WO2020222277A1 - User terminal and wireless communication method - Google Patents

Abstract

A user terminal according to the present invention comprises: a reception unit that receives setting information for a peripheral cell at a frequency to which channel sensing is applied; and a control unit that uses the setting information and monitors downlink transmission indicating time length information pertaining to a time length of a transmission opportunity. According to one aspect of the present disclosure, appropriate communication can be performed in an unlicensed band.

Description

User terminal and wireless communication method

The present disclosure relates to a user terminal and a wireless communication method in a next-generation mobile communication system.

In the Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) has been specified for the purpose of further high-speed data rate, low latency, etc. (Non-Patent Document 1). In addition, LTE-Advanced (3GPP Rel.10-14) has been specified for the purpose of further increasing the capacity and sophistication of LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

A successor system to LTE (for example, 5th generation mobile communication system (5G), 5G plus (+), New Radio (NR), 3GPP Rel.15 or later, etc.) is also being considered.

In an existing LTE system (for example, Rel.8-12), a frequency band (licensed band), a license carrier (licensed carrier), a license component carrier (licensed CC), etc. licensed by a telecommunications carrier (operator), etc. The specifications have been made on the assumption that exclusive operation will be performed in (also called). As the license CC, for example, 800 MHz, 1.7 GHz, 2 GHz and the like are used.

Further, in an existing LTE system (for example, Rel.13), in order to expand the frequency band, a frequency band different from the above licensed band (unlicensed band, unlicensed carrier, unlicensed CC). (Also called unlicensed CC)) is supported. As the unlicensed band, for example, a 2.4 GHz band or a 5 GHz band in which Wi-Fi (registered trademark) or Bluetooth (registered trademark) can be used is assumed.

Specifically, Rel. In 13, carrier aggregation (CA) that integrates a carrier (CC) of a licensed band and a carrier (CC) of an unlicensed band is supported. Communication performed using the unlicensed band together with the license band in this way is referred to as License-Assisted Access (LAA).

In future wireless communication systems (for example, 5G, 5G +, NR, Rel.15 or later), a transmitting device (for example, a base station for downlink (DL) and a user terminal (User Equipment (UE)) for uplink (UL)). ) Is listening (Listen Before Talk (LBT), Clear Channel Assessment () to confirm the presence or absence of transmission of other devices (for example, base station, UE, Wi-Fi device, etc.) before transmitting data in the unlicensed band. CCA), carrier sense, channel sensing, or channel access procedure (also called channel access procedure)).

In order for such a wireless communication system to coexist with other systems in the unlicensed band, it is conceivable to comply with regulations, requirements, etc. in the unlicensed band.

However, if the operation in the unlicensed band is not clearly determined, proper communication may not be possible in the unlicensed band, such as the operation in a specific communication situation does not conform to the rules and the utilization efficiency of wireless resources decreases. is there.

Therefore, one of the purposes of this disclosure is to provide a user terminal and a wireless communication method for performing appropriate communication in an unlicensed band.

The user terminal according to one aspect of the present disclosure uses a receiving unit that receives setting information of peripheral cells at a frequency to which channel sensing is applied, and the setting information to show time length information regarding the time length of a transmission opportunity. It has a control unit for monitoring downlink transmission.

According to one aspect of the present disclosure, appropriate communication can be performed in the unlicensed band.

FIG. 1 is a diagram showing an example of CSMA / CA with ACK. FIG. 2 is a diagram showing an example of data collision by a hidden terminal. FIG. 3 is a diagram showing an example of CSMA / CA with RTS / CTS. FIG. 4 is a diagram showing an example of RTS / CTS in the NR-U system. 5A and 5B are diagrams showing an example of COT sharing in an unlicensed CC. FIG. 6 is a diagram showing an example of transmission prohibition based on the COT start notification signal. FIG. 7 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 8 is a diagram showing an example of the configuration of the base station according to the embodiment. FIG. 9 is a diagram showing an example of the configuration of the user terminal according to the embodiment. FIG. 10 is a diagram showing an example of the hardware configuration of the base station and the user terminal according to the embodiment.

<Collision avoidance method in unlicensed band>
In the unlicensed band (for example, 2.4 GHz band or 5 GHz band), it is assumed that a plurality of systems such as a Wi-Fi system and a system supporting LAA (LAA system) coexist. It is considered that collision avoidance and / or interference control of transmission between systems is required.

An NR system using an unlicensed band (for example, also referred to as 5G, 5G +, NR, 3GPP Rel.15 or later) may be called an NR-Unlicensed (U) system, an NR LAA system, or the like. Dual Connectivity (DC) between licensed bands and unlicensed bands, Stand-Alone (SA) of unlicensed bands, etc. may also be adopted in NR-U.

For example, in a Wi-Fi system that uses an unlicensed band, Carrier Sense Multiple Access (CSMA) / Collision Avoidance (CA) is adopted for the purpose of collision avoidance and / or interference control.

FIG. 1 is a diagram showing an example of CSMA / CA. As shown in FIG. 1, the wireless terminal C (data transmitting side) examines the signal on the communication medium (carrier sense), and even if it determines that there is no signal, it does not immediately start data transmission and waits for a predetermined time. Then send the data. This waiting time is called Distributed access Inter Frame Space (DIFS). The access point B (data receiving side) that has received the data returns an acknowledgment (ACK). In order to give priority to ACK transmission, ACK can be transmitted only by waiting for a shorter time (SIFS: Short IFS) than DIFS. The wireless terminal C (data transmitting side) repeats retransmission until ACK is received. Therefore, the access method (first access method) shown in FIG. 1 is also called CSMA / CA with ACK.

In the Wi-Fi system, for the purpose of collision avoidance and / or interference control, a transmission request (Request to Send (RTS)) is transmitted before transmission, and if the receiving device can receive it, it can be received (Clear to Send (Clear to Send). RTS / CTS that responds with CTS)) is adopted. For example, RTS / CTS is effective in avoiding data collision by a hidden terminal. When a signal from a certain node does not reach the transmitting device and reaches the receiving device, the node is called a hidden terminal (hidden node) for the transmitting device. The hidden terminal may be referred to as a node that is not detected, a node that is not sensed, and so on. Data collision by a hidden terminal may be called a hidden node problem.

FIG. 2 is a diagram showing an example of data collision by a hidden terminal. In FIG. 2, since the radio wave of the wireless terminal C does not reach the wireless terminal A, the wireless terminal A cannot detect the transmission signal from the wireless terminal C even if the carrier sense is performed before the transmission. As a result, even if the wireless terminal C is transmitting to the access point B, it is assumed that the wireless terminal A also transmits to the access point B. In this case, the transmission signals from the wireless terminals A and C may collide with each other at the access point B, and the throughput may decrease.

