Method executed by terminal, device thereof and terminal

Abstract

The invention relates to a method executed by a terminal, a device thereof and the terminal. The present disclosure discloses a method by which a terminal performs a random access channel (RACH) procedure in an unlicensed band. Specifically, the method comprises the steps of: transmitting a first physical random access channel (PRACH) preamble through a message A; and receiving a random access response (RAR) through a message B related to contention resolution in response to the message A, in which the first PRACH preamble is a PRACH preamble mapped to a Physical Uplink Shared Channel (PUSCH) occasion for the message A, and the window for receiving the message B may start after at least one symbol from the last symbol of the PUSCH occasion.

Description

[0001] This application is a divisional application of the invention patent application with the original application number 202080068730.9 (International application number: PCT / KR2020 / 006586, application date: May 20, 2020, invention name: Method and device for performing a random access channel process by a terminal in an unlicensed frequency band). Technical Field

[0002] The present disclosure relates to a method and apparatus for performing a random access procedure by a terminal in an unlicensed frequency band, and more particularly, to a method and apparatus for performing a two-step random access procedure by a terminal in an unlicensed frequency band. Background Art

[0003] As more and more communication devices require greater communication services over time, a next-generation 5G system that improves wireless broadband communication compared to the existing LTE system is needed. In this next-generation 5G system called NewRAT, communication scenarios are divided into enhanced mobile broadband (eMBB) / ultra-reliability and low-latency communication (URLLC) / massive machine type communication (mMTC).

[0004] Here, eMBB is a next-generation mobile communication scenario with characteristics such as high spectral efficiency, high user experience data rate, and high peak data rate, URLLC is a next-generation mobile communication scenario with characteristics such as ultra-reliability, ultra-low latency, and ultra-high availability (e.g., V2X, emergency services, remote control), and mMTC is a next-generation mobile communication scenario with characteristics such as low cost, low energy, short packets, and large-scale connections (e.g., IoT). Summary of the invention

[0005] Technical issues

[0006] An object of the present disclosure is to provide a method for performing a two-step random access procedure by a terminal, and a device therefor.

[0007] The technical objectives to be achieved in the present disclosure are not limited to the above-mentioned technical objectives, and other technical objectives not mentioned can be clearly understood from the following description by a person of ordinary skill in the art to which the present disclosure belongs.

[0008] Technical Solution

[0009] According to an embodiment of the present disclosure, a method for a terminal to perform a random access channel (RACH) process in an unlicensed frequency band is provided, and the method may include the following steps: sending a first physical random access channel (PRACH) preamble to a base station through a message A; and receiving a random access response (RAR) from the base station through a message B related to contention resolution in response to the message A, wherein the first PRACH preamble may be a PRACH preamble mapped to a physical uplink shared channel (PUSCH) opportunity for the message A, and a window for receiving the message B may start at least one symbol after the last symbol of the PUSCH opportunity.

[0010] Here, the first PUSCH and the first PRACH preamble code based on the PUSCH opportunity can be sent through message A.

[0011] Additionally, the RAR may be a successful RAR including information about contention resolution.

[0012] In addition, only the first PRACH preamble code can be sent through message A.

[0013] Additionally, the RAR may be a fallback RAR including uplink (UL) grant information.

[0014] Alternatively, the window may start at the first symbol of a resource associated with monitoring of message B.

[0015] In addition, the PUSCH opportunity may be a valid PUSCH opportunity associated with the RACH opportunity of the first PRACH preamble.

[0016] According to an embodiment of the present disclosure, a device for performing a random access channel (RACH) process in an unlicensed frequency band is provided, the device may include: at least one processor; and at least one memory, the at least one memory being operatively connected to the at least one processor and storing instructions, the instructions performing specific operations based on being executed by the at least one processor, wherein the specific operations may include: sending a first physical random access channel (PRACH) preamble through message A; and receiving a random access response (RAR) through message B related to contention resolution in response to message A, wherein the first PRACH preamble may be a PRACH preamble mapped to a physical uplink shared channel (PUSCH) opportunity for message A, and a window for receiving message B may start at least one symbol after the last symbol of the PUSCH opportunity.

[0017] Here, the first PUSCH and the first PRACH preamble code based on the PUSCH opportunity can be sent through message A.

[0018] Additionally, the RAR may be a successful RAR including information about contention resolution.

[0019] In addition, only the first PRACH preamble code can be sent through message A.

[0020] Additionally, the RAR may be a fallback RAR including uplink (UL) grant information.

[0021] Alternatively, the window may start at the first symbol of a resource associated with monitoring of message B.

[0022] In addition, the PUSCH opportunity may be a valid PUSCH opportunity associated with the RACH opportunity of the first PRACH preamble.

[0023] According to an embodiment of the present disclosure, a terminal for performing a random access channel (RACH) process in an unlicensed frequency band is provided, and the terminal may include: at least one transceiver; at least one processor; and at least one memory, wherein the at least one memory is operatively connected to the at least one processor and stores instructions, wherein the instructions are executed based on the at least one processor to perform specific operations, wherein the specific operations may include: sending a first physical random access channel (PRACH) preamble to a base station through a message A; and receiving a random access response (RAR) from the base station through a message B related to contention resolution in response to the message A, wherein the first PRACH preamble may be a PRACH preamble mapped to a physical uplink shared channel (PUSCH) opportunity for the message A, and a window for receiving the message B may start at least one symbol after the last symbol of the PUSCH opportunity.

[0024] Beneficial Effects

[0025] According to the present disclosure, a terminal in an unlicensed frequency band can appropriately configure a time point for receiving a signal for performing a random access procedure, and can easily perform a two-step random access procedure.

[0026] Effects that can be obtained from the present disclosure are not limited to the above-mentioned effects, and other effects that are not mentioned can be clearly understood from the following description by a person of ordinary skill in the art to which the present disclosure pertains. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The diagram illustrates the control plane and user plane structures of a radio interface protocol between a terminal and E-UTRAN based on the 3GPP radio access network standard.

[0028] Figure 2 This is a diagram for explaining physical channels used in the 3GPP system and a general signal transmission method using these physical channels.

[0029] Figures 3 to 5 A diagram for explaining the structure of a radio frame and a time slot used in the NR system.

[0030] Figures 6 to 11 This is a diagram for explaining the composition and transmission method of the SS / PBCH block.

[0031] Fig.12 is a diagram illustrating an example of a random access procedure.

[0032] Fig.13 This is a diagram used to illustrate the multiplexing of long physical uplink control channel (PUCCH) and short PUCCH in the NR system.

[0033] Fig.14 The ACK / NACK transmission process is illustrated.

[0034] Figures 15 to 17 It is a diagram for explaining channel transmission in an unlicensed band.

[0035] Figures 18 to 20 This is a diagram used to illustrate the physical downlink control channel (PDCCH) in the NR system.

[0036] Figure 21 to Figure 22 It is a diagram for explaining a specific operation implementation example of a terminal and a base station according to an embodiment of the present disclosure.

[0037] Fig.23 This is a diagram illustrating the basic processing of 2-step RACH.

[0038] Fig.24 is a diagram illustrating an example of configuring a reception window of Msg B according to success or failure of LBT for Msg A PUSCH transmission.

[0039] Fig.25 is a diagram illustrating an example of configuring the reception window of Msg B regardless of the success or failure of LBT for Msg A PUSCH transmission.

[0040] Fig.26 is a diagram illustrating an example of configuring a reception window of MsgB according to a PUSCH opportunity in which LBT has succeeded among a plurality of PUSCH opportunities.

[0041] Fig. 27 is a diagram illustrating an example of configuring the reception window of Msg B according to the last PUSCH opportunity regardless of the success or failure of LBT among multiple PUSCH opportunities.

[0042] Fig.28An example of a wireless communication environment to which embodiments of the present disclosure may be applied is shown.

[0043] Figure 29 to Figure 32 Examples of various wireless devices to which the embodiments of the present disclosure are applied are shown.

[0044] Fig.33 An example of a signal processing circuit to which an embodiment of the present disclosure is applied is shown. DETAILED DESCRIPTION

[0045] The configuration, operation and other features of the present disclosure can be easily understood through the embodiments of the present disclosure described below with reference to the accompanying drawings. The embodiments described below are examples of applying the technical features of the present disclosure to a 3GPP system.

[0046] Although the present disclosure uses an LTE system, an LTE-A system, and an NR system to describe the embodiments of the present disclosure, these are merely examples and the embodiments of the present disclosure may be applied to any communication system falling within the above definitions.

[0047] In addition, in the present disclosure, the name of a base station may be used as a general term including a remote radio head (RRH), an eNB, a transmission point (TP), a reception point (RP), a relay, and the like.

[0048] The communication standard based on 3GPP defines downlink physical channels corresponding to resource elements carrying information from a higher layer, and downlink physical signals corresponding to resource elements used by the physical layer but not carrying information from a higher layer. For example, the physical downlink shared channel (PDSCH), the physical broadcast channel (PBCH), the physical multicast channel (PMCH), the physical control format indicator channel (PCFICH), the physical downlink control channel (PDCCH), and the physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, and reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also known as a pilot, refers to a signal of a predefined specific waveform known to the gNB and the UE, for example, a cell-specific RS, a UE-specific RS (UE-RS), a positioning RS (PRS), and a channel state information RS (CSI-RS) are defined as downlink reference signals. The 3GPP LTE / LTE-A standard defines uplink physical channels corresponding to resource elements carrying information from a higher layer, and uplink physical signals corresponding to resource elements used by the physical layer but not carrying information from a higher layer. For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are defined as uplink physical channels, and a demodulation reference signal (DMRS) for uplink control / data signals and a sounding reference signal (SRS) for uplink channel measurement are defined.

[0049] In the present disclosure, PDCCH (Physical Downlink Control Channel) / PCFICH (Physical Control Format Indicator Channel) / PHICH (Physical Hybrid Automatic Repeat Request Indicator Channel) / PDSCH (Physical Downlink Shared Channel) are a set of time-frequency resources or a set of resource elements carrying DCI (Downlink Control Information) / CFI (Control Format Indicator) / Downlink ACK / NACK (Acknowledgement / Negative ACK) / Downlink data, respectively. In addition, PUCCH (Physical Uplink Control Channel) / Physical Uplink Shared Channel (PUSCH) / Physical Random Access Channel (PRACH) respectively mean a set of time-frequency resources or a set of resource elements carrying uplink control information (UCI) / uplink data / random access signals. Specifically, the time-frequency resources or resource elements (REs) allocated to or belonging to PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH are respectively referred to as PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH REs or PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH resources. Hereinafter, the expression that the user equipment transmits PUCCH / PUSCH / PRACH respectively is used in the same meaning as transmitting uplink control information / uplink data / random access signal on or through PUSCH / PUCCH / PRACH. In addition, the expression that the gNB transmits PDCCH / PCFICH / PHICH / PDSCH respectively is used in the same meaning as transmitting downlink data / control information on or through PDCCH / PCFICH / PHICH / PDSCH.

[0050] Below, the OFDM symbol / subcarrier / RE to which CRS / DMRS / CSI-RS / SRS / UE-RS is assigned or configured is referred to as CRS / DMRS / CSI-RS / SRS / UE-RS symbol / carrier / subcarrier / RE. For example, the OFDM symbol to which the tracking RS (TRS) is assigned or configured is referred to as the TRS symbol, the subcarrier to which the TRS is assigned or configured is referred to as the TRS subcarrier, and the RE to which the TRS is assigned or configured is referred to as the TRS RE. In addition, the subframe configured to be sent by TRS is referred to as the TRS subframe. In addition, the subframe in which a broadcast signal is sent is referred to as a broadcast subframe or a PBCH subframe, and the subframe in which a synchronization signal (e.g., PSS and / or SSS) is sent is referred to as a synchronization signal subframe or a PSS / SSS subframe. The OFDM symbol / subcarrier / RE to which the PSS / SSS is assigned or configured is referred to as the PSS / SSS symbol / subcarrier / RE, respectively.

[0051] In the present disclosure, a CRS port, a UE-RS port, a CSI-RS port, and a TRS port respectively mean an antenna port configured to send a CRS, an antenna port configured to send a UE-RS, an antenna port configured to send a CSI-RS, and an antenna port configured to send a TRS. The antenna ports configured to send a CRS can be distinguished from each other according to the position of the RE occupied by the CRS according to the CRS port; the antenna ports configured to send a UE-RS can be distinguished from each other according to the position of the RE occupied by the UE-RS according to the UE-RS port; the antenna ports configured to send a CSI-RS can be distinguished from each other according to the position of the RE occupied by the CSI-RS according to the CSI-RS port. Therefore, the term CRS / UE-RS / CSI-RS / TRS port is also used as a term to mean the pattern of REs occupied by CRS / UE-RS / CSI-RS / TRS within a specific resource area.

[0052] Now, 5G communication including the NR system will be described.

[0053] The three main demand areas of 5G are (1) enhanced mobile broadband (eMBB), (2) massive machine-type communications (mMTC), and (3) ultra-reliable and low-latency communications (URLLC).

[0054] Some use cases may require multiple areas to be optimized, while others may focus on just one key performance indicator (KPI). 5G supports these different use cases in a flexible and reliable way.

[0055] eMBB goes far beyond basic mobile Internet access to cover rich interactive work, media and entertainment applications in the cloud or augmented reality. Data is one of the key drivers of 5G, and for the first time in the 5G era, we may not see dedicated voice services. In 5G, voice is simply expected to be processed as an application using the data connection provided by the communication system. The main reasons for the increase in traffic are the increase in content size and the increase in the number of applications that require high data rates. Streaming services (audio and video), interactive video, and mobile Internet connections will become more widely used as more devices are connected to the Internet. Many of these applications require always-on connections to push real-time information and notifications to users. Cloud storage and applications are growing rapidly in mobile communication platforms, which can be applied to work and entertainment. In addition, 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 lower end-to-end latency to maintain a good user experience when using tactile interfaces. Entertainment (e.g., cloud gaming and video streaming) is another key factor that increases the demand for mobile broadband capabilities. Entertainment is essential for smartphones and tablets everywhere, including in high-mobility environments such as trains, cars, and airplanes. Another use case is augmented reality for entertainment and information retrieval. Here, augmented reality requires very low latency and instantaneous data volume.

[0056] Additionally, one of the most anticipated 5G use cases involves the ability to seamlessly connect embedded sensors in all areas (i.e., mMTC). By 2020, the number of potential IoT devices is expected to reach 20.4 billion. Industrial IoT is one of the areas where 5G will play an important role in enabling smart cities, asset tracking, smart utilities, agriculture, and secure infrastructure.

[0057] URLLC includes new services that transform industries through ultra-reliable / available low-latency links (e.g., autonomous vehicles and remote control of critical infrastructure). This level of reliability and latency is critical for smart grid control, industrial automation, robotics, and drone control and coordination.

[0058] Next, many use cases in a 5G communication system including an NR system will be described in more detail.

[0059] 5G can complement fiber to the home (FTTH) and cable-based broadband (or DOCSIS) as a means of providing streaming at hundreds of megabits per second to gigabits per second. Such high speeds are needed to deliver TV at 4K and higher resolutions (6K, 8K and beyond) as well as virtual and augmented reality. Virtual reality (VR) and augmented reality (AR) applications almost include immersive sports events. Certain applications may require special network settings. For example, for VR games, gaming companies may need to integrate core servers with network operators' edge network servers to minimize latency.

