WO2020145497A1 - Method for measuring radio link in unlicensed band and device therefor - Google Patents

Abstract

The present disclosure provides a method for measuring a radio link in an unlicensed band by a terminal. Specifically, the method in the disclosure may include: receiving information concerning a receive window for discovery reference signals (DRSs); receiving at least one DRS from within the receive window; receiving at least one synchronization signal block (SSB) from outside the receive window; and measuring the respective radio link qualities of the at least one DRS and at least one SSB, wherein among the radio link qualities of the at least one DRS and at least one SSB, if one or more radio link qualities are greater than a threshold, the radio link is assessed as in-sync, and if all the radio link qualities of the at least one DRS and at least one SSB are smaller than or equal to the threshold, the radio link is assessed as out-of-sync or the at least one DRS and the at least one SSB are assessed as a discontinuous transmission (DTX).

Description

Method and apparatus for measuring radio link in unlicensed band

The present disclosure relates to a method for measuring a radio link in an unlicensed band and an apparatus therefor, and more particularly, to a method and apparatus for determining a radio link failure (RLF) in an unlicensed band.

As more and more communication devices require more communication traffic according to the trend of the times, the next generation 5G system, which is an improved wireless broadband communication than the existing LTE system, is required. In the next generation 5G system, called NewRAT, communication scenarios are classified into Enhanced Mobile BroadBand (eMBB)/ Ultra-reliability and low-latency communication (URLLC)/Massive Machine-Type Communications (mMTC).

Here, eMBB is a next-generation mobile communication scenario with characteristics such as High Spectrum Efficiency, High User Experienced Data Rate, High Peak Data Rate, and URLLC is a next-generation mobile communication scenario with characteristics such as Ultra Reliable, Ultra Low Latency, Ultra High Availability, etc. And (eg, V2X, Emergency Service, Remote Control), mMTC is a next-generation mobile communication scenario with low cost, low energy, short packet, and massive connectivity characteristics. (e.g., IoT).

The present disclosure is to provide a method and apparatus for measuring a radio link in an unlicensed band.

The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the description below. Will be able to.

In a method for a UE to measure a radio link in an unlicensed band according to an embodiment of the present disclosure, information related to a reception window for a discovery reference signal (DRS) is received, and at least one DRS is received within the reception window , Receiving at least one Synchronization Signal Block (SSB) outside the reception window, and measuring radio link qualities for each of the at least one DRS and at least one SSB, wherein the at least one DRS and at least one Of the radio link qualities for the SSB of the one or more, based on the one or more radio link quality is greater than a threshold, the radio link is determined to be In-Sync, the radio link quality for the at least one DRS and at least one SSB Based on all of them being below the threshold, the radio link may be determined to be Out-of-Sync or the at least one DRS and the at least one SSB may be determined to be DTX (Discontinuous Transmission).

In this case, the DRS may be SSB or CSI-RS (Channel State Information-Reference Signal).

Further, the information related to the reception window includes information on the period of the reception window, and the at least one SSB may be received from the reception window during a time period for the period.

Further, based on the determination that both the at least one DRS and the at least one SSB are DTX, the previous report content may be reported again.

In addition, the transmission power of the at least one DRS and the transmission power of the at least one SSB may be different.

In addition, the reporting period for reporting the radio link quality to the upper layer may be the same as the period of the reception window.

Further, the terminal may communicate with at least one of a terminal, a network, a base station, and an autonomous vehicle other than the terminal.

A terminal for measuring a radio link in an unlicensed band according to the present disclosure, comprising: at least one transceiver; At least one processor; And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a specific operation. Through at least one transceiver, receives information related to a reception window for a discovery reference signal (DRS), receives at least one DRS within the reception window through the at least one transceiver, and the at least one transceiver Through, receiving at least one Synchronization Signal Block (SSB) outside the receive window, and measuring radio link qualities for each of the at least one DRS and at least one SSB, wherein the at least one DRS and Of the radio link qualities for at least one SSB, one or more radio link qualities are greater than a threshold, and the radio link is determined to be In-Sync, and the radio for the at least one DRS and at least one SSB On the basis that all of the link qualities are below a threshold, the radio link may be determined to be Out-of-Sync or the at least one DRS and the at least one SSB may be determined to be DTX (Discontinuous Transmission).

In this case, the DRS may be SSB or CSI-RS (Channel State Information-Reference Signal).

Further, the information related to the reception window includes information on the period of the reception window, and the at least one SSB may be received from the reception window during a time period for the period.

Further, based on the determination that both the at least one DRS and the at least one SSB are DTX, the previous report content may be reported again.

In addition, the transmission power of the at least one DRS and the transmission power of the at least one SSB may be different.

In addition, the reporting period for reporting the radio link quality to the upper layer may be the same as the period of the reception window.

Further, the terminal may communicate with at least one of a terminal, a network, a base station, and an autonomous vehicle other than the terminal.

An apparatus for measuring a radio link in an unlicensed band according to the present disclosure, comprising: at least one processor; And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a specific operation. Receives information related to a receive window for (Discovery Reference Signal), receives at least one DRS within the receive window, receives at least one Synchronization Signal Block (SSB) outside the receive window, and the at least one And measuring radio link qualities for each of the DRS and the at least one SSB, based on one or more of the radio link qualities for the at least one DRS and the at least one SSB, wherein the radio link quality is greater than a threshold value. As a result, the radio link is determined to be In-Sync, and the radio links are determined to be out-of-sync based on the fact that all of the radio link qualities for the at least one DRS and the at least one SSB are below a threshold. It may be determined that the at least one DRS and the at least one SSB are DTX (Discontinuous Transmission).

According to the present disclosure, determination of radio link failure (RLF) of an unlicensed band may be more clearly determined.

The effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those skilled in the art from the description below. will be.

1 is a diagram illustrating a control plane and a user plane structure of a radio interface protocol between a terminal and an E-UTRAN based on a 3GPP radio access network standard.

FIG. 2 is a diagram for explaining physical channels used in a 3GPP system and a general signal transmission method using the physical channels.

3 to 5 are diagrams for explaining the structure of a radio frame and slot used in the NR system.

6 is a diagram for explaining analog beamforming in an NR system.

7 shows a beam sweeping operation for a synchronization signal and system information in a downlink transmission process.

8 to 9 are diagrams for explaining downlink channel transmission in an unlicensed band.

10 to 11 are diagrams for explaining the composition and transmission method of the SS/PBCH block.

12 is a diagram for explaining an example of reporting channel state information.

13 to 16 are diagrams for explaining an example of an operation implementation of a base station and a terminal according to the present disclosure.

17 shows an example of setting a DMTC (Discovery Measurement Timing Configuration) window and a DTTC (DRS Transmission Timing Configuration) window according to the present disclosure.

18 to 19 are diagrams for explaining an implementation example of determining In-sync/Out-of-sync according to the present disclosure.

20 shows an example of a communication system to which embodiments of the present disclosure are applied.

21 to 23 show examples of various wireless devices to which embodiments of the present disclosure are applied.

24 shows an example of a signal processing circuit to which embodiments of the present disclosure are applied.

The configuration, operation, and other features of the present disclosure will be readily understood by embodiments of the present disclosure described with reference to the accompanying drawings below. The embodiments described below are examples in which technical features of the present disclosure are applied to a 3GPP system.

Although this specification describes an embodiment of the present disclosure using an LTE system, an LTE-A system, and an NR system, this is an example and the embodiment of the present disclosure can be applied to any communication system corresponding to the above definition.

In addition, in this specification, the name of the base station may be used as a comprehensive term including a remote radio head (RRH), an eNB, a transmission point (TP), a reception point (RP), a relay, and the like.

The 3GPP-based communication standard includes downlink physical channels corresponding to resource elements carrying information originating from a higher layer and downlink corresponding to resource elements used by the physical layer but not carrying information originating from a higher layer. Physical signals are defined. For example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), a physical multicast channel (physical multicast channel, PMCH), a physical control format indicator channel (physical control) The format indicator channel (PCFICH), physical downlink control channel (PDCCH) and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, and reference signals and synchronization signals Is defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, refers to a signal of a predetermined special waveform known to each other by the gNB and the UE. For example, cell specific RS (UE), UE- A specific RS (UE-specific RS, UE-RS), positioning RS (positioning RS, PRS) and channel state information RS (channel state information RS, CSI-RS) are defined as downlink reference signals. The 3GPP LTE/LTE-A standard corresponds to uplink physical channels corresponding to resource elements carrying information originating from an upper layer and resource elements used by the physical layer but not carrying information originating from an upper layer. Defines uplink physical signals. For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), a physical random access channel (physical random access channel, PRACH) as an uplink physical channel It is defined, and a demodulation reference signal (DMRS) for uplink control/data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

In the present disclosure, PDCCH (Physical Downlink Control CHannel) / PCFICH (Physical Control Format Indicator CHannel) / PHICH ((Physical Hybrid automatic retransmit request Indicator CHannel) / PDSCH (Physical Downlink Shared CHannel), respectively, DCI (Downlink Control Information) / CFI ( Control Format Indicator)/downlink ACK/NACK (ACKnowlegement/Negative ACK)/ means a set of time-frequency resources or a set of resource elements carrying downlink data, and PUCCH (Physical Uplink Control CHannel)/PUSCH (Physical) Uplink Shared CHannel)/PRACH (Physical Random Access CHannel) means a set of time-frequency resources or a set of resource elements that carry uplink control information (UCI)/uplink data/random access signals, respectively. , PDCCH/PCFICH/PHICH/PDSCH/PUCCH/PUSCH/PRACH or time-frequency resource or resource element (RE) allocated to or belong to PDCCH/PCFICH/PHICH/PDSCH/PUCCH/PUSCH/PRACH RE or PDCCH, respectively. It is referred to as /PCFICH/PHICH/PDSCH/PUCCH/PUSCH/PRACH resource.In the following, the expression that the user equipment transmits PUCCH/PUSCH/PRACH is uplink control information/uplink data on or through PUSCH/PUCCH/PRACH respectively. /Random access signal is used in the same sense as that.. Also, the expression that the gNB transmits PDCCH/PCFICH/PHICH/PDSCH, respectively, on PDCCH/PCFICH/PHICH/PDSCH. It is used in the same sense as transmitting downlink data/control information through the network.

Hereinafter, CRS/DMRS/CSI-RS/SRS/UE-RS is assigned or configured (configured) OFDM symbol/subcarrier/RE to CRS/DMRS/CSI-RS/SRS/UE-RS symbol/carrier It is called /subcarrier/RE. For example, an OFDM symbol to which tracking RS (TRS) is assigned or configured is called a TRS symbol, and a subcarrier to which TRS is assigned or configured is called a TRS subcarrier, and a TRS is assigned. Or, the configured RE is called a TRS RE. Also, a subframe configured for TRS transmission is called a TRS subframe. Also, a subframe in which a broadcast signal is transmitted is referred to as a broadcast subframe or a PBCH subframe, and a subframe in which a synchronization signal (eg, PSS and/or SSS) is transmitted is a synchronization signal subframe or a PSS/SSS subframe. It is called. The OFDM symbols/subcarriers/REs to which the PSS/SSS is assigned or configured are called PSS/SSS symbols/subcarriers/RE, respectively.

In the present disclosure, the CRS port, UE-RS port, CSI-RS port, and TRS port are antenna ports configured to transmit CRS and antenna ports configured to transmit UE-RS, respectively. Refers to an antenna port configured to transmit CSI-RS and an antenna port configured to transmit TRS. Antenna ports configured to transmit CRSs may be distinguished from each other by positions of REs occupied by CRSs according to CRS ports, and antenna ports configured to transmit UE-RSs are configured to UEs. Depending on the RS ports, UE-RS may be distinguished by location of REs occupied, and antenna ports configured to transmit CSI-RSs are occupied by CSI-RS according to CSI-RS ports. It can be distinguished from each other by the location of the REs. Therefore, the term CRS/UE-RS/CSI-RS/TRS port is also used as a term for a pattern of REs occupied by CRS/UE-RS/CSI-RS/TRS in a certain resource region.

Now, let's look at 5G communication including the NR system.

The three main requirements areas of 5G are: (1) Enhanced Mobile Broadband (eMBB) area, (2) Massive Machine Type Communication (mMTC) area, and (3) Super-reliability and It includes the area of ultra-reliable and low latency communications (URLLC).

Some use cases may require multiple areas for optimization, and other use cases may focus only on one key performance indicator (KPI). 5G supports these various use cases in a flexible and reliable way.

eMBB goes far beyond basic mobile Internet access, and covers media and entertainment applications in rich interactive work, cloud or augmented reality. Data is one of the key drivers of 5G, and it may not be possible to see dedicated voice services for the first time in the 5G era. In 5G, voice is expected to be handled as an application program simply using the data connection provided by the communication system. The main causes for increased traffic volume are increased content size and increased number of applications requiring high data rates. Streaming services (audio and video), interactive video and mobile internet connections will become more widely used as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are rapidly increasing in mobile communication platforms, which can be applied to both work and entertainment. And, cloud storage is a special use case that drives the growth of uplink data rates. 5G is also used for remote work in the cloud, requiring much lower end-to-end delay to maintain a good user experience when a tactile interface is used. Entertainment For example, cloud gaming and video streaming are another key factor in increasing demand for mobile broadband capabilities. Entertainment is essential for smartphones and tablets anywhere, including high mobility environments such as trains, cars and airplanes. Another use case is augmented reality and information retrieval for entertainment. Here, augmented reality requires a very low delay and an instantaneous amount of data.

In addition, one of the most anticipated 5G use cases relates to the ability to seamlessly connect embedded sensors in all fields, namely mMTC. It is predicted that by 2020, there are 20 billion potential IoT devices. Industrial IoT is one of the areas where 5G plays a key role in enabling smart cities, asset tracking, smart utilities, agriculture and security infrastructure.