FIG. 3 is a diagram showing an example of CSMA / CA (CSMA / CA with RTS / CTS) with RTS / CTS. As shown in FIG. 3, when the wireless terminal C (transmitting side) confirms that there is no other transmission signal (idle) by the carrier sense in the predetermined time (DIFS) before transmission, it transmits RTS (note that FIG. In 2, the RTS does not reach the wireless terminal A (other terminal)). The RTS is preferably omni (omnidirectional) transmission. The RTS may be beamformed. When the access point B (reception side) receives the RTS from the wireless terminal C and confirms that there is no other transmission signal (idle, clear) due to the carrier sense in the predetermined time (Short Inter Frame Space (SIFS)), Send CTS. The CTS is preferably omni-transmission. The RTS may be referred to as a transmission request signal. The CTS may be referred to as a receivable signal.

In FIG. 2, since the CTS from the access point B also reaches the wireless terminal A (another device), the wireless terminal A senses that communication is being performed and postpones the transmission. Since a predetermined period (also referred to as Network Allocation Vector (NAV) or transmission prohibition period, etc.) is written in the RTS / CTS packet, the predetermined period (NAV "NAV (RTS)", CTS indicated in RTS) is described. The communication is suspended during the NAV "NAV (CTS)") shown in.

The wireless terminal C that has received the CTS from the access point B transmits data (frames) when it confirms that there is no other transmission signal (idle) by the carrier sense in the predetermined period (SIFS) before transmission. Upon receiving the data, the access point B transmits an ACK after the predetermined period (SIFS).

In FIG. 3, when the wireless terminal A, which is a hidden terminal of the wireless terminal C, detects the CTS from the access point B, the transmission is postponed, so that the collision of the transmission signals of the wireless terminals A and C at the access point B can be avoided.

In the LAA of an existing LTE system (eg, Rel.13), the data transmitter transmits data from another device (eg, base station, UE, Wi-Fi device, etc.) before transmitting the data in the unlicensed band. Listening (also called LBT, CCA, carrier sense, channel access operation, etc.) is performed to confirm the presence or absence of.

The transmitting device is, for example, a base station (for example, gNodeB, (gNB), a transmission / reception point (transmission / reception point (TRP)), a network (NW)) on the downlink (DL), and a UE on the uplink (UL). There may be. Further, the receiving device that receives the data from the transmitting device may be, for example, a UE in DL and a base station in UL.

In the LAA of an existing LTE system, the transmitter has a predetermined period of time (eg, immediately after or backoff (contention, contention,) after the detection of no other device's transmission (idle state, LBT-idle) in listening. Data transmission is started after the period (conflict) window), and when it is detected in listening that there is transmission of another device (busy state, LBT-busy), data transmission is not performed. However, even when the transmitting device transmits data based on the listening result, there is a possibility that data collision in the receiving device cannot be avoided as a result of the existence of the hidden terminal.

Therefore, in the NR-U system, it is considered to support the above-mentioned RTS / CTS in order to improve the avoidance rate of data collision in the receiving device.

FIG. 4 is a diagram showing an example of RTS / CTS in the NR-U system. In the NR-U system that supports RTS / CTS, the carrier (unlicensed carrier, unlicensed CC, LAA SCell (Secondary) of the unlicensed band before the transmitting device (base station) transmits the downlink data to the receiving device (UE). It is assumed that RTS is transmitted by (Cell) etc.).

When supporting the upstream unlicensed CC in such an NR-U system, as shown in FIG. 4, the downlink data receiving device (user terminal) may transmit the CTS using the upstream unlicensed CC. Conceivable. Instead of the upstream unlicensed CC, a TDD (Time Division Duplex, unpaired spectrum) unlicensed CC may be used.

The NR-U system may perform a carrier aggregation (CA) operation using an unlicensed CC and a licensed CC, may perform a dual connectivity (DC) operation using an unlicensed CC and a licensed CC, or may perform a dual connectivity (DC) operation. A stand-alone (SA) operation using only an unlicensed CC may be performed. CA, DC, or SA may be performed by any one system of NR and LTE. DC may be performed by at least two of NR, LTE, and other systems.

UL transmission in the unlicensed CC may be at least one of PUSCH, PUCCH, and SRS.

A node in NR-U (for example, a base station (for example, gNB), UE) acquires a transmission opportunity (Transmission Opportunity: TxOP, channel occupation (Channel Occupancy)) when the LBT result is idle (LBT-busy). However, if the LBT result is busy (LBT-busy), the transmission is not performed. The time of the transmission opportunity is called Channel Occupancy Time (COT).

The node may perform LBT in LTE LAA or receiver assisted LBT (receiver assisted LBT) as LBT (initial LBT, initial-LBT (I-LBT)) for acquiring COT. The LBT of LTE LAA in this case may be category 4.

The COT is the total time length between all transmissions within the transmission opportunity and the gap within the predetermined time, and may be less than or equal to the maximum COT (Maximum COT (MCOT)).

The number of slots m _p for determining the time to postpone transmission, the parameter CW _p indicating the contention window size, and the MCOT (T _{mcot, p} ) are the priority classes (channel) associated with base station transmission. It may be based on access priority class, LBT priority class). The base station does not transmit continuously for a period exceeding MCOT on the carrier where the transmission at the NR-U frequency is performed.

The base station that has acquired the MCOT by the LBT may perform scheduling for one or more UEs during the MCOT period.

<COT sharing>
In the NR-U system, the time of transmission opportunity (Transmission Opportunity (TxOP)) acquired by a node (base station or UE), that is, the channel occupancy time (COT) is shared among a plurality of nodes. Is being considered. The node may be either a UE or a base station, or may be a node of another system.

As a basic form of COT sharing, one-to-one communication between downlink and uplink can be assumed. For example, one-to-one communication between node A and node B can be assumed. Alternatively, as a form of COT sharing, one-to-many communication of downlink and uplink may be assumed.

5A and 5B are diagrams showing an example of COT sharing in an unlicensed CC. If node A performs LBT in an unlicensed CC and the LBT result is idle, node A acquires a transmission opportunity (TxOP) with a COT time length. In this case, node A transmits data in the unlicensed CC. The LBT performed immediately before the acquisition of the transmission opportunity (TxOP) is also called the initial LBT (Initial LBT (I-LBT)). Of the transmission opportunities (TxOP) acquired by node A, the remaining period of transmission by node A may be distributed to other nodes that can receive signals from node A.

If the gap between the node A transmission and the node B transmission is shorter than the predetermined time length (for example, 16 μs) (or less than or equal to the predetermined time length), the node B does not have to perform the LBT before the node B transmission (FIG. FIG. 5A) If the gap is greater than or equal to the predetermined time length (or longer than the predetermined time length), node B may perform LBT before node B transmission (FIG. 5B).

Node A may be a base station, and node B may be a UE.

The UE is a signal in PDCCH or group common PDCCH (group common (GC) -PDCCH) for detecting a transmission burst from a serving base station (for example, Reference Signal (RS) such as Demodulation Reference Signal (DMRS)). You may assume the existence of. The PDCCH may be a PDCCH for one UE (UE individual PDCCH, usually PDCCH (Regular PDCCH)). The GC-PDCCH may be a PDCCH common to one or more UEs (UE group common PDCCH).

