A method and apparatus for a terminal to receive a downlink signal based on an arbitrary connection process in an unlicensed band.

Abstract

To provide a method, apparatus and terminal for receiving, by a terminal, a downlink signal on the basis of a random access channel procedure in unlicensed band.SOLUTION: A terminal is configured to: transmit a first PRACH preamble through a message A; in response to the message A, receive an RAR through a message B related to contention resolution; receive information on at least one DRX timer for setting a DRX operation; and receive a downlink signal during an on-duration based on of the at least one DRX timer. The first PRACH preamble is a PRACH preamble mapped to a PUSCH occasion for the message A, and a window for reception of the message B may start after at least one symbol from the last symbol of the PUSCH occasion.SELECTED DRAWING: Figure 31

Description

[Technical Field]

[0001] This disclosure relates to a method and apparatus for receiving downlink signals in an unlicensed band based on an arbitrary connection process, and more particularly to a method and apparatus for receiving downlink signals in an unlicensed band based on a two-step arbitrary connection process and DRX (Discontinuous Reception) operation. [Background technology]

[0002] 5G is a means of delivering streams rated at hundreds of megabits per second to gigabits per second, and can complement FTTH (fiber-to-the-home) and cable-based broadband (or DOCSIS). Such high speeds are required for virtual and augmented reality, as well as for transmitting TV at resolutions of 4K and above (6K, 8K and beyond). VR (Virtual Reality) and AR (Augmented Reality) applications mostly include immersive sports competitions. Certain application programs may require special network configurations. For example, in the case of VR games, game companies must integrate their core servers with the network operator's edge network servers to minimize latency.

[0003] Automotive is expected to be a significant new driving force in 5G, with numerous use cases for mobile communications within vehicles. For example, passenger entertainment requires high capacity and high mobility mobile broadband simultaneously, as future users will continue to expect high-quality connectivity regardless of their location and speed. Another use case in the automotive sector is augmented reality dashboards, which overlay information on what the driver sees through the windshield, identifying objects in darkness and informing the driver about their distance and movement. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure structures, and information exchange between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems will guide drivers towards alternative routes of action to enable safer driving and reduce the risk of accidents. The next stage will be remotely controlled or self-driven vehicles, which require highly reliable and very fast communication between different self-driven vehicles and between vehicles and infrastructure. In the future, self-driving vehicles will handle all driving activities, allowing drivers to focus only on traffic anomalies that the vehicle itself cannot identify. The technical requirements for self-driving vehicles demand ultra-low latency and ultra-high-speed reliability to increase traffic safety to a level unattainable by humans.

[0004] Smart cities and smart homes, often referred to as smart societies, will be embedded in high-density wireless sensor networks. Distributed networks of intelligent sensors will identify the requirements for cost-effective and energy-efficient maintenance of cities or homes. Similar setups can be made for individual households. Temperature sensors, window and heating controllers, burglar alarms, and household appliances will all be wirelessly connected. Many of these sensors typically have low data transmission speeds, low power consumption, and low cost. However, real-time HD video, for example, may be required for certain types of devices for surveillance.

[0005] The consumption and distribution of energy, including heat and gas, is becoming highly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies so that they collect information and act accordingly. This information can include the behavior of providers and consumers, so that smart grids can improve efficiency, reliability, economics, production sustainability, and the automated distribution of fuels such as electricity. Smart grids can also be thought of as other low-latency sensor networks.

[0006] The healthcare sector possesses numerous application programs that can benefit from mobile communications. Communication systems can support telemedicine, providing clinical care from remote locations. This helps reduce distance barriers and improve access to healthcare services that are not sustainably available in remote rural areas. It can also be used to save lives in critical medical and emergency situations. Mobile communication-based wireless sensor networks can provide remote monitoring and sensing for parameters such as heart rate and blood pressure.

[0007] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring incurs high installation and maintenance costs. Therefore, the possibility of replacing cables with reconfigurable wireless links presents an attractive opportunity in many industrial sectors. However, achieving this requires wireless connectivity to operate with similar latency, reliability, and capacity to cables, and to be simplified in its management. Low latency and extremely low error probability are new requirements that need to be met by 5G connectivity.

[0008] Logistics and freight tracking are important use cases for mobile communications, enabling inventory and package tracking anywhere using location-based information systems. Logistics and freight tracking use cases typically require low data speeds but demand wide-area and highly reliable location information. [Overview of the project] [Problems that the invention aims to solve]

[0009] This disclosure aims to provide a method and apparatus for a terminal to receive a downlink signal based on a two-stage arbitrary connection process and DRX (Discontinuous Reception) operation.

[0010] The technical problems that this disclosure seeks to solve are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by a person with ordinary skill in the art to which this invention pertains from the following description. [Means for solving the problem]

[0011] In an embodiment of the present disclosure, a method for receiving a downlink signal on an unlicensed band based on a Random Access Channel Procedure (RACH Procedure) is provided, wherein a first PRACH (Physical Random Access Channel) preamble is transmitted to a base station in message A, a Random Access Response (RAR) is received from the base station in message B related to contention resolution as a response to message A, information about at least one DRX timer for setting up a Discontinuous Reception (DRX) operation is received from the base station, and a downlink signal is received from the base station during an on-duration based on the at least one DRX timer, wherein the first PRACH preamble is a PRACH preamble that is mapped to a PUSCH (Physical Uplink Shared Channel) Occasion for message A, and the window for receiving message B may begin at least one symbol after the last symbol of the PUSCH Occasion.

[0012] At this time, the first PUSCH based on the first PRACH preamble and the PUSCH opportunity may be transmitted in message A.

[0013] Furthermore, the RAR may be a success RAR that includes information for resolving the aforementioned conflicts.

[0014] Furthermore, only the first PRACH preamble may be transmitted in message A.

[0015] Furthermore, the RAR may be a fallback RAR that includes uplink (UL) grant information.

[0016] Furthermore, the window may start from the first symbol of the resource associated with monitoring message B.

[0017] Furthermore, the PUSCH opportunity may be a valid PUSCH opportunity related to the RACH opportunity for the first PRACH preamble.

[0018] An apparatus for receiving a downlink signal based on a random access channel procedure (RACH procedure) in an unlicensed band according to the present disclosure includes at least one processor; and at least one memory operably coupled to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform specific operations, where the specific operations include transmitting a first physical random access channel (PRACH) preamble in message A, receiving a random access response (RAR) in message B related to contention resolution as a response to message A, receiving information regarding at least one discontinuous reception (DRX) timer for setting a DRX operation, receiving a downlink signal during an on duration based on the at least one DRX timer, the first PRACH preamble being 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.

[0019] At this time, a first PUSCH based on the first PRACH preamble and the PUSCH opportunity may be transmitted in message A.

[0020] Also, the RAR may be a successful RAR including information for contention resolution.

[0021] Also, only the first PRACH preamble may be transmitted in message A.

[0022] Also, the RAR may be a fallback RAR including uplink (UL) grant information.

[0023] Also, the window may start from the first symbol of the resource related to the monitoring of the message B.

[0024] Also, the PUSCH opportunity may be a valid PUSCH opportunity related to the RACH opportunity for the first PRACH preamble.

[0025] A terminal for receiving a downlink signal based on a random access channel procedure in an unlicensed band according to the present disclosure includes at least one processor; and at least one memory operably coupled to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform specific operations. The specific operations include transmitting a first PRACH (Physical Random Access Channel) preamble to a base station with a message A, receiving a RAR (Random Access Response) with a message B related to contention resolution from the base station as a response to the message A, receiving information about at least one DRX timer for setting a DRX (Discontinuous Reception) operation from the base station, receiving a downlink signal from the base station during an on duration based on the at least one DRX timer, the first PRACH preamble being a PRACH preamble mapped to a PUSCH (Physical Uplink Shared Channel) opportunity for the message A, and the window for receiving the message B may start at least one symbol after the last symbol of the PUSCH opportunity.

Advantages of the Invention

[0026] According to this disclosure, a terminal can smoothly receive downlink signals using a two-step arbitrary connection process in an unlicensed bandwidth.

[0027] The effects derived from this disclosure are not limited to those mentioned above, and other effects not mentioned above will be clearly understood by a person with ordinary skill in the art to which the present invention pertains from the following description. [Brief explanation of the drawing]

[0028] [Figure 1] This figure shows examples of various wireless devices to which embodiments of this disclosure apply. [Figure 2] This figure shows examples of various wireless devices to which embodiments of this disclosure apply. [Figure 3] This figure shows examples of various wireless devices to which embodiments of this disclosure apply. [Figure 4] This figure shows examples of various wireless devices to which embodiments of this disclosure apply. [Figure 5] This figure shows an example of a signal processing circuit to which the embodiments of this disclosure are applied. [Figure 6] This diagram shows the structure of the control plane and user plane of the radio interface protocol between a terminal and E-UTRAN based on the 3GPP® wireless connectivity network standard. [Figure 7] This diagram illustrates the physical channels used in 3GPP systems and general signal transmission methods using them. [Figure 8] This diagram illustrates the Physical Downlink Control Channel (PDCCH) in an NR system. [Figure 9] This diagram illustrates the Physical Downlink Control Channel (PDCCH) in an NR system. [Figure 10]This diagram illustrates the Physical Downlink Control Channel (PDCCH) in an NR system. [Figure 11] This is a diagram illustrating one example of DRX (Discontinuous Reception) operation. [Figure 12] This diagram illustrates channel transmission in an unlicensed bandwidth. [Figure 13] This diagram illustrates channel transmission in an unlicensed bandwidth. [Figure 14] This diagram illustrates channel transmission in an unlicensed bandwidth. [Figure 15] This figure shows an example of a random access procedure. [Figure 16] This diagram illustrates the multiplexing of Long PUCCH (Long Physical Uplink Control Channel) and Short PUCCH (Short PUCCH) in an NR system. [Figure 17] This diagram illustrates the ACK / NACK transmission process. [Figure 18] This diagram illustrates the composition and transmission method of the SS / PBCH block. [Figure 19] This diagram illustrates the composition and transmission method of the SS / PBCH block. [Figure 20] This diagram illustrates the composition and transmission method of the SS / PBCH block. [Figure 21] This diagram illustrates the composition and transmission method of the SS / PBCH block. [Figure 22] This diagram illustrates the composition and transmission method of the SS / PBCH block. [Figure 23] This diagram illustrates the composition and transmission method of the SS / PBCH block. [Figure 24] This diagram illustrates the structure of wireless frames and slots used in NR systems. [Figure 25] This diagram illustrates the structure of wireless frames and slots used in NR systems. [Figure 26] This diagram illustrates the structure of wireless frames and slots used in NR systems. [Figure 27] This figure illustrates specific operational examples of terminals and base stations according to embodiments of the present disclosure. [Figure 28] This figure illustrates specific operational examples of terminals and base stations according to embodiments of the present disclosure. [Figure 29] This diagram shows the basic process of the two-stage RACH. [Figure 30] This figure illustrates an example of how the reception window for Msg B is defined by the success or failure of the LBT for sending Msg A PUSCH. [Figure 31] This figure shows an example of how the receive window for Msg B is configured, regardless of the success or failure of the LBT for sending Msg A PUSCH. [Figure 32] This figure illustrates one example of how the receive window for Msg B is constructed using the push opportunities that successfully complete the Last Blind Test (LBT) among multiple push opportunities. [Figure 33] This figure illustrates an example of how the reception window for Msg B is determined by the last push opportunity among multiple push opportunities, regardless of whether the LBT is successful or unsuccessful. [Figure 34] This figure shows an example of a communication system to which the embodiments of this disclosure apply. [Modes for carrying out the invention]

[0029] The configuration, operation, and other features of the present invention will be easily understood from the embodiments of the present invention described below with reference to the attached drawings. The embodiments described below are examples in which the technical features of the present invention are applied to a 3GPP system.