URLLC includes new services that will transform the industry through ultra-reliable/low-latency links, such as remote control of the main infrastructure and self-driving vehicles. Reliability and level of delay are essential for smart grid control, industrial automation, robotics, drone control and coordination.

Next, a plurality of use cases in a 5G communication system including an NR system will be described in more detail.

5G can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) as a means to provide streams rated at hundreds of megabits per second to gigabit per second. This fast speed is required to deliver TV in 4K (6K, 8K and above) resolutions as well as virtual and augmented reality. Virtual Reality (VR) and Augmented Reality (AR) applications include almost immersive sports events. Certain application programs may require special network settings. For VR games, for example, game companies may need to integrate the core server with the network operator's edge network server to minimize latency.

Automotive is expected to be an important new driver for 5G, along with many use cases for mobile communications to vehicles. For example, entertainment for passengers requires simultaneous high capacity and high mobility mobile broadband. The reason is that future users continue to expect high quality connections regardless of their location and speed. Another example of application in the automotive field is the augmented reality dashboard. It identifies objects in the dark over what the driver sees through the front window and superimposes information that tells the driver about the distance and movement of the object. In the future, wireless modules will enable communication between vehicles, exchange of information between the vehicle and the supporting infrastructure, and exchange of information between the vehicle and other connected devices (eg, devices carried by pedestrians). The safety system guides alternative courses of action to help the driver drive more safely, reducing the risk of accidents. The next step will be remote control or a self-driven vehicle. This is very reliable and requires very fast communication between different self-driving vehicles and between the vehicle and the infrastructure. In the future, self-driving vehicles will perform all driving activities, and drivers will focus only on traffic beyond which the vehicle itself cannot identify. The technical requirements of self-driving vehicles require ultra-low delays and ultra-high-speed reliability to increase traffic safety to levels beyond human reach.

Smart cities and smart homes, referred to as smart societies, will be embedded in high-density wireless sensor networks. The distributed network of intelligent sensors will identify the conditions for cost and energy-efficient maintenance of a city or home. Similar settings can be made for each assumption. Temperature sensors, window and heating controllers, burglar alarms and consumer electronics are all connected wirelessly. Many of these sensors are typically low data rates, low power and low cost. However, for example, real-time HD video may be required in certain types of devices for surveillance.

The consumption and distribution of energy, including heat or gas, is highly decentralized, requiring automated control of a distributed sensor network. The smart grid interconnects these sensors using digital information and communication technologies to collect information and act accordingly. This information can include supplier and consumer behavior, so smart grids can improve efficiency, reliability, economics, production sustainability and the distribution of fuels like electricity in an automated way. The smart grid can be viewed as another sensor network with low latency.

The health sector has a number of applications that can benefit from mobile communications. The communication system can support telemedicine that provides clinical care from a distance. This helps to reduce barriers to distance and can improve access to medical services that are not continuously available in remote rural areas. It is also used to save lives in critical care and emergency situations. A mobile communication based wireless sensor network can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Thus, the possibility of replacing cables with wireless links that can be reconfigured is an attractive opportunity in many industries. However, achieving this requires that the wireless connection operate with cable-like delay, reliability and capacity, and that management be simplified. Low latency and very low error probability are new requirements that need to be connected to 5G.

Logistics and freight tracking are important use cases for mobile communications that enable the tracking of inventory and packages from anywhere using location-based information systems. Logistics and cargo tracking use cases typically require low data rates, but require wide range and reliable location information.

1 is a diagram illustrating a control plane and a user plane structure of a radio interface protocol between a terminal and an E-UTRAN based on a 3GPP radio access network standard. The control plane refers to a path through which control messages used by a user equipment (UE) and a network to manage a call are transmitted. The user plane means a path through which data generated in the application layer, for example, voice data or Internet packet data, is transmitted.

The first layer, the physical layer, provides an information transfer service to an upper layer using a physical channel. The physical layer is connected to the upper medium access control layer through a transmission channel. Data is moved between the medium access control layer and the physical layer through the transmission channel. Data is moved between the physical layer of the transmitting side and the receiving side through a physical channel. The physical channel utilizes time and frequency as radio resources. Specifically, the physical channel is modulated with OFDMA (Orthogonal Frequency Division Multiple Access) in the downlink, and modulated with Single Carrier Frequency Division Multiple Access (SC-FDMA) in the uplink.

The medium access control (MAC) layer of the second layer provides a service to a radio link control (RLC) layer, which is an upper layer, through a logical channel. The RLC layer of the second layer supports reliable data transmission. The function of the RLC layer may be implemented as a function block inside the MAC. The packet data convergence protocol (PDCP) layer of the second layer performs a header compression function that reduces unnecessary control information in order to efficiently transmit IP packets such as IPv4 and IPv6 in a narrow bandwidth wireless interface.

The radio resource control (RRC) layer located at the bottom of the third layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transmission channels, and physical channels in connection with configuration, re-configuration, and release of radio bearers. The radio bearer means a service provided by the second layer for data transmission between the terminal and the network. To this end, the RRC layer of the terminal and the network exchanges RRC messages with each other. If there is an RRC connection (RRC Connected) between the terminal and the RRC layer of the network, the terminal is in the RRC connected state (Connected Mode), otherwise it is in the RRC idle state (Idle Mode). The NAS (Non-Access Stratum) layer above the RRC layer performs functions such as session management and mobility management.

The downlink transmission channel for transmitting data from the network to the terminal includes a broadcast channel (BCH) for transmitting system information, a PCH (Paging Channel) for transmitting paging messages, and a downlink shared channel (SCH) for transmitting user traffic or control messages. have. Traffic or control messages of a downlink multicast or broadcast service may be transmitted through a downlink SCH or may be transmitted through a separate downlink multicast channel (MCH). Meanwhile, an uplink transmission channel for transmitting data from a terminal to a network includes a random access channel (RACH) for transmitting an initial control message and an uplink shared channel (SCH) for transmitting user traffic or a control message. It is located on the top of the transmission channel, and the logical channels mapped to the transmission channels include BCCH (Broadcast Control Channel), PCCH (Paging Control Channel), CCCH (Common Control Channel), MCCH (Multicast Control Channel), and MTCH (Multicast). Traffic Channel).

2 is a diagram for explaining physical channels used in a 3GPP system and a general signal transmission method using them.

The terminal performs an initial cell search operation such as synchronizing with the base station when the power is turned on or newly enters the cell (S201). To this end, the terminal can receive a primary synchronization channel (P-SCH) and a secondary synchronization channel (Secondary Synchronization Channel; S-SCH) from the base station to synchronize with the base station and obtain information such as cell ID. have. Thereafter, the terminal may acquire a physical broadcast channel from the base station to obtain intra-cell broadcast information. Meanwhile, the UE may check a downlink channel state by receiving a downlink reference signal (DL RS) in an initial cell search step.

After completing the initial cell search, the UE acquires more detailed system information by receiving a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to the information carried on the PDCCH. It can be done (S202).

On the other hand, if the first access to the base station or there is no radio resource for signal transmission, the UE may perform a random access procedure (RACH) to the base station (steps S203 to S206). To this end, the UE may transmit a specific sequence as a preamble through a physical random access channel (PRACH) (S203 and S205), and receive a response message for the preamble through the PDCCH and the corresponding PDSCH ( S204 and S206). In the case of the contention-based RACH, an additional contention resolution procedure may be performed.

The UE that has performed the above-described procedure is a general uplink/downlink signal transmission procedure and then receives PDCCH/PDSCH (S207) and physical uplink shared channel (PUSCH)/physical uplink control channel (Physical Uplink). Control Channel (PUCCH) transmission (S208) may be performed. In particular, the terminal receives downlink control information (DCI) through the PDCCH. Here, the DCI includes control information such as resource allocation information for the terminal, and formats are different depending on the purpose of use.

Meanwhile, control information that the UE transmits to the base station through the uplink or that the UE receives from the base station includes a downlink/uplink ACK/NACK signal, a channel quality indicator (CQI), a precoding matrix index (PMI), and a rank indicator (RI). ) And the like. In the case of a 3GPP LTE system, the UE may transmit the control information such as CQI/PMI/RI described above through PUSCH and/or PUCCH.

Meanwhile, the NR system is considering using a high ultra-high frequency band, that is, a millimeter frequency band of 6 GHz or more, to transmit data while maintaining a high transmission rate to a plurality of users using a wide frequency band. 3GPP uses this under the name NR, and in the present disclosure, it will be referred to as an NR system in the future.

3 illustrates the structure of a radio frame used in NR.

In NR, uplink and downlink transmission are composed of frames. The radio frame has a length of 10 ms, and is defined as two 5 ms half-frames (HFs). The half-frame is defined by five 1ms subframes (Subframe, SF). The subframe is divided into one or more slots, and the number of slots in the subframe depends on Subcarrier Spacing (SCS). Each slot includes 12 or 14 OFDM(A) symbols according to a cyclic prefix (CP). Normally, if CP is used, each slot contains 14 symbols. When an extended CP is used, each slot includes 12 symbols. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol) and an SC-FDMA symbol (or DFT-s-OFDM symbol).

Table 1 exemplifies that when a CP is normally used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary according to SCS.

SCS (15*2^u)	N slot symb	N frame, u slot	N subframe, u slot
15KHz (u=0)	14	10	One
30KHz (u=1)	14	20	2
60KHz (u=2)	14	40	4
120KHz (u=3)	14	80	8
240KHz (u=4)	14	160	16

* N ^slot _symb : Number of symbols in slot

* N ^frame,u _slot : Number of slots in the frame

* N ^subframe,u _slot : Number of slots in the ^subframe

Table 2 illustrates that when an extended CP is used, the number of symbols for each slot, the number of slots for each frame, and the number of slots for each subframe vary according to the SCS.

SCS (15*2^u)	N slot symb	N frame, u slot	N subframe, u slot
60KHz (u=2)	12	40	4

In the NR system, OFDM(A) numerology (eg, SCS, CP length, etc.) may be set differently among a plurality of cells merged into one UE. Accordingly, a (absolute time) section of a time resource (eg, SF, slot, or TTI) composed of the same number of symbols (for convenience, collectively referred to as TU (Time Unit)) may be set differently between merged cells. 4 illustrates the slot structure of the NR frame. A slot contains multiple symbols in the time domain. For example, in the case of a normal CP, one slot includes 7 symbols, but in the case of an extended CP, one slot includes 6 symbols. The carrier includes a plurality of subcarriers in the frequency domain. Resource block (RB) is defined as a plurality of (eg, 12) consecutive subcarriers in the frequency domain. BWP (Bandwidth Part) is defined as a plurality of contiguous (P)RBs in the frequency domain, and may correspond to one pneumonology (eg, SCS, CP length, etc.). The carrier may include up to N (eg, 4) BWPs. Data communication is performed through the activated BWP, and only one BWP can be activated for one terminal. Each element in the resource grid is referred to as a resource element (RE), and one complex symbol may be mapped.

5 illustrates the structure of a self-contained slot. In an NR system, a frame is characterized by a self-contained structure in which a DL control channel, DL or UL data, UL control channel, etc. can all be included in one slot. For example, the first N symbols in the slot are used to transmit the DL control channel (hereinafter, DL control region), and the last M symbols in the slot can be used to transmit the UL control channel (hereinafter, UL control region). N and M are each an integer of 0 or more. The resource region (hereinafter referred to as a data region) between the DL control region and the UL control region may be used for DL data transmission or may be used for UL data transmission. As an example, the following configuration may be considered. Each section was listed in chronological order.

1.DL only configuration

2. UL only configuration

3. Mixed UL-DL configuration

-DL area + GP (Guard Period) + UL control area

-DL control area + GP + UL area

* DL area: (i) DL data area, (ii) DL control area + DL data area

* UL area: (i) UL data area, (ii) UL data area + UL control area

PDCCH may be transmitted in the DL control region, and PDSCH may be transmitted in the DL data region. PUCCH may be transmitted in the UL control region, and PUSCH may be transmitted in the UL data region. In the PDCCH, downlink control information (DCI), for example, DL data scheduling information and UL data scheduling information may be transmitted. In the PUCCH, uplink control information (UCI), for example, ACK/NACK (Positive Acknowledgement/Negative Acknowledgement) information for DL data, CSI (Channel State Information) information, and SR (Scheduling Request) may be transmitted. The GP provides a time gap in the process of the base station and the terminal switching from the transmission mode to the reception mode or the process from the reception mode to the transmission mode. In a subframe, some symbols at a time point of switching from DL to UL may be set to GP.

6 is a view showing an example of a block diagram of a transmitting end and a receiving end for hybrid beamforming (hybrid beamforming).

As a method for forming a narrow beam in the millimeter frequency band, a beamforming method in which BS or UE transmits the same signal using an appropriate phase difference to a large number of antennas to increase energy only in a specific direction is mainly considered. Such beamforming methods include digital beamforming, which creates a phase difference on a digital baseband signal, analog beamforming, which creates a phase difference using a time delay (ie, cyclic shift) on a modulated analog signal, digital beamforming, and analog beam. And hybrid beamforming using both forming. If an RF unit (or a transceiver unit (TXRU)) is provided to enable transmission power and phase adjustment for each antenna element, independent beamforming is possible for each frequency resource. However, there is a problem in that it is ineffective in terms of price to install the RF unit on all 100 antenna elements. In other words, the millimeter frequency band must be used by a large number of antennas to compensate for the rapid propagation attenuation characteristics, and digital beamforming corresponds to the number of antennas, so RF components (eg, digital analog converter (DAC), mixer, mixer, power) Since an amplifier (power amplifier, linear amplifier, etc.) is required, there is a problem in that the price of a communication device increases to implement digital beamforming in the millimeter frequency band. Therefore, when a large number of antennas are required, such as a millimeter frequency band, use of an analog beamforming or hybrid beamforming method is considered. The analog beamforming method maps a plurality of antenna elements to one TXRU and adjusts the direction of the beam with an analog phase shifter. This analog beamforming method has a disadvantage in that it can make only one beam direction in the entire band and thus cannot perform frequency selective beamforming (BF). Hybrid BF is a type of digital BF and analog BF, and has a number of B RF units less than Q antenna elements. In the case of the hybrid BF, although there are differences depending on the connection method of the B RF units and the Q antenna elements, the direction of beams that can be simultaneously transmitted is limited to B or less.