[0060] Cars are expected to be an important new driver for 5G, with many use cases for mobile communications in vehicles. For example, entertainment for passengers requires mobile broadband with both high capacity and high mobility. The reason is that future users continue to expect high-quality connections regardless of their location and speed. Another use case in the automotive industry is an augmented reality dashboard. It identifies objects in the dark and overlays information on the object the driver is seeing through the front window to inform the driver about the distance and movement of the object. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure, and information exchange between cars and other connected devices (e.g., devices carried by pedestrians). Safety systems can help drivers drive safely by guiding alternative action processes, thereby helping drivers reduce the risk of accidents. The next step is remote control or autonomous driving of vehicles. This requires very reliable and very fast communication between different autonomous vehicles and between vehicles and infrastructure. In the future, autonomous vehicles will perform all driving activities, allowing drivers to focus only on traffic anomalies that the vehicle itself cannot discern. The technical requirements for autonomous vehicles require ultra-low latency and ultra-fast reliability to improve traffic safety to a level that humans cannot achieve.

[0061] Smart cities and smart homes (referred to as smart societies) will be embedded with high-density wireless sensor networks. Distributed networks of smart sensors will identify the conditions for cost and energy efficiency maintenance of cities or houses. Similar settings can be performed for each family. Temperature sensors, window and heating controllers, burglar alarms, and electrical appliances are all wirelessly connected. Many of these sensors are typically low data rate, low power, and low cost. However, for example, real-time HD video may be required in certain types of devices for monitoring.

[0062] The consumption and distribution of energy (including heat or gas) is highly decentralized, requiring automated control of distributed sensor networks. Smart grids use digital information and communication technologies to interconnect these sensors to collect information and act on the sensors. This information can include supplier and consumer behavior, enabling smart grids to improve the efficiency, reliability, economy, and sustainability of the production and distribution of fuels (such as electricity) in an automated manner. Smart grids can also be viewed as another low-latency sensor network.

[0063] The health sector has many applications that can benefit from mobile communications. Communication systems can support telemedicine that provides clinical care from remote locations. This can help reduce distance barriers and improve healthcare services that are not always available in remote rural areas. It is also used to save lives in critical care and emergency situations. Wireless sensor networks based on mobile communications can provide remote monitoring and sensors of parameters such as heart rate and blood pressure.

[0064] Wireless and mobile communications are becoming increasingly important in industrial applications. Cabling is expensive to install and maintain. Therefore, the possibility of replacing cables with reconfigurable wireless links is an attractive opportunity for many industries. However, achieving this requires wireless connections to operate with cable-like latency, reliability, and capacity, and to simplify their management. Low latency and very low error probability are new requirements that need to be met for connectivity using 5G.

[0065] Logistics and cargo tracking are important use cases for mobile communications, which enable the use of location-based information systems to track inventory and packages from anywhere. Logistics and cargo tracking use cases typically require low data rates, but require wide range and reliable location information.

[0066] Figure 1 1 is a diagram illustrating a control plane and a user plane structure of a radio interface protocol between a terminal and E-UTRAN based on the 3GPP radio access network standard. Figure 1 (A), the control plane refers to a path through which control messages used by user equipment (UE) and the network to manage calls are sent. Figure 1 (B), the user plane refers to a path through which data generated in the application layer (for example, voice data or Internet packet data) is transmitted.

[0067] The physical layer as the first layer provides information transmission services to the upper layer by using physical channels. The physical layer is connected to the upper medium access control layer through a transmission channel. Data moves between the medium access control layer and the physical layer through the transmission channel. Data moves between the physical layer of the transmitting side and the physical layer of the receiving side through the physical channel. The physical channel uses time and frequency as radio resources. Specifically, the physical channel is modulated by an orthogonal frequency division multiple access (OFDMA) scheme in the downlink and by a single carrier frequency division multiple access (SC-FDMA) scheme in the uplink.

[0068] The medium access control (MAC) layer of the second layer provides services to the upper layer (radio link control (RLC) layer) through a logical channel. The RLC layer of the second layer supports reliable data transmission. The functions of the RLC layer can be implemented as a functional 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 send IP packets such as IPv4 or IPv6 over a narrow bandwidth air interface.

[0069] The Radio Resource Control (RRC) layer at the bottom of the third layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transport channels, and physical channels related to the configuration, reconfiguration, and release of radio bearers. Radio bearers refer to services provided by the second layer for data transmission between the UE and the network. To this end, the RRC layer of the UE and the RRC layer of the network exchange RRC messages with each other. If there is an RRC connection between the UE and the RRC layer of the network (RRC connected), the UE is in an RRC connected state (connected mode), otherwise the UE is in an RRC idle state (idle mode). The NAS (Non-Access Stratum) layer above the RRC layer performs functions such as session management and mobility management.

[0070] The downlink transmission channels for sending data from the network to the UE include BCH (broadcast channel) for transmitting system information, PCH (paging channel) for transmitting paging messages, and downlink SCH (shared channel) for transmitting user services or control messages. In the case of downlink multicast or broadcast service services or control messages, they can be transmitted through the downlink SCH, or can be transmitted through a separate downlink multicast channel (MCH). In addition, as an uplink transmission channel for transmitting data from the UE to the network, there is a random access channel (RACH) for transmitting initial control messages and an uplink shared channel (SCH) for sending user services or control messages. The logical channels located at the upper layer of the transmission channel and mapped to the transmission channel include broadcast control channel (BCCH), paging control channel (PCCH), common control channel (CCCH), multicast control channel (MCCH) and multicast service channel (MTCH).

[0071] Figure 2 This is a diagram for explaining physical channels used in the 3GPP system and a general signal transmission method using these physical channels.

[0072] When the UE is powered on or enters a new cell, it performs an initial cell search operation (such as synchronization with a base station) (S701). To this end, the UE can receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station, synchronize with the base station, and obtain information such as a cell ID. Thereafter, the UE can receive a physical broadcast channel (PBCH) from the base station to obtain intra-cell broadcast information. In addition, the UE can receive a downlink reference signal (DL RS) in the initial cell search step to check the downlink channel status.

[0073] The UE that has completed the initial cell search may receive a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to information carried on the PDCCH, and obtain more specific system information (S702).

[0074] In addition, when there are no radio resources for initial access to the base station or for signal transmission, the UE may perform a random access procedure (RACH procedure) with respect to the base station (S703 to S706). To this end, the UE may send a specific sequence as a preamble through a physical random access channel (PRACH) (S703 and S705), and receive a response message (random access response (RAR) message) in response to the preamble through a PDCCH and a corresponding PDSCH. In the case of a contention-based RACH, a contention resolution procedure (S706) may be additionally performed.

[0075] After performing the process as described above, the UE may perform PDCCH / PDSCH reception (S707) and physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) transmission (S708) as a general uplink / downlink signal transmission process. Specifically, the UE may receive downlink control information (DCI) via the PDCCH. Here, the DCI includes control information such as resource allocation information for the UE, and different formats may be applied depending on the purpose of use.

[0076] In addition, the control information sent by the UE to the base station through the uplink or received by the UE from the base station may include downlink / uplink ACK / NACK signals, CQI (channel quality indicator), PMI (precoding matrix index), RI (rank indicator), etc. The UE can send the above control information such as CQI / PMI / RI through PUSCH and / or PUCCH.

[0077] In addition, the NR system is considering a method of using a high ultra-high frequency band (i.e., a millimeter wave band of 6 GHz or higher) to send data to a large number of users using a wide frequency band while maintaining a high data rate. In 3GPP, this is called NR, and in this disclosure, it is referred to as an NR system.

[0078] NR supports multiple OFDM (Orthogonal Frequency Division Multiplexing) numerologies (or subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15kHz, it supports wide areas in traditional cellular bands, when the SCS is 30kHz / 60kHz, it supports dense cities, lower latency, and wider carrier bandwidth, and when the SCS is 60kHz or higher, it supports bandwidth greater than 24.25kHz to overcome phase noise.

[0079] The NR band is defined as two types of frequency ranges (FR1, FR2). FR1 is a range below 6 GHz, and FR2 is a range above 6 GHz, which may mean millimeter wave (mmW).

[0080] Table 1 below shows the definition of NR frequency bands.

[0081] [Table 1]

[0082] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz-7125MHz 15kHz, 30kHz, 60kHz FR2 24250MHz-52600MHz 60kHz, 120kHz, 240kHz

[0083] Figure 3 The structure of a radio frame used in NR is illustrated.

[0084] In NR, uplink and downlink transmissions are configured as frames. A radio frame has a length of 10ms and is defined as two half frames (HF) of 5ms. A half frame is defined as 5 subframes (SF) of 1ms. A subframe is divided into one or more time slots, and the number of time slots in a subframe depends on the subcarrier spacing (SCS). Each time slot includes 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP). When a normal CP is used, each time slot includes 14 OFDM symbols. When an extended CP is used, each time slot includes 12 OFDM symbols. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol), an SC-FDMA symbol (or DFT-s-OFDM symbol).

[0085] Table 2 illustrates that the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary according to the SCS when a normal CP is used.

[0086] [Table 2]

[0087]

[0088] *N slot symb : Number of symbols in a time slot * N frame,u slot : Number of time slots in a frame

[0089] *N subframe,u slot : Number of time slots in a subframe

[0090] Table 3 illustrates that when the extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary according to the SCS.

[0091] [Table 3]

[0092] SCS(15*2^u) <![CDATA[N slot symb ]]> <![CDATA[N frame,u slot ]]> <![CDATA[N subframe,u slot ]]> 60KHz(u=2) 12 40 4

[0093] In the NR system, OFDM (A) parameter sets (e.g., SCS, CP length, etc.) can be configured differently between multiple cells aggregated into one UE. Therefore, the (absolute time) duration (for convenience, referred to as TU (time unit)) of a time resource (e.g., SF, time slot, or TTI) consisting of the same number of symbols can be configured differently between the aggregated cells.

[0094] Figure 4The time slot structure of the NR frame is illustrated. A time slot includes multiple symbols in the time domain. For example, in the case of normal CP, a time slot includes 14 symbols, but in the case of extended CP, a time slot includes 12 symbols. The carrier includes multiple subcarriers in the frequency domain. A resource block (RB) is defined as a plurality of (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth part (BWP) is defined as a plurality of consecutive (P) RBs in the frequency domain and may correspond to a parameter set (e.g., SCS, CP length, etc.). A carrier may include up to N (e.g., 4) BWPs. Data communication is performed through an activated BWP, and only one BWP may be activated for a UE. Each element in the resource grid is called a resource element (RE) and may map a complex symbol.

[0095] Figure 5 The structure of a self-contained slot is illustrated. In the NR system, a frame is characterized by a self-contained structure in which a DL control channel, DL or UL data, and a UL control channel can all be included in one slot. For example, the first N symbols in a slot can be used to send a DL control channel (hereinafter referred to as a DL control region), and the last M symbols in a slot can be used to send a UL control channel (hereinafter referred to as a UL control region). N and M are each integers greater than or equal to 0. The resource region between the DL control region and the UL control region (hereinafter referred to as the data region) can be used for DL ​​data transmission or UL data transmission. As an example, the following configuration can be considered. Each duration is listed in chronological order.

[0096] 1. DL configuration only

[0097] 2. UL configuration only

[0098] 3. Hybrid UL-DL configuration

[0099] -DL area + protection period (GP) + UL control area

[0100] -DL control area + GP + UL area

[0101] *DL area: (i) DL data area, (ii) DL control area + DL data area

[0102] *UL area: (i) UL data area, (ii) UL data area + UL control area

[0103] The PDCCH may be sent in the DL control region, and the PDSCH may be sent in the DL data region. The PUCCH may be sent in the UL control region, and the PUSCH may be sent in the UL data region. In the PDCCH, downlink control information (DCI) (e.g., DL data scheduling information, UL data scheduling information, etc.) may be sent. In the PUCCH, uplink control information (UCI) (e.g., ACK / NACK (positive acknowledgement / negative acknowledgement) information for DL ​​data, CSI (channel state information) information, SR (scheduling request), etc.) may be sent. The GP provides a time gap in the process of switching from a transmission mode to a reception mode or from a reception mode to a transmission mode in the base station and the UE. Some symbols of the time of switching from DL to UL in a subframe may be configured as GPs.

[0104] Figure 6 The SSB structure is illustrated. The UE can perform cell search, system information acquisition, beam alignment for initial access, DL measurement, etc. based on the SSB. SSB and SS / PBCH (Synchronization Signal / Physical Broadcast Channel) blocks can be used interchangeably.

[0105] Reference Figure 6 , SSB consists of PSS, SSS and PBCH. SSB is configured with four consecutive OFDM symbols, and PSS, PBCH, SSS / PBCH and PBCH are sent for each OFDM symbol. PSS and SSS are composed of 1 OFDM symbol and 127 subcarriers respectively, while PBCH is composed of 3 OFDM symbols and 576 subcarriers. Polarity coding and quadrature phase shift keying (QPSK) are applied to PBCH. PBCH consists of data RE and demodulation reference signal (DMRS) RE for each OFDM symbol. There are three DMRS REs for each RB, and there are three data REs between DMRS REs.

[0106] Community Search

[0107] Cell search refers to a process in which the UE acquires time / frequency synchronization of a cell and detects a cell ID (e.g., 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.

[0108] The cell search process of the UE may be organized as shown in Table 4 below.

[0109] [Table 4]

[0110]

[0111] Figure 7 SSB transmission is illustrated.

[0112] The SSB is sent periodically according to the SSB periodicity. The SSB basic period assumed by the UE during the initial cell search is defined as 20ms. After cell access, the SSB periodicity can be set to one of {5ms, 10ms, 20ms, 40ms, 80ms, 160ms} by the network (e.g., base station). The SSB burst set is configured at the beginning of the SSB periodicity. The SSB burst set group is configured as a 5ms time window (i.e., half a frame), and the SSB can be sent up to L times within the SS burst set. The maximum number of SSB transmissions L can be given as follows according to the frequency band of the carrier. One time slot includes up to two SSBs.

[0113] - For the frequency range up to 3 GHz, L = 4

[0114] - For the frequency range from 3 GHz to 6 GHz, L = 8

[0115] - For the frequency range from 6 GHz to 52.6 GHz, L = 64

[0116] The temporal position of the SSB candidates in the SS burst set may be defined according to the SCS as follows: The temporal position of the SSB candidates is indexed in temporal order from 0 to L-1 (SSB index) within the SSB burst set (ie, half-frame).

[0117] - Case A - 15kHz SCS: The index of the starting symbol of the candidate SSB is given as {2,8}+14*n. If the carrier frequency is 3GHz or less, n=0, 1. If the carrier frequency is 3GHz to 6GHz, n=0, 1, 2, 3.

[0118] - Case B - 30kHz SCS: The index of the starting symbol of the candidate SSB is given as {4, 8, 16, 20} + 28*n. If the carrier frequency is 3 GHz or less, n = 0. When the carrier frequency is 3 GHz to 6 GHz, n = 0, 1.

[0119] - Case C - 30kHz SCS: The index of the starting symbol of the candidate SSB is given as {2,8}+14*n. If the carrier frequency is 3GHz or less, n=0, 1. If the carrier frequency is 3GHz to 6GHz, n=0, 1, 2, 3.

[0120] - Case D - 120kHz SCS: The index of the starting symbol of the candidate SSB is given as {4,8,16,20}+28*n. For carrier frequencies greater than 6GHz, n=0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18.

[0121] - Case E - 240kHz SCS: The indices of the starting symbols of the candidate SSBs are given as {8, 12, 16, 20, 32, 36, 40, 44} + 56*n. For carrier frequencies greater than 6GHz, n = 0, 1, 2, 3, 5, 6, 7, 8.

[0122] Figure 8 It illustrates that the UE obtains information about DL time synchronization.

[0123] The UE can acquire DL synchronization by detecting the SSB. The UE can identify the structure of the SSB burst set based on the detected SSB index and can therefore detect the symbol / time slot / half-frame boundary. The SFN information and half-frame indication information can be used to identify the number of frames / half-frames to which the detected SSB belongs.

[0124] Specifically, the UE can obtain 10-bit SFN (system frame number) information (s0 to s9) from the PBCH. In the 10-bit SFN information, 6 bits are obtained from the master information block (MIB) and the remaining 4 bits are obtained from the PBCH transport block (TB).