[0030] This specification describes embodiments of the present invention using LTE systems, LTE-A systems, and NR systems, but these are illustrative examples, and embodiments of the present invention are applicable to any communication system that falls under the above definition.

[0031] Furthermore, in this specification, the term "base station" may be used as a comprehensive term that includes RRH (remote radio head), eNB, TP (transmission point), RP (reception point), relay, etc.

[0032] The 3GPP-based communication standard defines downlink physical channels corresponding to resource elements that carry information originating from higher layers, and downlink physical signals corresponding to resource elements used by the physical layer but not that carry information originating from higher layers. For example, the physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), physical multicast channel (PMCH), physical control format indicator channel (PCFICH), physical downlink control channel (PDCCH), and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, while reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also called a pilot signal, is a predefined, special waveform signal that is known to both the gNB and the UE. Examples of downlink reference signals include cell-specific RS, UE-specific RS (UE-RS), positioning RS (PRS), and channel state information RS (CSI-RS). The 3GPP LTE / LTE-A standard defines uplink physical channels corresponding to resource elements that carry information originating from higher layers, and uplink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers.For example, the physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), and physical random access channel (PRACH) are defined as uplink physical channels, and the demodulation reference signal (DMRS) for uplink control / data signals and the sounding reference signal (SRS) used for measuring uplink channels are defined.

[0033] In this invention, PDCCH (Physical Downlink Control Channel) / PCFICH (Physical Control Format Indicator Channel) / PHICH (Physical Hybrid automatic retransmit request Indicator Channel) / PDSCH (Physical Downlink Shared Channel) each refers to a set of time-frequency resources or resource elements that carry DCI (Downlink Control Information) / CFI (Control Format Indicator) / downlink ACK / NACK (ACKnowlegement / Negative ACK) / downlink data. Furthermore, PUCCH (Physical Uplink Control Channel) / PUSCH (Physical Uplink Shared Channel) / PRACH (Physical Random Access Channel) each refers to UCI (Uplink Control This refers to a set of time-frequency resources or resource elements that carry information, uplink data, or random access signals. In this invention, in particular, time-frequency resources or resource elements (RE) assigned to or belonging to PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH are referred to as PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH RE or PDCCH / PCFICH / PHICH / PDSCH / PUCCH / PUSCH / PRACH resources, respectively. Hereinafter, the expression that a user device transmits PUCCH / PUSCH / PRACH is used interchangeably with transmitting uplink control information, uplink data, or random access signals over (or through) PUSCH / PUCCH / PRACH, respectively.Furthermore, the expression that gNB transmits PDCCH / PCFICH / PHICH / PDSCH is used interchangeably with the expression that it transmits downlink data / control information over (or via) PDCCH / PCFICH / PHICH / PDSCH, respectively.

[0034] In the following, OFDM symbols / subcarriers / REs that are assigned or configured with CRS / DMRS / CSI-RS / SRS / UE-RS will be referred to as CRS / DMRS / CSI-RS / SRS / UE-RS symbols / carriers / subcarriers / REs. For example, an OFDM symbol that is assigned or configured with tracking RS (TRS) will be referred to as a TRS symbol, a subcarrier that is assigned or configured with TRS will be referred to as a TRS subcarrier, and an RE that is assigned or configured with TRS will be referred to as a TRS RE. Furthermore, a subframe configured for TRS transmission will be referred to as a TRS subframe. Additionally, a subframe on which a broadcast signal is transmitted will be referred to as a broadcast subframe or PBCH subframe, and a subframe on which a synchronization signal (e.g., PSS and / or SSS) is transmitted will be referred to as a synchronization signal subframe or PSS / SSS subframe. OFDM symbols / subcarriers / REs that are assigned or configured with PSS / SSS are referred to as PSS / SSS symbols / subcarriers / REs, respectively.

[0035] In this invention, CRS port, UE-RS port, CSI-RS port, and TRS port refer to antenna ports configured to transmit CRS, antenna ports configured to transmit UE-RS, antenna ports configured to transmit CSI-RS, and antenna ports configured to transmit TRS, respectively. Antenna ports configured to transmit CRS may be distinguished by the location of RE occupied by CRS via CRS ports, antenna ports configured to transmit UE-RS may be distinguished by the location of RE occupied by UE-RS via UE-RS ports, and antenna ports configured to transmit CSI-RS may be distinguished by the location of RE occupied by CSI-RS via CSI-RS ports. Therefore, the terms CRS / UE-RS / CSI-RS / TRS port may also be used to refer to the pattern of RE occupied by CRS / UE-RS / CSI-RS / TRS within a given resource area.

[0036] Figure 1 illustrates a wireless device to which the present invention can be applied.

[0037] Referring to Figure 1, the first wireless device 100 and the second wireless device 200 can transmit and receive wireless signals using various wireless connectivity technologies (e.g., LTE, NR). Here, {first wireless device 100, second wireless device 200} may correspond to {wireless device 100x, base station 200} and / or {wireless device 100x, wireless device 100x} in Figure 30.

[0038] The first wireless device 100 includes one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106 and be configured to embody the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed herein. For example, the processor 102 may process information in the memory 104 to generate first information / signals, and then transmit a wireless signal containing the first information / signals from the transceiver 106. Alternatively, the processor 102 may receive a wireless signal containing second information / signals from the transceiver 106 and then store information obtained from signal processing of the second information / signals in the memory 104. The memory 104 may be linked to the processor 102 and can store various information related to the operation of the processor 102. For example, memory 104 may store software code that includes instructions for performing some or all of the processes controlled by processor 102, or for executing the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed herein. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to embody wireless communication technology (e.g., LTE, NR). Transceiver 106 may be coupled with processor 102 and can transmit and / or receive radio signals via one or more antennas 108. Transceiver 106 may include a transmitter and / or receiver. Transceiver 106 may be used synonymously with RF (Radio Frequency) unit. In this invention, wireless equipment may mean a communication modem / circuit / chip.

[0039] Specifically, instructions and / or operations controlled by the processor 102 of the first wireless device 100 according to an embodiment of the present invention and stored in the memory 104 will be described.

[0040] The following operations will be described from the perspective of processor 102 and based on the control operations of processor 102, but software code for performing such operations may be stored in memory 104.

[0041] The processor 102 can control the transceiver 106 to send a first PRACH (Physical Random Access Channel) preamble with message A. The processor 102 can also control the transceiver 106 to receive a RAR (Random Access Response) with message B related to contention resolution. The specific method by which the processor 102 controls the transceiver 106 to send message A and to receive message B can be obtained based on the embodiment described later.

[0042] Specifically, instructions and / or operations controlled by the processor 202 of the second wireless device 200 according to an embodiment of the present invention and stored in the memory 204 will be described.

[0043] The following operations will be described from the perspective of processor 202 and based on the control operations of processor 202, but software code for performing such operations may be stored in memory 204.

[0044] The processor 202 can control the transceiver 206 to receive the first PRACH (Physical Random Access Channel) preamble with message A. The processor 202 can then control the transceiver 206 to send a RAR (Random Access Response) with message B related to contention resolution. The specific method by which the processor 202 controls the transceiver 206 to receive message A and to send message B can be obtained based on the embodiment described later.

[0045] The hardware elements of the wireless devices 100,200 will be described in more detail below. However, one or more protocol layers may be embodied by one or more processors 102,202. For example, one or more processors 102,202 can embodied 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 PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) by means of the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this document. One or more processors 102,202 can generate messages, control information, data, or information by means of the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this document. One or more processors 102,202 can generate signals (e.g., baseband signals) containing PDUs, SDUs, messages, control information, data, or information by means of the functions, procedures, proposals and / or methods disclosed herein, and provide them to one or more transceivers 106,206. One or more processors 102,202 can receive signals (e.g., baseband signals) from one or more transceivers 106,206, and can acquire PDUs, SDUs, messages, control information, data, or information by means of the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed herein.

[0046] One or more processors 102,202 may be called controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102,202 may be embodied by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102,202. The descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed herein may be embodied using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed herein may be contained in one or more processors 102,202 or stored in one or more memories 104,204 and driven by one or more processors 102,202. The descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed herein may be embodied using firmware or software in the form of code, instructions and / or sets of instructions.

[0047] One or more memory units 104,204 may be connected to one or more processors 102,202 and can store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memory units 104,204 may consist of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memory units 104,204 may be located inside and / or outside of one or more processors 102,202. Furthermore, one or more memory units 104,204 may be connected to one or more processors 102,202 by various technologies such as wired or wireless connections.

[0048] One or more transceivers 106,206 can transmit user data, control information, radio signals / channels, etc., as referred to in the methods and / or operation sequence diagrams of this document, to one or more other devices. One or more transceivers 106,206 can receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this document, from one or more other devices. For example, one or more transceivers 106,206 may be connected to one or more processors 102,202 to transmit and receive radio signals. For example, one or more processors 102,202 can control one or more transceivers 106,206 to transmit user data, control information or radio signals to one or more other devices. Also, one or more processors 102,202 can control one or more transceivers 106,206 to receive user data, control information or radio signals from one or more other devices. Furthermore, one or more transceivers 106,206 may be connected to one or more antennas 108,208, and one or more transceivers 106,206 may be configured to transmit and receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this document, via 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). One or more transceivers 106,206 may convert the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing using one or more processors 102,202. One or more transceivers 106,206 may convert the user data, control information, radio signals / channels, etc., processed by one or more processors 102,202, from baseband signals to RF band signals. To this end, one or more transceivers 106,206 may include (analog) oscillators and / or filters.

[0049] Figure 2 shows another example of wireless equipment to which the present invention applies. Wireless equipment may be embodied in various forms depending on the example of use / service (see Figure 34).

[0050] Referring to Figure 2, the wireless devices 100,200 correspond to the wireless devices 100,200 in Figure 1 and may be composed of various elements, components, units, and / or modules. For example, the wireless devices 100,200 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 one or more processors 102,202 and / or one or more memories 104,204 in Figure 1. For example, the transceiver 114 may include one or more transceivers 106,206 and / or one or more antennas 108,208 in Figure 1. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional element 140 to control the various operations of the wireless device. For example, the control unit 120 can control the electrical / mechanical operation of wireless equipment based on programs / codes / instructions / information stored in the memory unit 130. Furthermore, the control unit 120 can transmit information stored in the memory unit 130 to an external source (e.g., another communication device) via a wireless / wired interface through the communication unit 110, or it can store information received from an external source (e.g., another communication device) via a wireless / wired interface through the communication unit 110 in the memory unit 130. Therefore, the specific operation process of the control unit 120 and the programs / codes / instructions / information stored in the memory unit 130 according to the present invention may correspond to at least one operation of the processors 102, 202 and at least one operation of the memories 104, 204 in Figure 2.