7 is a diagram illustrating a beam sweeping operation for a synchronization signal and system information in a downlink transmission process. In FIG. 7, a physical resource or physical channel in which system information of the New RAT system is broadcast is referred to as a physical broadcast channel (xPBCH). At this time, analog beams belonging to different antenna panels within one symbol may be simultaneously transmitted, and in order to measure a channel for each analog beam, as shown in FIG. 9, to a specific antenna panel A method for introducing a beam RS (BRS) that is a reference signal (RS) transmitted for a corresponding single analog beam is being discussed. The BRS may be defined for a plurality of antenna ports, and each antenna port of the BRS may correspond to a single analog beam. At this time, unlike the BRS, the synchronization signal (Synchronization signal) or xPBCH can be transmitted for all analog beams (Analog beam) included in the analog beam group (Analog beam group) so that any UE can receive well.

Tx-Rx beam association

The network uses a measurement reference signal (MRS) applied to each beam in order to allow the UE to perform measurement on beams used in the corresponding cell or used by the eNB (measurement reference signal; MRS), beam reference A known signal, such as a beam reference signal (BRS) and a beamformed channel state information reference signal (CSI-RS), may be configured. Hereinafter, signals known for convenience of description are collectively referred to as BRS.

The base station may transmit the BRS aperiodically/periodically, and the UE may select the eNB Tx beam suitable for the UE through the measurement of the BRS. When considering the Rx beam of the UE, the UE may perform measurement using different Rx beams and select beam combinations considering the Tx beam of the eNB and the Rx beam of the UE. After performing this process, the Tx-Rx beam association between the eNB and the UE may be determined as explicit or implicit.

1) Network decision based beam association

The network may instruct the UE to report the top X Tx-Rx beam combinations as a result of measurement. At this time, the number of beam combinations to be reported may be defined in advance, delivered by a network through higher layer signaling, or the like, and all beam combinations in which a measurement result exceeds a certain threshold may be reported.

At this time, a specific threshold may be defined in advance or signaled by a network. When decoding performance is different for each UE, a category considering the decoding performance of the UE is defined, and thresholds for each category are defined. It might be.

In addition, the report on the beam combination may be performed periodically or aperiodically by instructions of the network. Alternatively, if the previous report result and the current measurement result change more than a certain level, event triggering reporting may be performed. At this time, a predetermined level may be predefined or the network may signal through the upper layer.

Meanwhile, the UE may report one or more beam associations determined by the above-described scheme. When a plurality of beam indexes are reported, priority may be given for each beam. For example, it can be reported to be interpreted in the form of 1 ^st preferred beam, 2 ^nd preferred beam, 쪋.

2) UE decision based beam association (UE decision based beam association)

In the beam association based UE determination, the preferred beam reporting of the UE may be performed in the same manner as the explicit beam association proposed above.

QCL(Quasi-Co Location)

The UE may receive a list including up to M TCI-state settings, in order to decode the PDSCH according to the detected PDCCH with DCI intended for the UE and a given cell. Here, M depends on UE capability.

Each TCI-State includes parameters for establishing a QCL relationship between one or two DL RSs and DM-RS ports of the PDSCH. The QCL relationship is established with the RRC parameter qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS (if set).

The QCL type corresponding to each DL RS is given by the parameter'qcl-Type' in QCL-Info, and can take one of the following values:

-'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

-'QCL-TypeB': {Doppler shift, Doppler spread}

-'QCL-TypeC': {Doppler shift, average delay}

-'QCL-TypeD': {Spatial Rx parameter}

For example, when the target antenna port is a specific NZP CSI-RS, the corresponding NZP CSI-RS antenna ports may be indicated/set as a specific TRS in the QCL-Type A perspective and a specific SSB and QCL in the QCL-Type D perspective. have. UE receiving this indication/setting receives the corresponding NZP CSI-RS using the Doppler and delay values measured in QCL-TypeA TRS, and applies the received beam used for QCL-TypeD SSB reception to the corresponding NZP CSI-RS reception can do.

RRM (Radio Resource Management) measurement in LTE (Measurement)

In LTE system, power control, scheduling, cell search, cell reselection, handover, radio link or connection monitoring, connection It supports RRM operations including connection establish/re-establish. At this time, the serving cell (Serving Cell) may request the UE RRM measurement (measurement) information that is a measurement value for performing the RRM operation. In particular, in the LTE system, the UE may measure and report information such as cell search information for each cell, reference signal received power (RSRP), and reference signal received quality (RSRQ). Specifically, in the LTE system, the UE receives'measConfig' as a higher layer signal for RRM measurement from the serving cell. Then, the UE measures RSRP or RSRQ according to the information of the'measConfig'. Here, the definition of RSRP, RSRQ and RSSI according to TS 36.214 document of the LTE system is as follows.

- RSRP: RSRP, the cell specific reference signal transmitted in the measurement bandwidth is defined as the linear average of the power contribution ([W]) of;; (RE Resource Element) resource elements of (Cell specific reference signal CRS) . In addition, CRS R0 according to TS 36.211 is used for RSRP determination. In some cases, CRS R1 may be additionally used to increase reliability. The reference point for RSRP should be the antenna connector of the UE, and when receive diversity is used, the reported RSRP value should not be lower than any one of the individual diversity RSRPs.

-RSRQ: RSRQ is defined as N*RSRP/(RSSI of E-UTRA carrier). At this time, N is the RB number of the E-UTRA carrier RSSI measurement bandwidth. At this time, the measurement of'N*RSRP' and the measurement of'RSS of E-UTRA carrier' are performed through the same resource block set (RB set).

The E-UTRA carrier RSSI provides reference symbols for antenna port 0 on N resource blocks obtained from all sources including the same channel of a serving cell and a non-serving cell, adjacent channel interference, and thermal noise. It is obtained as a linear average value of the total received power measured only in the OFDM symbol.

If the higher layer signaling indicates a specific subframe for performing RSRP measurement, RSSI is measured on all indicated OFDM symbols. At this time, the reference point for the RSRQ should be the antenna connector of the UE, and when receive diversity is used, the reported RSRQ value should not be lower than any one of the individual diversity RSRQs.

RSSI: means wideband received power including noise and thermal noise generated within a bandwidth defined by a receiver pulse shaping filter. Again, the reference point for the RSSI should be the antenna connector of the UE, and when receive diversity is used, the reported RSSI value should not be lower than any one of the individual diversity RSSIs.

According to the above definition, the UE operating in the LTE system is 6, 15, 25, 50 through an allowable measurement bandwidth-related IE (information element) transmitted in system information block type 3 (SIB3) in case of intra-frequency measurement. , 75, 100 RB (resource block) is allowed to measure the RSRP in the bandwidth corresponding to one. In addition, in the case of inter-frequency measurement, it is allowed to measure RSRP in a bandwidth corresponding to one of 6, 15, 25, 50, 75, and 100 RB (resource block) through the allowed measurement bandwidth transmitted in SIB5. If there is no IE, RSRP can be measured in the frequency band of the entire downlink system by default. At this time, when the UE receives the Allowed measurement bandwidth, the UE can think of the value as the maximum measurement bandwidth (maximum measurement bandwidth) and freely measure the value of RSRP within the value.

However, if the serving cell transmits the IE defined as WB-RSRQ, and if the Allowed measurement bandwidth is set to 50 RB or more, the UE must calculate the RSRP value for the entire allowed measurement bandwidth. On the other hand, in the case of RSSI, RSSI is measured in the frequency band of the receiver of the UE according to the definition of the RSSI bandwidth.

NR communication systems are required to support significantly better performance than existing 4th generation (4G) systems in terms of data rate, capacity, latency, energy consumption and cost. Thus, NR systems need to make significant advances in the areas of bandwidth, spectral, energy, signaling efficiency, and cost per bit.

8 shows an example of a wireless communication system supporting unlicensed bands applicable to the present disclosure.

In the following description, a cell operating in a license band (hereinafter, L-band) is defined as an L-cell, and a carrier of the L-cell is defined as (DL/UL) LCC. In addition, a cell operating in an unlicensed band (hereinafter, U-band) is defined as a U-cell, and a carrier of the U-cell is defined as (DL/UL) UCC. The carrier/carrier-frequency of the cell may mean the operating frequency (eg, center frequency) of the cell. The cell/carrier (eg, CC) is collectively referred to as a cell.

When the terminal and the base station transmit and receive signals through carrier-coupled LCC and UCC as shown in FIG. 8(a), LCC may be set to PCC (Primary CC) and UCC to SCC (Secondary CC). 8(b), the terminal and the base station may transmit and receive signals through a single UCC or a plurality of carrier-coupled UCCs. That is, the terminal and the base station can transmit and receive signals through only UCC(s) without LCC.

Hereinafter, the signal transmission/reception operation in the unlicensed band described in the present disclosure may be performed based on all the above-described deployment scenarios (unless otherwise stated).

Meanwhile, the NR frame structure of FIG. 3 may be used for operation in an unlicensed band. The configuration of OFDM symbols occupied for uplink/downlink signal transmission in a frame structure for an unlicensed band may be set by a base station. Here, the OFDM symbol may be replaced with an SC-FDM(A) symbol.

For downlink signal transmission through the unlicensed band, the base station may inform the UE of the configuration of OFDM symbols used in subframe #n through signaling. Here, the subframe may be replaced with a slot or a time unit (TU).

Specifically, in the case of an LTE system supporting an unlicensed band, the UE subframe #n-1 or subframe #n through a specific field in the DCI received from the base station (eg, Subframe configuration for LAA field, etc.) It is possible to assume (or identify) the configuration of the OFDM symbols occupied in n.

Table 3 shows the configuration of OFDM symbols in which the subframe configuration for LAA field in the LTE system is used for transmission of a downlink physical channel and/or physical signal in a current subframe and/or a next subframe. Illustrate the method shown.

Value of ' Subframe configuration for LAA 'field in current subframe	Configuration of occupied OFDM symbols (current subframe, next subframe)
0000	(-,14)
0001	(-,12)
0010	(-,11)
0011	(-,10)
0100	(-,9)
0101	(-,6)
0110	(-,3)
0111	(14,*)
1000	(12,-)
1001	(11,-)
1010	(10,-)
1011	(9,-)
1100	(6,-)
1101	(3,-)
1110	reserved
1111	reserved
NOTE:- (-, Y) means UE may assume the first Y symbols are occupied in next subframe and other symbols in the next subframe are not occupied.- (X, -) means UE may assume the first X symbols are occupied in current subframe and other symbols in the current subframe are not occupied.- (X, *) means UE may assume the first X symbols are occupied in current subframe, and at least the first OFDM symbol of the next subframe is not occupied.

In order to transmit an uplink signal through an unlicensed band, the base station may inform the UE of information on the uplink transmission interval through signaling.

Specifically, in the case of an LTE system supporting an unlicensed band, the UE may acquire'UL duration' and'UL offset' information for subframe #n through the'UL duration and offset' field in the detected DCI.

Table 4 illustrates a method in which the UL duration and offset field indicates the UL offset and UL duration configuration in the LTE system.

Value of'UL duration and offset' field	UL offset, l (in subframes)	UL duration, d (in subframes)
00000	Not configured	Not configured
00001	One	One
00010	One	2
00011	One	3
00100	One	4
00101	One	5
00110	One	6
00111	2	One
01000	2	2
01001	2	3
01010	2	4
01011	2	5
01100	2	6
01101	3	One
01110	3	2
01111	3	3
10000	3	4
10001	3	5
10010	3	6
10011	4	One
10100	4	2
10101	4	3
10110	4	4
10111	4	5
11000	4	6
11001	6	One
11010	6	2
11011	6	3
11100	6	4
11101	6	5
11110	6	6
11111	reserved	reserved

As an example, when the UL duration and offset field sets (or indicates) UL offset l and UL duration d for subframe #n, the UE subframe #n+l+i (i=0,1,.. It is not necessary to receive downlink physical channels and/or physical signals within .,d-1).

The base station may perform one of the following unlicensed band access procedures (eg, Channel Access Procedure, CAP) for downlink signal transmission in the unlicensed band.

(1) First downlink CAP method

9 is a flowchart of a CAP operation for transmitting a downlink signal through an unlicensed band of a base station.

The base station may initiate a channel access process (CAP) for downlink signal transmission over an unlicensed band (eg, signal transmission including PDSCH/PDCCH/EPDCCH) (S910). The base station may arbitrarily select the backoff counter N within the contention window CW according to step 1. At this time, the N value is set to the initial value N _init (S920). N _init is selected as a random value between 0 and CW _p . Subsequently, if the backoff counter value N is 0 according to step 4 (S930; Y), the base station ends the CAP process (S932). Subsequently, the base station may perform Tx burst transmission including PDSCH/PDCCH/EPDCCH (S934). On the other hand, if the backoff counter value is not 0 (S930; N), the base station decreases the backoff counter value by 1 according to step 2 (S940). Subsequently, the base station checks whether the channel of the U-cell(s) is idle (S950), and if the channel is idle (S950; Y), checks whether the backoff counter value is 0 (S930). On the contrary, if the channel is not idle in step S950, that is, if the channel is busy (S950; N), the base station according to step 5 has a longer delay time than the slot time (eg, 9usec) (defer duration T _d ; 25usec or more) While, it is checked whether the corresponding channel is in an idle state (S960). If the channel is idle in the delay period (S970; Y), the base station can resume the CAP process again. Here, the delay period may be composed of 16usec intervals and m _p consecutive slot times immediately following (eg, 9usec). On the other hand, if the channel is busy during the delay period (S970; N), the base station again performs step S960 to check again whether the channel of the U-cell(s) is idle during the new delay period.

