application, and the like related to the operation of the terminal device 1550, and may include components such as a buffer.
  • the processor 1560 of the terminal device 1550 may be set to implement the operation of the terminal in the embodiments described in the present invention.
  • random access initialization may be performed before performing the random access procedure.
  • the processor 1570 of the terminal device 1550 may perform carrier selection in a random access initialization procedure.
  • the processor 1570 of the terminal device 1550 may perform the LBT operation in parallel for each of the SUL and the NUL in one serving cell.
  • the terminal device 1550 may operate in consideration of at least one or more of the operations of the above-described embodiments 1-1 to 1-4. It is not limited to the example.
  • the processor 1570 of the terminal device 1550 may sequentially perform LBT operations on the plurality of UL carriers as in the second embodiment.
  • the processor 1570 of the terminal device 1550 may receive, from the base station device 1500, signaling for selection of the first and second embodiments described above as in the third embodiment.
  • the processor 1570 of the terminal device 1550 may operate in consideration of a combination of license / unlicensed uplink configuration in one serving cell as in the fourth embodiment, and is not limited to the above-described embodiment. That is, the processor 1570 of the terminal device 1550 may perform operations for the above-described embodiment, and for this, at least one of the antenna unit 1562, the transceiver 1563, and the memory 1564 may be used. It may be, and is not limited to the above-described embodiment.
  • the processor 1520 of the base station apparatus 1500 may also perform an operation corresponding to the operation of the terminal apparatus 1550 described above.
  • the base station apparatus 1500 may perform a random access procedure with the terminal apparatus 1550 based on a carrier selected by the terminal apparatus 1550.
  • the base station apparatus 1500 may transmit signaling for the first and second embodiments to the terminal device 1550 as in the third embodiment.
  • the base station apparatus 1500 may perform a random access procedure by performing an operation corresponding to the operation of the terminal apparatus 1550 based on the above-described first to fourth embodiments.
  • the processor 1520 of the base station apparatus 1500 may also use at least one or more of the above-described antenna unit 1512, transceiver 1514, and memory 1516, which is not limited to the above-described embodiment.
  • Exemplary methods of the present disclosure are represented as a series of operations for clarity of description, but are not intended to limit the order in which the steps are performed, and each step may be performed simultaneously or in a different order as necessary.
  • the illustrated step may further include other steps, may include other steps except some, or may include additional other steps except some.
  • various embodiments of the present disclosure may be implemented by hardware, firmware, software, a combination thereof, or the like.
  • one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), General Purpose It may be implemented by a general processor, a controller, a microcontroller, a microprocessor, and the like.
  • the present invention can be applied in various systems.

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Abstract

La présente invention peut fournir un procédé pour effectuer une procédure d'accès aléatoire par un terminal. Le procédé de réalisation d'une procédure d'accès aléatoire par un terminal peut comprendre les étapes consistant à : déclencher un événement pour une procédure d'accès aléatoire; configurer des informations sur une procédure d'accès aléatoire; et sélectionner une porteuse pour effectuer la procédure d'accès aléatoire. Le terminal peut sélectionner au moins une porteuse parmi une porteuse NUL et une porteuse SUL et peut effectuer une procédure d'accès aléatoire sur la base de la porteuse sélectionnée.
PCT/KR2019/005639 2018-05-10 2019-05-10 Procédé d'émission ou de réception de signal dans un système nr pour une bande sans licence et appareil associé WO2019216697A1 (fr)

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CN113098670A (zh) * 2019-12-23 2021-07-09 中国电信股份有限公司 载波配置方法、装置、基站及计算机可读存储介质
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Publication number Priority date Publication date Assignee Title
US20220150964A1 (en) * 2018-08-09 2022-05-12 Ofinno, Llc Listen Before Talk Procedure and Uplink Switching
US11743942B2 (en) * 2018-08-09 2023-08-29 Ofinno, Llc Listen before talk procedure and uplink switching
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CN113098670B (zh) * 2019-12-23 2023-03-21 中国电信股份有限公司 载波配置方法、装置、基站及计算机可读存储介质
CN113784420A (zh) * 2020-06-10 2021-12-10 华为技术有限公司 一种随机接入方法及终端
EP4207913A4 (fr) * 2020-08-28 2024-02-28 Zte Corp Procédé, appareil et système d'accès aléatoires, support de stockage et dispositif électronique

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