[0051] The additional element 140 may be configured in various ways depending on the type of wireless device. For example, the additional element 140 may include at least one of a power unit / battery, an input / output unit (I / O unit), a drive unit, and a computing unit. However, wireless devices may be embodied in the form of robots (Figure 34, 100a), vehicles (Figure 34, 100b-1, 100b-2), XR devices (Figure 34, 100c), portable devices (Figure 34, 100d), home appliances (Figure 34, 100e), IoT devices (Figure 34, 100f), digital broadcasting terminals, hologram devices, public safety devices, MTC devices, medical devices, fintech devices (or financial devices), security devices, climate / environment devices, AI servers / devices (Figure 34, 400), base stations (Figure 34, 200), network nodes, etc. Depending on the example of use / service, the wireless device may be used in a mobile or fixed location.

[0052] In Figure 2, the various elements, components, units / parts, and / or modules within the wireless devices 100,200 may be interconnected as a whole through a wired interface, or at least some may be connected wirelessly via the communication unit 110. For example, the control unit 120 and the communication unit 110 within the wireless devices 100,200 may be connected by a wire, and the control unit 120 and the first units (e.g., 130,140) may be connected wirelessly via the communication unit 110. Furthermore, each element, component, unit / part, and / or module within the wireless devices 100,200 may further include one or more elements. For example, the control unit 120 may consist of one or more processor sets. For example, the control unit 120 may consist of a set of communication control processors, application processors, ECUs (Electronic Control Units), graphics processing processors, memory control processors, etc. As another example, the memory unit 130 may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0053] The concrete example shown in Figure 2 will be explained in more detail below with reference to the drawing.

[0054] Figure 3 illustrates a portable device to which the present invention applies. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), and portable computers (e.g., laptop computers). Portable devices may be referred to as MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), or WT (Wireless terminal).

[0055] Referring to Figure 3, the portable device 100 may include 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 part of the communication unit 110. Blocks 110-130 / 140a-140c correspond to blocks 110-130 / 140 in Figure 2, respectively.

[0056] The communication unit 110 can send and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit 120 can control the components of the portable device 100 to perform various operations. The control unit 120 may include an AP (Application Processor). The memory unit 130 can store data / parameters / programs / code / instructions necessary for operating the portable device 100. The memory unit 130 can also store input / output data / information, etc. The power supply unit 140a supplies power to the portable device 100 and may include wired / wireless charging circuits, batteries, etc. The interface unit 140b can support the connection of the portable device 100 with other external devices. The interface unit 140b may include various ports for connection with external devices (e.g., audio input / output ports, video input / output ports). The input / output unit 140c can receive or output video information / signals, audio information / signals, data, and / or information input from the user. The input / output section 140c may include a camera, microphone, user input section, display section 140d, speaker and / or haptic module, etc.

[0057] For example, in the case of data communication, the input / output unit 140c acquires information / signals input from the user (e.g., touch, text, voice, image, video), and the acquired information / signals may be stored in the memory unit 130. The communication unit 110 converts the information / signals stored in memory into a radio signal, and can transmit the converted radio signal directly to other radio devices or to a base station. Furthermore, after receiving a radio signal from another radio device or base station, the communication unit 110 can restore the received radio signal to its original information / signal. The restored information / signal is stored in the memory unit 130 and may be output via the input / output unit 140c in various forms (e.g., text, voice, image, video, haptic).

[0058] Figure 4 illustrates a vehicle or autonomous vehicle to which the present invention applies. The vehicle or autonomous vehicle may be embodied as a mobile robot, a vehicle, a train, a manned or unmanned aerial vehicle (AV), a ship, etc.

[0059] Referring to Figure 4, 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 driving unit 140d. The antenna unit 108 may be configured as part of the communication unit 110. Blocks 110 / 130 / 140a to 140d correspond to blocks 110 / 130 / 140 in Figure 2, respectively.

[0060] The communication unit 110 can send and receive signals (e.g., data, control signals, etc.) with other vehicles, base stations (e.g., base stations, roadside units, etc.), servers, and other external devices. The control unit 120 can control elements of the vehicle or autonomous vehicle 100 to perform various operations. The control unit 120 may include an ECU (Electronic Control Unit). The drive unit 140a can drive the vehicle or autonomous vehicle 100 on the ground. The drive unit 140a may include an engine, motor, powertrain, wheels, brakes, steering system, etc. The power supply unit 140b supplies power to the vehicle or autonomous vehicle 100 and may include a wired / wireless charging circuit, battery, etc. The sensor unit 140c can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit 140c may include an IMU (inertial measurement unit) sensor, collision sensor, wheel sensor, speed sensor, tilt sensor, weight sensor, heading sensor, position module, vehicle forward / reverse sensor, battery sensor, fuel sensor, tire sensor, steering sensor, temperature sensor, humidity sensor, ultrasonic sensor, illuminance sensor, pedal position sensor, etc. The autonomous driving unit 140d can implement technologies such as lane keeping while driving, automatic speed adjustment like adaptive cruise control, automatic driving along a predetermined route, and automatic route setting and driving once a destination is set.

[0061] For example, the communication unit 110 can receive map data, traffic information data, etc., from an external server. The autonomous driving unit 140d can generate an autonomous driving route and driving plan based on the acquired data. The control unit 120 can control the drive unit 140a so that the vehicle or autonomous vehicle 100 moves along the autonomous driving route based on the driving plan (e.g., speed / direction adjustment). During autonomous driving, the communication unit 110 can acquire the latest traffic information data from an external server on an irregular / periodic basis and acquire surrounding traffic information data from surrounding vehicles. Also, during autonomous driving, the sensor unit 140c can acquire vehicle status and surrounding environment information. The autonomous driving unit 140d can update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit 110 can transmit information such as vehicle position, autonomous driving route, and driving plan to an external server. The external server can predict traffic information data in advance using AI technology, etc., based on the information collected from the vehicle or autonomous vehicle, and can provide the predicted traffic information data to the vehicle or autonomous vehicle.

[0062] Figure 5 illustrates a signal processing circuit for the transmission signal.

[0063] Referring to Figure 5, 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. However, the operation / function of Figure 5 may be performed by the processors 102, 202 and / or transceivers 106, 206 of Figure 1. The hardware elements of Figure 5 may be implemented in the processors 102, 202 and / or transceivers 106, 206 of Figure 1. For example, blocks 1010-1060 may be implemented in the processors 102, 202 of Figure 1. Also, blocks 1010-1050 may be implemented in the processors 102, 202 of Figure 1, and block 1060 may be implemented in the transceivers 106, 206 of Figure 1.

[0064] The codeword may be converted into a radio signal via the signal processing circuit 1000 in Figure 5. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transmit block (e.g., UL-SCH transmit block, DL-SCH transmit block). The radio signal may be transmitted over various physical channels (e.g., PUSCH, PDSCH).

[0065] Specifically, the codeword may be converted into a bit sequence scrambled by the scrambler 1010. The scramble sequence used for scrambling is generated based on an initialization value, which may include the ID information of the radio equipment. The scrambled bit sequence may be modulated into a modulation symbol sequence by the modulator 1020. The modulation scheme can include pi / 2-BPSK (pi / 2-Binary Phase Shift Keying), m-PSK (m-Phase Shift Keying), m-QAM (m-Quadrature Amplitude Modulation), etc. The complex modulation symbol sequence may be mapped to one or more transmission layers by the layer mapper 1030. The modulation symbol of each transmission layer may be mapped to the corresponding antenna port by the precoder 1040 (precoding). The output z of the precoder 1040 can be obtained by multiplying the output y of the layer mapper 1030 by an N*M precoding matrix W. Here, N is the number of antenna ports and M is the number of transmission layers. The precoder 1040 can perform precoding after performing transform precoding (e.g., DFT transformation) for complex modulation symbols. Alternatively, the precoder 1040 can perform precoding without performing transform precoding.

[0066] The resource mapper 1050 can map the modulation symbols of each antenna port to a time-frequency resource. The time-frequency resource 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 the generated radio signal may be transmitted to other devices via each antenna. To this end, the signal generator 1060 may include an IFFT (Inverse Fast Fourier Transform) module, a CP (Cyclic Prefix) inserter, a DAC (Digital-to-Analog Converter), a frequency upconverter, and the like.

[0067] In wireless equipment, the signal processing process for a received signal may be the reverse of the signal processing process (1010-1060) in Figure 5. For example, wireless equipment (e.g., 100, 200 in Figure 1) can receive wireless signals from an external source via an antenna port / transceiver. The received wireless signal may be converted into a baseband signal by a signal restorer. For this purpose, the signal restorer may include a frequency downconverter, an analog-to-digital converter (ADC), a CP remover, and a Fast Fourier Transform (FFT) module. The baseband signal may then be restored to a codeword through a resource demapper process, a postcoding process, a demodulation process, and a descramble process. The codeword may be decoded to restore the original information blocks. Therefore, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource demapper, a postcoder, a demodulator, a descrambler, and a decoder.

[0068] Figure 6 shows the structure of the Control Plane and User Plane of the Radio Interface Protocol between a terminal and E-UTRAN based on the 3GPP wireless connectivity network standard. The Control Plane represents the path through which control messages used by the terminal (User Equipment; UE) and the network to manage calls are transmitted. The User Plane represents the path through which data generated at the application layer, such as voice data or internet packet data, is transmitted.

[0069] The first layer, the physical layer, provides information transfer services to higher layers using a physical channel. The physical layer is connected to the higher-level medium access control layer via a transport channel. Data moves between the medium access control layer and the physical layer through the transport channel. Data also moves between the transmitting and receiving physical layers via the physical channel. The physical channel utilizes time and frequency as wireless resources. Specifically, the physical channel is modulated using OFDMA (Orthogonal Frequency Division Multiple Access) in the downlink and SC-FDMA (Single Carrier Frequency Division Multiple Access) in the uplink.

[0070] The Medium Access Control (MAC) layer in Layer 2 provides services to the higher-layer Radio Link Control (RLC) layer via a Logical Channel. The RLC layer in Layer 2 supports reliable data transmission. The functions of the RLC layer may be embodied as functional blocks within the MAC. The Packet Data Convergence Protocol (PDCP) layer in Layer 2 is responsible for header compression, which reduces unnecessary control information to efficiently transmit IP packets such as IPv4 or IPv6 over narrow-bandwidth wireless interfaces.

[0071] The Radio Resource Control (RRC) layer, located at the bottom of the third layer, is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transmit channels, and physical channels in relation to the configuration, reconfiguration, and release of radio bearers. Radio bearers represent the services provided by the second layer for data transmission between terminals and the network. For this purpose, the RRC layers of the terminal and the network exchange RRC messages with each other. When there is an RRC Connected state between the terminal and the network's RRC layers, the terminal is in RRC Connected Mode; otherwise, it is in RRC Idle Mode. The Non-Access Stratum (NAS) layer, located above the RRC layer, is responsible for functions such as session management and mobility management.