Table 5 exemplifies that m _p , minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes applied to the CAP vary according to the channel access priority class. .

Channel Access Priority Class (p)	m p	CW min,p	CW max,p	T ultcot,p	Allowed CW p sizes
One	One	3	7	2 ms	{3,7}
2	One	7	15	3 ms	{7,15}
3	3	15	63	8 or 10 ms	{15,31,63}
4	7	15	1023	8 or 10 ms	{15,31,63,127,255,511,1023}

The contention window size applied to the first downlink CAP may be determined based on various methods. For example, the contention window size may be adjusted based on a probability that HARQ-ACK values corresponding to PDSCH transmission(s) in a certain time period (eg, a reference TU) are determined to be NACK. When the base station performs downlink signal transmission including the PDSCH associated with the channel access priority class p on the carrier, HARQ-ACK values corresponding to PDSCH transmission(s) in the reference subframe k (or reference slot k) are NACK. When the probability to be determined is at least Z = 80%, the base station increases the CW values set for each priority class to the next higher priority. Alternatively, the base station maintains the CW values set for each priority class as initial values. The reference subframe (or reference slot) may be defined as a start subframe (or start slot) in which at least some HARQ-ACK feedback is available on which a most recent signal transmission on a corresponding carrier is performed.

(2) 2nd downlink CAP method

The base station may perform a downlink signal transmission through an unlicensed band (eg, a signal transmission including discovery signal transmission and no PDSCH) based on the second downlink CAP method described later.

When the length of the signal transmission section of the base station is 1 ms or less, the base station transmits a downlink signal (eg, discovery signal transmission) through an unlicensed band immediately after the corresponding channel is sensed as idle for at least sensing period T _drs =25 us. And PDSCH). Here, T _drs is composed of one slot section T _sl = 9us, followed by section T _f (=16us).

(3) 3rd downlink CAP method

The base station may perform the following CAP for downlink signal transmission through multiple carriers in an unlicensed band.

1) Type A: The base station performs CAP on multiple carriers based on counter N (counter N considered in CAP) defined for each carrier, and performs downlink signal transmission based on this.

-Type A1: Counter N for each carrier is determined independently of each other, and downlink signal transmission through each carrier is performed based on the counter N for each carrier.

-Type A2: Counter N for each carrier is determined as an N value for the carrier having the largest contention window size, and downlink signal transmission through the carrier is performed based on the counter N for each carrier.

2) Type B: The base station performs a CAP based on the counter N only for a specific carrier among a plurality of carriers, and performs downlink signal transmission by determining whether or not to channel idle for the remaining carriers before signal transmission on the specific carrier .

-Type B1: A single contention window size is defined for a plurality of carriers, and the base station utilizes a single contention window size when performing CAP based on Counter N for a specific carrier.

-Type B2: The contention window size is defined for each carrier, and when determining the N _init value for a specific carrier, the largest contention window size among the contention window sizes is used.

10 illustrates the SSB structure. The UE may perform cell search, system information acquisition, beam alignment for initial access, DL measurement, and the like based on the SSB. SSB is mixed with SS/PBCH (Synchronization Signal/Physical Broadcast channel) block.

Referring to Figure 10, SSB is composed of PSS, SSS and PBCH. SSB is composed of four consecutive OFDM symbols, and PSS, PBCH, SSS/PBCH and PBCH are transmitted for each OFDM symbol. PSS and SSS are each composed of 1 OFDM symbol and 127 subcarriers, and PBCH is composed of 3 OFDM symbols and 576 subcarriers. Polar coding and quadrature phase shift keying (QPSK) are applied to the PBCH. The PBCH is composed of a data RE and a DMRS (Demodulation Reference Signal) RE for each OFDM symbol. There are three DMRS REs for each RB, and three data REs exist between the DMRS REs.

Cell search refers to a process in which a terminal acquires time/frequency synchronization of a cell and detects a cell ID (eg, physical layer cell ID, PCID) of the cell. PSS is used to detect a cell ID within a cell ID group, and SSS is used to detect a cell ID group. PBCH is used for SSB (time) index detection and half-frame detection.

The cell search process of the terminal may be summarized as in Table 6 below.

	Type of Signals		Operations
1 st step	PSS	* SS/PBCH block (SSB) symbol timing acquisition* Cell ID detection within a cell ID group (3 hypothesis)
2 nd Step	SSS	* Cell ID group detection (336 hypothesis)
3 rd Step	PBCH DMRS	* SSB index and Half frame (HF) index (Slot and frame boundary detection)
4 th Step	PBCH	* Time information (80 ms, System Frame Number (SFN), SSB index, HF) * Remaining Minimum System Information (RMSI) Control resource set (CORESET)/Search space configuration
5 th Step	PDCCH and PDSCH	* Cell access information* RACH configuration

336 cell ID groups exist, and 3 cell IDs exist for each cell ID group. There are a total of 1008 cell IDs. Information about the cell ID group to which the cell ID of the cell belongs is provided/obtained through the SSS of the cell, and information about the cell ID among the 336 cells in the cell ID is provided/obtained through the PSS

11 illustrates multi-beam transmission of SSB.

Beam sweeping means that a transmission reception point (TRP) (eg, a base station/cell) changes a beam (direction) of a radio signal according to time (hereinafter, the beam and beam direction may be mixed). Referring to FIG. 8, the SSB may be periodically transmitted using beam sweeping. In this case, the SSB index is implicitly linked with the SSB beam. The SSB beam may be changed in SSB (index) units, or may be changed in SSB (index) group units. In the latter case, the SSB beam remains the same within the SSB (index) group. That is, the transmission beam reflection of the SSB is repeated in a plurality of consecutive SSBs. The maximum number of transmissions L of the SSB in the SSB burst set has a value of 4, 8 or 64 depending on the frequency band to which the carrier belongs. Therefore, the maximum number of SSB beams in the SSB burst set can also be given as follows according to the frequency band of the carrier.

-For frequency range up to 3 GHz, Max number of beams = 4

-For frequency range from 3GHz to 6 GHz, Max number of beams = 8

-For frequency range from 6 GHz to 52.6 GHz, Max number of beams = 64

However, when multi-beam transmission is not applied, the number of SSB beams is one.

When the terminal attempts an initial access to the base station, the terminal may align the beam with the base station based on the SSB. For example, the terminal performs SSB detection and then identifies the best SSB. Thereafter, the UE may transmit the RACH preamble to the base station using the PRACH resource linked/corresponding to the index (ie, beam) of the best SSB. SSB can be used to align the beam between the base station and the terminal even after the initial connection.

CSI Feedback

In the 3GPP LTE (-A) system, the user equipment (UE) is defined to report the channel state information (CSI) to the base station (BS). The channel state information (CSI) refers to information that can indicate the quality of a radio channel (or link) formed between a UE and an antenna port. For example, a rank indicator (RI), a precoding matrix indicator (PMI), and a channel quality indicator (CQI) may correspond to this. Here, RI represents the rank information of the channel, which means the number of streams that the UE receives through the same time-frequency resource. Since this value is determined by being dependent on the long term fading of the channel, it is fed back from the UE to the BS with a period that is usually longer than the PMI and CQI. PMI is a value reflecting channel space characteristics and indicates a precoding index preferred by the UE based on a metric such as SINR. CQI is a value indicating the strength of a channel, and generally means a received SINR obtained when a BS uses PMI.

In the 3GPP LTE (-A) system, the base station sets a plurality of CSI processes to the UE, and can report and receive CSI for each process. Here, the CSI process consists of CSI-RS for measuring signal quality from a base station and CSI-interference measurement (CSI-IM) resource for interference measurement.

CSI-related behavior

In the New Radio (NR) system, the channel state information-reference signal (CSI-RS) is time and/or frequency tracking (time/frequency tracking), CSI calculation (computation), RSRP (reference signal received power) calculation (computation) And for mobility. Here, CSI calculation is related to CSI acquisition, and RSRP calculation is related to beam management (BM).

12 is a flowchart illustrating an example of a CSI-related process.

-To perform one of the uses of the CSI-RS, the UE receives configuration information related to CSI from the BS through RRC signaling (S1201).

The CSI-related configuration information includes CSI-IM (interference management) resource related information, CSI measurement configuration related information, CSI resource configuration related information, and CSI-RS resource related information. Or, it may include at least one of CSI report configuration (report configuration) related information.

i) CSI-IM resource-related information may include CSI-IM resource information, CSI-IM resource set information, and the like. The CSI-IM resource set is identified by the CSI-IM resource set ID, and one resource set includes at least one CSI-IM resource. Each CSI-IM resource is identified by a CSI-IM resource ID.

ii) CSI resource configuration related information may be expressed by CSI-ResourceConfig IE. The CSI resource configuration related information defines a group including at least one of a non-zero power (NZP) CSI-RS resource set, a CSI-IM resource set, or a CSI-SSB resource set. That is, the CSI resource setting related information includes a CSI-RS resource set list, and the CSI-RS resource set list includes at least one of a NZP CSI-RS resource set list, a CSI-IM resource set list, or a CSI-SSB resource set list. It can contain one. The CSI-RS resource set is identified by the CSI-RS resource set ID, and one resource set includes at least one CSI-RS resource. Each CSI-RS resource is identified by a CSI-RS resource ID.

RRC parameters (eg, BM-related'repetition' parameter, tracking-related'trs-Info' parameter) indicating the use of CSI-RS for each NZP CSI-RS resource set may be set.

iii) CSI report configuration related information includes a report configuration type parameter indicating time domain behavior and a reportQuantity parameter indicating CSI related quantity for reporting. . The time domain behavior may be periodic, aperiodic or semi-persistent.

-The UE measures the CSI based on the configuration information related to the CSI (S1203). The CSI measurement may include (1) a CSI-RS reception process of the UE (S1205) and (2) a process of calculating CSI through the received CSI-RS (S1207). In CSI-RS, resource element (RE) mapping of CSI-RS resources in a time and frequency domain is set by the RRC parameter CSI-RS-ResourceMapping.

-The UE reports the measured CSI to the BS (S1209).

Beam failure recovery (BFR) process

In a beamformed system, radio link failure (RLF) may occur frequently due to UE rotation, movement, or beamforming blockage. Therefore, BFR is supported in the NR to prevent frequent RLF from occurring. BFR is similar to the radio link failure recovery process, and can be supported when the UE knows the new candidate beam(s).

For beam failure detection, the BS sets beam failure detection reference signals to the UE, and the UE has the number of beam failure indications from the physical layer of the UE within a period set by the RRC signaling of the BS. When the threshold set by RRC signaling is reached, a beam failure is declared.

After beam failure is detected, the UE triggers beam failure recovery by initiating a random access process on the PCell; Beam failure recovery is performed by selecting a suitable beam (if the BS provides dedicated random access resources for certain beams, they are prioritized by the UE). Upon completion of the random access procedure, beam failure recovery is considered complete.

In the NR system, a radio link monitoring-reference signal (RLM-RS), which is a reference signal for radio link monitoring, can use SS/PBCH block and CSI-RS with periodic transmission characteristics. Can. In particular, in the case of using multiple beams, beam failure detection (BFD) is determined based on channel quality for the serving beam, but radio link monitoring not only provides channel quality for the serving beam, but also the base station to the corresponding UE. It is possible to determine whether In-Sync/Out-of-Sync is based on channel quality for all potential beams. Further, for this purpose, a plurality of SS/PBCH blocks or a plurality of CSI-RS resources may be set as RLM-RS resources for RLM.

Here, the SS/PBCH block can be used for various purposes such as cell acquisition, time & frequency tracking, and RRM measurement for mobility support. In addition, since the SS/PBCH block is always transmitted in the primary serving cell that controls call setup, it can be used for radio link monitoring without additional resource allocation.

However, since the SS/PBCH block is transmitted in a narrow band even in a wideband system, the characteristics of the wideband channel cannot be fully reflected, and because it is composed of multiple OFDM symbols, in a system composed of very many beams, the SS/PBCH block Transmission can act as a large overhead. On the other hand, CSI-RS is not only capable of broadband transmission depending on resource configuration, but also can be transmitted as one OFDM symbol. Therefore, depending on the configuration of the system, it may be advantageous to use CSI-RS for beam management and radio link monitoring. In the present disclosure, radio link monitoring based on CSI-RS transmitted in such a wideband will be described. However, for convenience of description, in the present disclosure, the terms SS/PBCH block and CSI-RS are collectively referred to as embodiments of the present disclosure using the term RLM-RS.

In an NR system, radio link monitoring (RLM) may be performed using a wideband RLM-RS. In addition, the operation of performing RLM using a wideband RLM-RS may be performed in an unlicensed band. However, in the case of NR-U operating an NR system in an unlicensed band operated by one operator, unlike licensed bands, other systems such as Wi-Fi and licensed-assisted LAA operated by other operators Access) and/or the NR-U system may be operated simultaneously in the same band.

To this end, a system operating in an unlicensed band performs a Channel Clearance Assessment (CCA) operation to determine whether a channel is occupied and used by another system before performing transmission for coexistence with other systems. . That is, the signal can be transmitted only when it is determined that the frequency band to be transmitted through the CCA is in an idle state.