[0125] Next, the UE can obtain 1-bit half-frame indication information (c0). When the carrier frequency is 3 GHz or lower, the half-frame indication information can be implicitly signaled using PBCH DMRS. The PBCH DMRS indicates 3 bits of information by using one of eight PBCH DMRS sequences. Therefore, in the case of L=4, after indicating the SSB index among the 3 bits that can be indicated using 8 PBCH DMRS sequences, the remaining one bit can be used for half-frame indication.

[0126] Finally, the UE can obtain the SSB index based on the DMRS sequence and the PBCH payload. The SSB candidates are indexed in time order from 0 to L-1 within the SSB burst set (i.e., half-frame). When L=8 or 64, 8 different PBCH DMRS sequences can be used to indicate the LSB (least significant bit) 3 bits (b0 to b2) of the SSB index. When L=64, the MSB (most significant bit) 3 bits (b3 to b5) of the SSB index are indicated by PBCH. When L=2, four different PBCH DMRS sequences can be used to indicate the LSB 2 bits (b0, b1) of the SSB index. When L=4, after indicating the SSB index among the 3 bits that can be indicated using 8 PBCH DMRS sequences, the remaining one bit can be used for half-frame indication (b2).

[0127] Get system information

[0128] Fig. 9 The system information (SI) acquisition process is illustrated. The UE can acquire AS / NAS information through the SI acquisition process. The SI acquisition process can be applied to UEs in the RRC_IDLE state, the RRC_INACTIVE state, and the RRC_CONNECTED state.

[0129] SI is divided into MIB (Master Information Block) and multiple SIBs (System Information Blocks). MIB and multiple SIBs can be divided into minimum SI and other SI. Here, the minimum SI can be composed of MIB and SIB1, and includes information for obtaining basic information and other information required for initial access. Here, SIB1 can be called remaining minimum system information (RMSI). For more details, please refer to the following content.

[0130] -MIB includes information / parameters related to SIB1 (SystemInformationBlockType1) reception and is transmitted through the PBCH of SSB. For initial cell selection, the UE assumes that the half frame with SSB is repeated with a periodicity of 20ms. The UE can check whether there is a control resource set (CORESET) for the Type0-PDCCH common search space based on the MIB. The Type0-PDCCH common search space is a type of PDCCH search space and is used to send a PDCCH that schedules SI messages. When a Type0-PDCCH common search space exists, the UE can determine, based on the information in the MIB (e.g., pdcch-ConfigSIB1), (i) multiple consecutive RBs and one or more consecutive symbols constituting the CORESET, and (ii) the PDCCH timing (i.e., the time domain position for receiving the PDCCH). When there is no Type0-PDCCH common search space, pdcch-ConfigSIB1 provides information about the frequency position where SSB / SIB1 exists and the frequency range where SSB / SIB1 does not exist.

[0131] -SIB1 includes information related to the availability and scheduling (e.g., transmission periodicity, SI window size) of the remaining SIBs (hereinafter, SIBx, x is an integer greater than or equal to 2). For example, SIB1 can inform whether SIBx is broadcast periodically or provided by an on-demand method based on the request of the UE. When SIBx is provided by the on-demand method, SIB1 may include information required by the UE to perform an SI request. SIB1 is transmitted through PDSCH, the PDCCH that schedules SIB1 is transmitted through the Type0-PDCCH common search space, and SIB1 is transmitted through the PDSCH indicated by the PDCCH.

[0132] - SIBx is included in the SI message and transmitted through the PDSCH. Each SI message is transmitted within a periodically occurring time window (ie, SI window).

[0133] Beam Alignment

[0134] Fig.10 Multi-beam transmission of SSB is illustrated.

[0135] Beam scanning refers to the transmission reception point (TRP) (e.g., base station / cell) changing the beam (direction) of the radio signal according to time (hereinafter, beam and beam direction can be used interchangeably). Beam scanning can be used to periodically transmit SSBs. In this case, the SSB index is implicitly linked to the SSB beam. The SSB beam can be changed in units of SSB (index) or in units of SSB (index) groups. In the latter case, the SSB beam remains the same within the SSB (index) group. That is, the transmission beam direction of the SSB is repeated in multiple consecutive SSBs. Depending on the frequency band to which the carrier belongs, the maximum number of transmissions L of the SSB in the SSB burst set has a value of 4, 8, or 64. 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.

[0136] -For frequency range up to 3 GHz, maximum number of beams = 4

[0137] -For the frequency range from 3 GHz to 6 GHz, maximum number of beams = 8

[0138] -For the frequency range from 6 GHz to 52.6 GHz, maximum number of beams = 64

[0139] *When multi-beam transmission is not applied, the number of SSB beams is one.

[0140] When a UE attempts to initially access a base station, the UE may align the beam with the base station based on the SSB. For example, the UE identifies the best SSB after performing SSB detection. Thereafter, the UE may use the PRACH resource corresponding to the index (i.e., beam) linked to the best SSB / the index (i.e., beam) of the best SSB to send a RACH preamble to the base station. Even after initial access, the SSB may be used to align the beam between the base station and the UE.

[0141] Channel Measurement and Rate Matching

[0142] Fig.11 A method of notifying the actually transmitted SSB (SSB_tx) is illustrated.

[0143] A maximum of L SSBs can be transmitted in an SSB burst set, and the number / position of the SSBs actually transmitted may vary for each base station / cell. The number / position of the SSBs actually transmitted is used for rate matching and measurement, and information about the SSBs actually transmitted is indicated as follows.

[0144] - Cases related to rate matching: It can be indicated by UE-specific RRC signaling or RMSI. UE-specific RRC signaling includes a complete (e.g., length L) bitmap in both the frequency range below 6 GHz and above 6 GHz. In addition, as shown in the figure, RMSI includes a complete bitmap below 6 GHz and includes a compressed bitmap above 6 GHz. Specifically, a group bitmap (8 bits) + an intra-group bitmap (8 bits) can be used to indicate information about the SSB actually transmitted. Here, the resources (e.g., RE) indicated by UE-specific RRC signaling or RMSI are reserved for SSB transmission, and PDSCH / PUSCH, etc. can consider the SSB resources for rate matching.

[0145] - Measurement-related cases: In the case of RRC connected mode, the network (e.g., base station) may indicate the SSB set to be measured during the measurement period. The SSB set may be indicated for each frequency layer. If there is no indication related to the SSB set, the default SSB set is used. The default SSB set includes all SSBs in the measurement period. The SSB set may be indicated using a full (e.g., length L) bitmap of RRC signaling. In the case of RRC idle mode, the default SSB set is used.

[0146] Random Access (RA) Procedure

[0147] Fig.12 An example of a random access procedure is illustrated. Specifically, Fig.12 A contention-based random access procedure is illustrated.

[0148] First, the UE may transmit a random access preamble of Msg 1 as a random access procedure in UL through PRACH.

[0149] Two different lengths of random access preamble sequences are supported: the long sequence length 839 is applicable to subcarrier spacings of 1.25kHz and 5kHz, and the short sequence length 139 is applicable to subcarrier spacings of 15kHz, 30kHz, 60kHz, and 120kHz.

[0150] Multiple preamble formats are defined by one or more RACH OFDM symbols and different cyclic prefixes (and / or guard times). The RACH configuration for the initial bandwidth of the primary cell (Pcell) is included in the system information of the cell and provided to the UE. The RACH configuration includes information about the subcarrier spacing of the PRACH, available preambles, preamble formats, etc. The RACH configuration includes association information between SSBs and RACH (time-frequency) resources. The UE sends a random access preamble in the RACH time-frequency resource associated with the detected SSB or the selected SSB.

[0151] The threshold of the SSB associated with the RACH resource can be configured by the network, and the transmission or retransmission of the RACH preamble is performed based on the SSB, wherein the measured reference signal received power (RSRP) meets the threshold based on the SSB. For example, the UE can select one of the SSBs that meets the threshold and send or retransmit the RACH preamble based on the RACH resource associated with the selected SSB. For example, when retransmitting the RACH preamble, the UE can reselect one of the SSBs and retransmit the RACH preamble based on the RACH resource associated with the reselected SSB. That is, the RACH resource used for the retransmission of the RACH preamble can be the same and / or different from the RACH resource used to send the RACH preamble.

[0152] When the base station (BS) receives a random access preamble from the UE, the BS sends a random access response (RAR) message (Msg 2) to the UE. The PDCCH that schedules the PDSCH carrying the RAR is CRC-scrambled and sent using the random access (RA) radio network temporary identifier (RNTI) (RA-RNTI). The UE that detects the PDCCH CRC-scrambled using the RA-RNTI can receive the RAR from the PDSCH scheduled by the DCI carried by the PDCCH. The UE checks whether the random access response information (i.e., Msg 1) of the preamble sent by the UE itself is in the RAR. Whether the random access information of Msg 1 sent by the UE itself exists can be determined by whether the random access preamble ID of the preamble sent by the UE exists. If there is no response to Msg 1, the UE can retransmit the RACH preamble within a predetermined number of times while performing power ramping. The UE calculates the PRACH transmit power for retransmission of the preamble based on the most recent transmit power, power increment, and power ramp counter.

[0153] The random access response information includes a preamble sequence sent by the UE, a temporary cell RNTI (TC-RNTI) assigned by the base station to the UE that has attempted random access, uplink transmission time alignment information, uplink transmission power adjustment information, and uplink radio resource allocation information. When the UE receives its own random access response information on the PDSCH, the UE can obtain the timing advance information, the initial UL grant, and the TC-RNTI for UL synchronization. The timing advance information is used to control the uplink signal transmission timing. In order to better align the PUSCH / PUCCH transmission of the UE with the subframe timing of the network end, the network (e.g., BS) obtains the timing advance information based on the timing information detected in the PRACH preamble received from the UE, and can send the corresponding timing advance information to the UE. The UE can send UL transmission as a random access procedure on the uplink shared channel based on the random access response information. Msg 3 may include an RRC connection request and a UE identifier. In response to Msg 3, the network may send Msg 4, which may be regarded as a contention resolution message on the DL. By receiving Msg 4, the UE can enter the RRC connected state.

[0154] In addition, a contention-free random access procedure can be used when the UE is in the process of switching to another cell or BS, or a contention-free random access procedure can be performed when requested by a command of the BS. The basic process of the contention-free random access procedure is similar to the contention-based random access procedure. However, unlike the contention-based random access procedure in which the UE randomly selects the preamble to be used from a plurality of random access preambles, in the case of a contention-free random access procedure, the preamble to be used by the UE (hereinafter, a dedicated random access preamble) is determined by the BS and allocated to the UE. Information about the dedicated random access preamble may be included in an RRC message (e.g., a handover command), or may be provided to the UE via a PDCCH command. When the random access procedure is initiated, the UE sends a dedicated random access preamble to the BS. When the UE receives a random access response from the BS, the random access procedure is completed.

[0155] As mentioned above, the UL grant in RAR schedules the PUSCH transmission for the UE. The PUSCH that carries the initial UL transmission through the UL grant in RAR is also called Msg 3PUSCH. The content of the RAR UL grant starts at the MSB and ends at the LSB and is given in Table 5.

[0156] [Table 5]

[0157] RAR UL Permit Field Number of bits Frequency Hopping Flag 1 Msg 3PUSCH frequency resource allocation 12 Msg 3PUSCH time resource allocation 4 Modulation and Coding Scheme (MCS) 4 Transmit Power Control (TPC) for Msg 3PUSCH 3 CSI Request 1

[0158] The TPC command is used to determine the transmission power of Msg 3 PUSCH and is interpreted according to, for example, Table 6.

[0159] [Table 6]

[0160] TPC Command Value [dB] 0 -6 1 -4 2 -2 3 0 4 2 5 4 6 6 7 8

[0161] In the contention-free random access procedure, the CSI request field in the RARUL grant indicates whether the UE includes aperiodic CSI reports in the corresponding PUSCH transmission. The subcarrier spacing for Msg 3PUSCH transmission is provided by RRC parameters. The UE shall transmit PRACH and Msg 3PUSCH on the same uplink carrier of the same serving cell. The UL BWP for Msg 3PUSCH transmission is indicated by System Information Block 1 (SIB1).

[0162] Multiplexing of short PUCCH and long PUCCH

[0163] Fig.13 A multiplexing configuration of a long Physical Uplink Control Channel (PUCCH) and a short PUCCH is illustrated.

[0164] PUCCH (e.g., PUCCH format 0 / 2) and PUSCH can be multiplexed in TDM or FDM scheme. Short PUCCH and long PUCCH from different UEs can be multiplexed in TDM or FDM scheme. Short PUCCH in one slot from a single UE can be multiplexed in TDM scheme. Short PUCCH and long PUCCH in one slot from a single UE can be multiplexed in TDM or FDM scheme.

[0165] ACK / NACK transmission

[0166] Fig.14 The ACK / NACK sending process is illustrated. Fig.14 , the UE may detect the PDCCH in slot #n. Here, the PDCCH includes downlink scheduling information (e.g., DCI formats 1_0 and 1_1), and the PDCCH indicates DL assignment to PDSCH offset (K0) and PDSCH-HARQ-ACK report offset (K1). For example, DCI formats 1_0 and 1_1 may include the following information.

[0167] - Frequency domain resource assignment: It indicates the RB set allocated to PDSCH.

[0168] - Time domain resource assignment: K0, which indicates the starting position (eg, OFDM symbol index) and length (eg, number of OFDM symbols) of the PDSCH in a slot.

[0169] -PDSCH to HARQ_feedback timing indicator: It indicates K1

[0170] Thereafter, the UE may send UCI in slot #(n+K1) through PUCCH after receiving PDSCH in slot #(n+K0) according to the scheduling information of slot #n. Here, the UCI includes a HARQ-ACK response for the PDSCH. If the PDSCH is configured to send up to 1 TB, the HARQ-ACK response may be configured with 1 bit. If the PDSCH is configured to send up to two TBs, the HARQ-ACK response may be configured with 2 bits when the spatial bundle is not configured, and with 1 bit when the spatial bundling is configured. When the HARQ-ACK transmission time for multiple PDSCHs is designated as slot #(n+K1), the UCI sent in slot #(n+K1) includes HARQ-ACK responses for multiple PDSCHs.

[0171] Bandwidth Part (BWP)

[0172] In NR systems, up to 400MHz per carrier can be supported. If a UE operating on such a wideband carrier always operates with the radio frequency (RF) module turned on for the entire carrier, the UE battery consumption may increase. Alternatively, when considering multiple use cases operating on one wideband carrier (e.g., eMBB, URLLC, mMTC, V2X, etc.), different parameter sets (e.g., subcarrier spacing) for each frequency band within the corresponding carrier may be supported. Alternatively, the capacity of the maximum bandwidth may be different for each UE. Taking the above into account, the base station can instruct the UE to operate only in part of the bandwidth rather than the entire bandwidth of the wideband carrier, and the part of the bandwidth is called a bandwidth part (BWP). In the frequency domain, a BWP is a subset of contiguous common resource blocks defined by a parameter set μi in a bandwidth part i on a carrier, and a parameter set (e.g., subcarrier spacing, CP length, slot / microslot duration) can be configured.

[0173] In addition, the base station may configure one or more BWPs in one carrier configured for the UE. Alternatively, when the UE is concentrated in a specific BWP, some UEs may be moved to another BWP for load balancing. Alternatively, considering the frequency domain inter-cell interference elimination between adjacent cells, the middle part of the spectrum from the entire bandwidth may be excluded, and two edge BWPs of the cell may be configured in the same time slot. That is, the base station may configure at least one DL / UL BWP to the UE associated with the broadband carrier, and activate (through L1 signaling as a physical layer control signal, MAC control element (CE) as a MAC layer control signal, or RRC signaling, etc.) at a specific time at least one DL / UL BWP among the configured DL / UL BWPs, indicate (through L1 signaling, MAC CE, or RRC signaling, etc.) switching to another configured DL / UL BWP or setting a timer value and causing the UE to switch to the determined DL / UL BWP when the timer expires. Here, in order to indicate switching to another configured DL / UL BWP, DCI format 1_1 or DCI format 0_1 ​​may be used. The activated DL / UL BWP is specifically referred to as an active DL / UL BWP. In situations such as when the UE is in an initial access process or before the UE's RRC connection is established, the UE may not receive a configuration for the DL / UL BWP. In this case, the DL / UL BWP assumed by the UE is referred to as the initial active DL / UL BWP.