[0072] Downstream transmission channels that send data from the network to a terminal include the Broadcast Channel (BCH) for sending system information, the Paging Channel (PCH) for sending paging messages, and the Shared Channel (SCH) for sending user traffic and control messages. Downstream multicast or broadcast service traffic or control messages may be sent through the Shared Channel (SCH) or through a separate Multicast Channel (MCH). On the other hand, upstream transmission channels that send data from a terminal to the network include the Random Access Channel (RACH) for sending initial control messages and the Shared Channel (SCH) for sending user traffic and control messages. Logical channels that are higher up than transmission channels and are mapped to transmission channels include the Broadcast Control Channel (BCCH), Paging Control Channel (PCCH), Common Control Channel (CCCH), Multicast Control Channel (MCCH), and Multicast Traffic Channel (MTCH).

[0073] Figure 7 illustrates the physical channels used in 3GPP systems and general signal transmission methods using them.

[0074] When a terminal is powered on or enters a new cell, it performs initial cell search operations, such as synchronizing with the base station (S701). To do this, the terminal receives a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) from the base station to synchronize with the base station and obtain information such as the cell ID. Subsequently, the terminal receives the Physical Broadcast Channel (PBCH) from the base station and obtains intra-cell broadcast information. Meanwhile, during the initial cell search phase, the terminal receives a Downlink Reference Signal (DL RS) and can check the downlink channel status.

[0075] After completing the initial cell search, the terminal can obtain more specific system information by receiving the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH) according to the information carried on the PDCCH (S702).

[0076] On the other hand, if there are no radio resources available to initially connect to a base station or to transmit signals, the terminal can perform a Random Access Procedure (RACH) to the base station (S703-S706). To do this, the terminal transmits a specific sequence as a preamble through a Physical Random Access Channel (PRACH) (S703 and S705), and can receive a Random Access Response (RAR) message for the preamble through the PDCCH and the corresponding PDSCH. In a conflict-based RACH, a Contention Resolution Procedure can also be performed (S706).

[0077] A terminal that has performed the procedures described above can then perform general uplink / downlink signal transmission procedures, such as PDCCH / PDSCH reception (S707) and Physical Uplink Shared Channel (PUSCH) / Physical Uplink Control Channel (PUCCH) transmission (S708). In particular, the terminal can receive Downlink Control Information (DCI) through PDCCH. Here, DCI includes control information such as resource allocation information for the terminal, and its format may be individually applied according to its intended use.

[0078] On the other hand, control information that a terminal transmits to or receives from a base station on the uplink may include downlink / uplink ACK / NACK signals, CQI (Channel Quality Indicator), PMI (Precoding Matrix Index), RI (Rank Indicator), etc. The terminal can transmit the aforementioned control information such as CQI / PMI / RI via PUSCH and / or PUCCH.

[0079] On the other hand, NR systems consider using a high ultra-high frequency band, i.e., a millimeter frequency band of 6 GHz or higher, in order to transmit data to multiple users while maintaining a high transmission rate using a wide frequency band. 3GPP has named this NR, but in this invention, it will be referred to as an NR system.

[0080] NR supports multiple numerologies (or SCS (subcarrier spacing)) to support various 5G services. For example, an SCS of 15kHz supports wide area in traditional cellular bands, an SCS of 30kHz / 60kHz supports dense-urban areas, lower latency, and wider carrier bandwidth, and an SCS of 60kHz or higher supports bandwidths greater than 24.25kHz to overcome phase noise.

[0081] The NR frequency band is defined as a frequency range of two types (FR1 and FR2). FR1 is the range below 6 GHz, and FR2 is the range above 6 GHz, which can represent millimeter waves (mmW).

[0082] Table 1 below shows the definition of the NR frequency band.

[0083] [Table 1]

[0084] Downlink channel structure

[0085] The base station transmits the relevant signals to the terminal via the downlink channel described later, and the terminal receives the relevant signals from the base station via the downlink channel described later.

[0086] (1) Physical Downlink Shared Channel (PDSCH)

[0087] PDSCH carries downlink data (e.g., DL-shared channel transport block, DL-SCH TB) and applies modulation methods such as QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 64QAM, and 256QAM. It encodes the TB to generate a codeword. 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 a resource along with a DMRS (Demodulation Reference Signal) and generated as an OFDM symbol signal, which is transmitted via the corresponding antenna port.

[0088] (2) Physical Downlink Control Channel (PDCCH)

[0089] The PDCCH carries downlink control information (DCI) and is modulated using the QPSK modulation method. One PDCCH consists of 1, 2, 4, 8, or 16 Control Channel Elements (CCEs) depending on the Aggregation Level (AL). One CCE consists of 6 Resource Element Groups (REGs). One REG is defined as one OFDM symbol and one (P)RB.

[0090] Figure 8 illustrates a single REG structure. In Figure 8, 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 in the frequency domain direction within a single symbol.

[0091] PDCCH is transmitted through a Control Resource Set (CORESET). A CORESET is defined as a set of REGs with a given numerology (e.g., SCS, CP length, etc.). Multiple CORESETs for a single terminal may overlap in the time / frequency domain. A CORESET may be configured by system information (e.g., MIB) or terminal-specific (UE-specific) upper-layer (e.g., RRC (Radio Resource Control) layer) signaling. Specifically, the number of RBs and symbols (up to 3) that make up a CORESET may be configured by upper-layer signaling.

[0092] The precoder granularity in the frequency domain for each CORESET is set to one of the following by upper-layer signaling:

[0093] - sameAsREG-bundle: Same as REG bundle size in the frequency domain

[0094] - allContiguousRBs: Same as the number of consecutive RBs in the frequency domain within CORESET.

[0095] In CORESET, REGs are numbered based on a time-first mapping manner. That is, REGs are numbered sequentially starting from 0, beginning with the first OFDM symbol in the lowest-numbered resource block within CORESET.

[0096] The mapping type from CCE to REG is set to either an uninterleaved CCE-REG mapping type or an interleaved CCE-REG mapping type. Figure 9(a) illustrates an uninterleaved CCE-REG mapping type, and Figure 9(b) illustrates an interleaved CCE-REG mapping type.

[0097] - Non-interleaved CCE-REG mapping type (or localized mapping type): Six REGs for a given CCE form one REG bundle, and all REGs for a given CCE are contiguous. One REG bundle corresponds to one CCE.

[0098] - Interleaved CCE-REG mapping type (or distributed mapping type): Two, three, or six REGs for a given CCE constitute one REG bundle, and the REG bundle is interleaved within the CORESET. A REG bundle in a CORESET consisting of one or two OFDM symbols consists of two or six REGs, and a REG bundle in a CORESET consisting of three OFDM symbols consists of three or six REGs. The size of the REG bundle is set per CORESET.

[0099] Figure 10 illustrates a block interleaver. The number of rows (A) of the (block) interleaver for the interleaving operation described above is set to either 2, 3, or 6. If the number of interleaving units for a given CORESET is P, the number of columns of the block interleaver is P / A. Write operations to the block interleaver are performed in a row-first direction, as shown in Figure 10, and read operations are performed in a column-first direction. Cyclic shifts (CS) of interleaving units are applied based on IDs that can be set for DMRS and IDs that can be set independently.

[0100] The terminal decodes (also known as blind decoding) a set of PDCCH candidates and obtains the DCI transmitted through the PDCCH. The set of PDCCH candidates that the terminal decodes is defined as the PDCCH Search Space set. The search space set may be a common search space or a UE-specific search space. The terminal can monitor PDCCH candidates in one or more search space sets configured by MIB or higher-layer signaling and obtain the DCI. Each CORESET setting is associated with one or more search space sets, and each search space set is associated with one CORESET setting. A single search space set is determined based on the following parameters:

[0101] - controlResourceSetId: Represents the control resource set associated with the search space set.

[0102] - monitoringSlotPeriodicityAndOffset: Represents the PDCCH monitoring period interval (per slot) and the PDCCH monitoring period offset (per slot).

[0103] - monitoringSymbolsWithinSlot: Represents the PDCCH monitoring pattern in the slot for PDCCH monitoring (for example, representing the first symbol of the control resource set).

[0104] - nrofCandidates:AL={1,2,4,8,16} represents the number of PDCCH candidates (one of the values ​​0, 1, 2, 3, 4, 5, 6, or 8).

[0105] Table 2 illustrates the characteristics of different search space types.

[0106] [Table 2]

[0107] Table 3 illustrates the DCI format transmitted through PDCCH.

[0108] [Table 3]

[0109] DCI format 0_0 is used to schedule TB-based (or TB-level) PUSCHs, and DCI format 0_1 ​​may be used to schedule TB-based (or TB-level) PUSCHs or CBG (Code Block Group)-based (or CBG-level) PUSCHs. DCI format 1_0 is used to schedule TB-based (or TB-level) PDSCHs, and DCI format 1_1 may be used to schedule TB-based (or TB-level) PDSCHs or CBG-based (or CBG-level) PDSCHs. DCI format 2_0 is used to transmit dynamic slot format information (e.g., dynamic SFI) to terminals, and DCI format 2_1 is used to transmit downlink pre-emption information to terminals. DCI format 2_0 and / or DCI format 2_1 may be transmitted to terminals within a group via a Group common PDCCH, which is a PDCCH transmitted to terminals defined as a group.

[0110] DRX (Discontinuous Reception) operation

[0111] The terminal can perform DRX operation while performing the procedures and / or methods described / proposed earlier. A terminal with DRX configured can reduce power consumption by receiving DL signals discontinuously. DRX may be performed in the RRC (Radio Resource Control)_IDLE state, RRC_INACTIVE state, or RRC_CONNECTED state. In the RRC_IDLE and RRC_INACTIVE states, DRX is used to receive paging signals discontinuously. The following describes DRX performed in the RRC_CONNECTED state (RRC_CONNECTED DRX).

[0112] Figure 11 illustrates the DRX cycle (RRC_CONNECTED state).

[0113] Referring to Figure 11, a DRX cycle consists of an On Duration and an Opportunity for DRX. The DRX cycle defines a time interval in which the On Duration is periodically repeated. The On Duration represents a time interval in which the terminal monitors to receive a PDCCH. When DRX is set, the terminal performs PDCCH monitoring during the On Duration. If a PDCCH is successfully detected during PDCCH monitoring, the terminal activates an inactivity timer and maintains an awake state. On the other hand, if no PDCCH is successfully detected during PDCCH monitoring, the terminal enters a sleep state after the On Duration ends. Therefore, when DRX is set, PDCCH monitoring / reception may occur discontinuously in the time domain when performing the previously described / proposed procedures and / or methods. For example, when DRX is set, the PDCCH reception opportunities (e.g., slots having a PDCCH search space) in this invention may be set discontinuously by the DRX setting. On the other hand, if DRX is not set, PDCCH monitoring / reception may be performed continuously in the time domain. For example, if DRX is not set, PDCCH reception opportunities (e.g., slots having a PDCCH search space) may be set continuously in the present invention. On the other hand, regardless of whether DRX is set or not, PDCCH monitoring may be restricted in time intervals set in the measurement gap.

[0114] Table 4 shows the terminal process related to DRX (RRC_CONNECTED state). Referring to Table 4, DRX configuration information is received by upper-layer (e.g., RRC) signaling, and DRX ON / OFF is controlled by MAC layer DRX commands. Once DRX is configured, the terminal can perform PDCCH monitoring discontinuously when performing the procedures and / or methods described / proposed in the present invention, as illustrated in Figure 11.