On the other hand, even in the case of the CCA for the RLM-RS of the broadband basically, it can be determined whether the channel is occupied for the entire system band used by the terminal. However, in general, a frequency band that can be used in an NR-U system may be larger than a basic frequency band used by an existing system such as Wi-Fi. For example, if the frequency band of the unlicensed band in which the NR-U system is operated is 80 MHz, while a system such as Wi-Fi or LAA is operating in 20 MHz units, the channel is performed by CCA operation performed for 80 MHz. The probability of being judged to be occupied can be much higher. In other words, even if only one 20MHz band is occupied by another system among four 20MHz unit bands included in the 80MHz band, it may be determined that the entire 80MHz band is occupied, so that the channel is determined to be occupied. The probability can be much higher.

In particular, in the case of a signal that is periodically transmitted, such as RLM-RS, the probability of determining that the channel is occupied may be increased due to the above-described problem, and accordingly, the periodic signal may be transmitted within a time period allocated for transmission of the periodic signal. The probability of transmission failure may increase. For example, when a channel is determined to be occupied by a CCA for a periodic signal, a plurality of transmittable candidate time positions during a specific time period may be preset in order to increase a transmission probability of the periodic signal. In addition, if the LBT (Listen Before Talk) fails at any one candidate time location, a periodic signal may be transmitted by delaying to the next possible candidate time location. In this case, due to the CCA of the entire band of the periodic signal transmitted over the wideband, if the channel is determined to be occupied, the UE may not perform an operation for periodically measuring the channel quality, and thus the reliability of the channel quality may decrease. have.

Therefore, in the present disclosure, considering the LBT, a method for periodically transmitting a wideband RLM-RS and a resource allocation method for the same are proposed. Also, a method of deriving a measurement result of radio link monitoring based on a transmission method and a resource allocation method according to an embodiment of the present disclosure will be described.

First, referring to FIG. 13, an example of implementing an operation of a network according to embodiments 1 to 2 of the present disclosure will be described.

Referring to FIG. 13, the base station may divide the entire frequency band to which the RLM-RS is allocated into a plurality of LBT subbands (S1301), and perform CCA in units of each LBT subband (S1303). Thereafter, the RLM-RS may be transmitted to the UE through each LBT subband based on the CCA performance result of each LBT subband (S1305). In this case, a specific method for transmitting RLM-RS by performing CCA in units of LBT subbands in S1303 to S1305 may be based on the first embodiment.

On the other hand, the terminal receiving the RLM-RS transmitted through each of the LBT subbands measures the RLM-RS (S1307), and the radio link is in-sync or out based on the RLM-RS measurement result. It may be determined whether it is -of-sync (S1309). In this case, a method of determining whether the terminal is In-sync/Out-of-sync of a radio link in steps S1307 to S1309 may be based on Example 2 described below.

Embodiment 1. Wideband RLM-RS transmission and LBT operation

One RLM-RS resource may be allocated to have an arbitrary frequency band within the system frequency band for the UE. However, in general, as described above, the frequency band for RLM-RS resources is allocated to occupy all or most of the frequency bands of the system frequency band. In this case, when the system frequency band is broadband and the entire frequency band is used as a frequency band for performing CCA (hereinafter referred to as'LBT sub-band)', RLM- within a time interval for RLM-RS transmission The probability that the periodic transmission of RS may fail may increase.

Therefore, in the case of a broadband system, it may be desirable to set the frequency band for the LBT subband to be smaller than the entire system band, not the entire system band. In addition, the LBT sub-band used when transmitting the RLM-RS may also be set smaller than the frequency band set for the RLM-RS. Meanwhile, in the present disclosure,'broadband' may mean a wider frequency band than the basic frequency band used by other systems that coexist with the NR-U system.

In other words, when the transmission frequency band of the RLM-RS is larger than the sub-band for the LBT, the RLM-RS may be transmitted through partial bands smaller than the set frequency band. Specifically, the RLM-RS may be transmitted according to the following embodiments, and the channel quality measurement method of the terminal may also be performed according to the following embodiments.

(1) Example 1-1

When the bandwidth of the wideband RLM-RS is about the size of the N LBT sub-bands, and the M LBT sub-bands are determined to be idle, the M LBT sub-bands RLM-RS may be transmitted only through (sub-band) and RLM-RS may not be transmitted for NM LBT subbands. In this case, the terminal measures the channel quality for at least one LBT subband (up to M LBT subbands) among the M LBT subbands, and derives the channel quality of the bandwidth of the entire broadband RLM-RS based on this. can do.

In this case, the channel quality measurement may be attempted at the location of the LBT subband where the RLM-RS is expected to be transmitted. If it is determined that the RLM-RS has not been transmitted by the base station in any LBT subband, attempts to detect the RLM-RS at the candidate time location allocated after the candidate time location for the RLM-RS that also measures the current channel quality. can do. For example, among the LBT subbands included in all candidate time positions, the UE may repeat the channel quality measurement until it is determined that the base station has successfully transmitted the RLM-RS through at least one LBT subband. .

(2) Example 1-2

When it is determined that the M LBT sub-bands are idle while the bandwidth of the broadband RLM-RS is about the size of N LBT sub-bands, the M LBT subs are determined. After transmitting the RLM-RS only through the sub-band and performing the CCA based on the LBT sub-band at the next candidate time location set for the delay transmission of the RLM-RS for the NM LBT sub-bands, the channel is idle. If it is determined that the (idle) state, it is possible to perform the delay transmission of the RLM-RS. In this case, the UE can measure the channel quality for all candidate time positions expected to be delayed and use all possible results as channel quality for the entire band. However, when deriving the final channel quality, how many LBT subbands to use for the measurement result can be determined by considering the accuracy of the channel quality for at least one LBT subband.

(3) Examples 1-3

For Examples 1-1 or 1-2, if the terminal is determined to be occupied frequently because the entire frequency band may need to be measured at all times, unnecessary channel quality measurement may be performed.

Due to this, in order to alleviate the complexity of the terminal, the base station sets a reference LBT sub-band among the LBT sub-bands when the frequency band of the RLM-RS is larger than the LBT sub-band, and the reference LBT sub A plurality of candidate time locations capable of transmitting RLM-RS for a reference LBT sub-band may be defined. And, when it is determined that the channel for the reference LBT subband is occupied, the base station may attempt to delay transmission for transmission of the RLM-RS through the reference LBT subband. However, if it is determined that the channel is occupied at the first RLM-RS transmission location for the LBT subband other than the reference LBT subband, additional attempts for RLM-RS transmission may not be performed. In this case, the UE determines channel quality measurement and RLM-RS transmission for all LBT subbands only at the first RLM-RS transmission location, and channel quality measurement only for reference LBT subbands for the remaining candidate time locations. An operation for determining whether or not to transmit may be performed. In addition, the complexity of the terminal can be alleviated through this.

(4) Example 1-4

If it is determined that a channel is occupied even in one LBT sub-band among the LBT sub-bands, the base station may set the operation of the embodiment 1-1 or the embodiment 1-2 to the terminal without transmitting the entire RLM-RS. In this case, the terminal can also measure the channel quality based on Example 1-1 or Example 1-2 depending on the setting of the base station. If there is no setting in Examples 1-1 or 1-2, the UE may determine whether to transmit the RLM-RS for all bands and determine whether channel quality measurement performed for all frequency bands is valid. .

On the other hand, as in the above-described embodiments 1-1 to 1-4, similar to allocating one RLM-RS resource and performing partial band transmission through the CCA, multiple beams for one beam RLM-RS resources may be allocated in units of LBT subbands, and a plurality of allocated RLM-RS resources may be bundled to configure an RLM-RS resource set. Since each of these RLM-RS resource sets corresponds to one beam, the UE can derive one measurement metric for one RLM-RS resource set.

At this time, the RLM-RS transmission operation of the base station and the operation of the terminal accordingly may be performed in the same manner as in Example 1-1 and Example 1-2. However, in Example 1-1, a partial band is transmitted for each LBT sub-band for one RLM-RS resource, but in the above-described case, the RLM-RS resource for each RLM-RS resource. CCA and RLM-RS transmission may be performed in units of the included LBT subbands.

In other words, when the UE measures channel quality, a plurality of RLM-RS resources are allocated, but derives one representative channel quality measurement result from RLM-RS resources in one RLM-RS resource set. Can.

On the other hand, the LBT operation of the RLM-RS described above is RRM-RS (Radio Resource Management) for mobility support to perform operations similar to radio link monitoring as well as radio link monitoring. The same can be applied to RRM measurement using -Reference Signal) or beam tracking using BM-RS (Beam Management-Reference Signal).

Embodiment 2: In-Sync/Out-of-Sync determination method according to partial band transmission

The RLM-RS transmission method of Examples 1-1 to 1-4 enables partial band transmission of a broadband RLM-RS set for a broadband system. For partial band transmission of such a broadband signal, the terminal may receive RLM-RS in LBT sub-band units. In addition, the base station may determine whether to transmit the RLM-RS according to the LBT in LBT sub-band (sub-band) units.

In the second embodiment, a method for determining how to determine the channel quality for the entire system frequency band by the UE after determining whether the base station determines whether to transmit the RLM-RS in LBT sub-band units is described.

Here, the method for determining channel quality may mean a method of determining In-sync/Out-of-sync for each beam for radio link monitoring. In the NR system, as a result of determining whether the cell is the final In-sync/Out-of-sync, when the channel quality for each beam of all configured beams is Out-of-sync, it can be determined as the final Out-of-sync. . Therefore, if there is no special mention in Examples 2-1 to 2-4 described later, whether In-sync/Out-of-sync or channel quality is In-sync/Out-of-sync for each beam or channel quality for each beam Can mean In addition, the final channel quality result may follow the definition of In-sync/Out-of-sync in the NR system.

(1) Example 2-1

The UE determines whether to transmit RLM-RS in units of LBT sub-bands, and one representative LBT sub-band among LBT sub-bands determined to have been transmitted by RLM-RS. ). The UE may calculate a subcarrier signal to noise ratio (SNR) for the selected LBT sub-band and obtain an average SNR or a hypothetical PDCCH BLER (Block Error Rate). Since the average SNR and/or virtual PDCCH BLER represents the channel quality for the entire frequency band, it is possible to determine whether In-sync/Out-of-sync using the average SNR or virtual PDCCH BLER and Qin/Qout values. have. In other words, the base station transmits the broadband RLM-RS through a plurality of LBT subbands, but the terminal can perform final radio link monitoring using one LBT subband. .

(2) Example 2-2

According to the embodiment 2-1, it is not possible to acquire the channel quality for the entire broadband according to the broadband RLM-RS transmission, and there is an effect of increasing only the possibility of periodic transmission of the RLM-RS. Therefore, in Example 2-2, a method for determining whether to perform in-sync/out-of-sync will be described so as to obtain channel quality for a wide frequency band as well as possible periodic transmission of RLM-RS.

To this end, the subcarrier SNR and the average SNR are calculated in LBT sub-band units, and after each LBT sub-band is determined to be LBT, the LBT sub-band in which the RLM-RS is determined is transmitted. Using (sub-band) subcarrier SNR and average SNR, average SNR and/or hypothetical PDCCH BLER for RLM-RS resource or RLM-RS resource set can be obtained. In addition, in-sync/out-of-sync using average SNR and/or hypothetical PDCCH BLER value and Qin/Qout value for the obtained RLM-RS resource or RLM-RS resource set Can judge.

(3) Example 2-3

On the other hand, determining whether to transmit the RLM-RS according to the LBT in a low SNR environment may result in a high missing probability or a high false alarm probability. In this case, it may be determined that the RLM-RS has not been transmitted even though the actual SNR is measured higher than Qout according to the decision metric used. Conversely, even though the actual SNR is measured lower than Qout, it may be determined that the RLM-RS is transmitted.

As such, if there is an error in the determination of the success or failure of the LBT, according to the accuracy of the determination of whether to transmit the RLM-RS according to the LBT, the average SNR and/or the RLM-RS resource or the RLM-RS resource set Or, the hypothetical PDCCH BLER can be affected a lot. In order to reduce this effect, it is determined whether in-sync/out-of-sync is performed for each LBT sub-band, and if it is determined to be out-of-sync in all LBT sub-bands, corresponding Channel quality for an RLM-RS resource or an RLM-RS resource set may be determined as out-of-sync. However, when it is determined that all LBT subbands are out-of-sync, it should be determined that the RLM-RS has been transmitted even in at least one LBT subband (sub-band). It can be judged as sync. That is, if it is not determined that the RLM-RS is transmitted in any LBT sub-band, even if the SNRs of all LBT sub-bands are lower than Qout, it may not be determined to be out-of-sync.

In addition, In-Sync can be defined as a state other than Out-of-Sync. In other words, even if one LBT sub-band is determined to be In-Sync, the channel quality for the corresponding RLM-RS resource may be defined as In-Sync.

(4) Example 2-4

Similar to Example 2-3, the average SNR and/or hypothetical PDCCH BLER is measured in units of LBT subbands, and In-sync based on the LBT subband with the highest average SNR and/or lowest BLER /Out-of-sync can be determined. In addition, according to the determination, it is possible to determine whether the corresponding RLM-RS resource or the corresponding RLM-RS resource set is In-sync/Out-of-sync.

14 to 16 are diagrams for describing an example of an operation implementation of a terminal, a base station, and a network according to embodiments 3 to 4 of the present disclosure.