The base station may transmit a specific PDCCH (PDCCH or GC-PDCCH) including a specific DMRS notifying the start of the COT at the start of the COT triggered by the base station. At least one of the specific PDCCH and the specific DMRS may be referred to as a COT start notification signal. The base station may transmit a COT start notification signal to one or more specific UEs.

The UE may recognize COT when it detects a specific DMRS.

The base station may schedule UL transmission in the COT of the UE by the specific PDCCH. UL transmission in COT is called a scheduled specific UE. The particular UE may be a UE scheduled to transmit a UL signal in the COT (eg, the first UL signal in the COT).

In NR-U, the handshake procedure between the transmitter and the receiver is being studied. It is being studied that a UE designated by a specific PDCCH realizes a handshake procedure between a base station and a UE by transmitting a specific UL signal (response signal) such as SRS after LBT.

As described above, in the NR-U, the specific PDCCH (COT start notification signal) is used as the transmission request signal (RTS), and the response signal triggered by the specific PDCCH is used as the receivable state notification signal (CTS). As a result, access methods close to CSMA / CA with RTS / CTS (receiver assisted access (RAA), handshake procedure, access method using RTS / CTS, second access method) are being studied.

However, even if the specific UE transmits a response signal, the peripheral node may transmit it in the COT, and the specific UE may receive interference from the hidden terminal in the reception operation in the COT.

Therefore, the present inventors have conceived a method in which the nodes of the neighbor cells recognize the COT at the start of the COT of a certain cell in the unlicensed band.

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. The wireless communication methods according to each embodiment may be applied individually or in combination.

In the present disclosure, frequency, band, frequency band, spectrum, carrier, component carrier (CC), cell, channel, subband, LBT subband, active bandwidth part (BWP), and active BWP part may be read as each other. Good.

In the present disclosure, listening, Listen Before Talk (LBT), Clear Channel Assessment (CCA), carrier sense, sensing, channel sensing, or channel access procedure may be read interchangeably.

In the present disclosure, NR-U frequency, NR-U target frequency, NR-U band, shared spectrum, unlicensed band, unlicensed spectrum, LAA SCell, LAA cell, primary cell (Primary Cell ( PCell), Primary Secondary Cell (PSCell), Special Cell (SpCell)), secondary cell (Secondary Cell (SCell)), and frequency band to which channel sensing is applied may be read as each other.

In the present disclosure, NR frequency, NR target frequency, licensed band, license spectrum, PCell, PSCell, SpCell, SCell, non-NR-U frequency, Rel. 15, NR, and frequency bands to which channel sensing is not applied may be read interchangeably.

Different frame structures may be used for the NR-U target frequency and the NR target frequency.

The wireless communication system (NR-U, LAA system) may be compliant with the first wireless communication standard (for example, NR, LTE, etc.) (supports the first wireless communication standard).

Other systems (coexistence system, coexistence device) coexisting with this wireless communication system and other wireless communication devices (coexistence device) include LTE, Wi-Fi, Bluetooth (registered trademark), WiGig (registered trademark), and wireless Local Area. It may be compliant with the second wireless communication standard (supporting the second wireless communication standard) different from the first wireless communication standard, such as Network (LAN), IEEE802.11, Low Power Wide Area (LPWA), or the first. It may support wireless communication standards. The coexistence system may be a system that receives interference from the wireless communication system, or may be a system that interferes with the wireless communication system.

In the present disclosure, UE transmission, UL transmission, UL signal, physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), sounding reference signal (SRS), uplink (UL) -reference signal (RS), preamble, The random access channel (RACH) and the physical random access channel (PRACH) may be read as each other.

In the present disclosure, base station transmission, DL transmission, DL signal, physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), downlink (DL) -reference signal (RS), degradation reference signal (DMRS) for PDCCH. , DMRS for PDSCH, may be read as each other.

In the present disclosure, nodes, UEs, base stations, transmission / reception points (Transmission / Reception Point (TRP)), wireless communication devices, and devices may be read as each other.

Further, the NR-U of the present disclosure is not limited to LAA, and may include a case where an unlicensed band is used standalone.

(Wireless communication method)
<Embodiment 1>
The base station that has acquired the COT may transmit a COT start notification signal (for example, downlink transmission) indicating information about the COT (time length information). Information about COT includes COT (COT length (duration)), maximum COT (Maximum COT (MCOT), MCOT length), COT structure, LBT priority class, and contention window size. At least one may be indicated.

The COT start notification signal may include GC-PDCCH, PDCCH, or DMRS. The COT start notification signal may include information on scheduling transmission (UL or DL) within the COT. A particular field in the DCI in the COT start notification signal may indicate information about the COT length. Specific fields are described in Rel. It may be a new field not specified in 15, or it may be a replacement of an existing field.

The base station in the first cell may notify at least one of the base station and the UE in the peripheral cell (second cell) of the setting information used for receiving the COT start notification signal. The setting information includes the cell identifier (ID) of the first cell, the temporary wireless network identifier (radio network temporary Identifier (RNTI)) used for the COT start notification signal, and the public land mobile network (Public Land Mobile Network) of the first cell. (PLMN)) It may contain at least one of an identifier (ID). The PLMN ID may be based on at least one identification of the network and the operator. The COT start notification signal may include a DCI having a Cyclic Redundancy Check (CRC) scrambled by the RNTI indicated in the setting information.

RNTI is Rel. It may be a new RNTI not specified in 15, or an existing RNTI.

RNTI may be different depending on at least one of the cell, network and operator.

For example, the base station in the first cell may notify at least one of the base station and the UE in the second cell of the setting information by RRC signaling. The base station in the second cell may transmit the setting information received from the base station in the first cell to the UE in the second cell. For example, the base station in the second cell may notify the UE connected to the second cell of the setting information by RRC signaling.

Each node may be notified of the setting information for receiving the COT start notification signal from its own cell (serving cell) and the setting information for receiving the COT start notification signal from neighboring cells.

The base station may notify a plurality of peripheral cells of the setting information for receiving the COT start notification signal of its own cell. The node may be notified of the setting information from a plurality of peripheral cells.

At least a part of the setting information for receiving the COT start notification signal from the own cell and at least a part of the setting information for receiving the COT start notification signal from the peripheral cells may be different.

The RNTI used for the COT start notification signal from the peripheral cells may be different from the RNTI in the setting information for the own cell. The node may monitor the COT start notification signal using these RNTIs and recognize whether the detected COT start notification signal is transmitted from its own cell or a peripheral cell by the RNTI that succeeds in detection.

Even if the node monitors the COT start notification signal using a plurality of cell IDs and recognizes whether the detected COT start notification signal is transmitted from its own cell or a neighboring cell by the cell ID that has been successfully detected. Good.

At least a part of the setting information for receiving the COT start notification signal from the own cell and at least a part of the setting information for receiving the COT start notification signal from the peripheral cells may be the same.