[0115] [Table 4]

[0116] Here, MAC-CellGroupConfig contains the configuration information necessary to set the MAC (Medium Access Control) parameters for the cell group. MAC-CellGroupConfig can also contain configuration information related to DRX. For example, MAC-CellGroupConfig can contain the information necessary to define DRX as follows: - Value of drx-OnDurationTimer: Defines the length of the start interval of the DRX cycle.

[0117] - Value of drx-InactivityTimer: Defines the length of the time interval during which the terminal is awake after a PDCCH opportunity in which a PDCCH indicating initial UL or DL ​​data is detected.

[0118] - Value of drx-HARQ-RTT-TimerDL: Defines the maximum time interval length between the reception of the initial DL transmission and the reception of the DL retransmission.

[0119] - Value of drx-HARQ-RTT-TimerDL: Defines the maximum time interval length between receiving a grant for the initial UL transmission and receiving a grant for the UL retransmission.

[0120] - drx-LongCycleStartOffset: Defines the duration and start time of the DRX cycle.

[0121] - drx-ShortCycle(optional): Defines the duration of a short DRX cycle.

[0122] If any one of the following is running: drx-OnDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-TimerDL, or drx-HARQ-RTT-TimerDL, the terminal will maintain an awake state and perform PDCCH monitoring at each PDCCH opportunity.

[0123] Unlicensed band / shared spectrum system

[0124] Figure 12 shows an example of a wireless communication system supporting an unlicensed band to which various embodiments of this disclosure can be applied.

[0125] In the following explanation, a cell operating in the licensed band (hereinafter referred to as L-band) is defined as an L-cell, and the carrier of an L-cell is defined as (DL / UL)LCC. Similarly, a cell operating in the unlicensed band (hereinafter referred to as U-band) is defined as a U-cell, and the carrier of a U-cell is defined as (DL / UL)UCC. The cell's carrier / carrier-frequency can mean the cell's operating frequency (e.g., center frequency). The cell / carrier (e.g., CC) is collectively referred to as a cell.

[0126] As shown in Figure 12(a), when a terminal and a base station transmit and receive signals through a carrier-coupled LCC and UCC, the LCC may be set as the PCC (Primary CC) and the UCC as the SCC (Secondary CC).

[0127] As shown in Figure 12(b), the terminal and base station can transmit and receive signals through a single UCC or multiple carrier-coupled LCCs and UCCs. That is, the terminal and base station can transmit and receive signals through UCC(s) alone without an LCC. The signal transmission and reception operations in the unlicensed band described in the various embodiments of this disclosure below may be carried out based on all of the above-described deployment scenarios (unless otherwise specified).

[0128] 1. Wireless frame structure for unlicensed bands

[0129] For operation 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 set by the base station. Here, OFDM symbols may be replaced with SC-FDM(A) symbols.

[0130] For downlink signaling over unlicensed bandwidth, the base station can signal the configuration of the OFDM symbols used in subframe #n to the terminal. In the following description, subframes may be replaced with slots or TUs (Time Units).

[0131] Specifically, in a wireless communication system supporting unlicensed bands, a terminal can use a specific field in the DCI received from the base station in subframe #n-1 or subframe #n (e.g., the Subframe configuration for LAA field) to assume (or identify) the configuration of the occupied OFDM symbol in subframe #n.

[0132] Table 5 illustrates how the 'Subframe configuration for LAA' field in a wireless communication system indicates the configuration of OFDM symbols used for transmitting the downlink physical channel and / or physical signals in the current and / or next subframe.

[0133] [Table 5]

[0134] For uplink signal transmission over unlicensed bandwidth, base stations can signal information about the uplink transmission section to terminals.

[0135] Specifically, in an LTE system supporting unlicensed bandwidth, the terminal can obtain 'UL duration' and 'UL offset' information for subframe #n using the 'UL duration and offset' field in the detected DCI.

[0136] Table 6 illustrates how the 'UL duration and offset' field in a wireless communication system indicates the UL offset and UL duration configuration.

[0137] [Table 6]

[0138] 2. General Channel Access Procedures

[0139] The following definitions may apply to the terms used in the descriptions of the various embodiments of this disclosure, unless otherwise noted.

[0140] - A channel can refer to a carrier or a part of a carrier that consists of a contiguous set of RBs (Routing Blocks) in which channel connection procedures are performed within a shared spectrum.

[0141] - A channel access procedure may be a sensing-based procedure for evaluating the availability of a channel for transmission. The basic unit of sensing may be a sensing slot with a duration of Tsl = 9us. A sensing slot Tsl may be considered idle if the base station or UE senses a channel during a sensing slot duration and determines that the detected power sensed within at least 4us of the sensing slot duration is less than the energy detection threshold XThresh. Otherwise, the sensing slot Tsl may be considered busy.

[0142] - Channel occupancy refers to transmission on a channel by the base station / UE after the corresponding channel connection procedure in this section.

[0143] - Channel occupancy time refers to the total time that a base station / UE and any other base stations / UE sharing the channel occupancy transmit on the channel after the base station / UE has performed the channel connection procedure described in this section. To determine the channel occupancy time, if the transmission gap is 25us or less, the gap duration may be counted as channel occupancy time. Channel occupancy time may be shared for transmission between base stations and the corresponding UEs.

[0144] 3. Downlink channel access procedure

[0145] The base station may perform the following downlink channel access procedure (CAP) on the unlicensed band for the purpose of transmitting downlink signals in the unlicensed band.

[0146] 3.1. Type 1 Downlink Channel Access Procedures

[0147] This section describes the channel connection procedure performed by the base station, where the time duration occupied by idle and sensing slots before downlink transmission is random. This section may apply to the following transmissions:

[0148] - Transmission(s) initiated by a base station including PDSCH / PDCCH / EPDCCH, or

[0149] - Transmission(s) initiated by a base station including a unicast PDSCH with user plane data, or a unicast PDSCH with user plane data and a unicast PDCCH scheduling user plane data, or

[0150] - A base station-initiated transmission having only a discover burst, or a discover burst combined with non-unicast information and multiplexed discover bursts, where the transmission interval is greater than 1 ms, or the transmission can have a discover burst duty cycle greater than 1 / 20.

[0151] The base station has a delay period (defer duration) T dDuring the sensing slot interval, the system senses whether the channel is idle, and after counter N becomes 0 in step 4 below, a transmission can be sent. At this time, counter N is adjusted by channel sensing for an additional sensing slot duration by the following procedure:

[0152] 1) N=N init Set to N init It starts from 0 to CW p Any random number uniformly distributed between 0 and CW p ) Next, proceed to step 4.

[0153] 2) If N > 0 and the base station chooses to decrease the counter, set N = N-1.

[0154] 3) Sensing a channel for an additional sensing slot section. If the additional sensing slot section is idle, proceed to step 4. Otherwise, proceed to step 5.

[0155] 4) If N=0, stop the procedure. Otherwise, proceed to step 2.

[0156] 5) Additional delay section T d A busy sensing slot is detected in the additional delay interval T. d The channel is sensed until all sensing slots are detected as idle.

[0157] 6) The additional delay section T d If the channel in question is sensed as idle during the entire sensing slot interval, proceed to step 4. Otherwise, proceed to step 5.

[0158] Figure 13 illustrates a DL CAP for unlicensed bandwidth transmission to which various embodiments of this disclosure can be applied.

[0159] The various embodiments of this disclosure apply to a Type 1 downlink channel connection procedure for unlicensed bandwidth transmission, which can be summarized as follows:

[0160] A transmitting node (e.g., a base station) can initiate a channel connection process (CAP) for downlink transmission (2010).

[0161] The base station can arbitrarily select a backoff counter N within the competition window (CW) according to step 1. At this time, the value of N is set to the initial value Ninit (2020). Any value between 0 and CWp can be selected for Ninit.

[0162] Next, according to step 4, if the backoff counter value (N) is 0 (2030; Y), the base station terminates the CAP process (2032). Subsequently, the base station can perform a Tx burst transmission (2034). On the other hand, if the backoff counter value is not 0 (2030; N), the base station decreases the backoff counter value by 1 according to step 2 (2040).

[0163] Next, the base station checks whether the channel is idle (2050), and if the channel is idle (2050; Y), it checks whether the backoff counter value is 0 (2030).

[0164] Conversely, if the channel is not idle during operation 2050, i.e., if the channel is busy (2050; N), the base station checks whether the channel is idle or not during a delay period longer than the sensing slot time (e.g., 9 usec) (defer duration Td; 25 usec or more) according to step 5 (2060). If the channel is idle during the delay period (2070; Y), the base station can restart the CAP process.

[0165] For example, if the backoff counter value Ninit is 10, and the channel is determined to be busy after the backoff counter value has decreased to 5, the base station will sense the channel during the delay period to determine whether it is idle or not. If the channel is idle during the delay period, the base station will not set the backoff counter value Ninit, but will instead perform the CAP process again from the backoff counter value of 5 (or from 4 after decreasing the backoff counter value by 1).

[0166] On the other hand, if the channel is busy during the delay period (2070;N), the base station re-executes step 2060 to check again whether the channel is idle or not during the new delay period.

[0167] In the procedure described above, if the base station does not transmit a transmission after step 4, the base station may transmit a transmission on the channel if the following conditions are met:

[0168] When the base station is prepared to transmit, and the channel is sensed as idle for at least the sensing slot interval Tsl, and immediately before the transmission, the channel is sensed as idle for the entire sensing slot interval of the delay interval Td.

[0169] Conversely, if the base station senses the channel after it has been prepared to transmit, and the channel is not sensed as idle during the sensing slot interval Tsl, or if the channel is not sensed as idle during any one of the sensing slot intervals of the delay interval Td immediately before the intended transmission, the base station proceeds to step 1 after sensing the channel as idle during the sensing slot interval of the delay interval Td.

[0170] The aforementioned delay interval Td consists of an interval Tf (=16us) that immediately follows mp consecutive sensing slot intervals. Here, each sensing slot interval (Tsl) is 9us, and Tf includes an idle sensing slot interval (Tsl) at its starting point.

[0171] Table 7 illustrates how the mp, minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes applied to the CAP vary according to the channel connection priority class.

[0172] [Table 7]

[0173] 3.2. Type 2 Downlink Channel Access Procedures

[0174] 3.2.1. Type 2A DL Channel Connection Procedure

[0175] A base station can transmit immediately after the channel in question is sensed as idle during at least a sensing interval Tshort dl = 25us. Here, Tshort dl consists of a interval Tf (= 16us) immediately following a sensing slot interval. Tf includes a sensing slot at its beginning. If two sensing slots within Tshort dl are sensed as idle, the channel is considered to be idle during Tshort dl.

[0176] 3.2.2. Type 2B DL ​​Channel Connection Procedure

[0177] A base station can transmit immediately after the channel is sensed as idle during Tf = 16us. Tf includes sensing slots that occur within the last 9us of Tf. A channel is considered idle during Tf if it is sensed as idle for at least 5us in total, along with at least 4us of sensing occurring in a sensing slot.

[0178] 3.2.3. Type 2C DL Channel Connection Procedure

[0179] When a base station follows the procedures in this section to transmit a transmission, the base station does not sense the channel before transmitting the transmission. The duration of the transmission is a maximum of 584 us.