[0174] Furthermore, here, the DL BWP is a BWP for transmitting and receiving downlink signals such as PDCCH and / or PDSCH, and the UL BWP is a BWP for transmitting and receiving uplink signals such as PUCCH and / or PUSCH.

[0175] In the NR system, downlink channels and / or downlink signals may be transmitted / received within an active DL downlink bandwidth part (BWP). In addition, uplink channels and / or uplink signals may be transmitted / received within an active UL uplink bandwidth part (BWP).

[0176] Unlicensed Band / Shared Spectrum Systems

[0177] Fig.15 is a diagram illustrating an example of a wireless communication system supporting an unlicensed band to which various embodiments of the present disclosure can be applied.

[0178] In the following description, a cell operating in a licensed frequency band (hereinafter referred to as an L band) is defined as an L cell, and a carrier of the L cell is defined as a (DL / UL) LCC. In addition, a cell operating in an unlicensed frequency band (hereinafter referred to as an U band) is defined as a U cell, and a carrier of the U cell is defined as a (DL / UL) UCC. The carrier / carrier frequency of a cell may refer to an operating frequency (e.g., a center frequency) of the cell. A cell / carrier (e.g., a CC) may be referred to as a cell.

[0179] like Fig.15 As shown in (a), when the UE and the base station transmit and receive signals through the LCC and UCC via carrier aggregation, the LCC may be set as a primary CC (PCC) and the UCC may be set as a secondary CC (SCC).

[0180] like Fig.15 As shown in (b), the UE and the base station can send and receive signals through one UCC or multiple LCCs and UCCs aggregated by carriers. That is, the UE and the base station can send and receive signals only through the UCC without the LCC. In the following, the signal transmission / reception operation in the unlicensed band described in various embodiments of the present disclosure can be performed based on all the deployment scenarios described above (unless otherwise described).

[0181] 1. Radio frame structure for unlicensed bands

[0182] For operations in unlicensed bands, LTE frame structure type 3 or NR frame structure may be used. The configuration of OFDM symbols occupied for uplink / downlink signal transmission in the frame structure for unlicensed bands may be configured by the base station. Here, OFDM symbols may be replaced with SC-FDM (A) symbols.

[0183] For downlink signal transmission through the unlicensed band, the base station may notify the UE of the configuration of OFDM symbols used in subframe #n through signaling. In the following description, a subframe may be replaced with a slot or a time unit (TU).

[0184] Specifically, in the case of a wireless communication system supporting an unlicensed frequency band, the UE can assume (or identify) the configuration of the OFDM symbols occupied in subframe #n based on a specific field in the DCI received from the base station in subframe #n-1 or subframe #n (for example, the subframe configuration for the LAA field, etc.).

[0185] Table 7 illustrates a method of indicating configuration of OFDM symbols used for transmission of downlink physical channels and / or physical signals in a current subframe and / or a next subframe through a subframe configuration of an LAA field in a wireless communication system.

[0186] [Table 7]

[0187]

[0188] For uplink signal transmission through the unlicensed frequency band, the base station may notify the UE of information about uplink transmission duration through signaling.

[0189] Specifically, in the case of an LTE system supporting an unlicensed band, the UE may obtain "UL duration" and "UL offset" information for subframe #n through the "UL duration and offset" field in the detected DCI.

[0190] Table 8 illustrates a method in which the UL Duration and Offset fields indicate a UL offset and a UL duration configuration in a wireless communication system.

[0191] [Table 8]

[0192]

[0193] 2. General channel access process

[0194] Unless otherwise described, the following definitions may be applied to terms used in the description of various embodiments of the present disclosure to be described later.

[0195] - A channel may mean a carrier or a part of a carrier consisting of a set of consecutive RBs on which a channel access procedure is performed in a shared spectrum.

[0196] - The channel access procedure may be a sensing-based procedure for evaluating the availability of a channel for performing transmission. The basic unit of sensing may be a sensing slot of duration Ts1 = 9us. When the base station or UE senses the channel during the sensing slot duration and determines that the detected power sensed for at least 4us within the sensing slot duration is less than the energy detection threshold XThresh, the sensing slot duration Ts1 may be considered idle. Otherwise, the sensing slot duration Ts1 may be considered busy.

[0197] - Channel occupancy may mean transmissions performed by a base station / UE in a channel after performing a channel access procedure corresponding to the present section.

[0198] - Channel occupancy time may mean the total time that a base station / UE and any base station / UE sharing the channel occupancy perform transmission in a channel after the base station / UE performs the channel access procedure corresponding to this section. To determine the channel occupancy time, if the transmission gap is 25us or less, the gap duration may be counted as the channel occupancy time. The channel occupancy time may be shared for transmissions between a base station and a corresponding UE.

[0199] 3. Downlink channel access process

[0200] The base station may perform the following downlink channel access procedure (channel access procedure; CAP) for the unlicensed band for downlink signal transmission in the unlicensed band.

[0201] 3.1. Type 1 Downlink (DL) Channel Access Procedure

[0202] In this section, the channel access procedure performed from the base station is described based on the fact that the duration spanned by the sensing slots sensed as idle before the downlink transmission is random. This section may apply to the following transmissions:

[0203] - A transmission initiated by a base station including PDSCH / PDCCH / EPDCCH, or,

[0204] - a transmission initiated by a base station comprising a unicast PDSCH with user plane data or a unicast PDSCH with user plane data and a unicast PDCCH scheduling user plane data, or

[0205] - Transmission initiated by a base station with discovery burst only or with discovery burst multiplexed with non-unicast information. Here, the transmission duration may be greater than 1 ms, or the transmission may cause the discovery burst duty cycle to exceed 1 / 20.

[0206] The base station delays for a duration of T d During the sensing time slot duration of the additional sensing time slot, the channel is sensed whether it is in an idle state, and the transmission can be sent after the counter N becomes 0 in the subsequent step 4. In this case, the counter N is adjusted by channel sensing during the additional sensing time slot duration according to the following process:

[0207] 1) Set N = N init Here, N init is evenly distributed between 0 and CW p Then, proceed to step 4.

[0208] 2) If N>0 and the base station chooses to decrement the counter, set N=N-1.

[0209] 3) Sense the channel during the additional sensing time slot duration. Here, if the additional sensing time slot duration is idle, the process moves to step 4. If the additional sensing time slot duration is not idle, proceed to step 5.

[0210] 4) If N=0, stop the corresponding process. Otherwise, go to step 2.

[0211] 5) The channel is sensed until the additional delay duration T d A busy sensing time slot is detected within 1 second, or an additional delay duration T is added d All sensing slots are detected as idle.

[0212] 6) If the corresponding channel is in the additional delay duration T d If the sensor is sensed as idle during all sensing time slot durations, the process moves to step 4. Otherwise, proceed to step 5.

[0213] Fig.16 2 is a diagram for explaining a DL CAP for unlicensed band transmission to which various embodiments of the present disclosure can be applied.

[0214] A type 1 downlink channel access procedure for unlicensed band transmission to which various embodiments of the present disclosure may be applied may be summarized as follows.

[0215] For downlink transmissions, a transmitting node (eg, a base station) may initiate a channel access procedure (CAP) (2010).

[0216] The base station may randomly select a backoff counter N within the contention window (CW) according to step 1. Here, the value of N is set to an initial value Ninit (2020). Ninit is selected to be any value between 0 and CWp.

[0217] Next, according to step 4, if the backoff counter value (N) is 0 (2030; Y), the base station ends the CAP process (2032). Then, the base station can perform Tx burst transmission (2034). In addition, if the backoff counter value is not 0 (2030; N), according to step 2, the base station decreases the backoff counter value by 1 (2040).

[0218] Next, the base station checks whether the channel is in an idle state (2050), and if the channel is in an idle state (2050; Y), checks whether the backoff counter value is 0 (2030).

[0219] Furthermore, in the operation of 2050, if the channel is not in an idle state (i.e., if the channel is in a busy state) (2050; N), the base station checks whether the corresponding channel is in an idle state during a delay duration (Td; 25usec or more) longer than the sensing time slot time (e.g., 9usec) according to step 5 (2060). If the channel is in an idle state during the delay duration (2070; Y), the base station may resume the CAP process again.

[0220] For example, when the backoff counter value Ninit is 10 and the channel is determined to be in a busy state after the backoff counter value is reduced to 5, the base station senses the channel during the delay duration to determine whether it is in an idle state. Here, if the channel is in an idle state during the delay duration, the base station does not set the backoff counter value Ninit, but performs the CAP process again from the backoff counter value 5 (or from 4 after reducing the backoff counter value by 1).

[0221] Furthermore, if the channel is busy during the delay duration (2070; N), the base station re-executes step 2060 to check again whether the channel is idle during the new delay period.

[0222] In the case where the base station does not send a transmission after step 4 in the above process, the base station may send a transmission on the channel if the following conditions are met:

[0223] The base station prepares to send a transmission and the corresponding channel is sensed as idle for at least the sensing slot duration Ts1 and the channel is sensed as idle for all sensing slot durations of the delay duration Td immediately preceding the transmission.

[0224] In addition, when the base station senses the channel after preparing to send, the channel is not sensed as idle during the sensing slot duration Ts1, or when the channel is not sensed as idle during any one of the sensing slot durations of the delay duration Td immediately before the expected transmission, the base station proceeds to step 1 after sensing that the channel is idle during the sensing slot duration of the delay duration Td.

[0225] The delay duration Td consists of a period Tf (=16 us) immediately following mp consecutive sensing slot durations. Here, each sensing slot duration Ts1 is 9 us, and Tf includes an idle sensing slot duration Ts1 at the starting point of Tf.

[0226] Table 9 illustrates the mp , minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW size vary according to the channel access priority class.

[0227] [Table 9]

[0228]

[0229] 3.2. Type 2 Downlink (DL) Channel Access Procedure

[0230] 3.2.1. Type 2A DL channel access procedure

[0231] The base station may transmit immediately after the corresponding channel is sensed to be idle for at least the sensing duration Tshort d1 = 25 us. Here, Tshort d1 consists of the duration Tf (= 16 us) immediately following the duration of one sensing slot. Tf includes the sensing slot at the starting point of Tf. When two sensing slots in Tshort d1 are sensed to be idle, the channel is considered to be idle during Tshort d1.

[0232] 3.2.2. Type 2B DL ​​channel access procedure

[0233] The base station may transmit immediately after the corresponding channel is sensed to be idle for Tf=16us. Tf includes the sensing slots occurring within the last 9us of Tf. If the channel is sensed to be idle for at least 5us in total and at least 4us of sensing occurs in the sensing slots, the channel is considered idle during Tf.

[0234] 3.2.3. Type 2C DL channel access procedure

[0235] When the base station follows the procedure of this section to send a transmission, the base station does not sense the channel before sending the transmission. The duration corresponding to the transmission is up to 584us.

[0236] 4. Channel access procedure for transmission on multiple channels

[0237] The base station can access multiple channels through which transmission is performed by one of the following Type A or Type B procedures.

[0238] 4.1. Type A multi-carrier access process

[0239] According to the process disclosed in this section, the base station i Channel access is performed on ∈C. Here, C is a set of channels that the base station intends to transmit, i=0, 1, ..., q-1, and q is the number of channels that the base station intends to transmit.

[0240] For each channel c i Determine the counter N considered in the CAP and in this case the counter for each channel is given by Nc i To express.

[0241] 4.1.1. Type A1 multi-channel access procedure

[0242] For each channel c i Determine the counter N considered in the CAP, and the counter for each channel is given by Nc i express.

[0243] If the base station stops any channel c j ∈C, if it can be guaranteed in the long term (e.g., by adjusting the level) that there is no other technology sharing the channel, then for each channel c i (Here, c i With c j Different, c i ≠c j ), waiting for 4T s1 After an interval of i When an idle sensing time slot is detected later, the base station can restore Nc i of decreasing.

[0244] 4.1.2. Type A2 Multi-channel Access Procedure

[0245] According to the above description, it can be determined that for each channel c j ∈C, and in this case, the counter for each channel is Nc j Here, c j It can mean having the maximum CW p For each channel c j , it can be configured as Nc i =Nc j .

[0246] When the base station stops targeting the determined Nc i When any channel of the base station sends, the base station reinitializes Nc for all channels i .

[0247] 4.2. Type B multi-channel access process

[0248] The base station can select channel c as follows j ∈C.

[0249] - In multi-channel c j Before each transmission on ∈C, the base station uniformly randomly selects c from C j ,or,

[0250] - The base station selects c every 1 second j No more than or equal to once.

[0251] Here, C is a set of channels that the base station intends to transmit, i=0, 1, ..., q-1, and q is the number of channels that the base station intends to transmit.

[0252] For channel c j The base station transmits on channel c according to the dedicativity described in Section 4.2.1 or Section 4.2.2 above and the process described in Section 3.1. j Channel access is performed on the

[0253] For channel c i ≠c j The transmission on channel c j ∈C,

[0254] For each channel c i , the base station is in channel c i Sense channel c immediately before sending i Up to at least the sensing interval T mc = 28us. Then, the base station can sense channel c j Immediately after being idle for at least the sensing interval, i When the channel is sensed as idle for a given interval T mc Inner channel c j During all time intervals of idle sensing, channel c j Can be considered idle for T mc .

[0255] The base station is in channel c i ≠c j (Here, c i ∈C) does not execute the sending of T exceeding the above table 10 mcot,p Here, the channel c is used j The channel access parameters are used to determine T mcot,p .

[0256] In the procedures of this section, the channel frequencies of the channel set C selected by the gNB are a subset of one of the predefined channel frequency sets.

[0257] 4.2.1. Type B1 multi-channel access procedure

[0258] Maintain a single CW for channel set C p value.

[0259] In order to determine the channel c j CW on channel access p , modify step 2 of the process described in Section 3.1 above as follows.

[0260] -When all channels c jWhen at least Z = 80% of the HARQ-ACK values ​​corresponding to the PDSCH transmissions in the reference subframe k of ∈C are determined as NACKs, CW is incremented for all priority classes p∈{1, 2, 3, 4} p To the next higher allowed value. Otherwise, proceed to step 1.

[0261] 4.2.2. Type B2 Multi-channel Access Procedure

[0262] For each channel c i ∈C independently maintains CW p In order to determine the channel c i The CW p , can be used with channel c i Any PDSCH that is fully or partially overlapped. In order to determine the channel c j N init , using channel c j1 CW of ∈C p Here, c j1 is the channel with the largest CW among all channels in set C p channel.

[0263] 5. Uplink channel access process

[0264] The UE and the base station that schedules or configures UL transmission for the UE perform the following process for accessing the channel (performing LAAScell ​​transmission). In the following description, it is assumed that the Pcell as the licensed band and the Scell ​​as one or more unlicensed bands are basically configured for the UE and the base station to describe in detail the uplink CAP operation to which various embodiments of the present disclosure can be applied. However, the uplink CAP operation can be similarly applied to the case where only the unlicensed band is configured for the UE and the base station.

[0265] The UE may access a channel performing UL transmission according to a Type 1 or Type 2 UL channel access procedure.

[0266] Table 10 illustrates that mp, minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW size applied to CAP vary according to channel access priority class.