14 is a view for explaining an example of the operation of the terminal according to the present disclosure. Referring to FIG. 14, the UE may receive a Discovery Reference Signal (DRS) within a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window and measure the reception quality of the DRS (S1401). ). At this time, the DRS may include SSB (Synchronization Signal Block) and CSI-RS (Channel State Information-Reference Signal). For example, the DRS may be an SSB or CSI-RS transmitted in a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window.

In addition, the terminal may receive the SSB outside the DMTC window and/or DTTC window, and measure the reception quality of the SSB (S1403). In addition, the terminal may determine whether a radio link failure (RLF) occurs based on the result of measuring DRS in the DMTC window and/or DTTC window and the result of measuring the SSB outside the DMTC window and/or DTTC window (S1405). . That is, the terminal may determine whether In-sync/Out-of-sync is based on the result of measuring the DRS in the DMTC window and/or DTTC window and the result of measuring the SSB outside the DMTC window and/or DTTC window. In this case, a method for determining whether a specific RLF is generated may be based on Examples 3 to 4 described later. Meanwhile, the terminal according to FIG. 14 may be any one of various wireless devices disclosed in FIGS. 21 to 23. For example, the terminal may be the first wireless device 100 of FIG. 21 or the wireless devices 100 and 200 of FIG. 22. In other words, the operation of the terminal according to FIG. 14 may be executed or performed by any one of various wireless devices disclosed in FIGS. 21 to 23.

15 is a view for explaining an example of the operation of the base station according to the present disclosure. Referring to FIG. 15, the base station may transmit a discovery reference signal (DRS) within a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window (S1501). At this time, the DRS may include SSB (Synchronization Signal Block) and CSI-RS (Channel State Information-Reference Signal). For example, the DRS may be an SSB or CSI-RS transmitted in a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window.

In addition, the base station may transmit the SSB outside the DMTC window and/or DTTC window (S1503). Meanwhile, specific operation processes of S1501 to S1503 may be based on Examples 3 to 4.

Meanwhile, the base station according to FIG. 15 may be any one of various wireless devices disclosed in FIGS. 21 to 23. For example, the base station may be the second wireless device 200 of FIG. 21 or the wireless devices 100 and 200 of FIG. 22. In other words, the operation of the base station according to FIG. 15 may be performed or performed by any one of various wireless devices disclosed in FIGS. 21 to 23.

16 is a diagram for explaining an example of implementing an operation of a network according to the present disclosure. Referring to FIG. 16, the base station may transmit a discovery reference signal (DRS) within a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window (S1501). At this time, the DRS may include SSB (Synchronization Signal Block) and CSI-RS (Channel State Information-Reference Signal).

When the terminal receives the DRS, it can measure the reception quality of the received DRS (S1603). In addition, the base station may transmit the SSB outside the DMTC window and/or DTTC window (S1605). Upon receiving the SSB, the UE can measure the reception quality of the SSB (S1607). The terminal may determine whether radio link failure (RLF) occurs based on the result of measuring DRS in the DMTC window and/or DTTC window and the result of measuring SSB outside the DMTC window and/or DTTC window (S1609). That is, the terminal may determine whether In-sync/Out-of-sync is based on the result of measuring the DRS in the DMTC window and/or DTTC window and the result of measuring the SSB outside the DMTC window and/or DTTC window. In this case, a method for determining whether a specific RLF is generated may be based on Examples 3 to 4 described later.

Example 3: In-sync / out-of-sync instruction / judgment method considering the SSB transmission method

In the unlicensed band, prior to transmitting a signal for coexistence with other systems, it is first checked whether the corresponding channel is idle, and then the corresponding signal can be transmitted when it is determined that the channel is idle. This can be called CCA (Channel Clearance Assessment).

On the other hand, in the case of a system that determines the transmission of a data channel by a scheduler, such as an NR system, if the channel is determined to be busy by the CCA in a state where the scheduler determines transmission of a specific signal, a specific signal until the corresponding channel is determined to be idle. You can either delay the transmission of, or give up and reschedule the transmission of a specific signal. However, in the case of a channel or a signal having a periodic transmission characteristic such as SSB (Synchronization Signal Block), if it is determined that the channel is busy, SSB transmission must be waited for as long as the SSB transmission period until SSB is retransmitted. Can be delayed. This may significantly delay the connection of the terminal to be connected to the system or cause a delay in the measurement of the channel quality of the terminal measuring the channel quality of the corresponding cell, thereby significantly degrading the mobility quality of the terminal.

Therefore, in the case of the NR-U system, similar to the Discovery Measuring Timing Configuration (DMTC) window of the Licensed Assisted Access (LAA) system, a DTRS (DRS transmission timing configuration) window for ensuring the maximum transmission of a discovery signal (DRS) is provided. Can be defined. Meanwhile, the DRS may include SSB and CSI-RS. That is, DRS may be one of SSB and CSI-RS, and among SSB or CSI-RS transmitted, an SSB or CSI-RS transmitted in a DMTC window or DTTC window may be referred to as DRS.

In this DTTC window, even if the channel is busy, delay transmission of the channel can be allowed in the DTTC window without waiting for the next cycle. Accordingly, in the NR-U system, SSB-based radio link monitoring (RRM) may be performed using all or part of DRS transmitted in the DTTC window. Therefore, it is possible to ensure periodic transmission of RLM-RS (radio link monitoring-reference signal) for RLM as much as possible. Here, RLM-RS means a reference signal for performing RLM, and may be, for example, SSB or CSI-RS. In other words, in the present disclosure, RLM-RS and DRS may be signals of the same type. That is, even if it is the same SSB or CSI-RS, the SSB or CSI-RS transmitted in the DMTC window or the DTTC window may mean DRS. On the other hand, RLM-RS may mean the entire SSB or CSI-RS transmitted for RLM regardless of whether it is transmitted within the DMTC window or DTTC window or outside the DMTC window or DTTC window.

As described above, when performing SSB transmission using DRS through the DTTC window, if the period of the DTTC window is set too small, the resource efficiency of the system decreases. As shown in FIG. 17, the base station shows the period of the DTTC window. It can be set longer than the transmission period of the SSB. Referring to FIG. 17, the SSB is transmitted at a time when the channel in the DTTC window is idle, and when the SSB transmission time determined based on the SSB transmission period outside the DTTC window is busy, the SSB is not transmitted until the next SSB transmission period without additional transmission. It may not.

As described above, in the case of RLM based on the unlicensed band SSB, receiving RLM using only the SSB corresponding to the DRS means that the SSB transmitted outside the DTTC window or the DMTC window is busy when the channel is busy. This is to ensure the maximum periodicity for channel quality measurement by using only the SSB corresponding to the DRS, since the periodicity of reporting on the channel quality cannot be secured when the SSB transmission is abandoned because the system abandons the transmission.

This is because the periodicity for channel quality measurement should be secured as much as possible, so that the UE can reduce the burden on detecting whether the DTX for the RLM-RS is DTX. For example, when the UE determines that the channel quality value of the SSB is higher than the set threshold, it is determined that it is In-Sync, so it can be sure that it is not DTX. However, when it is determined that the channel quality value of the SSB is lower than the set threshold, it is necessary to determine whether the channel quality is bad or the SSB is not transmitted because the channel is busy.

Therefore, in NR-U, SSB (that is, DRS) transmitted in the DTTC window may be used to minimize the effects of the above. However, even in this case, there is a possibility that a DTX detection error occurs for DRS, and when a DTX detection error occurs, unnecessary radio link failure (RLF) declaration may occur.

In order to solve this problem as much as possible, the terminal can perform detection of channel quality in as many locations as possible. For example, even if a DMTC window and/or DTTC window is set, the terminal may perform RLM using an SSB transmitted outside the DMTC window and/or DTTC window. For example, referring to FIG. 18, the terminal measures the channel quality for the SSB transmitted outside the DMTC window and/or DTTC window, and when the channel quality is higher than a set threshold, the SSB in the DMTC window and/or DTTC window Even if the channel quality is lower than the set threshold, there is a possibility that the channel quality measured in the DMTC window and/or DTTC window is a detection error due to DTX, so that the terminal determines the RLM result as In-Sync and reports it. Can.

That is, when the DMTC window and/or DTTC window for RLM is set, the terminal is an SSB transmitted outside the DMTC window and/or DTTC window, and a DRS transmitted within the DMTC window and/or DTTC window (eg, SSB and/or CSI-RS) channel quality is measured, and when it is determined that at least one channel quality corresponds to In-Sync, the UE may determine the radio link as In-Sync and periodically report it to the upper layer. have. At this time, the reporting period for reporting In-Sync/Out-of-Sync to the upper layer may be the same as the DMTC period for RLM. In other words, even if the channel quality is measured outside the DMTC window and/or DTTC window, the reporting period is the same as the DMTC period, and the reporting period may not be changed. That is, SSBs transmitted between two DMTC windows and/or DTTC windows and DRSs transmitted in the corresponding DMTC window and/or DTTC window can be assumed as one channel quality report as one set. have.

On the other hand, as shown in FIG. 19, the channel quality of the SSB transmitted between the DMTC window and/or DTTC window and the DRS (eg, SSB) transmitted within the DMTC window and/or DTTC window is measured, and all SSB and DRS If the channel quality does not correspond to In-Sync, the corresponding radio link can be defined as Out-Of-Sync and reported to the upper layer. At this time, the reporting period for reporting In-Sync/Out-of-Sync to the upper layer may be the same as the DMTC period for RLM. In other words, even if the channel quality is measured outside the DMTC window and/or DTTC window, the reporting period is the same as the DMTC period, and the reporting period may not be changed. That is, SSBs transmitted between two DMTC windows and/or DTTC windows and DRSs transmitted in the corresponding DMTC window and/or DTTC window can be assumed as one channel quality report as one set. have.

Here, it does not correspond to In-Sync may mean that it is determined as Out-Of-Sync or DTX. At this time, the terminal may determine that it is DTX for all SSBs. In addition, according to the descriptions based on FIGS. 18 to 19, the terminal secures the periodicity of reporting on In-Sync/Out-Of-Sync to the upper layer while minimizing the effect on the DTX detection error, RLM operation in a licensed band may be maintained.

Meanwhile, the SSB transmitted outside the DMTC window and/or the DTTC window may be transmitted by changing transmission power according to the operation of the base station. In this case, it may not be desirable to directly apply the value of Q_IN/Q_OUT for determining In-Sync/Out-Of-Sync. Accordingly, Q_IN/O_OUT for determining In-Sync/Out-Of-Sync may be separately set after measuring channel quality for SSBs other than DRS.

As described above, the RLM reporting period to the upper layer can be determined to be the same as the period of the DMTC window and/or DTTC window for RLM, but the RLM result is transmitted to the upper layer for each transmission period of the SSB for quick out-of-sync determination. You can also report. In this case, In-Sync/Out-Of-Sync can be determined by reflecting the channel quality measured based on N SSBs before reporting the RLM result to the upper layer in order to minimize the effect of the DTX detection error. Meanwhile, the N SSBs may be SSBs transmitted in the DMTC window and/or DTTC window, or SSBs transmitted outside the DMTC window and/or DTTC window. In addition, regardless of whether it is inside or outside the DMTC window and/or the DTTC window, it may be the most recently transmitted N SSBs based on the RLM reporting time. Here, N may be determined as the number of SSBs that can be transmitted within the DTTC window and/or DMTC window period, or may be separately set by the base station.

On the other hand, as described above, in the present disclosure, when setting the DMTC window for RLM, the terminal proposes to use the SSB existing between the DMTC window and the DMTC window to determine In-Sync/Out-Of-Sync. . At this time, when the UE determines the channel quality of all SSBs as DTX, ambiguity may occur in the operation of the UE. For example, in the case of an NR system operating in a licensed band, as a result of radio link quality measurement, only In-Sync/Out-Of-Sync existed, but unlicensed band Unlike in DTX, DTX also exists, so it is necessary to define the operation of the terminal. For example, the operation in the case where the terminal determines to be DTX may be as follows.

1) If a DTX other than In-Sync/Out-Of-Sync is not defined in the lower layer, and the channel quality is measured very low by DTX, the UE determines that the wireless link is Out-Of-Sync without additional judgment. By determining, the operation of all terminals can be the same as the operation of the RLM in a licensed band.

2) When the status of all SSBs in the lower layer is DTX, the terminal may finally determine as DTX, and maintain the previously reported status in the upper layer to report. For example, if in-sync is reported to the upper layer at the time of the previous report, if the channel quality of all SSBs is DTX, it can be reported as In-sync to the upper layer. Conversely, if out-of-sync is reported to the upper layer at the previous reporting time point, if the channel quality of all SSBs is DTX, it can be reported as out-of-sync to the upper layer.

If it is determined that all SSBs are DTX continuously, the In-sync/Out-of-Sync report corresponding to the earliest time from the time when it is determined to be DTX can be reported identically. The operation of the upper layer may be the same as the operation of the RLM in the licensed band. On the other hand, if the DTX is continuously detected above a certain value, or if the probability that the DTX is detected is above a certain value, the UE may report it to an upper layer, declare an RLF, or move to another frequency band.

3) When reporting the RLM results from the lower layer to the upper layer, when defining the DTX and channel quality of all SSBs is DTX, the DTX may be reported to the upper layer. At this time, a separate operation may be defined for DTX in the upper layer as described above. For example, when the upper layer reports DTX, the upper layer may determine the last reported In-Sync/Out-Of-Sync as the current channel quality. That is, if the channel quality report was previously In-Sync, even if DTX is reported, it can be assumed to be In-Sync. In addition, when the DTX is reported, the upper layer may maintain a value for a timer or counter and may not perform a separate operation.