[0180] 4. Channel access procedure for transmission(s) on multiple channels

[0181] A base station can connect to multiple channels where transmission is carried out by either the following Type A or Type B procedure.

[0182] 4.1. Type A multi-carrier access procedures

[0183] In accordance with the procedures disclosed in this section, the base station will operate each channel A channel connection is established on JPEG0007857263000008.jpg12151. Here, C is the set of channels that the base station intends to transmit. The image is JPEG0007857263000009.jpg12151, where q is the number of channels the base station intends to transmit through.

[0184] The counter N considered in CAP is for each channel JPEG0007857263000010.jpg11153 is determined separately, and in this case, each channel counter is It will display as JPEG0007857263000011.jpg12151.

[0185] 4.1.1. Type A1 Multiple Channel Connection Procedure

[0186] The counter N considered in CAP is for each channel JPEG0007857263000012.jpg12154 is determined separately, and each channel counter is It will display as JPEG0007857263000013.jpg12155.

[0187] The base station is on any one channel If transmission on JPEG0007857263000014.jpg13153 is terminated, and if the absence of any other technology sharing the channel can be guaranteed for a long period of time (e.g., by level of regulation), then each channel ci (where ci is different from cj) will be terminated. For JPEG0007857263000015.jpg13154), After having the section JPEG0007857263000016.jpg12154 or If an idle sensing slot is detected after JPEG0007857263000017.jpg11151 has been reinitialized, the base station will The reduction of JPEG0007857263000018.jpg13151 can be resumed.

[0188] 4.1.2. Type A2 Multiple Channel Connection Procedure

[0189] Each channel JPEG0007857263000019.jpg12150 The separate counter N may be determined by the details described above, and in this case, each channel counter is It is displayed as JPEG0007857263000020.jpg12151. Here, JPEG0007857263000021.jpg12151 can mean a channel having the maximum CW p value. For each channel JPEG0007857263000022.jpg13152, it may be set to JPEG0007857263000023.jpg12151.

[0190] When the base station ceases transmission for any one of the channels for which JPEG0007857263000024.jpg13152 is to be determined, the base station reinitialises JPEG0007857263000025.jpg12153 for all channels. JPEG0007857263000025.jpg12153.

[0191] 4.2. Type B multi-channel access procedure

[0192] Channel JPEG000785726300002,6.jpg12152 may be selected by the base station as follows.

[0193] - Prior to each transmission on the multi-channel JPEG0007857263000027.jpg11151, the base station randomly and uniformly selects JPEG0007857263000028.jpg1215 from among the Cs, JPEG0007857263000028.jpg12151, or

[0194] - The base station does not select JPEG0007857263000029.jpg12152 more than once every second. JPEG0007857263000029.jpg12152.

[0195] Here, C is the set of channels that the base station intends to transmit on, The image is JPEG0007857263000030.jpg13151, where q is the number of channels the base station intends to transmit through.

[0196] channel For transmission on JPEG0007857263000031.jpg12150, the base station shall channel in accordance with the procedures disclosed in Section 3.1, along with the modifications (medication) disclosed in Section 4.2.1 or 4.2.2. Establish a channel connection on JPEG0007857263000032.jpg12153.

[0197] Of the channels in JPEG0007857263000033.jpg12151, For transmission on JPEG0007857263000034.jpg12153,

[0198] Each channel For JPEG0007857263000035.jpg11151, the base station is channel Immediately before transmission on JPEG0007857263000036.jpg12151, at least during the sensing interval Channel The base station senses JPEG0007857263000038.jpg12152. Channels between JPEG0007857263000039.jpg12151 Immediately after sensing that JPEG0007857263000040.jpg12153 is idle, the channel Transmission can be performed on JPEG0007857263000041.jpg11150. Given section In JPEG0007857263000042.jpg11150, the channel If the channel is sensed as idle during the entire time interval in which idle sensing is performed on JPEG0007857263000043.jpg11151, JPEG0007857263000044.jpg10151 is It may be considered an idol for JPEG0007857263000045.jpg11151.

[0199] The aforementioned base station, channel JPEG0007857263000046.jpg11151 (here, On JPEG0007857263000047.jpg11151), transmission is not performed for a period exceeding Tmcot,p as shown in Table 7. Here, Tmcot,p is the channel Determined using the channel connection parameters used for JPEG0007857263000048.jpg12151.

[0200] In the procedure described in this section, the channel frequencies of channel set C selected by gNB are a subset of a predefined set of channel frequencies.

[0201] 4.2.1. Type B1 Multiple Channel Connection Procedure

[0202] Single CW p The value is maintained for channel set C.

[0203] channel CW for channel connection on JPEG0007857263000049.jpg12152 p To determine this, step 2 of the procedure detailed in section 3.1 above is modified as follows:

[0204] - All channels At least the HARQ-ACK value corresponding to the PDSCH transmission in reference subframe k of JPEG0007857263000050.jpg10151 If JPEG0007857263000051.jpg10153 is determined to be NACK, all priority classes CW for JPEG0007857263000052.jpg12151 p Increase it to the next higher allowed value. Otherwise, proceed to step 1.

[0205] 4.2.2. Type B2 Multiple Channel Connection Procedure

[0206] CW p The value is for each channel Maintained independently for JPEG0007857263000053.jpg12151. Channel CW for JPEG0007857263000054.jpg11151 p To determine the channel Any PDSCH that completely or partially overlaps with JPEG0007857263000055.jpg10151 may be used. N for JPEG0007857263000056.jpg10152 init To determine the channel CW of JPEG0007857263000057.jpg12151 p A value is used. Here, JPEG0007857263000058.jpg10152 is the largest CW channel among all channels in set C. p It is a channel that has [a certain characteristic].

[0207] 5. Uplink channel access procedures

[0208] The UE and the base station scheduling or configuring UL transmissions for the UE perform the following procedures to connect to the channel (for LAA S-cell transmissions). In the following description, the various embodiments of this disclosure will be described in detail, assuming that the terminal and base station are configured with licensed P-cells and one or more unlicensed S-cells. However, the uplink CAP operation may also be applied in the same way when only unlicensed bands are configured for the terminal and base station.

[0209] The UE can connect on the channel where the UL transmission takes place, following a Type 1 or Type 2 UL channel connection procedure.

[0210] Table 8 illustrates how the mp, minimum CW, maximum CW, maximum channel occupancy time (MCOT), and allowed CW sizes applied to CAP vary according to the channel connection priority class.

[0211] [Table 8]

[0212] 5.1. Type 1 UL channel access procedure

[0213] This section describes the channel connection procedure performed by the UE, where the time duration occupied by idle and sensing slots before uplink transmission is random. This section may apply to the following transmissions:

[0214] - PUSCH / SRS transmission scheduled and / or configured from the base station

[0215] - Transmission of scheduled and / or configured PUCCH from the base station

[0216] - Sending related to RAP (random access procedure)

[0217] Figure 14 is a diagram illustrating a UL CAP for unlicensed bandwidth transmission to which various embodiments of this disclosure can be applied.

[0218] The various embodiments of this disclosure can be applied to Type 1 UL CAP UEs for unlicensed bandwidth transmission, which can be summarized as follows:

[0219] For uplink transmission, a transmitting node (e.g., UE) can initiate a channel connection process (CAP) to operate in unlicensed bandwidth (2110).

[0220] The UE can arbitrarily select a backoff counter N within the conflict window (CW) according to step 1. At this time, the value of N is set to the initial value Ninit (2120). Ninit is selected from any value between 0 and CWp.

[0221] Next, according to step 4, if the backoff counter value (N) is 0 (2130; Y), the UE terminates the CAP process (2132). Subsequently, the UE can perform a Tx burst transmission (2134). On the other hand, if the backoff counter value is not 0 (2130; N), the UE decreases the backoff counter value by 1 according to step 2 (2140).

[0222] Next, the UE checks whether the channel is idle (2150), and if the channel is idle (2150; Y), it checks whether the backoff counter value is 0 (2130).

[0223] Conversely, if the channel is not idle during operation 2150, i.e., if the channel is busy (2150; N), the UE checks, according to step 5, whether the channel is idle during a delay period longer than the slot time (e.g., 9 usec) (defer duration Td; 25 usec or more) (2160). If the channel is idle during the delay period (2170; Y), the UE can restart the CAP process.

[0224] For example, if the backoff counter value Ninit is 10, and the channel is determined to be busy after the backoff counter value has decreased to 5, the UE senses the channel during the delay period to determine whether it is idle or not. In this case, if the channel is idle during the delay period, the UE does not set the backoff counter value Ninit, but can perform the CAP process again from the backoff counter value of 5 (or from 4 after decreasing the backoff counter value by 1).

[0225] On the other hand, if the channel is busy during the delay period (2170;N), the UE re-executes operation 2160 to check again whether the channel is idle during the new delay period.

[0226] In the procedure described above, if the UE does not transmit a UL transmission on the channel on which the transmission is to be made after step 4 of the procedure described in detail above, the UE may transmit a UL transmission on the channel if the following conditions are met:

[0227] - When the UE is ready to transmit and the channel in question is sensed as idle, at least within the sensing slot interval Tsl,

[0228] - If the channel is sensed as idle immediately before the transmission, during the entire slot interval of the delay interval Td.

[0229] Conversely, if, after the UE has finished preparing for transmission, the channel is sensed as idle or not sensed within the sensing slot interval Tsl when the channel is first sensed, or if the corresponding channel is not sensed as idle during any sensing slot interval within the delay interval Td immediately before the intended transmission, the UE proceeds to step 1 after the corresponding channel is sensed as idle during the slot interval of the delay interval Td.

[0230] The delay interval Td is composed of an interval Tf (= 16 μs) following immediately after mp consecutive slot intervals. Here, each slot interval (Tsl) is 9 μs, and Tf includes an idle slot interval (Tsl) at the start point of Tf.

[0231] 5.2. Type 2 UL channel access procedure

[0232] 5.2.1 Type 2A UL Channel Connection Procedure

[0233] If the UE is instructed to perform a type 2A UL channel connection procedure, the UE uses the type 2A channel connection procedure for UL transmission. The UE senses that the channel is idle for at least the sensing interval JPEG0007857263, and can transmit immediately after sensing that the channel is idle. Tshort_ul is composed of an interval JPEG0007857263 immediately followed by an interval JPEG0007857263. Tf includes a sensing slot at the start point of Tf. When the 2 sensing slots of Tshort_ul are sensed as idle, the channel is considered to be idle during Tshort_ul.

[0234] 5.2.2. Type 2B UL Channel Connection Procedure

[0235] If the UE is instructed to perform a Type 2B UL channel connection procedure, the UE will use the Type 2B channel connection procedure for UL transmission. The UE can transmit immediately after the channel is sensed as idle during Tf = 16us. Tf includes sensing slots that occur within the last 9us of Tf. The channel is considered idle during Tf if it is sensed as idle for at least 5us in total, along with at least 4us of sensing occurring in the sensing slots.

[0236] 5.2.3. Type 2C UL Channel Connection Procedure

[0237] If the UE is instructed to perform a Type 2C UL channel connection procedure, the UE does not sense the channel before transmitting the transmit in order to transmit the transmit. The duration of the transmit is a maximum of 584us.