[0267] [Table 10]

[0268]

[0269] 5.1. Type 1 UL channel access procedure

[0270] This section describes the channel access procedure performed from a UE where the duration spanned by the sensing slots sensed as idle prior to an uplink transmission is random. This section may apply to the following transmissions:

[0271] - PUSCH / SRS transmission scheduled and / or configured by the base station

[0272] - PUCCH transmission scheduled and / or configured by the base station

[0273] - Random Access Procedure (RAP) related transmission

[0274] Fig.17 is a diagram for explaining a UL CAP for unlicensed band transmission to which various embodiments of the present disclosure can be applied.

[0275] A Type 1 UL CAP for UE for unlicensed band transmission to which various embodiments of the present disclosure are applicable may be summarized as follows.

[0276] For uplink transmission, a transmitting node (eg, UE) may initiate a channel access procedure (CAP) to operate in an unlicensed band (2110).

[0277] The UE may randomly select a backoff counter N within the contention window (CW) according to step 1. Here, the value of N is set to an initial value Ninit (2120). Ninit is selected as any value between 0 and CWp.

[0278] Next, according to step 4, if the backoff counter value (N) is 0 (2130; Y), the UE terminates the CAP process (2132). Then, the UE can perform Tx burst transmission (2134). In addition, if the backoff counter value is not 0 (2130; N), according to step 2, the UE reduces the backoff counter value by 1 (2140).

[0279] Next, the UE checks whether the channel is in an idle state (2150), and if the channel is in an idle state (2150; Y), checks whether the backoff counter value is 0 (2130).

[0280] Furthermore, in operation 2150, if the channel is not in an idle state, that is, if the channel is in a busy state (2150; N), the UE checks whether the corresponding channel is in an idle state for a delay duration (Td; 25usec or more) longer than the slot time (e.g., 9usec) according to step 5 (2160). If the channel is in an idle state during the delay duration (2170; Y), the UE may resume the CAP process again.

[0281] For example, when the backoff counter value Ninit is 10 and the channel is determined to be in a busy state after the backoff counter value is reduced to 5, the UE senses the channel during the delay duration to determine whether it is in an idle state. Here, if the channel is in an idle state during the delay duration, the UE does not set the backoff counter value Ninit, but may perform the CAP process again from the backoff counter value 5 (or from 4 after decrementing the backoff counter value by 1).

[0282] Furthermore, if the channel is busy during the delay period (2170; N), the UE re-executes step 2160 to check again whether the channel is in an idle state during the new delay duration.

[0283] In the above process, if after step 4 of the above process, the UE does not send an UL transmission on the channel on which the transmission is performed, the UE may send an UL transmission on the channel if the following conditions are met:

[0284] - the UE is ready to transmit and the corresponding channel is sensed to be idle for at least the sensing slot duration Tsl, and

[0285] - The channel is sensed as idle during all time slot durations of the delay duration Td immediately preceding the transmission.

[0286] In addition, if the channel is not sensed as idle within the sensing slot duration Ts1 when the UE first senses the channel after being ready to perform transmission, or if the corresponding channel is not sensed as idle during any sensing slot duration of the delay duration Td immediately before the intended transmission, the UE proceeds to step 1 after sensing that the corresponding channel is idle during the slot duration of the delay duration Td.

[0287] The delay duration Td consists of a period Tf (=16 us) immediately following the mp continuous time slot duration. Here, each time slot duration Ts1 is 9 us, and Tf includes an idle time slot duration Ts1 at the starting point of Tf.

[0288] 5.2. Type 2 UL channel access procedure

[0289] 5.2.1. Type 2A UL channel access procedure

[0290] If the UE is instructed to perform a Type 2A UL channel access procedure, the UE uses the Type 2A channel access procedure for UL transmission. The UE may sense that the channel is idle for at least the sensing duration T short_ul =Send immediately after 25us. short_ul Includes a sensing time slot duration Tsl = 9us followed by duration T f = 16us. T f Included in T f The sensing time slot at the starting point of short_u1 If two sensing time slots in T are sensed as idle, the channel is short_ul The period is considered idle.

[0291] 5.2.2. Type 2B UL Channel Access Procedure

[0292] If the UE is instructed to perform a Type 2B UL channel access procedure, the UE uses a Type 2B channel access procedure for UL transmissions. The UE may transmit immediately after the corresponding channel is sensed to be idle for Tf=16us. Tf includes sensing slots occurring within the last 9us of Tf. If a channel is sensed to be idle for a total of at least 5us and sensing occurs for at least 4us in a sensing slot, the channel is considered idle during Tf.

[0293] 5.2.3. Type 2C UL Channel Access Procedure

[0294] If the UE is instructed to perform a Type 2C UL channel access procedure, the UE does not sense the channel before sending a transmission in order to send the transmission. The duration corresponding to the transmission is up to 584us.

[0295] 6. Channel Access Procedure for UL Multi-Channel Transmission

[0296] If the UE:

[0297] - is scheduled to transmit on channel set C, then if the UL scheduling grant for UL transmission on channel set C indicates a type 1 channel access procedure, if the UL transmission is scheduled to start transmission simultaneously for all channels in channel set C, and / or

[0298] - intends to perform uplink transmission on resources configured on channel set C using a Type 1 channel access procedure, and

[0299] If the channel frequencies of channel set C are a subset of one of the pre-configured channel frequency sets, then:

[0300] -UE can use type 2 channel access procedure on channel c i ∈C and execute the sending.

[0301] --If it is adjacent to channel c j ∈C (where i≠j) before sending, i Type 2 channel access procedure is performed on

[0302] --If the UE has accessed channel c using the Type 1 channel access procedure j ,but

[0303] ---Before performing the Type 1 channel access procedure on any channel in channel set C, the UE uniformly randomly selects channel c from channel set C j .

[0304] - If the UE fails to access any channel, the UE may select a channel c that is not within the bandwidth of the carrier whose bandwidth is scheduled or configured by the UL resource. i ∈C for sending.

[0305] Downlink channel structure

[0306] The base station transmits a relevant signal to the UE through a downlink channel to be described later, and the UE receives a relevant signal from the base station through a downlink channel to be described later.

[0307] (1) Physical Downlink Shared Channel (PDSCH)

[0308] PDSCH carries downlink data (e.g., DL shared channel transport block, DL-SCH TB), and modulation methods such as QPSK (quadrature phase shift keying), 16QAM (quadrature amplitude modulation), 64QAM, 256QAM, etc. are applied. Codewords are generated by encoding TBs. PDSCH can carry up to two codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword are mapped to one or more layers (layer mapping). Each layer is mapped to resources together with a demodulation reference signal (DMRS), generated as an OFDM symbol signal, and sent through the corresponding antenna port.

[0309] (2) Physical Downlink Control Channel (PDCCH)

[0310] PDCCH carries downlink control information (DCI) and applies QPSK modulation method. One PDCCH consists of 1, 2, 4, 8 or 16 control channel elements (CCE) according to the aggregation level (AL). One CCE consists of six resource element groups (REGs). One REG is defined as one OFDM symbol and one (P)RB.

[0311] Fig.18 A REG structure is shown in Figure 1. Fig.18 In FIG. 1 , D represents a resource element (RE) to which DCI is mapped, and R represents an RE to which DMRS is mapped. DMRS is mapped to RE#1, RE#5, and RE#9 along the frequency domain within one symbol.

[0312] The PDCCH is transmitted through a control resource set (CORESET). A CORESET is defined as a set of REGs with a given parameter set (e.g., SCS, CP length, etc.). Multiple CORESETs for one UE may overlap in the time / frequency domain. The CORESET may be configured through system information (e.g., MIB) or UE-specific higher layer (e.g., radio resource control RRC layer) signaling. Specifically, the number of RBs and the number of symbols (maximum 3) constituting the CORESET may be configured by higher layer signaling.

[0313] The precoder granularity of each CORESET in the frequency domain is configured by higher layer signaling as one of the following:

[0314] -sameAsREG-bundle: same as REG bundle size in frequency domain

[0315] -allContiguousRBs: equal to the number of contiguous RBs in the frequency domain within CORESET

[0316] The REGs in the CORESET are numbered based on a time-first mapping approach, that is, starting from the first OFDM symbol in the lowest numbered resource block in the CORESET, the REGs are numbered sequentially from 0.

[0317] The mapping type from CCE to REG is configured as one of a non-interleaved CCE-REG mapping type or an interleaved CCE-REG mapping type. Fig.19 (a) illustrates a non-interleaved CCE-REG mapping type, and Fig.19 (b) illustrates the interleaved CCE-REG mapping type.

[0318] - Non-interleaved CCE-REG mapping type (or localized mapping type): 6 REGs for a given CCE constitute one REG bundle, and all REGs for a given CCE are continuous. One REG bundle corresponds to one CCE

[0319] - Interleaved CCE-REG mapping type (or distributed mapping type): 2, 3, or 6 REGs for a given CCE form a REG bundle, and the REG bundle is interleaved within a CORESET. Within a CORESET consisting of 1 OFDM symbol or 2 OFDM symbols, the REG bundle consists of 2 or 6 REGs, and within a CORESET consisting of 3 OFDM symbols, the REG bundle consists of 3 or 6 REGs. The REG bundle size is configured per CORESET

[0320] Fig. 20The block interleaver is illustrated. The number of rows (A) of the (block) interleaver used for the above interleaving operation is configured to be one of 2, 3, or 6. When the number of interleaving units for a given CORESET is P, the number of columns of the block interleaver is equal to P / A. The write operation on the block interleaver is as follows Fig. 20 The interleaving operation is performed in the row-first direction as shown, and the readout operation is performed in the column-first direction. The cyclic shift (CS) of the interleaving unit is applied based on an ID that can be configured independently of the ID that can be configured for the DMRS.

[0321] The UE obtains the DCI sent through the PDCCH by performing decoding (referred to as blind decoding) on ​​the PDCCH candidate set. The PDCCH candidate set decoded by the UE is defined as a PDCCH search space set. The search space set can be a common search space or a UE-specific search space. The UE can acquire DCI by monitoring the PDCCH candidates in one or more search space sets configured by MIB or higher layer signaling. Each CORESET configuration is associated with one or more search space sets, and each search space set is associated with one CORESET configuration. A search space set is determined based on the following parameters.

[0322] -controlResourceSetId: Indicates the control resource set associated with the search space set

[0323] -monitoringSlotPeriodicityAndOffset: Indicates the PDCCH monitoring periodicity duration (in time slots) and the PDCCH monitoring duration offset (in time slots)

[0324] - monitoringSymbolsWithinSlot: indicates the PDCCH monitoring mode within the slot used for PDCCH monitoring (e.g., indicating the first symbol of the control resource set)

[0325] -nrofCandidates: indicates the number of PDCCH candidates per AL = {1, 2, 4, 8, 16} (a value among 0, 1, 2, 3, 4, 5, 6, 8)

[0326] Table 11 illustrates the characteristics of each search space type.

[0327] [Table 11]

[0328]

[0329] Table 12 illustrates a DCI format transmitted through the PDCCH.

[0330] [Table 12]

[0331]

[0332] DCI format 0_0 can be used to schedule TB-based (or TB-level) PUSCH, and DCI format 0_1 ​​can be used to schedule TB-based (or TB-level) PUSCH or code block group (CBG) (or CBG-level) PUSCH. DCI format 1_0 can be used to schedule TB-based (or TB-level) PDSCH, and DCI format 1_1 can be used to schedule TB-based (or TB-level) PDSCH or CBG-based (or CBG-level) PDSCH. DCI format 2_0 can be used to convey dynamic slot format information (e.g., dynamic SFI) to the UE, and DCI format 2_1 can be used to convey downlink preemption information to the UE. DCI format 2_0 and / or DCI format 2_1 can be delivered to the UEs in the group via a group common PDCCH, which is a PDCCH delivered to UEs defined as a group.

[0333] Before describing in detail, we will refer to Figure 21 to Figure 22 An example of operations of a UE and a base station according to an embodiment of the present disclosure is described.

[0334] Fig.21 1 is a diagram for explaining an example of an operation implementation of a UE according to the present disclosure. Fig.21 , the UE may send a first physical random access channel (PRACH) preamble code through message A (S2101). And in response to message A, a random access response (RAR) may be received through message B related to contention resolution (S2103). Here, the specific method in which the UE performs the random access process in S2101 to S2103 may be based on the implementation methods and features to be described below.

[0335] also, Fig.21 The UE can be Figures 1 to 4 Any of the various wireless devices disclosed. For example, Fig.21 The UE can be Figure 1 The first wireless device 100 or Figure 2 In other words, Fig.21 The operation processing can be done by Figures 1 to 4 The invention may be executed and implemented by any of the various wireless devices illustrated.

[0336] Fig. 22 1 is a diagram for explaining an example of an operation implementation of a base station according to the present disclosure. Fig. 22, the base station may receive a first physical random access channel (PRACH) preamble code through message A (S2201), and in response to message A, may send a random access response (RAR) through message B related to contention resolution (S2203). Here, the specific method for the base station to perform the random access process in S2201 to S2203 may be based on the embodiments and features described below.

[0337] also, Fig. 22 The base station can be Figures 1 to 4 Any of the various wireless devices disclosed. For example, Fig. 22 The base station can be Figure 1 The second wireless device 200 or Figure 2 In other words, Fig. 22 The operation processing can be done by Figures 1 to 4 The invention may be executed and implemented by any of the various wireless devices illustrated.

[0338] In LTE and / or NR networks, the UE can perform UL transmission through a random access procedure (RACH procedure) without receiving a direct uplink (UL) transmission schedule from a given base station or cell. From the UE's point of view, the random access process in the LTE and / or system is a 4-step process, including the following steps: 1) transmission of a random access preamble, 2) reception of a message (Msg) 2 corresponding to a random access response (RAR), 3) transmission of Msg 3 including a physical uplink shared channel (PUSCH), 4) reception of Msg 4 including information about contention resolution.

[0339] Here, Msg 2 is a message for allocating such UL resources by the base station receiving the random preamble, that is, the UL resources are to be used by the UE that has sent the corresponding preamble for sending Msg 3. Through Msg 3, the UE can send information related to the connection request, etc. and its own identification information (for example, the International Mobile User Identity (International Mobile User Identity; IMSI) or the Temporary Mobile User Identity (Temporary Mobile User Identity; TMSI)). When receiving Msg 3, the base station can send the identification information of the corresponding UE and the information required for random access through Msg4, thereby preventing possible conflicts between different UEs during the random access process, and completing the random access process of the corresponding UE.

[0340] Unlike the RACH procedure in the existing LTE and NR rel-15 configured in 4 steps as described above, in the newly introduced NR rel-16, research on the 2-step RACH procedure is being conducted to simplify the processing delay of the 4 steps and utilize the RACH procedure even in a small cell or unlicensed bandwidth. In the 2-step RACH, the steps of transmitting message 3 (Msg 3) including the physical uplink shared channel (PUSCH) and the steps of transmitting Msg 4 including the contention resolution message in the existing 4-step RACH are omitted. Instead, in the first step of the random access procedure, the UE directly transmits a message corresponding to the preamble together with Msg 3 as Msg A to the base station, and in response to Msg A, the base station transmits a message corresponding to the RAR together with Msg 4 as Msg B to the UE. When receiving Msg B, the UE decodes Msg B and completes the random access procedure, and thereafter performs data transmission / reception.

[0341] Fig.23 is a diagram illustrating the basic process of 2-step RACH. Fig.23 , the UE may receive 2-step RACH related configuration information included in the broadcast system information from the base station (S2301). When receiving the 2-step RACH related configuration information, the UE sends Msg A including a RACH preamble (or PRACH preamble) and a PUSCH based on the configuration information to perform a random access procedure for the base station (S2303). Here, the RACH preamble and the PUSCH may be sent at predetermined intervals in the time domain or may be sent continuously, and the corresponding PUSCH includes the identifier (ID) information of the UE. The base station may detect the preamble and may predict and receive the PUSCH at corresponding intervals or continuously. After receiving an access request and / or response from an upper layer based on the ID information of the UE sent through the PUSCH, the base station sends Msg B including information such as RAR and contention resolution as a response to Msg A to the UE (S2305). Thereafter, depending on whether the UE receives Msg B, the UE completes access to the base station in the same or similar manner as after receiving Msg 4 in the existing 4-step RACH procedure, and can send and receive data with the base station.