The RNTI used for the COT start notification signal from the peripheral cells may be the same as the RNTI in the setting information for the own cell. The node may decode the DCI included in the COT start notification signal, and may recognize whether the detected COT start notification signal is transmitted from its own cell or a peripheral cell based on the decoded DCI.

Each node in the first cell and the second cell may monitor the COT start notification signal using the setting information. By notifying the node of the second cell of the setting information, the node of the second cell can also receive (monitor, decode) the COT start notification signal of the first cell.

If the setting information is common to the NR-U system, it is possible that the monitoring of the COT start notification signal cannot be operated flexibly and the confidentiality becomes low. On the other hand, by notifying the setting information in advance, the monitoring of the COT start notification signal can be flexibly operated and the confidentiality can be improved.

When the node in the second cell receives the COT start notification signal, the node receives the COT start notification signal within the period (COT) from the reception of the COT start notification signal to the COT length indicated by the COT start notification signal. LBT may not be performed or signal transmission may not be performed in the band based on. The band based on the COT start notification signal may be the frequency of the COT start notification signal, or may be a band including the COT start notification signal (CC, LBT band (LBT subband), etc.). , The band may be the band scheduled by the COT start notification signal.

When the node in the second cell receives the COT start notification signal, the node receives the COT start notification signal within the period (COT) from the reception of the COT start notification signal to the COT length indicated by the COT start notification signal. It is not necessary to perform monitoring in the band based on. This monitoring is performed on the COT start notification signal of the first cell, the COT start notification signal of the second cell, the downlink control channel (at least one of GC-PDCCH, PDCCH, and DMRS) of the first cell, and the second cell. At least one monitoring of the downlink control channel (at least one of GC-PDCCH, PDCCH, DMRS) may be performed.

In the example of FIG. 6, the node A of the first cell that has acquired the COT transmits a COT start notification signal (for example, GC-PDCCH) indicating the COT length. Node A may schedule node A transmission (eg, PDSCH) and node B transmission (eg, PUSCH) in the same first cell. Node B may perform scheduled transmission after node A transmission.

Node C, which has received the COT start notification signal in the second cell, does not have to perform at least one of LBT, signal transmission, and monitoring in the band based on the COT start notification signal in the COT based on the COT start notification signal. Good.

When the UE in the second cell receives the COT start notification signal from the first cell, it may perform power saving (for example, sleep) in the COT based on the COT start notification signal.

By notifying the nodes of the first cell and the second cell of the information about the COT of the first cell, it is possible to prevent (prohibit) the transmission of the unscheduled node in the COT, and the interference can be reduced.

According to the above-described first embodiment, it is possible to reduce the probability of arrival of an interference wave from a peripheral cell in the COT of a certain cell. It is possible to avoid reception failure due to interference from peripheral cells, and it is possible to improve the efficiency of wireless resource utilization. By reducing the frequency of monitoring UEs in peripheral cells, the power consumption of the UEs can be reduced.

(Wireless communication system)
Hereinafter, the configuration of the wireless communication system according to the embodiment of the present disclosure will be described. In this wireless communication system, communication is performed using any one of the wireless communication methods according to each of the above-described embodiments of the present disclosure or a combination thereof.

FIG. 7 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE), 5th generation mobile communication system New Radio (5G NR), etc. specified by Third Generation Partnership Project (3GPP). ..

Further, the wireless communication system 1 may support dual connectivity between a plurality of Radio Access Technology (RAT) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC is a dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), and a dual connectivity between NR and LTE (NR-E). -UTRA Dual Connectivity (NE-DC)) may be included.

In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is MN, and the LTE (E-UTRA) base station (eNB) is SN.

The wireless communication system 1 has dual connectivity between a plurality of base stations in the same RAT (for example, dual connectivity (NR-NR Dual Connectivity (NN-DC)) in which both MN and SN are NR base stations (gNB). )) May be supported.

The wireless communication system 1 includes a base station 11 that forms a macro cell C1 having a relatively wide coverage, and a base station 12 (12a-12c) that is arranged in the macro cell C1 and forms a small cell C2 that is narrower than the macro cell C1. You may prepare. The user terminal 20 may be located in at least one cell. The arrangement, number, and the like of each cell and the user terminal 20 are not limited to the mode shown in the figure. Hereinafter, when the base stations 11 and 12 are not distinguished, they are collectively referred to as the base station 10.

The user terminal 20 may be connected to at least one of the plurality of base stations 10. The user terminal 20 may use at least one of carrier aggregation (Carrier Aggregation (CA)) and dual connectivity (DC) using a plurality of component carriers (Component Carrier (CC)).

Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1 and the small cell C2 may be included in FR2. For example, FR1 may be in a frequency band of 6 GHz or less (sub 6 GHz (sub-6 GHz)), and FR2 may be in a frequency band higher than 24 GHz (above-24 GHz). The frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a frequency band higher than FR2.

Further, the user terminal 20 may perform communication using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

The plurality of base stations 10 may be connected by wire (for example, optical fiber compliant with Common Public Radio Interface (CPRI), X2 interface, etc.) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, the base station 11 corresponding to the host station is an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to a relay station (relay) is IAB. It may be called a node.

The base station 10 may be connected to the core network 30 via another base station 10 or directly. The core network 30 may include at least one such as Evolved Packet Core (EPC), 5G Core Network (5GCN), and Next Generation Core (NGC).

The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

In the wireless communication system 1, a wireless access method based on Orthogonal Frequency Division Multiplexing (OFDM) may be used. For example, at least one of the downlink (Downlink (DL)) and the uplink (Uplink (UL)), Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple. Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), etc. may be used.

The wireless access method may be called a waveform. In the wireless communication system 1, another wireless access system (for example, another single carrier transmission system, another multi-carrier transmission system) may be used as the UL and DL wireless access systems.

In the wireless communication system 1, as downlink channels, downlink shared channels (Physical Downlink Shared Channel (PDSCH)), broadcast channels (Physical Broadcast Channel (PBCH)), and downlink control channels (Physical Downlink Control) shared by each user terminal 20 are used. Channel (PDCCH)) and the like may be used.

Further, in the wireless communication system 1, as the uplink channel, the uplink shared channel (Physical Uplink Shared Channel (PUSCH)), the uplink control channel (Physical Uplink Control Channel (PUCCH)), and the random access channel shared by each user terminal 20 are used. (Physical Random Access Channel (PRACH)) or the like may be used.

User data, upper layer control information, System Information Block (SIB), etc. are transmitted by PDSCH. User data, upper layer control information, and the like may be transmitted by the PUSCH. In addition, Master Information Block (MIB) may be transmitted by PBCH.

Lower layer control information may be transmitted by PDCCH. The lower layer control information may include, for example, downlink control information (Downlink Control Information (DCI)) including scheduling information of at least one of PDSCH and PUSCH.