Embodiment 4: Operation of the terminal when a plurality of SSBs are set in the frequency axis

In the third embodiment, considering that the SSB is not transmitted by the CCA operation such as LBT (Listen Before Talk), the DRS transmitted in the DMTC window and/or DTTC window, as well as the SSB transmitted outside the DMTC window and/or DTTC window It was proposed to measure channel quality by using and to determine In-Sync/Out-Of-Sync based on this. This is to minimize errors in DTX detection, thereby minimizing possible system effects caused by incorrect judgment of In-Sync/Out-Of-Sync. For example, if there are multiple RS transmission candidate locations for RLM, it may be desirable to use RLM-RS transmitted from the serving cell as much as possible for the operation of the unlicensed band RLM.

The NR system supports broadband, and the terminal can operate in a narrower frequency band than the system band if necessary. In this environment, in order to distribute the load of traffic in multiple frequency bands, the base station may transmit a plurality of SSBs in the system band. However, in the NR system, even if a plurality of SSBs are transmitted from the same base station, it is not necessary to use all of the SSBs for the operation of the terminal, and thus, information on all SSBs is not provided, and only the serving SSB used to access the cell is used. RLM/RRM can be performed. Here, the SSB used to access the cell may be referred to as a cell-defining SSB.

On the other hand, in the unlicensed band (unlicensed band), when transmitting the SSB through a plurality of frequencies, the frequency band for LBT (hereinafter referred to as'LBT subband') is smaller than the entire system frequency band LBT subband (sub-band) Not much can perform the LBT operation. Accordingly, according to the LBT result for each LBT subband, SSBs located at a specific frequency band may be transmitted even if SSBs located at a specific frequency band are not transmitted. Therefore, if the UE knows that all SSBs are transmitted from the same base station and have the same cell ID in an environment in which a plurality of SSBs are set, the UE SSBs in all frequency bands where the SSB is likely to be transmitted for RLM. Channel quality can be measured using.

Therefore, for SSB-based RLM operation in an unlicensed ban, when SSBs are transmitted in a plurality of frequency bands, related information such as frequency location and cell ID information of SSBs transmitted from a corresponding serving cell to the UE If notified, the terminal can determine whether In-Sync/Out-Of-Sync is performed using all possible SSBs. At this time, the definition of In-Sync/Out-Of-Sync is one channel among channel qualities for all SSBs used by the UE for channel measurement among SSBs indicated similarly to the method presented in Example 3 If the quality is higher than the threshold, the terminal may determine the radio link as In-Sync. If the channel qualities for all SSBs used by the UE among the indicated SSBs are lower than a preset threshold, the radio link may be determined as Out-Of-Sync. Meanwhile, the operation mentioned in Example 3 may be performed even when the detection for DTX is performed and it is determined that DTX is performed for all SSBs.

Meanwhile, the SSB in Example 4 may include not only the SSB transmitted in the DMTC window and/or DTTC window, but also the SSB transmitted outside the DMTC window and/or DTTC window.

Meanwhile, the methods mentioned in Example 4 can be performed in combination with the methods mentioned in Example 3. For example, RLM may be performed using a plurality of SSBs in the time axis according to Example 3 and the frequency axis according to Example 4, and In-Sync/Out-Of-Sync may be determined.

Without being limited thereto, various descriptions, functions, procedures, suggestions, methods and/or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication/connection (eg, 5G) between devices. have.

Hereinafter, with reference to the drawings will be illustrated in more detail. In the following drawings/description, the same reference numerals may exemplify the same or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise indicated.

20 illustrates a communication system 1 applied to the present invention.

Referring to FIG. 20, the communication system 1 applied to the present invention includes a wireless device, a base station and a network. Here, the wireless device means a device that performs communication using a wireless access technology (eg, 5G NR (New RAT), Long Term Evolution (LTE)), and may be referred to as a communication/wireless/5G device. Although not limited to this, the wireless device includes a robot 100a, a vehicle 100b-1, 100b-2, an XR (eXtended Reality) device 100c, a hand-held device 100d, and a home appliance 100e. ), Internet of Thing (IoT) device 100f, and AI device/server 400. For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous driving vehicle, a vehicle capable of performing inter-vehicle communication, and the like. Here, the vehicle may include a UAV (Unmanned Aerial Vehicle) (eg, a drone). XR devices include Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) devices, Head-Mounted Device (HMD), Head-Up Display (HUD) provided in vehicles, televisions, smartphones, It may be implemented in the form of a computer, wearable device, home appliance, digital signage, vehicle, robot, or the like. The mobile device may include a smart phone, a smart pad, a wearable device (eg, a smart watch, smart glasses), a computer (eg, a notebook, etc.). Household appliances may include a TV, a refrigerator, and a washing machine. IoT devices may include sensors, smart meters, and the like. For example, the base station and the network may also be implemented as wireless devices, and the specific wireless device 200a may operate as a base station/network node to other wireless devices.

The wireless devices 100a to 100f may be connected to the network 300 through the base station 200. AI (Artificial Intelligence) technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI server 400 through the network 300. The network 300 may be configured using a 3G network, a 4G (eg, LTE) network, or a 5G (eg, NR) network. The wireless devices 100a to 100f may communicate with each other through the base station 200/network 300, but may also directly communicate (e.g. sidelink communication) without going through the base station/network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g. Vehicle to Vehicle (V2V)/Vehicle to everything (V2X) communication). In addition, the IoT device (eg, sensor) may directly communicate with other IoT devices (eg, sensors) or other wireless devices 100a to 100f.

Wireless communication/ connections 150a, 150b, and 150c may be achieved between the wireless devices 100a to 100f/base station 200 and the base station 200/base station 200. Here, the wireless communication/connection is various wireless access such as uplink/downlink communication 150a and sidelink communication 150b (or D2D communication), base station communication 150c (eg relay, IAB (Integrated Access Backhaul)). It can be achieved through technology (eg, 5G NR), and wireless devices/base stations/wireless devices, base stations and base stations can transmit/receive radio signals to each other through wireless communication/ connections 150a, 150b, 150c. For example, the wireless communication/ connections 150a, 150b, 150c can transmit/receive signals through various physical channels.To do this, based on various proposals of the present invention, for the transmission/reception of wireless signals, At least some of various configuration information setting processes, various signal processing processes (eg, channel encoding/decoding, modulation/demodulation, resource mapping/demapping, etc.), resource allocation processes, and the like may be performed.

21 illustrates a wireless device that can be applied to the present invention.

Referring to FIG. 21, the first wireless device 100 and the second wireless device 200 may transmit and receive wireless signals through various wireless access technologies (eg, LTE and NR). Here, {the first wireless device 100, the second wireless device 200} is {wireless device 100x, base station 200} and/or {wireless device 100x), wireless device 100x in FIG. }.

The first wireless device 100 includes one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and/or one or more antennas 108. The processor 102 controls the memory 104 and/or transceiver 106 and may be configured to implement the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. For example, the processor 102 may process information in the memory 104 to generate the first information/signal, and then transmit the wireless signal including the first information/signal through the transceiver 106. In addition, the processor 102 may receive the wireless signal including the second information/signal through the transceiver 106 and store the information obtained from the signal processing of the second information/signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, memory 104 may be used to perform some or all of the processes controlled by processor 102, or instructions to perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. You can store software code that includes Here, the processor 102 and the memory 104 may be part of a communication modem/circuit/chip designed to implement wireless communication technology (eg, LTE, NR). The transceiver 106 can be coupled to the processor 102 and can transmit and/or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and/or receiver. The transceiver 106 may be mixed with a radio frequency (RF) unit. In the present invention, the wireless device may mean a communication modem/circuit/chip.

Specifically, the command and/or operations controlled by the processor 102 of the first wireless device 100 according to an embodiment of the present invention and stored in the memory 104 will be described.

The following operations are described based on the control operation of the processor 102 from the viewpoint of the processor 102, but may be stored in the memory 104 or the like for software code for performing the operation.

The processor 102 controls the transceiver 106 to receive a Discovery Reference Signal (DRS) within a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window, and measures the reception quality of the DRS. Can. At this time, the DRS may include SSB (Synchronization Signal Block) and CSI-RS (Channel State Information-Reference Signal). For example, the DRS may be an SSB or CSI-RS transmitted in a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window.

Further, the processor 102 may control the transceiver 106 to receive the SSB outside the DMTC window and/or the DTTC window, and measure the reception quality of the SSB. In addition, the processor 102 may determine whether radio link failure (RLF) occurs based on the result of measuring DRS in the DMTC window and/or DTTC window and the result of measuring SSB outside the DMTC window and/or DTTC window. . That is, the processor 102 may determine whether In-sync/Out-of-sync based on the result of measuring DRS in the DMTC window and/or DTTC window and the result of measuring SSB outside the DMTC window and/or DTTC window. Can. At this time, a method of determining whether a specific RLF is generated may be based on the above-described embodiments 3 to 4.

The second wireless device 200 includes one or more processors 202, one or more memories 204, and may further include one or more transceivers 206 and/or one or more antennas 208. Processor 202 controls memory 204 and/or transceiver 206 and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed herein. For example, the processor 202 may process information in the memory 204 to generate third information/signal, and then transmit a wireless signal including the third information/signal through the transceiver 206. In addition, the processor 202 may receive the wireless signal including the fourth information/signal through the transceiver 206 and store the information obtained from the signal processing of the fourth information/signal in the memory 204. The memory 204 may be connected to the processor 202, and may store various information related to the operation of the processor 202. For example, the memory 204 is an instruction to perform some or all of the processes controlled by the processor 202, or to perform the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. You can store software code that includes Here, the processor 202 and the memory 204 may be part of a communication modem/circuit/chip designed to implement wireless communication technology (eg, LTE, NR). The transceiver 206 can be coupled to the processor 202 and can transmit and/or receive wireless signals through one or more antennas 208. Transceiver 206 may include a transmitter and/or receiver. Transceiver 206 may be mixed with an RF unit. In the present invention, the wireless device may mean a communication modem/circuit/chip.

Specifically, a command and/or operation controlled by the processor 202 of the second wireless device 200 according to an embodiment of the present invention and stored in the memory 204 will be described.

The following operations are described based on the control operation of the processor 202 from the viewpoint of the processor 202, but may be stored in the memory 204 in software code or the like for performing the operation.

The processor 202 may control the transceiver 206 to transmit a discovery reference signal (DRS) within a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window. At this time, the DRS may include SSB (Synchronization Signal Block) and CSI-RS (Channel State Information-Reference Signal). For example, the DRS may be an SSB or CSI-RS transmitted in a Discovery Measuring Timing Configuration (DMTC) window and/or a DRS Transmission Timing Configuration (DTTC) window.

In addition, the processor 202 may control the transceiver 206 to transmit the SSB outside the DMTC window and/or DTTC window. The above-described operation process of the processor 202 may be based on the third to fourth embodiments.

Hereinafter, hardware elements of the wireless devices 100 and 200 will be described in more detail. Without being limited to this, one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102, 202 may implement one or more layers (eg, functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). The one or more processors 102 and 202 may include one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. Can be created. The one or more processors 102, 202 may generate messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein. The one or more processors 102, 202 generate signals (eg, baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, suggestions and/or methods disclosed herein. , To one or more transceivers 106, 206. One or more processors 102, 202 may receive signals (eg, baseband signals) from one or more transceivers 106, 206, and descriptions, functions, procedures, suggestions, methods and/or operational flow diagrams disclosed herein PDUs, SDUs, messages, control information, data, or information may be obtained according to the fields.

The one or more processors 102, 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. The one or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) May be included in one or more processors 102, 202. Descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this document may be implemented using firmware or software, and firmware or software may be implemented to include modules, procedures, functions, and the like. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein are either firmware or software set to perform or are stored in one or more processors 102, 202 or stored in one or more memories 104, 204. It can be driven by the above processors (102, 202). The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein may be implemented using firmware or software in the form of code, instructions and/or instructions.

The one or more memories 104, 204 may be coupled to one or more processors 102, 202, and may store various types of data, signals, messages, information, programs, codes, instructions, and/or instructions. The one or more memories 104, 204 may be comprised of ROM, RAM, EPROM, flash memory, hard drive, register, cache memory, computer readable storage medium, and/or combinations thereof. The one or more memories 104, 204 may be located inside and/or outside of the one or more processors 102, 202. Also, the one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as a wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, control information, radio signals/channels, and the like referred to in the methods and/or operational flowcharts of this document to one or more other devices. The one or more transceivers 106, 206 may receive user data, control information, radio signals/channels, and the like referred to in the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed herein from one or more other devices. have. For example, one or more transceivers 106, 206 may be coupled to one or more processors 102, 202, and may transmit and receive wireless signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Additionally, the one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be coupled to one or more antennas 108, 208, and one or more transceivers 106, 206 may be described, functions described herein through one or more antennas 108, 208. , It may be set to transmit and receive user data, control information, radio signals/channels, etc. referred to in procedures, suggestions, methods and/or operation flowcharts. In this document, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (eg, antenna ports). The one or more transceivers 106 and 206 process the received wireless signal/channel and the like in the RF band signal to process the received user data, control information, wireless signal/channel, and the like using one or more processors 102 and 202. It can be converted to a baseband signal. The one or more transceivers 106 and 206 may convert user data, control information, and radio signals/channels processed using one or more processors 102 and 202 from a baseband signal to an RF band signal. To this end, the one or more transceivers 106, 206 may include (analog) oscillators and/or filters.

22 shows another example of a wireless device applied to the present invention. The wireless device may be implemented in various forms according to usage-example/service (see FIG. 20).