[0342] In NR, since the UE can perform a random access procedure in an unlicensed band, the listen-before-talk (LBT) processing required for signal transmission and reception in the unlicensed band can also be applied to signal transmission and reception in the random access procedure. That is, in the NR-Unlicensed Spectrum (NR-U) system, before the base station and the UE send / receive signals, LBT is always performed to check the idle or busy state of the transmission / reception channel, and for the 2-step RACH process in the unlicensed band, LBT can also be performed in the process of sending and receiving Msg A and Msg B.

[0343] Specifically, since the transmission of Msg A in the 2-step RACH process includes the transmission of the Msg A PRACH preamble and the transmission of the Msg A PUSCH, the random access process performed thereafter may be changed according to the success or failure of the LBT for the Msg A PUSCH after the transmission of the Msg A PRACH preamble. For example, if the UE transmits the Msg A PRACH preamble, then successfully performs LBT on the Msg A PUSCH and transmits the Msg APUSCH without any particular problem, the base station correctly receives both the Msg APRACH preamble and the Msg APUSCH, and transmits the Msg B including the contention resolution information to the UE, so that the 2-step RACH process can be completed. Otherwise, if the UE fails to perform LBT on MsgA PUSCH after sending the Msg A PRACH preamble, the UE cannot send Msg A PUSCH, and the base station that only receives the Msg A PRACH preamble but does not receive the Msg A PUSCH can indicate to fall back to Msg 3 through Msg B, so that the UE can switch to the 4-step RACH process.

[0344] Therefore, for the 2-step RACH procedure in the unlicensed band, whether the LBT for Msg A PUSCH is successful or failed should be considered in the Msg A PUSCH transmission and the subsequent Msg B reception, and in particular, it may be necessary to avoid the processing delay that occurs when the LBT fails. Hereinafter, in order to maintain the advantage of fast access of the 2-step RACH procedure, a method of configuring a single or multiple resources for Msg APUSCH in consideration of LBT failure will be described, and a method of configuring the reception window (or contention resolution timer; CR timer) of Msg B according to the configured resources will be described.

[0345] 1. Case where RACH timing and Msg A PUSCH timing have a one-to-one mapping relationship

[0346] For the transmission of Msg A, the RACH opportunity (RO) in which the Msg A PRACH preamble is transmitted and the PUSCH opportunity (PO) in which the Msg APUSCH is transmitted can be mapped one to one. Therefore, in the case where the UE transmits the Msg A PRACH preamble, the Msg A PUSCH opportunity corresponding to the transmitted Msg A PRACH preamble is configured as one, and for the one Msg A PUSCH opportunity, it is determined whether to transmit the Msg A PUSCH according to the success or failure of the LBT.

[0347] The window or timer used by the UE to receive Msg B can be configured as follows: 1) If LBT is successful, the timer starts or the window is configured after the Msg APUSCH opportunity, or if LBT fails, the window is not configured or the timer does not start. Alternatively, it can be configured as follows: 2) Regardless of whether LBT is successful or failed, the timer always starts or the window is always configured after the Msg A PUSCH opportunity.

[0348] Here, the UE selects the Msg A PRACH preamble for the 2-step RACH procedure, and even if the UE succeeds in the LBT for the MsgAPUSCH, or regardless of whether the LBT succeeds or fails, in the event of a situation where the channel state deteriorates such as the one Msg A PUSCH opportunity, the UE can predict the detection error probability for the Msg A PUSCH for itself, and can send only the Msg A PRACH preamble without sending the Msg A PUSCH. That is, whether the Msg A PUSCH is sent can be changed according to the success or failure of the LBT or according to the UE's independent determination and selection of the transmission or non-transmission of the Msg A PUSCH.

[0349] In a situation where whether to send Msg A PUSCH can be determined as described above, the start time of the window or timer for receiving Msg B can be configured as in the following example, and here, among the following examples, those examples that can be utilized regardless of the success or failure of LBT are not limited to being applied to the NR-U system, and can be applied to authorized carriers.

[0350] (1) Example 1: In the case of successful LBT, at least one symbol from the last symbol of the PUSCH opportunity After the first symbol, set the start time of the window or timer from the first symbol

[0351] Example 1 is a method of configuring a window or timer for receiving Msg B only when LBT succeeds and Msg A PUSCH can be transmitted, and not configuring a window or timer for receiving Msg B when LBT fails and Msg A cannot be transmitted. That is, even if there is an Msg APUSCH opportunity corresponding to the Msg A PRACH preamble transmitted by the UE, if LBT fails, Msg A PUSCH transmission in the corresponding Msg A PUSCH opportunity is not performed, so that the window or timer for receiving Msg B is not started. In addition, if LBT succeeds, Msg A PUSCH transmission in the corresponding Msg A PUSCH opportunity is performed normally, and the window or timer for receiving Msg B can also be started.

[0352] Here, the start time of the window or timer for receiving Msg B may be a symbol after at least one symbol from the last symbol of the Msg A PUSCH opportunity corresponding to the Msg APRACH preamble sent by the UE. In other words, the window or timer for receiving Msg B may be configured to start at an interval of at least one symbol from the Msg A PUSCH opportunity in a symbol unit. In addition, on the premise that resources for monitoring Msg B are configured, the start time of the window or timer may be the first symbol of the resources for monitoring Msg B. Here, the resources for monitoring Msg B may be resources corresponding to the earliest CORESET of the Type1-PDCCH common search space of the PDCCH set for the UE to receive Msg B.

[0353] Therefore, in the case where a UE that has sent a Msg A PRACH preamble succeeds in LBT and can then send Msg APUSCH, the window or timer configured to receive Msg B can start from the first symbol of the resources used to monitor Msg B, and the corresponding start time can be a time point after at least one symbol from the last symbol of the Msg APUSCH opportunity.

[0354] Fig.24 is a diagram illustrating an example of configuring a reception window of Msg B according to success or failure of LBT for Msg A PUSCH transmission. Fig.24 In (A), for the PO corresponding to the RO related to the Msg A PRACH preamble sent by the UE, when the LBT for sending Msg A PUSCH fails, the UE does not send Msg A PUSCH and does not configure a window or timer for receiving Msg B. In addition, Fig.24In (B), for the PO corresponding to the RO related to the Msg A PRACH preamble code sent by the UE, when the LBT for Msg A PUSCH transmission is successful, the UE transmits Msg APUSCH and configures a window or timer for receiving Msg B. Here, the window or timer configured to receive Msg B starts from the first symbol of the resource for monitoring Msg B, and the corresponding start time is a time point after at least one symbol from the last symbol of the PUSCH opportunity.

[0355] (2) Example 2: After at least one symbol from the last symbol of the PUSCH opportunity, the LBT is successful or Failure to set the start time of the window or timer from the first symbol independently

[0356] Unlike Example 1, Example 2 is a method of setting a window or timer for receiving Msg B even if the UE fails to transmit MsgAPUSCH due to LBT failure for Msg A PUSCH. That is, if there is a PUSCH opportunity corresponding to the Msg A PRACH preamble transmitted by the UE, the reception window or timer of Msg B can be started regardless of whether LBT succeeds or fails, and the UE can expect to receive Msg B. The method of Example 2 can be applied without distinguishing between a licensed carrier and an unlicensed carrier.

[0357] In Example 2, the start time of the window or timer for receiving Msg B may be a symbol after at least one symbol from the last symbol of the Msg A PUSCH opportunity corresponding to the Msg APRACH preamble transmitted by the UE. In other words, the window or timer for receiving Msg B may be configured to start at an interval of at least one symbol from the Msg APUSCH opportunity in a symbol unit. In addition, on the premise that resources for monitoring Msg B are configured, the start time of the window or timer may be the first symbol of the resources for monitoring Msg B. Here, the resources for monitoring Msg B may be resources corresponding to the earliest CORESET of the Type1-PDCCH common search space of the PDCCH set for the UE to receive Msg B.

[0358] When a UE that has transmitted a Msg A PRACH preamble fails to transmit a Msg A PUSCH due to a failed LBT, or does not transmit a Msg A PUSCH according to an independent determination of a channel state, the UE may expect to receive a fallback RAR including uplink (UL) grant information for transmitting a Msg 3 through Msg B. The base station also transmits a fallback RAR including UL grant information to the UE through Msg B, thereby causing a fallback of the UE's Msg 3 transmission together with a 4-step RACH procedure. Here, even if a random access preamble index (RAPID) included in the detected Msg_A PRACH preamble is a RAPID for a 2-step RACH procedure, and if the base station fails to decode the Msg_A PSCH for a certain period of time, the base station may assume that the UE has a failed LBT and does not transmit the Msg A PSCH, and may transmit a fallback RAR to the UE.

[0359] A UE that expects to receive a fallback RAR due to the UE's failure to send Msg A PUSCH may ignore a successful RAR including its own RAPID even if it detects it, and may expect to receive a fallback RAR whose RAPID matches its own RAPID during the duration of a given window or timer. If the UE does not receive a RAR within the time when the window or timer expires, the UE may perform a random access resource selection procedure for random access after a specific back-off time, up to a specified maximum number of transmissions, and then may perform a radio link failure (RLF) procedure.

[0360] On the other hand, if the UE that has sent the Msg APRACH preamble succeeds in the LBT and sends the Msg APUSCH, the UE can expect to receive a successful RAR including information about contention resolution through Msg B, and can expect its RAPID and a specific value (e.g., a UE-specific identifier (UE-identifier; UE-ID) to be included in the content of Msg B. The base station can also notify the UE that the 2-step RACH procedure of the UE can be successfully performed by sending a successful RAR including information about contention resolution to the UE via Msg B. If the UE does not identify its RAPID and UE-ID through Msg B, the UE continues to perform blind decoding until the reception window or timer of Msg B expires. Here, if the UE fails to identify the RAPID and UE-ID according to the expiration time, the UE can perform a resource selection procedure for random access after a specific backoff time, up to a specified maximum number of transmissions, and then can perform a radio link failure procedure.

[0361] The above example can be similarly applied to a situation where multiple UEs perform a 2-step RACH procedure with respect to one base station. In the case where there are two UEs that simultaneously select the Msg A PRACH preamble code including the same RAPID, it may happen that one UE sends Msg APUSCH while the other UE fails to send Msg APUSCH. Here, as described above, the UE that sends Msg APUSCH expects to receive a successful RAR, and also expects its RAPID and UE-ID to be included in the content of Msg B. If the UE does not identify its RAPID and UE-ID through Msg B, the UE continues to perform blind decoding according to the time when the window or timer expires, and if the UE does not identify its RAPID and UE-ID until the expiration, the UE can perform a resource selection process for random access after the backoff time and the radio link failure (RLF) process. On the other hand, the UE that failed to send Msg A PUSCH expects a fallback RAR that matches its RAPID during the window or timer duration as described above, and even if it detects a successful RAR including its own RAPID, it can ignore it. A UE that fails to receive the RAR at the time of expiration of the window or timer may perform a resource selection procedure for random access after a specific backoff time and a radio link failure procedure.

[0362] Fig.25 is a diagram illustrating an example of configuring the reception window of Msg B regardless of the success or failure of LBT for Msg A PUSCH transmission. Fig.25 In (A), for the PO corresponding to the RO related to the Msg A PRACH preamble sent by the UE, even if the LBT for Msg A PUSCH transmission fails and the UE does not send Msg A PUSCH, a window or timer for receiving Msg B can be configured. Fig.25 In (B), for the PO corresponding to the RO related to the Msg A PRACH preamble sent by the UE, if the LBT sent for the Msg A PUSCH is successful, the UE sends the Msg APUSCH and configures a window or timer for receiving the Msg B. Here, Fig.25 (A) or Fig.25 The window or timer configured to receive Msg B in (B) starts from the first symbol of the resource used to monitor Msg B, and the corresponding start time may be a time point after at least one symbol from the last symbol of the PUSCH opportunity.

[0363] 2. Case where RACH timing and Msg A PUSCH timing have a one-to-many mapping relationship

[0364] For Msg A transmission, a RACH opportunity (RO) in which a Msg A PRACH preamble is transmitted may be mapped to a plurality of PUSCH opportunities (PO) in which Msg A PUSCH is transmitted. Here, the plurality of Msg A PUSCH opportunities may be continuously allocated in a time division multiplexing (TDM) form without a time gap between the Msg A PUSCH opportunities. Alternatively, the plurality of Msg A PUSCH opportunities may be allocated with a constant time gap.

[0365] The one-to-many mapping relationship between RACH opportunities and Msg A PUSCH opportunities can be configured according to various schemes. As a simple example, the preambles used for all 2-step RACH procedures can be mapped to all multiple Msg APUSCH opportunities respectively.

[0366] Alternatively, as another example, the preamble used for the 2-step RACH process can be divided into N subsets, and the number of Msg APUSCH opportunities mapped to the preamble can be configured differently for each subset. That is, with respect to the preambles divided into N subsets, 1) in the case of a subset including preambles corresponding to #0 to #A-1, each preamble can be mapped to one Msg APUSCH opportunity to form a one-to-one mapping relationship, and 2) in the case of a subset including preambles corresponding to #A to #B-1, each preamble can be mapped to two Msg APUSCH opportunities to form a one-to-two mapping relationship. In addition to this, 3) in the case of a subset including preambles corresponding to #B to #C-1, each preamble can be mapped to three Msg A PUSCH opportunities to form a one-to-three mapping relationship, and further settings for the mapping relationship are also possible.

[0367] In the above example in which the number of Msg A PUSCH opportunities mapped to the preamble is configured differently for each subset, the preamble included in the subset of 1) has a one-to-one mapping relationship with the Msg APUSCH opportunity, and thus one PUSCH opportunity corresponding to the transmitted PRACH preamble is configured, and for the corresponding one PUSCH opportunity, it is determined whether to transmit the Msg APUSCH according to the success or failure of the LBT. The preamble included in the subset of 2) has a one-to-two mapping relationship with the Msg A PUSCH opportunity, and thus two PUSCH opportunities corresponding to the transmitted PRACH preamble are configured, and for the corresponding two PUSCH opportunities, it is determined whether to transmit the Msg APUSCH according to the success or failure of the LBT. Similarly, the preamble included in the subset of 3) has a one-to-three mapping relationship with the Msg A PUSCH opportunity, and thus three PUSCH opportunities corresponding to the transmitted PRACH preamble are configured, and for the corresponding three PUSCH opportunities, it is determined whether to transmit the Msg A PUSCH according to the success or failure of the LBT.

[0368] Since multiple LBT attempts can be made as the number of resources corresponding to the transmitted PRACH preamble increases, the probability of Msg APUSCH transmission can be increased despite the failure of LBT. That is, the probability of MsgAPUSCH transmission can be changed for each subset, and considering the channel state or priority of the signal to be transmitted, the UE can select a subset including preambles with a relatively high Msg APUSCH transmission probability or a low Msg APUSCH transmission probability. For example, the UE can select a subset based on the reference signal received power (RSRP) of a reference signal such as a received synchronization signal block (SSB) or a channel state information-reference signal (CSI-RS), or can select a subset based on a priority criterion such as the size of the MsgAPUSCH to be transmitted. Based on the selected subset, the UE can perform LBT for the PUSCH opportunity corresponding to the preamble included in the subset, attempt to send Msg A PUSCH, and configure a window or timer for receiving Msg B.