[0238] 6. Channel access procedure for UL multi-channel transmission(s)

[0239] Let's say UE:

[0240] - Scheduled to transmit on a set of channels C, and if a UL scheduling grant for UL transmission on the set of channels C instructs a type 1 channel connection procedure, and if the UL transmission is scheduled to begin transmitting at the same time for all channels in the set of channels C, and / or

[0241] - The intention is to perform uplink transmission on resources configured on channel set C using the Type 1 channel connection procedure, and

[0242] Suppose the channel frequency of channel set C is a subset of one of the pre-configured channel frequency sets:

[0243] - The UE can transmit on the channel / using a Type 2 channel connection procedure.

[0244] -- Let's assume a channel JPEG0007857263000063.jpg11151 (here, Immediately before the UE transmission of JPEG0007857263000064.jpg11151), the channel If a Type 2 channel connection procedure is performed on JPEG0007857263000065.jpg11152, and

[0245] -- If the aforementioned UE uses a Type 1 channel connection procedure If connected to JPEG0007857263000066.jpg12152 (the UE has accessed channel) JPEG0007857263000067.jpg10152 (using Type1 channel access procedure),

[0246] --- Prior to performing a Type 1 channel connection procedure on any one (any) channel within the set of channels C, JPEG0007857263000068.jpg11151 is selected uniformly and randomly from channel set C by the UE.

[0247] - If the UE cannot connect to any one channel, the UE will use a channel within the carrier bandwidth of the scheduled or UL resource-defined carrier bandwidth. You do not need to send it as JPEG0007857263000069.jpg12151.

[0248] Random Access (RA) process

[0249] FIG. 15 illustrates an example of the random access procedure. In particular, FIG. 15 illustrates the contention-based random access procedure.

[0250] First, the UE can transmit a random access preamble as Msg1 of the random access procedure in UL through the PRACH.

[0251] Random access preamble sequences with two different lengths are supported. The long sequence length 839 is applicable to subcarrier spacings of 1.25 and 5 kHz, and the short sequence length 139 is applicable to subcarrier spacings of 15, 30, 60, and 120 kHz.

[0252] Multiple preamble formats are defined by one or more RACH OFDM symbols and different cyclic prefixes (and / or guard times). The RACH configuration regarding the initial bandwidth of the Pcell (Primary Cell) is included in the cell's system information and provided to the terminal. The RACH configuration includes information regarding the subcarrier spacing of the PRACH, available preambles, preamble formats, etc. The RACH configuration includes the related information between the SSB and the RACH (time-frequency) resources. The UE transmits the random access preamble on the RACH time-frequency resources related to the detected or selected SSB.

[0253] A critical value for SSBs related to RACH resources may be set by the network, and the transmission or retransmission of the RACH preamble is performed based on the SSB whose reference signal received power (RSRP), measured on an SSB basis, satisfies the critical value. For example, a UE can select one of the SSBs that satisfies the critical value and transmit or retransmit the RACH preamble based on the RACH resources associated with the selected SSB. For example, when retransmitting a RACH preamble, a terminal can re-select one of the SSBs and retransmit the RACH preamble based on the RACH resources associated with the re-selected SSB. That is, the RACH resources for retransmitting the RACH preamble may be the same and / or different from the RACH resources for transmitting the RACH preamble.

[0254] When a base station (BS) receives an arbitrary access preamble from a UE, the BS sends a random access response (RAR) message (Msg2) to the UE. The PDCCH that schedules the PDSCH carrying the RAR is transmitted after being CRC scrambled with a random access radio network temporary identifier (RNTI) (RA-RNTI). A UE that detects a PDCCH scrambled with RA-RNTI can receive the RAR from the PDSCH scheduled by the DCI carried by the PDCCH. The UE checks whether the RAR contains the arbitrary access response information for the preamble it transmitted, i.e., Msg1. Whether or not arbitrary access information for the Msg1 it transmitted exists can be determined by whether or not an arbitrary access preamble ID exists for the preamble transmitted by the UE. If there is no response to Msg1, the UE can retransmit the RACH preamble up to a certain number of times while performing power ramping. The UE calculates the PRACH transmit power for the retransmission of the preamble based on the last transmit power, power increment, and power ramping counter.

[0255] The arbitrary connection response information may include the preamble sequence transmitted by the terminal, the temporary cell-RNTI (TC-RNTI) assigned by the base station to the terminal attempting to establish an arbitrary connection, uplink transmit time alignment information, uplink transmit power alignment information, and uplink radio resource allocation information. When a terminal receives the arbitrary connection response information for itself on the PDSCH, the terminal knows the timing advance information for UL synchronization, the initial UL grant, and the TC-RNTI. The timing advance information is used to control the uplink signal transmission timing. To ensure that PUSCH / PUCCH transmissions by the UE are better aligned with subframe timing at the network edge, the network (e.g., BS) may obtain timing advance information based on timing information detected from the PRACH preamble received from the terminal and send this timing advance information to the terminal. Based on the arbitrary connection response information, the UE may transmit a UL transmission on the uplink shared channel as Msg3 of the arbitrary connection process. Msg3 may contain an RRC concatenation request and a UE identifier. In response to Msg3, the network may send Msg4, which may be treated as a conflict resolution message on the DL. Upon receiving Msg4, the UE can enter an RRC concatenation state.

[0256] On the other hand, a non-conflict arbitrary connection process may be used when a UE is handing over to another cell or BS, or when requested by an instruction from the BS. The basic process of a non-conflict arbitrary connection process is similar to that of a conflict-based arbitrary connection process. However, unlike a conflict-based arbitrary connection process in which the UE arbitrarily selects which preamble to use from among several arbitrary connection preambles, in a non-conflict arbitrary connection process, the preamble to be used by the UE (hereinafter referred to as a dedicated arbitrary connection preamble) is assigned to the UE by the BS. Information regarding the dedicated arbitrary connection preamble may be included in an RRC message (e.g., a handover instruction) or provided to the UE by a PDCCH order. When an arbitrary connection process is initiated, the UE sends the dedicated arbitrary connection preamble to the BS. When the UE receives the arbitrary connection process from the BS, the arbitrary connection process is completed.

[0257] As mentioned earlier, UL grants within the RAR schedule a PUSCH transmission to the UE. The PUSCH carrying the initial UL transmission by the UL grant within the RAR can also be referred to as the Msg3 PUSCH. The content of the RAR UL grant starts from the MSB and ends with the LSB, as shown in Table 9.

[0258] [Table 9]

[0259] The TPC instruction is used to determine the transmit power of Msg3 PUSCH, and is interpreted, for example, according to Table 10.

[0260] [Table 10]

[0261] In a no-conflict arbitrary connection process, the CSI request field in the RAR UL grant indicates whether the UE includes a non-periodic CSI report in the PUSCH transmission. The subcarrier interval for the Msg3 PUSCH transmission is provided by the RRC parameter. The UE will transmit PRACH and Msg3 PUSCH on the same uplink carrier of the same service-providing cell. The UL BWP for the Msg3 PUSCH transmission is indicated by SIB1 (SystemInformationBlock1).

[0262] Multiplexing of short and long PUCCH

[0263] Figure 16 illustrates a configuration in which short PUCCH and long PUCCH signals are multiplexed with the uplink signal.

[0264] PUCCH (for example, PUCCH format 0 / 2) and PUSCH may be multiplexed using TDM or FDM. Short PUCCH and long PUCCH from different terminals may be multiplexed using TDM or FDM. Short PUCCH from a single terminal in a single slot may be multiplexed using TDM. Short PUCCH and long PUCCH from a single terminal in a single slot may be multiplexed using TDM or FDM.

[0265] ACK / NACK transmission

[0266] Figure 17 illustrates the ACK / NACK transmission process. Referring to Figure 17, the terminal can detect the PDCCH in slot #n. Here, the PDCCH contains downlink scheduling information (e.g., DCI format 1_0, 1_1), and the PDCCH indicates the DL assignment-to-PDSCH offset (K0) and the PDSCH-HARQ-ACK reporting offset (K1). For example, DCI format 1_0, 1_1 may include the following information:

[0267] - Frequency domain resource assignment: Indicates the RB set assigned to PDSCH.

[0268] - Time domain resource assignment: K0 indicates the starting position (e.g., OFDM symbol index) and length (e.g., number of OFDM symbols) of the PDSCH within the slot.

[0269] - The PDSCH-to-HARQ_feedback timing indicator shows K1.

[0270] Subsequently, depending on the scheduling information for slot #n, the terminal can receive a PDSCH at slot #(n+K0) and then transmit a UCI via PUCCH at slot #(n+K1). Here, the UCI includes a HARQ-ACK response to the PDSCH. If the PDSCH is configured to transmit up to one TB, the HARQ-ACK response may consist of one bit. If the PDSCH is configured to transmit up to two TBs, the HARQ-ACK response may consist of two bits if spatial bundling is not configured, and one bit if spatial bundling is configured. If the time for transmitting HARQ-ACKs to multiple PDSCHs is specified as slot #(n+K1), the UCI transmitted at slot #(n+K1) includes HARQ-ACK responses to multiple PDSCHs.

[0271] Figure 18 illustrates an SSB structure. Based on the SSB, terminals can perform cell search, system information acquisition, beam alignment for initial connection, DL measurements, and more. SSB may be used interchangeably with SS / PBCH (Synchronization Signal / Physical Broadcast channel) block.

[0272] Referring to Figure 18, SSB consists of PSS, SSS, and PBCH. SSB consists of four consecutive OFDM symbols, and PSS, PBCH, SSS / PBCH, and PBCH are transmitted for each OFDM symbol. PSS and SSS each consist of one OFDM symbol and 127 subcarriers, while PBCH consists of three OFDM symbols and 576 subcarriers. Polar coding and QPSK (Quadrature Phase Shift Keying) are applied to PBCH. PBCH consists of a data RE and a DMRS (Demodulation Reference Signal) RE for each OFDM symbol. There are three DMRS REs for each RB, and three data REs between DMRS REs.

[0273] Cell search

[0274] Cell search refers to the process by which a terminal synchronizes the time / frequency of a cell and detects the cell's Identifier (e.g., Physical Layer Cell ID, PCID). PSS is used to detect cell IDs within cell ID groups, and SSS is used to detect cell ID groups. PBCH is used for SSB (time) index detection and half-frame detection.

[0275] The cell search process of the terminal can be organized as shown in Table 11 below.

[0276] [Table 11]

[0277] Figure 19 illustrates SSB transmission.

[0278] SSB is transmitted periodically according to the SSB period. During initial cell discovery, the terminal assumes a basic SSB period of 20ms. After cell connection, the SSB period may be set by the network (e.g., base station) to one of the following: {5ms, 10ms, 20ms, 40ms, 80ms, 160ms}. An SSB burst set is formed at the beginning of the SSB period. An SSB burst set consists of a 5ms time window (i.e., half frame), and SSB may be transmitted up to L times within an SSB burst set. The maximum number of SSB transmissions L may be given by the carrier frequency bandwidth as follows: One slot contains a maximum of two SSBs.

[0279] -For frequency range up to 3GHz,L=4

[0280] - For frequency range from 3GHz to 6GHz,L=8

[0281] - For frequency range from 6GHz to 52.6GHz,L=64

[0282] Within the SS burst set, the time position of an SSB candidate may be defined by the SCS as follows: The time position of an SSB candidate is indexed from 0 to L-1 in time order within the SSB burst set (i.e., half frame) (SSB index).