Referring to FIG. 22, the wireless devices 100 and 200 correspond to the wireless devices 100 and 200 of FIG. 21, and various elements, components, units/units, and/or modules ). For example, the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional elements 140. The communication unit may include a communication circuit 112 and a transceiver(s) 114. For example, communication circuit 112 may include one or more processors 102,202 and/or one or more memories 104,204 of FIG. For example, the transceiver(s) 114 may include one or more transceivers 106,206 and/or one or more antennas 108,208 of FIG. 21. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional element 140, and controls the overall operation of the wireless device. For example, the controller 120 may control the electrical/mechanical operation of the wireless device based on the program/code/command/information stored in the memory unit 130. In addition, the control unit 120 transmits information stored in the memory unit 130 to the outside (eg, another communication device) through the wireless/wired interface through the communication unit 110, or externally (eg, through the communication unit 110). Information received through a wireless/wired interface from another communication device) may be stored in the memory unit 130. Accordingly, the operation process of the specific control unit 120 according to the present invention and the programs/codes/instructions/information stored in the memory unit 130 include at least one operation and memory 104, 204 of the processors 102, 202 of FIG. ).

The additional element 140 may be variously configured according to the type of wireless device. For example, the additional element 140 may include at least one of a power unit/battery, an input/output unit (I/O unit), a driving unit, and a computing unit. Although not limited to this, wireless devices include robots (FIGS. 20, 100A), vehicles (FIGS. 20, 100B-1, 100B-2), XR devices (FIGS. 20, 100C), portable devices (FIGS. 20, 100D), and household appliances. (Fig. 20, 100e), IoT device (Fig. 20, 100f), digital broadcasting terminal, hologram device, public safety device, MTC device, medical device, fintech device (or financial device), security device, climate/environment device, It may be implemented in the form of an AI server/device (Figs. 20 and 400), a base station (Figs. 20 and 200), and a network node. The wireless device may be mobile or may be used in a fixed place depending on use-example/service.

In FIG. 22, various elements, components, units/parts, and/or modules in the wireless devices 100 and 200 may be connected to each other through a wired interface, or at least some of them may be connected wirelessly through the communication unit 110. For example, in the wireless devices 100 and 200, the control unit 120 and the communication unit 110 are connected by wire, and the control unit 120 and the first unit (eg, 130, 140) are connected through the communication unit 110. It can be connected wirelessly. Further, each element, component, unit/unit, and/or module in the wireless devices 100 and 200 may further include one or more elements. For example, the controller 120 may be composed of one or more processor sets. For example, the control unit 120 may include a set of communication control processor, application processor, electronic control unit (ECU), graphic processing processor, and memory control processor. As another example, the memory unit 130 includes random access memory (RAM), dynamic RAM (DRAM), read only memory (ROM), flash memory, volatile memory, and non-volatile memory (non- volatile memory) and/or combinations thereof.

Hereinafter, the implementation example of FIG. 22 will be described in more detail with reference to the drawings.

23 illustrates a vehicle or an autonomous vehicle applied to the present invention. Vehicles or autonomous vehicles can be implemented as mobile robots, vehicles, trains, aerial vehicles (AVs), ships, and the like.

Referring to FIG. 23, a vehicle or an autonomous vehicle 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a driving unit 140a, a power supply unit 140b, a sensor unit 140c, and autonomous driving It may include a portion (140d). The antenna unit 108 may be configured as part of the communication unit 110. Blocks 110/130/140a-140d correspond to blocks 110/130/140 in FIG. 22, respectively.

The communication unit 110 may transmit and receive signals (eg, data, control signals, etc.) with external devices such as other vehicles, a base station (e.g. base station, road side unit, etc.) and a server. The controller 120 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 100. The controller 120 may include an electronic control unit (ECU). The driving unit 140a may cause the vehicle or the autonomous vehicle 100 to travel on the ground. The driving unit 140a may include an engine, a motor, a power train, wheels, brakes, and steering devices. The power supply unit 140b supplies power to the vehicle or the autonomous vehicle 100 and may include a wired/wireless charging circuit, a battery, and the like. The sensor unit 140c may obtain vehicle status, surrounding environment information, user information, and the like. The sensor unit 140c includes an inertial measurement unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a tilt sensor, a weight sensor, a heading sensor, a position module, and a vehicle forward /Reverse sensor, battery sensor, fuel sensor, tire sensor, steering sensor, temperature sensor, humidity sensor, ultrasonic sensor, illumination sensor, pedal position sensor, and the like. The autonomous driving unit 140d maintains a driving lane, automatically adjusts speed, such as adaptive cruise control, and automatically moves along a predetermined route, and automatically sets a route when a destination is set. Technology, etc. can be implemented.

For example, the communication unit 110 may receive map data, traffic information data, and the like from an external server. The autonomous driving unit 140d may generate an autonomous driving route and a driving plan based on the acquired data. The controller 120 may control the driving unit 140a such that the vehicle or the autonomous vehicle 100 moves along the autonomous driving path according to a driving plan (eg, speed/direction adjustment). During autonomous driving, the communication unit 110 may acquire the latest traffic information data non-periodically from an external server, and may acquire surrounding traffic information data from nearby vehicles. Also, during autonomous driving, the sensor unit 140c may acquire vehicle status and surrounding environment information. The autonomous driving unit 140d may update the autonomous driving route and driving plan based on newly acquired data/information. The communication unit 110 may transmit information regarding a vehicle location, an autonomous driving route, and a driving plan to an external server. The external server may predict traffic information data in advance using AI technology or the like based on the information collected from the vehicle or autonomous vehicles, and provide the predicted traffic information data to the vehicle or autonomous vehicles.

24 illustrates a signal processing circuit for a transmission signal.

Referring to FIG. 24, the signal processing circuit 1000 may include a scrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040, a resource mapper 1050, and a signal generator 1060. have. Without being limited thereto, the operations/functions of FIG. 24 may be performed in the processors 102, 202 and/or transceivers 106, 206 of FIG. The hardware elements of FIG. 24 can be implemented in the processors 102, 202 and/or transceivers 106, 206 of FIG. 21. For example, blocks 1010 to 1060 may be implemented in processors 102 and 202 of FIG. 21. Also, blocks 1010 to 1050 may be implemented in the processors 102 and 202 of FIG. 21, and block 1060 may be implemented in the transceivers 106 and 206 of FIG. 21.

The codeword may be converted into a wireless signal through the signal processing circuit 1000 of FIG. 24. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transport block (eg, UL-SCH transport block, DL-SCH transport block). The radio signal may be transmitted through various physical channels (eg, PUSCH, PDSCH).

Specifically, the codeword may be converted into a scrambled bit sequence by the scrambler 1010. The scramble sequence used for scramble is generated based on the initialization value, and the initialization value may include ID information of the wireless device. The scrambled bit sequence may be modulated by a modulator 1020 into a modulation symbol sequence. The modulation method may include pi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying (m-PSK), m-Quadrature Amplitude Modulation (m-QAM), and the like. The complex modulated symbol sequence may be mapped to one or more transport layers by the layer mapper 1030. The modulation symbols of each transport layer may be mapped to the corresponding antenna port(s) by the precoder 1040 (precoding). The output z of the precoder 1040 can be obtained by multiplying the output y of the layer mapper 1030 by the precoding matrix W of N*M. Here, N is the number of antenna ports and M is the number of transport layers. Here, the precoder 1040 may perform precoding after performing transform precoding (eg, DFT transformation) on complex modulation symbols. Further, the precoder 1040 may perform precoding without performing transform precoding.

The resource mapper 1050 may map modulation symbols of each antenna port to time-frequency resources. The time-frequency resource may include a plurality of symbols (eg, CP-OFDMA symbol, DFT-s-OFDMA symbol) in the time domain, and may include a plurality of subcarriers in the frequency domain. The signal generator 1060 generates a radio signal from the mapped modulation symbols, and the generated radio signal can be transmitted to other devices through each antenna. To this end, the signal generator 1060 may include an Inverse Fast Fourier Transform (IFFT) module and a Cyclic Prefix (CP) inserter, a Digital-to-Analog Converter (DAC), a frequency uplink converter, etc. .

The signal processing process for the received signal in the wireless device may be configured as the inverse of the signal processing processes 1010 to 1060 of FIG. 19. For example, a wireless device (eg, 100 and 200 in FIG. 17) may receive a wireless signal from the outside through an antenna port/transceiver. The received radio signal may be converted into a baseband signal through a signal restorer. To this end, the signal recoverer may include a frequency downlink converter (ADC), an analog-to-digital converter (ADC), a CP remover, and a Fast Fourier Transform (FFT) module. Thereafter, the baseband signal may be restored to a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scramble process. The codeword can be restored to the original information block through decoding. Accordingly, the signal processing circuit (not shown) for the received signal may include a signal restorer, a resource de-mapper, a post coder, a demodulator, a de-scrambler and a decoder.

The embodiments described above are those in which the components and features of the present invention are combined in a predetermined form. Each component or feature should be considered optional unless stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to constitute an embodiment of the invention by combining some components and/or features. The order of the operations described in the embodiments of the present invention can be changed. Some configurations or features of one embodiment may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is obvious that the claims may be combined with claims that do not have an explicit citation relationship in the claims, or may be included as new claims by amendment after filing.

In this document, a specific operation described as being performed by a base station may be performed by an upper node in some cases. That is, it is apparent that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station can be performed by a base station or other network nodes other than the base station. The base station may be replaced by terms such as a fixed station, gNode B (gNB), Node B, eNode B (eNB), access point, and the like.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the characteristics of the present invention. Accordingly, the above detailed description should not be construed as limiting in all respects, but should be considered illustrative. The scope of the invention should be determined by rational interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

A method for transmitting and receiving a reference signal for wireless link monitoring in the unlicensed band as described above and an apparatus therefor have been mainly described as an example applied to the 5th generation NewRAT system, but it is applicable to various wireless communication systems in addition to the 5th generation NewRAT system. It is possible.

Claims (15)

1. In the method for measuring the radio link by the terminal in the unlicensed band,

   Receive information related to the reception window for DRS (Discovery Reference Signal),

   Receiving at least one DRS within the reception window,

   Receiving at least one Synchronization Signal Block (SSB) outside the reception window,

   Measuring radio link qualities for each of the at least one DRS and the at least one SSB,

   Among the radio link qualities for the at least one DRS and the at least one SSB, the radio link is determined to be In-Sync based on one or more radio link quality is greater than a threshold,

   Based on that both the radio link qualities for the at least one DRS and the at least one SSB are below a threshold, the radio link is determined to be out-of-sync or the at least one DRS and the at least one SSB are both Determined to be DTX (Discontinuous Transmission),

   How to measure wireless links.
2. According to claim 1,

   The DRS,

   SSB or CSI-RS (Channel State Information-Reference Signal),

   How to measure wireless links.
3. According to claim 1,

   The information related to the reception window includes information on the period of the reception window,

   The at least one SSB is received during the time period for the period from the reception window,

   How to measure wireless links.
4. According to claim 1,

   Based on the determination that both the at least one DRS and the at least one SSB are DTX, the previous report content is reported again,

   How to measure wireless links.
5. According to claim 1,

   The transmission power of the at least one DRS and the transmission power of the at least one SSB are different,

   How to measure wireless links.
6. According to claim 1,

   The reporting period for reporting the radio link quality to the upper layer,

   The same as the period of the reception window,

   How to measure wireless links.
7. According to claim 1,

   The terminal can communicate with at least one of a terminal, a network, a base station, and an autonomous vehicle other than the terminal,

   How to measure wireless links.
8. In the terminal for measuring the radio link in the unlicensed band,

   At least one transceiver;

   At least one processor; And

   And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a specific operation.

   The specific operation,

   Through the at least one transceiver, receives information related to a reception window for DRS (Discovery Reference Signal),

   Receiving at least one DRS in the reception window through the at least one transceiver,

   Through the at least one transceiver, receive at least one Synchronization Signal Block (SSB) outside the receive window,

   Measuring radio link qualities for each of the at least one DRS and the at least one SSB,

   Among the radio link qualities for the at least one DRS and the at least one SSB, the radio link is determined to be In-Sync based on one or more radio link quality is greater than a threshold,

   Based on that both the radio link qualities for the at least one DRS and the at least one SSB are below a threshold, the radio link is determined to be out-of-sync or the at least one DRS and the at least one SSB are both Determined to be DTX (Discontinuous Transmission),

   Terminal.
9. The method of claim 8,

   The DRS,

   SSB or CSI-RS (Channel State Information-Reference Signal),

   Terminal.
10. The method of claim 8,

    The information related to the reception window includes information on the period of the reception window,

    The at least one SSB is received during the time period for the period from the reception window,

    Terminal.
11. The method of claim 8,

    Based on the determination that both the at least one DRS and the at least one SSB are DTX, the previous report content is reported again,

    Terminal.
12. The method of claim 8,

    The transmission power of the at least one DRS and the transmission power of the at least one SSB are different,

    Terminal.
13. The method of claim 8,

    The reporting period for reporting the radio link quality to the upper layer,

    The same as the period of the reception window,

    Terminal.
14. The method of claim 8,

    The terminal can communicate with at least one of a terminal, a network, a base station, and an autonomous vehicle other than the terminal,

    Terminal.
15. An apparatus for measuring a radio link in an unlicensed band,

    At least one processor; And

    And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a specific operation.

    The specific operation,

    Receive information related to the reception window for DRS (Discovery Reference Signal),

    Receiving at least one DRS within the reception window,

    Receiving at least one Synchronization Signal Block (SSB) outside the reception window,

    Measuring radio link qualities for each of the at least one DRS and the at least one SSB,

    Among the radio link qualities for the at least one DRS and the at least one SSB, the radio link is determined to be In-Sync based on one or more radio link quality is greater than a threshold,

    Based on that all of the radio link qualities for the at least one DRS and the at least one SSB are below a threshold, the radio link is determined to be out-of-sync or the at least one DRS and the at least one SSB is a DTX (Discontinuous Transmission),

    Device.

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