[0369] In this case, for a preamble with a one-to-one mapping relationship, Msg A PUSCH can be sent according to Example 1 or Example 2 above, and a window or timer for receiving Msg B can be configured. In the case where multiple PUSCH opportunities are mapped to one preamble instead of a one-to-one mapping relationship, the possibility of collision of multiple PUSCH opportunities with multiple Msg APUSCHs in the NR system should be considered. For example, in order to reduce the possibility of collision of multiple Msg APUSCHs, among the multiple Msg A PUSCH opportunities corresponding to the preamble, a modulo operation of the UE-ID based on the total number (M) of the multiple Msg APUSCH opportunities is applied, and one Msg APUSCH opportunity is determined, and the Msg APUSCH can be sent through the one Msg APUSCH opportunity. Here, the modulo operation is (UE-ID) mod (M), and each preamble is sequentially mapped to a PUSCH opportunity according to the result value of (UE-ID) mod (M) based on the UE-ID included in each preamble, and the UE can send Msg A PUSCH based on the mapped MsgAPUSCH opportunity. In this case, a window or timer for receiving Msg B can be started after one of the mapped PUSCH opportunities.

[0370] As another method of Msg A PUSCH transmission for the case where multiple PUSCH opportunities are mapped to one preamble, even if there is a possibility of collision of multiple Msg A PUSCHs, in order to increase the diversity and transmission probability of Msg A PUSCH, the UE may transmit Msg APUSCH in all Msg A PUSCH opportunities corresponding to the preamble. In this case, the UE attempts to transmit Msg APUSCH in multiple PUSCH opportunities corresponding to the preamble, and performs LBT on all multiple PUSCH opportunities in the NR-U system. Therefore, it is necessary to configure which PUSCH opportunities among the multiple PUSCH opportunities will become the basis for starting the window or timer for receiving Msg B, and for this purpose, the following example can be used.

[0371] Here, similar to Examples 1 and 2, even if the UE succeeds in LBT, or regardless of whether LBT succeeds or fails, in the event of a situation where the channel state deteriorates such as the one PUSCH opportunity, the UE can predict the detection error probability for Msg A PUSCH for itself, and can send only the Msg APRACH preamble without sending Msg APUSCH. That is, among the following examples, those examples that can be utilized regardless of the success or failure of LBT are not limited to being applied to the NR-U system, and can be applied to authorized carriers.

[0372] (1) Example 3: Among multiple PUSCH opportunities, the last PUSCH opportunity for which LBT has been successfully performed After at least one symbol from the symbol, the time starts from the first symbol configuration window or timer

[0373] Example 3 is a method in which a UE performs LBT on each of a plurality of PUSCH opportunities, and configures a window or timer for receiving Msg B based on a PUSCH opportunity that succeeds in LBT. Example 3 is similar to Example 1 in that a window or timer for receiving Msg B is configured based on a PUSCH opportunity that has succeeded in LBT. For the case of Example 3, when the UE fails LBT for all the plurality of PUSCHs, a window or timer for receiving Msg B is not configured. That is, when the UE fails to send Msg APUSCH, a window or timer for receiving Msg B is not started.

[0374] In Example 3, if the LBT of a specific PUSCH opportunity is successful, the MsgAPUSCH transmission in the corresponding PUSCH opportunity is performed normally, and a window or timer for receiving Msg B may also be started. Here, the start time of the window or timer for receiving Msg B may be after at least one symbol from the last symbol of the PUSCH opportunity corresponding to the Msg APRACH preamble sent by the UE. In other words, the window or timer for receiving Msg B may be configured to start at an interval of at least one symbol from the PUSCH opportunity in a symbol unit. In addition, on the premise of configuring resources for monitoring MsgB, the start time of the window or timer may be the first symbol of the resources for monitoring Msg B. Here, the resources for monitoring Msg B may be resources corresponding to the earliest CORESET of the Type1-PDCCH common search space of the PDCCH set for the UE to receive Msg B.

[0375] Therefore, in the case where a UE that has sent a Msg APRACH preamble succeeds in LBT and can then send Msg APUSCH, the window or timer configured to receive Msg B can start from the first symbol of the resources used to monitor Msg B, and the corresponding start time can be a time point after at least one symbol from the last symbol of the Msg A PUSCH opportunity.

[0376] Fig.26 : is a diagram illustrating an example of configuring a window for receiving Msg B according to a PUSCH opportunity that has succeeded in LBT among a plurality of PUSCH opportunities. Fig.26In the embodiment, for multiple POs corresponding to the RO associated with the Msg APRACH preamble code sent by the UE, when the LBT for a specific PO fails, the UE does not configure a window or timer for receiving Msg B based on the specific PO. Instead, the UE performs LBT until a PO in which LBT succeeds occurs, sends MsgAPUSCH in the PO in which LBT succeeds, and the window or timer for receiving Msg B can be configured at a time point after at least one symbol from the last symbol of the corresponding PO. Here, Fig.26 The shown PO corresponds to one MsgAPRACH preamble in the one-to-many scheme and may be a resource redundantly allocated in the form of TDM.

[0377] (2) Example 4: Regardless of whether LBT succeeds or fails, the last PUSCH among multiple PUSCH opportunities The timing window or timer is configured from the start time of the first symbol after at least one symbol from the last symbol of the timing window or timer

[0378] Example 4 is a method of always configuring a window or timer for receiving Msg B based on the last PUSCH opportunity among the multiple PUSCH opportunities corresponding to the Msg A PRACH preamble, regardless of whether the LBT for each PUSCH opportunity is successful or failed. That is, in order to prepare for the LBT failure of all corresponding multiple PUSCH opportunities and to expect the reception of the fallback RAR, the window or timer for receiving Msg B is always configured to start after at least one symbol from the last symbol of the last PUSCH opportunity among the multiple TDM PUSCH opportunities. The method of Example 4 is a method applicable without distinguishing between a licensed carrier and an unlicensed carrier, and the operations of the UE and the base station related to Example 4 may be the same as the operations described in Example 2.

[0379] In Example 4, if LBT for a specific Msg APUSCH opportunity is successful, Msg APUSCH transmission in the corresponding Msg APUSCH opportunity is performed normally, and a reception window or timer for Msg B may also be started based on the Msg APUSCH opportunity in which LBT is successful. In this case, the UE that sends Msg A PUSCH can expect to receive a successful RAR and can expect to successfully complete the 2-step RACH procedure.

[0380] However, if LBT continues to fail for the last Msg A PUSCH opportunity, the window or timer for receiving Msg B is configured based on the last Msg APUSCH opportunity regardless of whether LBT succeeds or fails. If the UE fails to send Msg A PUSCH even in the last Msg APUSCH opportunity, the UE may expect to receive a fallback RAR and may expect to send Msg 3 by falling back to the 4-step RACH procedure.

[0381] In this case, as described above, the time point at which the window or timer for receiving Msg B starts may be at least one symbol after the last symbol of the corresponding last Msg A PUSCH opportunity. In other words, the window or timer for receiving Msg B may be configured to start at an interval of at least one symbol from the Msg APUSCH opportunity in a symbol unit. In addition, on the premise that resources for monitoring Msg B are configured, the start time of the window or timer may be the first symbol of the resources for monitoring Msg B. Here, the resources for monitoring Msg B may be resources corresponding to the earliest CORESET of the Type1-PDCCH common search space of the PDCCH set for the UE to receive Msg B.

[0382] Fig. 27 is a diagram illustrating an example of configuring a window for receiving Msg B according to the last Msg APUSCH opportunity regardless of success or failure of LBT among a plurality of Msg A PUSCH opportunities. Fig. 27 In the example, even if LBT fails for all three POs corresponding to the RO associated with the Msg A PRACH preamble sent by the UE, a window or timer for receiving Msg B may be configured based on the last PO. In particular, the UE may configure a window or timer for receiving Msg B at a time point at least one symbol after the last symbol of the corresponding last PO. Here, Fig. 27 The shown PO corresponds to one Msg A PRACH preamble in the one-to-many scheme and may be a resource redundantly allocated in the form of TDM.

[0383] (3) Example 5: Regardless of whether LBT succeeds or fails, the first PUSCH timing among multiple PUSCH timings is Set the start time of the window or timer at least one symbol after the last symbol of

[0384] In Example 5, for multiple Msg A PUSCH opportunities corresponding to the Msg A PUSCH preamble code, regardless of whether the LBT for each Msg APUSCH opportunity is successful or failed. The window or timer for receiving Msg B is always set based on the first Msg A PUSCH opportunity among the multiple Msg A PUSCH opportunities. That is, the window or timer start time for receiving Msg B is set after at least one symbol from the last symbol of the first Msg APUSCH opportunity among multiple TDM Msg APUSCH opportunities. Here, after the reception window or timer of MsgB based on the first Msg APUSCH opportunity according to Example 5 starts, the operations of the UE and the base station can be the same as the operations described in Example 2, and at the same time, the UE can perform LBT on multiple remaining Msg A PUSCH opportunities thereafter.

[0385] The UE configures a window or timer for receiving Msg B after the first Msg A PUSCH opportunity and expects to receive Msg B while performing LBT for subsequent Msg A PUSCH opportunities so that the reception time of Msg B can be before or after the transmission time of Msg A PUSCH depending on which Msg A PUSCH opportunity the UE successfully transmits Msg A PUSCH. For example, if the UE successfully performs LBT for the first PUSCH opportunity and transmits Msg APUSCH through the first Msg A PUSCH opportunity, the reception time of Msg B can be after the transmission time of Msg APUSCH. However, if the UE fails to perform LBT for multiple Msg APUSCH opportunities including the first Msg APUSCH opportunity and transmits Msg APUSCH only in the Msg A PUSCH opportunity after the window or timer for Msg B reception expires, the reception time of Msg B can be before the transmission time of MsgAPUSCH.

[0386] Therefore, the subsequent operation of the UE that performs LBT for multiple Msg A PUSCH opportunities may vary as follows depending on whether the UE that performs LBT finally successfully performs LBT but receives Msg B at a time before sending Msg APUSCH or receives Msg B at a time point after PUSCH is sent. Here, as described in Example 2, depending on whether the UE has sent Msg APUSCH or the UE has not yet sent Msg_APUSCH, the target object (such as a successful RAR or fallback RAR signal) that each UE expects to receive may be different. In addition, the problem of repeated transmission of successful RAR or fallback RAR can also be solved by applying a method similar to the method of Example 2.

[0387] First, in the case where the UE receives Msg B from the base station before transmitting Msg A PUSCH, the base station receives the Msg APRACH preamble and fails to receive the Msg APUSCH, and therefore, the Msg B transmitted by the base station includes a fallback RAR including information about fallback and Msg 3 transmission. Here, if the configured Msg APUSCH opportunities still exist, the UE stores the fallback RAR and performs LBT on the remaining Msg A PUSCH opportunities in anticipation of the transmission of the Msg A PUSCH. If the UE fails to perform LBT before the last Msg A PUSCH opportunity and cannot finally transmit the Msg A PUSCH, the UE falls back to the 4-step RACH procedure using the information included in the previously received fallback RAR and transmits Msg 3. Here, in consideration of the fact that the base station initially allocates a plurality of Msg APUSCH opportunities, transmission information such as a grant for Msg 3 transmitted through the fallback RAR of Msg B may indicate subsequent resources.

[0388] On the other hand, if the UE receives Msg B from the base station after successfully performing LBT and sending Msg APUSCH, the subsequent operation of the UE varies depending on the content of Msg B sent by the base station. From the UE's point of view, since Msg APUSCH has been sent, if Msg B includes a fallback RAR, the fallback RAR can be ignored and a successful RAR can be expected to be received. If no successful RAR is received during the reception window or timer period of Msg B, the UE can fall back to the 4-step RACH process based on the previously received fallback RAR and send Msg 3. Alternatively, if no successful RAR is received during the reception window or timer period of Msg B, the UE can perform a resource selection process for random access after a set backoff time to avoid conflict with redundantly sent RAPID.

[0389] With regard to the example described in the present disclosure, the UE may identify an operation after the configured window or timer for receiving Msg B has expired as an operation according to unsuccessful contention resolution. In this case, the UE may select a 2-step RACH procedure or a 4-step RACH procedure again according to a channel state after a pre-configured back-off time, and perform a resource selection procedure for random access.

[0390] Although not limited to this, the various descriptions, functions, processes, proposals, methods and / or operational flowcharts of the present disclosure disclosed in this document may be applied to various fields where wireless communication / connection (e.g., 5G) is required between devices.

[0391] In the following, a more detailed illustration will be made with reference to the accompanying drawings. In the following drawings / descriptions, unless otherwise specified, the same reference numerals may represent the same or corresponding hardware blocks, software blocks or functional blocks.

[0392] Fig.28 An example of a wireless communication environment to which embodiments of the present disclosure may be applied is shown.

[0393] Reference Fig.28 , the communication system 1 applied to the present disclosure 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 (e.g., 5G NR (new RAT), LTE (long term evolution)), 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 extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things device 100f, and an AI device / server 400. For example, a 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 an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device includes an AR (augmented reality) / VR (virtual reality) / MR (mixed reality) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) provided in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, and the like. Portable devices may include smart phones, smart tablets, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptop computers), etc. Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device 200a may operate as a base station / network node for other wireless devices.

[0394] The wireless devices 100a to 100f may be connected to the network 300 through the base station 200. Artificial intelligence (AI) 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 (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices 100a to 100f may communicate with each other through the base station 200 / network 300, but may also communicate directly without going through the base station / network (e.g., side link communication). 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, an IoT device (e.g., a sensor) may communicate directly with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0395] Wireless communication / connection 150a, 150b, 150c can be performed between wireless devices 100a to 100f and base station 200 and between base station 200 and base station 200. Here, wireless communication / connection can be performed through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication) and inter-base station communication 150c. Through wireless communication / connection 150a, 150b and 150c, wireless devices and base stations / wireless devices and base stations and base stations can send / receive radio signals to each other. For example, wireless communication / connection 150a, 150b and 150c can send / receive signals through various physical channels. To this end, based on various proposals of the present disclosure, at least a portion of various configuration information configuration processing, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processing, etc. can be performed.

[0396] Fig.29 A wireless device to which the present disclosure is applied is exemplified.

[0397] Reference Fig.29 , the first wireless device 100 and the second wireless device 200 can send / receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device 100, the second wireless device 200} can be connected to Fig.24 The wireless device 100x and the base station 200 correspond to each other.

[0398] The first wireless device 100 includes one or more processors 102 and one or more memories 104, and may also include one or more transceivers 106 and / or one or more antennas (antenna units) 108. The processor 102 controls the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed herein. For example, the processor 102 may process the information in the memory 104 to generate first information / signals, and then transmit a wireless signal including the first information / signals through the transceiver 106. In addition, the processor 102 may receive a radio signal including second information / signals through the transceiver 106, and then store information obtained from the signal processing of the second information / signals 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, the memory 104 may store software code including instructions for performing some or all of the processing controlled by the processor 102, or for performing the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in this document. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver 106 may be connected to the processor 102 and may send and / or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0399] In detail, instructions and / or operations controlled by the processor 102 of the first wireless device 100 and stored in the memory 104 according to an embodiment of the present disclosure will be described.

[0400] The following operations are described based on control operations of the processor 102 from the perspective of the processor 102 , but may be stored in the memory 104 such as software codes for executing the operations.

[0401] The processor 102 may control the transceiver 106 to transmit a first physical random access channel (PRACH) preamble through a message A. And the processor 102 may control the transceiver 106 to receive a random access response (RAR) through a message B related to contention resolution. In this case, the specific method in which the processor 102 controls the transceiver 106 to transmit the message A and controls the transceiver 106 to receive the message B may be based on the following example.

[0402] Specifically, instructions and / or operations controlled by the processor 202 of the second wireless device 200 and stored in the memory 204 according to an embodiment of the present disclosure will be described.

[0403] The following operations are described based on control operations of the processor 202 from the perspective of the processor 202 , but software codes such as for executing the operations may be stored in the memory 204 .