The DCI that schedules PDSCH may be called DL assignment, DL DCI, etc., and the DCI that schedules PUSCH may be called UL grant, UL DCI, etc. The PDSCH may be read as DL data, and the PUSCH may be read as UL data.

A control resource set (COntrol REsource SET (CORESET)) and a search space (search space) may be used to detect the PDCCH. CORESET corresponds to a resource that searches for DCI. The search space corresponds to the search area and search method of PDCCH candidates (PDCCH candidates). One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a search space based on the search space settings.

One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. The "search space", "search space set", "search space setting", "search space set setting", "CORESET", "CORESET setting", etc. of the present disclosure may be read as each other.

Depending on the PUCCH, channel state information (Channel State Information (CSI)), delivery confirmation information (for example, it may be called Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.) and scheduling request (Scheduling Request ( Uplink Control Information (UCI) including at least one of SR)) may be transmitted. The PRACH may transmit a random access preamble for establishing a connection with the cell.

In this disclosure, downlinks, uplinks, etc. may be expressed without "links". Further, it may be expressed without adding "Physical" at the beginning of various channels.

In the wireless communication system 1, a synchronization signal (Synchronization Signal (SS)), a downlink reference signal (Downlink Reference Signal (DL-RS)), and the like may be transmitted. In the wireless communication system 1, the DL-RS includes a cell-specific reference signal (Cell-specific Reference Signal (CRS)), a channel state information reference signal (Channel State Information Reference Signal (CSI-RS)), and a demodulation reference signal (DeModulation). Reference Signal (DMRS)), positioning reference signal (Positioning Reference Signal (PRS)), phase tracking reference signal (Phase Tracking Reference Signal (PTRS)), and the like may be transmitted.

The synchronization signal may be, for example, at least one of a primary synchronization signal (Primary Synchronization Signal (PSS)) and a secondary synchronization signal (Secondary Synchronization Signal (SSS)). The signal block including SS (PSS, SSS) and PBCH (and DMRS for PBCH) may be referred to as SS / PBCH block, SS Block (SSB) and the like. In addition, SS, SSB and the like may also be called a reference signal.

Further, in the wireless communication system 1, even if a measurement reference signal (Sounding Reference Signal (SRS)), a demodulation reference signal (DMRS), or the like is transmitted as an uplink reference signal (Uplink Reference Signal (UL-RS)). Good. The DMRS may be called a user terminal specific reference signal (UE-specific Reference Signal).

(base station)
FIG. 8 is a diagram showing an example of the configuration of the base station according to the embodiment. The base station 10 includes a control unit 110, a transmission / reception unit 120, a transmission / reception antenna 130, and a transmission line interface 140. The control unit 110, the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission line interface 140 may each be provided with one or more.

Note that, in this example, the functional blocks of the feature portion in the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. A part of the processing of each part described below may be omitted.

The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, a control circuit, and the like described based on the common recognition in the technical field according to the present disclosure.

The control unit 110 may control signal generation, scheduling (for example, resource allocation, mapping) and the like. The control unit 110 may control transmission / reception, measurement, and the like using the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission line interface 140. The control unit 110 may generate data to be transmitted as a signal, control information, a sequence, and the like, and transfer the data to the transmission / reception unit 120. The control unit 110 may perform call processing (setting, release, etc.) of the communication channel, state management of the base station 10, management of radio resources, and the like.

The transmission / reception unit 120 may include a baseband unit 121, a Radio Frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transmission / reception unit 120 includes a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmission / reception circuit, and the like, which are described based on common recognition in the technical fields according to the present disclosure. be able to.

The transmission / reception unit 120 may be configured as an integrated transmission / reception unit, or may be composed of a transmission unit and a reception unit. The transmission unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiving unit may be composed of a receiving processing unit 1212, an RF unit 122, and a measuring unit 123.

The transmitting / receiving antenna 130 can be composed of an antenna described based on common recognition in the technical field according to the present disclosure, for example, an array antenna.

The transmission / reception unit 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, and the like. The transmission / reception unit 120 may receive the above-mentioned uplink channel, uplink reference signal, and the like.

The transmission / reception unit 120 may form at least one of a transmission beam and a reception beam by using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), and the like.

The transmission / reception unit 120 (transmission processing unit 1211) processes, for example, Packet Data Convergence Protocol (PDCP) layer processing and Radio Link Control (RLC) layer processing (for example, RLC) for data, control information, etc. acquired from control unit 110. RLC retransmission control), Medium Access Control (MAC) layer processing (for example, HARQ retransmission control), etc. may be performed to generate a bit string to be transmitted.

The transmission / reception unit 120 (transmission processing unit 1211) performs channel coding (may include error correction coding), modulation, mapping, filtering, and discrete Fourier transform (Discrete Fourier Transform (DFT)) for the bit string to be transmitted. The base band signal may be output by performing processing (if necessary), inverse fast Fourier transform (IFFT) processing, precoding, digital-analog transform, and other transmission processing.

The transmission / reception unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to the radio frequency band, and transmit the signal in the radio frequency band via the transmission / reception antenna 130. ..

On the other hand, the transmission / reception unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, or the like on the signal in the radio frequency band received by the transmission / reception antenna 130.

The transmission / reception unit 120 (reception processing unit 1212) performs analog-digital transformation, fast Fourier transform (FFT) processing, and inverse discrete Fourier transform (IDFT) on the acquired baseband signal. )) Processing (if necessary), filtering, demapping, demodulating, decoding (may include error correction decoding), MAC layer processing, RLC layer processing, PDCP layer processing, and other reception processing are applied. User data and the like may be acquired.

The transmission / reception unit 120 (measurement unit 123) may perform measurement on the received signal. For example, the measuring unit 123 may perform Radio Resource Management (RRM) measurement, Channel State Information (CSI) measurement, or the like based on the received signal. The measuring unit 123 has received power (for example, Reference Signal Received Power (RSRP)) and reception quality (for example, Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)). , Signal strength (for example, Received Signal Strength Indicator (RSSI)), propagation path information (for example, CSI), and the like may be measured. The measurement result may be output to the control unit 110.

The transmission line interface 140 transmits and receives signals (backhaul signaling) to and from devices included in the core network 30, other base stations 10, and the like, and provides user data (user plane data) and control plane for the user terminal 20. Data or the like may be acquired or transmitted.

The transmitter and receiver of the base station 10 in the present disclosure may be composed of at least one of the transmitter / receiver 120 and the transmitter / receiver antenna 130.

(User terminal)
FIG. 9 is a diagram showing an example of the configuration of the user terminal according to the embodiment. The user terminal 20 includes a control unit 210, a transmission / reception unit 220, and a transmission / reception antenna 230. The control unit 210, the transmission / reception unit 220, and the transmission / reception antenna 230 may each be provided with one or more.

Note that this example mainly shows the functional blocks of the feature portion in the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. A part of the processing of each part described below may be omitted.

The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, a control circuit, and the like described based on the common recognition in the technical field according to the present disclosure.