[0404] The processor 202 may control the transceiver 206 to receive a first physical random access channel (PRACH) preamble through a message A. In addition, the processor 202 may control the transceiver 206 to send a random access response (RAR) through a message B related to contention resolution. In this case, the specific method in which the processor 202 controls the transceiver 206 to receive the message A and controls the transceiver 206 to send the message B may be based on the following example.

[0405] In the following, the hardware components of the wireless devices 100 and 200 will be described in more detail. Although not limited to this, one or more protocol layers can be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 can implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors 102, 202 can generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the descriptions, functions, processes, proposals, methods, and / or operational flowcharts disclosed herein. One or more processors 102, 202 can generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or flowcharts disclosed herein. One or more processors 102 and 202 generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed herein, and provide them to one or more transceivers 106 and 206. One or more processors 102, 202 may receive signals (e.g., baseband signals) from one or more transceivers 106, 206, and may obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flow charts disclosed herein.

[0406] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. 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. The descriptions, functions, processes, suggestions, methods, and / or flowcharts of the operations disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to perform the descriptions, functions, processes, suggestions, methods, and / or flowcharts disclosed herein may be included in one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions of operations, functions, processes, suggestions, methods, and / or flow diagrams disclosed herein may be implemented using firmware or software in the form of codes, instructions and / or instruction sets.

[0407] One or more memories 104, 204 may be coupled to one or more processors 102, 202 and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or instructions. 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 a combination thereof. One or more memories 104, 204 may be placed inside and / or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be coupled to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0408] One or more transceivers 106, 206 can send user data, control information, radio signals / channels, etc. involved in the methods and / or operational flow charts herein to one or more other devices. The one or more transceivers 106, 206 can receive user data, control information, radio signals / channels, etc. involved in the descriptions, functions, processes, suggestions, methods and / or flow charts disclosed herein from one or more other devices. For example, one or more transceivers 106, 206 can be connected to one or more processors 102, 202, and can send and receive wireless signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to send user data, control information or wireless signals to one or more other devices. In addition, 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 connected to one or more antennas 108, 208, and may be configured to send and receive user data, control information, radio signals / channels, etc. mentioned in the description, function, process, proposal, method and / or operation flow chart through the one or more antennas 108, 208. In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 convert the received radio signals / channels, etc. from RF band signals to baseband signals to process the received user data, control information, radio signals / channels, etc. using the one or more processors 102, 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals / channels, etc. processed using the one or more processors 102 and 202 from baseband signals to RF band signals. To this end, the one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0409] Fig.30 Another example of a wireless device applied to the present disclosure is shown. The wireless device can be implemented in various forms according to use cases / services (see Fig. 22 ).

[0410] Reference Fig.30 , the wireless devices 100 and 200 can communicate with Fig.23The wireless devices 100 and 200 of the present invention correspond to each other and may be composed of various elements, components, units / components 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 an additional element 140. The communication unit may include a communication circuit 112 and a transceiver 114. For example, the communication circuit 112 may include Fig.23 The one or more processors 102, 202 and / or one or more memories 104, 204 of the present invention may include: Fig.23 one or more transceivers 106, 206 and / or one or more antennas 108, 208. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional element 140, and controls the general operation of the wireless device. For example, the control unit 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 may transmit the information stored in the memory unit 130 to the outside (e.g., another communication device) via the wireless interface / wired interface through the communication unit 110, or may store the information received from the outside (e.g., another communication device) via the wireless interface / wired interface through the communication unit 110 in the memory unit 130. Therefore, the specific operation process of the control unit 120 according to the present disclosure and the program / code / instruction / information stored in the memory unit 130 may correspond to Fig.30 The operation of at least one of the processors 102 and 202 and the operation of at least one of the memories 104 and 204.

[0411] The additional element 140 may be configured differently depending on the type of the wireless device. For example, the additional element 140 may include at least one of a power supply unit / battery, an input / output unit (I / O unit), a drive unit, and a computing unit. Although not limited thereto, the wireless device may include a robot ( Fig. 22 100a), vehicles ( Fig. 22 100b-1, 100b-2), XR device ( Fig. 22 100c in), mobile devices ( Fig. 22 100d) and household appliances ( Fig. 22 100e in), IoT devices ( Fig. 22 100f in), digital broadcast terminals, holographic devices, public safety devices, MTC devices, medical devices, financial technology (fintech) devices (or financial devices), security devices, climate / environmental devices, which can be AI servers / devices ( Fig. 22 400 in), base station ( Fig. 22The wireless device may be mobile or used in a fixed location depending on the use case / service.

[0412] exist Fig.30 In the wireless devices 100 and 200, various elements, components, units / components and / or modules in the wireless devices 100 and 200 may all be interconnected through a wired interface, or at least some of them may be wirelessly connected 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 wiring, and the control unit 120 and the first unit (e.g., 130, 140) may be wirelessly connected to the communication unit 110 through the communication unit 110. In addition, each element, component, unit / component and / or module in the wireless devices 100 and 200 may also include one or more elements. For example, the control unit 120 may be configured with one or more processor groups. For example, the control unit 120 may be configured as a group of communication control processors, application processors, electronic control units (ECUs), graphics processing processors, memory control processors, etc. As another example, the memory unit 130 may include: random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), flash memory, volatile memory, and non-volatile memory, and / or combinations thereof.

[0413] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. Fig.30 An implementation example of .

[0414] Fig.31 Portable devices to which the present disclosure is applied are illustrated. Portable devices may include smart phones, smart tablets, wearable devices (e.g., smart watches, smart glasses), and portable computers (e.g., laptop computers). Mobile devices may be referred to as mobile stations (MS), user terminals (UTs), mobile subscriber stations (MSSs), subscriber stations (SSs), advanced mobile stations (AMSs), or wireless terminals (WTs).

[0415] Reference Fig.31 , the portable device 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a memory unit 130, a power supply unit 140a, an interface unit 140b, and an input / output unit 140c. The antenna unit 108 may be configured as a part of the communication unit 110. The blocks 110 to 130 / 140a to 140c are respectively Fig.30 The blocks 110 to 130 / 140 correspond.

[0416] The communication unit 110 may send and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit 120 may perform various operations by controlling the components of the portable device 100. The control unit 120 may include an application processor (AP). The memory unit 130 may store data / parameters / programs / codes / commands required for driving the portable device 100. In addition, the memory unit 130 may store input / output data / information. The power supply unit 140a supplies power to the portable device 100 and may include a wired / wireless charging circuit, a battery, etc. The interface unit 140b may support the connection between the portable device 100 and other external devices. The interface unit 140b may include various ports (e.g., audio input / output ports and video input / output ports) for connecting to external devices. The input / output unit 140c may receive or output image information / signals, audio information / signals, data, and / or information input from a user. The input / output unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker, and / or a tactile module.

[0417] For example, in the case of data communication, the input / output unit 140c obtains information / signals (e.g., touch, text, voice, image, video) input from the user, and can store the obtained information / signals in the memory unit (130). The communication unit 110 can convert the information / signals stored in the memory into wireless signals, and directly send the converted wireless signals to another wireless device or base station. In addition, after receiving a radio signal from another wireless device or base station, the communication unit 110 can restore the received radio signal to the original information / signal. After the restored information / signal is stored in the memory unit 130, it can be output in various forms (e.g., text, voice, image, video, touch) through the input / output unit 140c.

[0418] Fig.32 The vehicle or autonomous driving vehicle to which the present disclosure is applied is exemplified. The vehicle or autonomous driving vehicle can be implemented as a mobile robot, a transportation vehicle, a train, an aircraft (AV), a ship, etc.

[0419] Reference Fig.32 , the vehicle or autonomous vehicle 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a drive unit 140a, a power supply unit 140b, a sensor unit 140c, and an autonomous drive unit 140d. The antenna unit 108 may be configured as a part of the communication unit 110. The blocks 110 / 130 / 140a to 140d are respectively Fig.30 Corresponding to blocks 110 / 130 / 140.

[0420] The communication unit 110 can send and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations, etc.), servers, etc. The control unit 120 can control the elements of the vehicle or autonomous driving vehicle 100 to perform various operations. The control unit 120 may include an electronic control unit (ECU). The drive unit 140a can enable the vehicle or autonomous driving vehicle 100 to travel on the ground. The drive unit 140a may include: an engine, a motor, a powertrain, wheels, brakes, a steering device, etc. The power supply unit 140b supplies power to the vehicle or autonomous driving vehicle 100, and may include a wired / wireless charging circuit, a battery, etc. The sensor unit 140c can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit 140c may include 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 location module, a vehicle forward movement / reverse movement sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illumination sensor, a pedal position sensor, etc. The autonomous driving unit 140d may implement a technology for maintaining a driving lane, a technology for automatically adjusting a speed (e.g., adaptive cruise control), a technology for autonomous driving along a predetermined route, and a technology for automatically setting a route when a destination is set.

[0421] As an example, the communication unit 110 may receive map data, traffic information data, etc. 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 control unit 120 may control the drive unit 140a to move the vehicle or the autonomous driving vehicle 100 along the autonomous driving path (e.g., speed / direction adjustment) according to the driving plan. During autonomous driving, the communication unit 110 may obtain the latest traffic information data from the external server aperiodically / periodically, and may obtain surrounding traffic information data from surrounding vehicles. In addition, during autonomous driving, the sensor unit 140c may obtain vehicle status and surrounding environment information. The autonomous driving unit 140d may update the autonomous driving route and driving plan based on the latest acquired data / information. The communication unit 110 may send information about the vehicle position, autonomous driving route, driving plan, etc. to an external server. The external server may use AI technology, etc. to predict traffic information data in advance based on information collected from the vehicle or autonomous driving vehicle, and may provide the predicted traffic information data to the vehicle or autonomous driving vehicle.

[0422] Fig.33 A signal processing circuit for transmitting a signal is illustrated.

[0423] Reference Fig.33, 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. Although not limited, Fig.33 The operations / functions can be Fig.23 The processors 102 and 202 and / or the transceivers 106 and 206 may be used for execution. Fig.33 The hardware components can be found in Fig.23 102, 202 and / or transceiver 106, 206. For example, blocks 1010 to 1060 may be implemented in Fig.23 In addition, blocks 1010 to 1050 may be implemented in processors 102 and 202 of the present invention. Fig.23 1 and 202, and block 1060 may be implemented in Fig.23 is implemented in the transceivers 106 and 206.

[0424] Codewords can be passed Fig.33 The signal processing circuit 1000 is converted into a wireless signal. Here, the codeword is a coded bit sequence of an information block. The information block may include a transport block (e.g., UL-SCH transport block, DL-SCH transport block). The radio signal may be transmitted through various physical channels (e.g., PUSCH, PDSCH).

[0425] Specifically, the codeword may be converted into a scrambled bit sequence by the scrambler 1010. A scrambling sequence for scrambling is generated based on an initialization value, and the initialization value may include ID information of a wireless device, etc. The scrambled bit sequence may be modulated into a modulation symbol sequence by the modulator 1020. 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), etc. The complex modulation symbol sequence may be mapped to one or more transmission layers by the layer mapper 1030. The modulation symbol (precoding) of each transmission layer may be mapped to the corresponding antenna port by the precoder 1040. The output z of the precoder 1040 may 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 transmission layers. Here, the precoder 1040 may perform precoding after performing transform precoding (e.g., DFT transform) on the complex modulation symbol. In addition, the precoder 1040 may perform precoding without performing transform precoding.

[0426] The resource mapper 1050 may map the modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include multiple symbols in the time domain (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) and multiple subcarriers in the frequency domain. The signal generator 1060 generates a radio signal from the mapped modulation symbols, and may send the generated radio signal to another device 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, and the like.

[0427] Can be used with Fig.33 The signal processing processes 1010 to 1060 of the wireless device are oppositely configured to process the signal for the signal received in the wireless device. For example, the wireless device (e.g., Fig.23 100 and 200 in ) can receive a wireless signal from the outside through an antenna port / transceiver. The received radio signal can be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Thereafter, the baseband signal can be restored to a codeword through resource demapper processing, post-coding processing, demodulation processing, and descrambling processing. The codeword can be restored to the original information block by decoding. Therefore, the signal processing circuit (not shown) for the received signal may include a signal restorer, a resource demapper, a post-coder, a demodulator, a descrambler, and a decoder.

[0428] The above examples are those examples in which the elements and features of the present disclosure are combined in a predetermined form. Unless otherwise expressly provided, each component or function should be considered optional. Each component or feature can be implemented in a form that is not combined with other components or features. In addition, the examples of the present disclosure can also be configured by combining some elements and / or features. The order of operations described in the examples of the present disclosure can be changed. Some configurations or features of an implementation example can be included in other examples, or can be replaced by corresponding configurations or features of other examples. Obviously, claims that are not clearly cited in the claims can be combined to form examples, or can be included as new claims by modification after submission.

[0429] In some cases, a specific operation described in the present disclosure as being performed by a base station may be performed by its upper node. That is, it is obvious that various operations performed in a network including multiple network nodes (including a base station) for communicating with a terminal may be performed by a base station or other network nodes other than a base station. A base station may be replaced by terms such as a fixed station, gNodeB (gNB), Node B, eNodeB (eNB), access point, etc.

[0430] Those skilled in the art will appreciate that the present disclosure may be specifically implemented in other specific forms without departing from the features of the present disclosure. Therefore, the description detailed above should not be interpreted as restrictive in all aspects, but should be interpreted as exemplary. The scope of the present disclosure should be determined by the reasonable interpretation of the attached claims, and all modifications within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0431] Industrial Applicability

[0432] As described above, the method for performing a random access procedure by a terminal in an unlicensed frequency band and the apparatus therefor have been mainly described using an example applied to the fifth-generation NewRAT system, but may be applied to various other wireless communication systems other than the fifth-generation NewRAT system.

Claims

1. A method performed by a terminal, the method comprising the following steps: Send message A to the base station; receiving a random access response RAR from the base station via a message B, Among them, for the two situations of i) in response to sending only the physical random access channel PRACH without sending the physical uplink shared channel PUSCH through the message A and ii) in response to sending the PRACH and the PUSCH through the message A, the window for detecting the message B starts at least one symbol after the last symbol of the PUSCH opportunity corresponding to the PRACH transmission.

2. The method according to claim 1, in, The RAR is a fallback RAR, and the fallback RAR includes uplink UL grant information.

3. The method according to claim 2, in, transmitting a PUSCH scheduled by the UL grant information included in the fallback RAR, and Among them, a PDSCH for contention resolution is received.

4. The method according to claim 1, in, The RAR is a successful RAR including information about contention resolution.

5. The method according to claim 1, in, The window starts at the first symbol of the resource associated with the monitoring of the message B.

6. A device, comprising: at least one processor; as well as at least one memory operatively connected to the at least one processor and storing instructions for performing specific operations upon execution by the at least one processor, The specific operations include: Send message A to the base station; receiving a random access response RAR from the base station via a message B, Among them, for the two situations of i) in response to sending only the physical random access channel PRACH without sending the physical uplink shared channel PUSCH through the message A and ii) in response to sending the PRACH and the PUSCH through the message A, the window for detecting the message B starts at least one symbol after the last symbol of the PUSCH opportunity corresponding to the PRACH transmission.

7. A terminal, comprising: at least one transceiver; at least one processor; as well as at least one memory operatively connected to the at least one processor and storing instructions for performing specific operations upon execution by the at least one processor, The specific operations include: Send message A to the base station; receiving a random access response RAR from the base station via a message B, Among them, for the two situations of i) in response to sending only the physical random access channel PRACH without sending the physical uplink shared channel PUSCH through the message A and ii) in response to sending the PRACH and the PUSCH through the message A, the window for detecting the message B starts at least one symbol after the last symbol of the PUSCH opportunity corresponding to the PRACH transmission.

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