The control unit 210 may control signal generation, mapping, and the like. The control unit 210 may control transmission / reception, measurement, and the like using the transmission / reception unit 220 and the transmission / reception antenna 230. The control unit 210 may generate data to be transmitted as a signal, control information, a sequence, and the like, and transfer the data to the transmission / reception unit 220.

The transmission / reception unit 220 may include a baseband unit 221 and an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transmission / reception unit 220 can be composed of a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmission / reception circuit, and the like, which are described based on the common recognition in the technical field according to the present disclosure.

The transmission / reception unit 220 may be configured as an integrated transmission / reception unit, or may be composed of a transmission unit and a reception unit. The transmission unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a receiving processing unit 2212, an RF unit 222, and a measuring unit 223.

The transmitting / receiving antenna 230 can be composed of an antenna described based on common recognition in the technical field according to the present disclosure, for example, an array antenna.

The transmission / reception unit 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, and the like. The transmission / reception unit 220 may transmit the above-mentioned uplink channel, uplink reference signal, and the like.

The transmission / reception unit 220 may form at least one of a transmission beam and a reception beam by using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), and the like.

The transmission / reception unit 220 (transmission processing unit 2211) performs PDCP layer processing, RLC layer processing (for example, RLC retransmission control), and MAC layer processing (for example, for data, control information, etc. acquired from the control unit 210). , HARQ retransmission control), etc., to generate a bit string to be transmitted.

The transmission / reception unit 220 (transmission processing unit 2211) performs channel coding (may include error correction coding), modulation, mapping, filtering processing, DFT processing (if necessary), and IFFT processing for the bit string to be transmitted. , Precoding, digital-to-analog conversion, and other transmission processing may be performed to output the baseband signal.

Whether or not to apply the DFT process may be based on the transform precoding setting. The transmission / reception unit 220 (transmission processing unit 2211) described above for transmitting a channel (for example, PUSCH) using the DFT-s-OFDM waveform when the transform precoding is enabled. The DFT process may be performed as the transmission process, and if not, the DFT process may not be performed as the transmission process.

The transmission / reception unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. to the radio frequency band on the baseband signal, and transmit the signal in the radio frequency band via the transmission / reception antenna 230. ..

On the other hand, the transmission / reception unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, or the like on the signal in the radio frequency band received by the transmission / reception antenna 230.

The transmission / reception unit 220 (reception processing unit 2212) performs analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering processing, demapping, demodulation, and decoding (error correction) for the acquired baseband signal. Decoding may be included), MAC layer processing, RLC layer processing, PDCP layer processing, and other reception processing may be applied to acquire user data and the like.

The transmission / reception unit 220 (measurement unit 223) may perform measurement on the received signal. For example, the measuring unit 223 may perform RRM measurement, CSI measurement, or the like based on the received signal. The measuring unit 223 may measure received power (for example, RSRP), reception quality (for example, RSRQ, SINR, SNR), signal strength (for example, RSSI), propagation path information (for example, CSI), and the like. The measurement result may be output to the control unit 210.

The transmission unit and the reception unit of the user terminal 20 in the present disclosure may be composed of at least one of the transmission / reception unit 220, the transmission / reception antenna 230, and the transmission line interface 240.

The transmission / reception unit 220 may receive setting information of peripheral cells at a frequency to which channel sensing is applied (for example, NR-U frequency). The control unit 210 may monitor the downlink transmission (for example, a COT start notification signal) indicating the time length information regarding the time length (for example, COT length) of the transmission opportunity by using the setting information.

The control unit 210 does not have to perform transmission at the frequency during the period from the reception of the downlink transmission to the time length.

The control unit 210 does not have to perform monitoring at the frequency during the period from the reception of the downlink transmission to the time length.

The setting information may include at least one of the cell identifier of the peripheral cell, the wireless network temporary identifier (RNTI), and the public land mobile network (PLMN) identifier.

The downlink transmission may be a group common physical downlink control channel (GC-PDCCH).

(Hardware configuration)
The block diagram used in the description of the above embodiment shows a block of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized by using one device that is physically or logically connected, or directly or indirectly (for example, by two or more devices that are physically or logically separated). , Wired, wireless, etc.) and may be realized using these plurality of devices. The functional block may be realized by combining the software with the one device or the plurality of devices.

Here, the functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and deemed. , Broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc. Not limited. For example, a functional block (constituent unit) for functioning transmission may be referred to as a transmitting unit (transmitting unit), a transmitter (transmitter), or the like. As described above, the method of realizing each of them is not particularly limited.

For example, the base station, user terminal, and the like in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. FIG. 10 is a diagram showing an example of the hardware configuration of the base station and the user terminal according to the embodiment. The base station 10 and the user terminal 20 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like. ..

In the present disclosure, the terms of devices, circuits, devices, sections, units, etc. can be read as each other. The hardware configuration of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured not to include some of the devices.

For example, although only one processor 1001 is shown, there may be a plurality of processors. Further, the processing may be executed by one processor, or the processing may be executed simultaneously, sequentially, or by using other methods by two or more processors. The processor 1001 may be mounted by one or more chips.

For each function of the base station 10 and the user terminal 20, for example, by loading predetermined software (program) on hardware such as the processor 1001 and the memory 1002, the processor 1001 performs an operation and communicates via the communication device 1004. It is realized by controlling at least one of reading and writing of data in the memory 1002 and the storage 1003.

The processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, registers, and the like. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), and the like may be realized by the processor 1001.

Further, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and operating in the processor 1001, and may be realized in the same manner for other functional blocks.

The memory 1002 is a computer-readable recording medium, for example, at least a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically EPROM (EEPROM), a Random Access Memory (RAM), or any other suitable storage medium. It may be composed of one. The memory 1002 may be referred to as a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, or the like that can be executed to implement the wireless communication method according to the embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, for example, a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (for example, a compact disc (Compact Disc ROM (CD-ROM)), a digital versatile disk, etc.). At least one of Blu-ray® disks, removable disks, hard disk drives, smart cards, flash memory devices (eg cards, sticks, key drives), magnetic stripes, databases, servers, and other suitable storage media. It may be composed of. The storage 1003 may be referred to as an auxiliary storage device.

The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to realize at least one of frequency division duplex (Frequency Division Duplex (FDD)) and time division duplex (Time Division Duplex (TDD)). It may be configured to include. For example, the transmission / reception unit 120 (220), the transmission / reception antenna 130 (230), and the like described above may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be physically or logically separated from the transmission unit 120a (220a) and the reception unit 120b (220b).

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a Light Emitting Diode (LED) lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

Further, each device such as the processor 1001 and the memory 1002 is connected by the bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using a different bus for each device.

Further, the base station 10 and the user terminal 20 include a microprocessor, a digital signal processor (Digital Signal Processor (DSP)), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), and the like. It may be configured to include hardware, and a part or all of each functional block may be realized by using the hardware. For example, processor 1001 may be implemented using at least one of these hardware.

(Modification example)
The terms described in the present disclosure and the terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, channels, symbols and signals (signals or signaling) may be read interchangeably. Also, the signal may be a message. The reference signal can also be abbreviated as RS, and may be called a pilot, a pilot signal, or the like depending on the applied standard. Further, the component carrier (Component Carrier (CC)) may be referred to as a cell, a frequency carrier, a carrier frequency, or the like.

The wireless frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting the wireless frame may be referred to as a subframe. Further, the subframe may be composed of one or more slots in the time domain. The subframe may have a fixed time length (eg, 1 ms) that is independent of numerology.

Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel. Numerology includes, for example, subcarrier spacing (SubCarrier Spacing (SCS)), bandwidth, symbol length, cyclic prefix length, transmission time interval (Transmission Time Interval (TTI)), number of symbols per TTI, and wireless frame configuration. , A specific filtering process performed by the transmitter / receiver in the frequency domain, a specific windowing process performed by the transmitter / receiver in the time domain, and the like may be indicated.

The slot may be composed of one or more symbols (Orthogonal Frequency Division Multiple Access (OFDMA) symbol, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time domain. In addition, the slot may be a time unit based on numerology.

The slot may include a plurality of mini slots. Each minislot may consist of one or more symbols in the time domain. Further, the mini slot may be called a sub slot. A minislot may consist of a smaller number of symbols than the slot. A PDSCH (or PUSCH) transmitted in time units larger than the minislot may be referred to as a PDSCH (PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the minislot may be referred to as PDSCH (PUSCH) mapping type B.

The wireless frame, subframe, slot, minislot and symbol all represent the time unit when transmitting a signal. The radio frame, subframe, slot, minislot and symbol may have different names corresponding to each. The time units such as frames, subframes, slots, mini slots, and symbols in the present disclosure may be read as each other.

For example, one subframe may be called TTI, a plurality of consecutive subframes may be called TTI, and one slot or one minislot may be called TTI. That is, at least one of the subframe and TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (eg, 1-13 symbols), or a period longer than 1 ms. It may be. The unit representing TTI may be called a slot, a mini slot, or the like instead of a subframe.

Here, TTI refers to, for example, the minimum time unit of scheduling in wireless communication. For example, in the LTE system, the base station schedules each user terminal to allocate radio resources (frequency bandwidth that can be used in each user terminal, transmission power, etc.) in TTI units. The definition of TTI is not limited to this.

The TTI may be a transmission time unit such as a channel-encoded data packet (transport block), a code block, or a code word, or may be a processing unit such as scheduling or link adaptation. When a TTI is given, the time interval (for example, the number of symbols) to which the transport block, code block, code word, etc. are actually mapped may be shorter than the TTI.

When one slot or one mini slot is called TTI, one or more TTIs (that is, one or more slots or one or more mini slots) may be the minimum time unit for scheduling. Further, the number of slots (number of mini-slots) constituting the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be referred to as a normal TTI (TTI in 3GPP Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, or the like. TTIs shorter than normal TTIs may be referred to as shortened TTIs, short TTIs, partial TTIs (partial or fractional TTIs), shortened subframes, short subframes, minislots, subslots, slots, and the like.

The long TTI (for example, normal TTI, subframe, etc.) may be read as a TTI having a time length of more than 1 ms, and the short TTI (for example, shortened TTI, etc.) is less than the TTI length of the long TTI and 1 ms. It may be read as a TTI having the above TTI length.

A resource block (Resource Block (RB)) is a resource allocation unit in the time domain and the frequency domain, and may include one or a plurality of continuous subcarriers in the frequency domain. The number of subcarriers contained in the RB may be the same regardless of the numerology, and may be, for example, 12. The number of subcarriers contained in the RB may be determined based on numerology.

Further, the RB may include one or more symbols in the time domain, and may have a length of 1 slot, 1 mini slot, 1 subframe or 1 TTI. Each 1TTI, 1 subframe, etc. may be composed of one or a plurality of resource blocks.

In addition, one or more RBs are a physical resource block (Physical RB (PRB)), a sub-carrier group (Sub-Carrier Group (SCG)), a resource element group (Resource Element Group (REG)), a PRB pair, and an RB. It may be called a pair or the like.

Further, the resource block may be composed of one or a plurality of resource elements (Resource Element (RE)). For example, 1RE may be a radio resource area of 1 subcarrier and 1 symbol.

Bandwidth Part (BWP) (which may also be called partial bandwidth) represents a subset of consecutive common resource blocks (RBs) for a neurology in a carrier. May be good. Here, the common RB may be specified by the index of the RB with respect to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

The BWP may include UL BWP (BWP for UL) and DL BWP (BWP for DL). One or more BWPs may be set in one carrier for the UE.

At least one of the configured BWPs may be active, and the UE may not expect to send or receive a given signal / channel outside the active BWP. In addition, "cell", "carrier" and the like in this disclosure may be read as "BWP".

Note that the above-mentioned structures such as wireless frames, subframes, slots, mini slots, and symbols are merely examples. For example, the number of subframes contained in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots contained within a slot, the number of symbols and RBs contained in a slot or minislot, included in the RB. The number of subcarriers, the number of symbols in the TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

In addition, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values from predetermined values, or using other corresponding information. It may be represented. For example, radio resources may be indicated by a given index.

The names used for parameters, etc. in this disclosure are not limited in any respect. Further, mathematical formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not limiting in any way. ..

The information, signals, etc. described in this disclosure may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

In addition, information, signals, etc. can be output from the upper layer to the lower layer and from the lower layer to at least one of the upper layers. Information, signals, etc. may be input / output via a plurality of network nodes.

The input / output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input / output information, signals, etc. can be overwritten, updated, or added. The output information, signals, etc. may be deleted. The input information, signals, etc. may be transmitted to other devices.

The notification of information is not limited to the mode / embodiment described in the present disclosure, and may be performed by using another method. For example, the notification of information in the present disclosure includes physical layer signaling (for example, downlink control information (DCI)), uplink control information (Uplink Control Information (UCI))), and higher layer signaling (for example, Radio Resource Control). (RRC) signaling, broadcast information (master information block (MIB), system information block (SIB), etc.), medium access control (MAC) signaling), other signals or combinations thereof May be carried out by.

Note that the physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), and the like. Further, the RRC signaling may be called an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration) message, or the like. Further, MAC signaling may be notified using, for example, a MAC control element (MAC Control Element (CE)).

In addition, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit notification, but implicitly (for example, by not notifying the predetermined information or another information). May be done (by notification of).

The determination may be made by a value represented by 1 bit (0 or 1), or by a boolean value represented by true or false. , May be done by numerical comparison (eg, comparison with a given value).

Software is an instruction, instruction set, code, code segment, program code, program, subprogram, software module, whether called software, firmware, middleware, microcode, hardware description language, or another name. , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc. should be broadly interpreted to mean.

In addition, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, a website where software uses at least one of wired technology (coaxial cable, fiber optic cable, twist pair, digital subscriber line (DSL), etc.) and wireless technology (infrared, microwave, etc.). When transmitted from a server, or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

The terms "system" and "network" used in this disclosure may be used interchangeably. "Network" may mean a device (eg, a base station) included in the network.

In the present disclosure, "precoding", "precoder", "weight (precoding weight)", "pseudo-colocation (Quasi-Co-Location (QCL))", "Transmission Configuration Indication state (TCI state)", "space". "Spatial relation", "spatial domain filter", "transmission power", "phase rotation", "antenna port", "antenna port group", "layer", "number of layers", Terms such as "rank", "resource", "resource set", "resource group", "beam", "beam width", "beam angle", "antenna", "antenna element", "panel" are compatible. Can be used for

In the present disclosure, "base station (BS)", "wireless base station", "fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "Access point", "Transmission point (Transmission Point (TP))", "Reception point (Reception Point (RP))", "Transmission / reception point (Transmission / Reception Point (TRP))", "Panel" , "Cell", "sector", "cell group", "carrier", "component carrier" and the like can be used interchangeably. Base stations are sometimes referred to by terms such as macrocells, small cells, femtocells, and picocells.

The base station can accommodate one or more (for example, three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a small indoor base station (Remote Radio)). Communication services can also be provided by Head (RRH))). The term "cell" or "sector" refers to part or all of the coverage area of at least one of the base stations and base station subsystems that provide communication services in this coverage.

In this disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" are used interchangeably. Can be done.

Mobile stations include subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals. , Handset, user agent, mobile client, client or some other suitable term.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, or the like. At least one of the base station and the mobile station may be a device mounted on the mobile body, the mobile body itself, or the like. The moving body may be a vehicle (eg, car, airplane, etc.), an unmanned moving body (eg, drone, self-driving car, etc.), or a robot (manned or unmanned). ) May be. It should be noted that at least one of the base station and the mobile station includes a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

Further, the base station in the present disclosure may be read by the user terminal. For example, communication between a base station and a user terminal has been replaced with communication between a plurality of user terminals (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the user terminal 20 may have the function of the base station 10 described above. In addition, words such as "up" and "down" may be read as words corresponding to inter-terminal communication (for example, "side"). For example, the uplink, downlink, and the like may be read as side channels.

Similarly, the user terminal in the present disclosure may be read as a base station. In this case, the base station 10 may have the functions of the user terminal 20 described above.

In the present disclosure, the operation performed by the base station may be performed by its upper node (upper node) in some cases. In a network including one or more network nodes having a base station, various operations performed for communication with a terminal are performed by the base station and one or more network nodes other than the base station (for example,). Mobility Management Entity (MME), Serving-Gateway (S-GW), etc. can be considered, but it is not limited to these), or it is clear that it can be performed by a combination thereof.

Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched with execution. In addition, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be changed as long as there is no contradiction. For example, the methods described in the present disclosure present elements of various steps using exemplary order, and are not limited to the particular order presented.

Each aspect / embodiment described in the present disclosure includes Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system ( 4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802. 20, Ultra-WideBand (UWB), Bluetooth®, other systems that utilize suitable wireless communication methods, next-generation systems extended based on these, and the like. In addition, a plurality of systems may be applied in combination (for example, a combination of LTE or LTE-A and 5G).

The phrase "based on" as used in this disclosure does not mean "based on" unless otherwise stated. In other words, the statement "based on" means both "based only" and "at least based on".

Any reference to elements using designations such as "first", "second", etc. as used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in the present disclosure as a convenient way to distinguish between two or more elements. Thus, references to the first and second elements do not mean that only two elements can be adopted or that the first element must somehow precede the second element.

The term "determining" used in this disclosure may include a wide variety of actions. For example, "judgment (decision)" means judgment (judging), calculation (calculating), calculation (computing), processing (processing), derivation (deriving), investigation (investigating), search (looking up, search, inquiry) ( For example, searching in a table, database or another data structure), ascertaining, etc. may be considered to be "judgment".

In addition, "judgment (decision)" means receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), access (for example). It may be regarded as "judgment (decision)" of "accessing" (for example, accessing data in memory).

In addition, "judgment (decision)" is regarded as "judgment (decision)" of solving, selecting, choosing, establishing, comparing, and the like. May be good. That is, "judgment (decision)" may be regarded as "judgment (decision)" of some action.

In addition, "judgment (decision)" may be read as "assuming", "expecting", "considering", and the like.

The "maximum transmission power" described in the present disclosure may mean the maximum value of the transmission power, may mean the nominal UE maximum transmit power, or may mean the rated maximum transmission power (the). It may mean rated UE maximum transmit power).

The terms "connected", "coupled", or any variation thereof, as used in this disclosure, are any direct or indirect connections or connections between two or more elements. Means, and can include the presence of one or more intermediate elements between two elements that are "connected" or "joined" to each other. The connection or connection between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access".

In the present disclosure, when two elements are connected, using one or more wires, cables, printed electrical connections, etc., and as some non-limiting and non-comprehensive examples, the radio frequency domain, microwaves. It can be considered to be "connected" or "coupled" to each other using frequency, electromagnetic energy having wavelengths in the light (both visible and invisible) regions, and the like.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". The term may mean that "A and B are different from C". Terms such as "separate" and "combined" may be interpreted in the same way as "different".

When "include", "including" and variations thereof are used in the present disclosure, these terms are as comprehensive as the term "comprising". Is intended. Furthermore, the term "or" used in the present disclosure is intended not to be an exclusive OR.

In the present disclosure, if articles are added by translation, for example, a, an and the in English, the disclosure may include that the nouns following these articles are in the plural.

Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented as a modified or modified mode without departing from the spirit and scope of the invention determined based on the description of the claims. Therefore, the description of the present disclosure is for purposes of illustration and does not bring any limiting meaning to the invention according to the present disclosure.

Claims (6)

1. A receiver that receives peripheral cell setting information at the frequency to which channel sensing is applied, and
   A user terminal having a control unit for monitoring downlink transmission indicating time length information regarding the time length of a transmission opportunity using the setting information.
2. The user terminal according to claim 1, wherein the control unit does not transmit at the frequency during the period from the reception of the downlink transmission to the time length.
3. The user terminal according to claim 1, wherein the control unit does not perform monitoring at the frequency during the period from the reception of the downlink transmission to the time length.
4. The setting information includes at least one of a cell identifier of the peripheral cell, a wireless network temporary identifier (RNTI) used for the downlink transmission, and a public land mobile network (PLMN) identifier of the peripheral cell. The user terminal according to any one of claims 1 to 3.
5. The user terminal according to any one of claims 1 to 4, wherein the downlink transmission is a group common physical downlink control channel (GC-PDCCH).
6. The step of receiving the setting information of the peripheral cells at the frequency to which the channel sensing is applied, and
   A wireless communication method of a user terminal having a step of monitoring downlink transmission indicating time length information regarding the time length of a transmission opportunity using the setting information.

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