[0283] - Case A - 15kHz SCS: The index of the starting symbol for the candidate SSB is given as {2,8}+14*n. When the carrier frequency is 3GHz or less, n=0, 1. When the carrier frequency is between 3GHz and 6GHz, n=0, 1, 2, 3.

[0284] - Case B - 30kHz SCS: The index of the starting symbol for the candidate SSB is given as {4,8,16,20}+28*n. When the carrier frequency is 3GHz or less, n=0. When the carrier frequency is between 3GHz and 6GHz, n=0 or 1.

[0285] - Case C-30kHz SCS: The index of the starting symbol for the candidate SSB is given as {2,8}+14*n. When the carrier frequency is 3GHz or less, n=0, 1. When the carrier frequency is between 3GHz and 6GHz, n=0, 1, 2, 3.

[0286] - Case D-120kHz SCS: The index of the starting symbol for the candidate SSB is given as {4,8,16,20}+28*n. When the carrier frequency is greater than 6GHz, n=0,1,2,3,5,6,7,8,10,11,12,13,15,16,17,18.

[0287] - Case E-240kHz SCS: The index of the starting symbol for the candidate SSB is given as {8,12,16,20,32,36,40,44}+56*n. When the carrier frequency is greater than 6GHz, n=0,1,2,3,5,6,7,8.

[0288] Figure 20 illustrates how a device obtains information regarding download time synchronization.

[0289] The terminal can achieve DL synchronization by detecting SSBs. Based on the detected SSB index, the terminal can identify the structure of the SSB burst set, thereby detecting symbol / slot / half-frame boundaries. The frame / half-frame number to which the detected SSB belongs can be identified using SFN information and half-frame indicator information.

[0290] Specifically, the terminal can obtain 10 bits of SFN (System Frame Number) information from the PBCH (s0~s9). Of the 10 bits of SFN information, 6 bits are obtained from the MIB (Master Information Block), and the remaining 4 bits are obtained from the PBCH TB (Transport Block).

[0291] Next, the terminal can acquire 1-bit half-frame indication information (c0). When the carrier frequency is 3 GHz or less, the half-frame indication information may be implicitly signaled by the PBCH DMRS. The PBCH DMRS indicates 3 bits of information using one of the eight PBCH DMRS sequences. Therefore, when L=4, of the 3 bits that can be indicated using the eight PBCH DMRS sequences, the 1 bit remaining after indicating the SSB index may be used for half-frame indication.

[0292] Finally, the terminal can obtain the SSB index based on the DMRS sequence and the PBCH payload. SSB candidates are indexed 0 to L-1 in chronological order within the SSB burst set (i.e., half frame). When L=8 or 64, the three LSB (Least Significant Bit) bits of the SSB index may be indicated by eight different PBCH DMRS sequences (b0 to b2). When L=64, the three MSB (Most Significant Bit) bits of the SSB index are indicated by the PBCH (b3 to b5). When L=2, the two LSB bits of the SSB index may be indicated by four different PBCH DMRS sequences (b0, b1). When L=4, of the three bits that can be indicated using the eight PBCH DMRS sequences, the one bit remaining after indicating the SSB index may be used for half-frame indication (b2).

[0293] System Information Retrieval

[0294] Figure 21 illustrates the system information (SI) acquisition process. A terminal can acquire AS / NAS information through the SI acquisition process. The SI acquisition process may be applied to terminals in the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states.

[0295] System Information (SI) is divided into a Master Information Block (MIB) and multiple System Information Blocks (SIBs). The MIB and multiple SIBs can be further divided into a Minimum SI and Other SIs. Here, the Minimum SI may consist of the MIB and SIB 1, and contains the basic information required for initial connection and information for obtaining other SIs. Here, SIB 1 can be called the Remaining Minimum System Information (RMSI). For further details, see the following.

[0296] - The MIB contains information / parameters related to the reception of SIB 1 (System Information Block Type 1) and is transmitted via the PBCH of SSB. During initial cell selection, the terminal assumes that half frames with SSB are repeated every 20ms. Based on the MIB, the terminal can check if a CORESET (Control Resource Set) exists for the Type 0-PDCCH common search space. The Type 0-PDCCH common search space is a type of PDCCH search space used to transmit PDCCHs that schedule SI messages. If the Type 0-PDCCH common search space exists, the terminal can determine (i) a series of consecutive RBs and one or more consecutive symbols that constitute the CORESET, and (ii) a PDCCH opportunity (i.e., a time-domain position for PDCCH reception), based on the information in the MIB (e.g., pdcch-ConfigSIB1). If a Type0-PDCCH common search space does not exist, pdcch-ConfigSIB1 provides information about the frequency locations where SSB / SIB1 exists and the frequency ranges where SSB / SIB1 does not exist.

[0297] - SIB1 includes information related to the availability and scheduling (e.g., transmission period, SI window size) of the remaining SIBs (hereinafter, SIBx, where x is an integer of 2 or more). For example, SIB1 may indicate whether SIBx is broadcast periodically or provided on demand upon request from a terminal. If SIBx is provided on demand, SIB1 may include information necessary for the terminal to make an SI request. SIB1 is transmitted via PDSCH, the PDCCH that schedules SIB1 is transmitted via the Type0-PDCCH common search space, and SIB1 is transmitted via the PDSCH indicated by the PDCCH.

[0298] - SIBx is included in the SI message and transmitted via PDSCH. Each SI message is transmitted within a periodically occurring time window (i.e., SI window).

[0299] beam alignment

[0300] Figure 22 illustrates SSB multi-beam transmission.

[0301] Beam sweeping means that a TRP (Transmission Reception Point) (e.g., a base station / cell) changes the beam (direction) of a radio signal over time (hereinafter, beam and beam direction may be used interchangeably). SSB may be transmitted periodically using beam sweeping. In this case, the SSB index is implicitly linked to the SSB beam. The SSB beam may be changed on an SSB (index) basis or on an SSB (index) group basis. In the latter case, the SSB beam is maintained identically within the SSB (index) group. That is, the transmission beam direction of the SSB is repeated in multiple consecutive SSBs. The maximum number of SSB transmissions L in an SSB burst set has a value of 4, 8, or 64 depending on the frequency band to which the carrier belongs. Therefore, the maximum number of SSB beams in an SSB burst set may also be given as follows, depending on the frequency band of the carrier.

[0302] - For frequency range up to 3 GHz,Max number of beams=4

[0303] - For frequency range from 3GHz to 6GHz,Max number of beams=8

[0304] - For frequency range from 6GHz to 52.6GHz,Max number of beams=64

[0305] *When multi-beam transmission is not applied, the number of SSB beams is one.

[0306] When a terminal attempts an initial connection to a base station, the terminal can align its beam with the base station based on SSB. For example, after SSB detection, the terminal identifies the best SSB. The terminal can then send a RACH preamble to the base station using a PRACH resource linked to / corresponding to the index (i.e., beam) of the best SSB. SSB may also be used to align the beam between the base station and the terminal after the initial connection.

[0307] Channel measurement and rate matching

[0308] Figure 23 illustrates how to indicate the SSB (SSB_tx) that will actually be sent.

[0309] Within an SSB burst set, up to L SSBs may be transmitted, and the number / location of SSBs actually transmitted may vary from base station / cell to base station / cell. The number / location of SSBs actually transmitted is used for rate matching and measurement, and information about the actually transmitted SSBs is indicated as follows:

[0310] - In the case of rate matching: This may be indicated by terminal-specific RRC signaling or RMSI. Terminal-specific RRC signaling includes a full bitmap (e.g., length L) in both the below 6GHz and above 6GHz frequency ranges. In contrast, RMSI includes a full bitmap below 6GHz, and a compressed bitmap above 6GHz as shown in the figure. Specifically, information about the SSB actually transmitted can be indicated using a group bitmap (8 bits) + an intra-group bitmap (8 bits). Here, the resource indicated by terminal-specific RRC signaling or RMSI (e.g., RE) is reserved for SSB transmission, and PDSCH / PUSCH etc. may be rate-matched considering the SSB resource.

[0311] - In relation to measurement: When in RRC connected mode, the network (e.g., base station) can specify the SSB set to be measured within the measurement interval. The SSB set may be specified by frequency layer. If no SSB set is specified, the default SSB set is used. The default SSB set includes all SSBs within the measurement interval. The SSB set may be specified by the full (e.g., length L) bitmap of the RRC signaling. When in RRC idle mode, the default SSB set is used.

[0312] Figure 24 illustrates the structure of a wireless frame used in NR.

[0313] In NR, uplink and downlink transmissions consist of frames. A radio frame has a length of 10ms and is defined as two 5ms half-frames (HF). A half-frame is defined as five 1ms subframes (SF). A subframe is divided into one or more slots, and the number of slots within a subframe depends on SCS (Subcarrier Spacing). Each slot contains 12 or 14 OFDM(A) symbols by a cyclic prefix (CP). When a general CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, symbols can include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or DFT-s-OFDM symbols).

[0314] Table 12 illustrates how, when a general CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe are changed by the SCS.

[0315] [Table 12]

[0316] * Nslotsymb: Number of symbols in a slot * Nframe,uslot: Number of slots in a frame

[0317] * Nsubframe,uslot: Number of slots in the subframe

[0318] Table 13 illustrates how the number of symbols per slot, the number of slots per frame, and the number of slots per subframe are changed by the SCS when the extended CP is used.

[0319] [Table 13]

[0320] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be individually configured between multiple cells merged into a single terminal. This allows the (absolute time) intervals of time resources (e.g., SF, slots, or TTI) (collectively referred to as TU (Time Unit) for convenience), which consist of the same number of symbols, to be configured differently between the merged cells.

[0321] Figure 25 illustrates the slot structure of an NR frame. A slot contains multiple symbols in the time domain. For example, in the case of a general CP, one slot contains 14 symbols, and in the case of an extended CP, one slot contains 12 symbols. A carrier wave contains multiple subcarriers in the frequency domain. An RB (Resource Block) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) is defined as multiple consecutive (P)RBs in the frequency domain and may correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier wave can contain up to N (e.g., 4) BWPs. Data communication takes place in activated BWPs, and only one BWP may be activated for a single terminal. In a resource grid, each element is called a Resource Element (RE) and may be mapped to a single complex symbol.

[0322] Figure 26 illustrates the structure of a self-contained slot. In an NR system, a frame is characterized by a self-contained structure in which a single slot can contain a DL control channel, DL or UL data, and a UL control channel. For example, the first N symbols in a slot may be used to transmit the DL control channel (hereinafter referred to as the DL control area), and the last M symbols in a slot may be used to transmit the UL control channel (hereinafter referred to as the UL control area). N and M are integers greater than or equal to 0. The resource area (hereinafter referred to as the data area) between the DL control area and the UL control area may be used for transmitting DL data or UL data. As an example, the following configuration can be considered. Each section is arranged in chronological order.

[0323] 1. DL only configuration

[0324] 2. UL only configuration

[0325] 3. Mixed UL-DL configuration

[0326] - DL area + GP (Guard Period) + UL control area

[0327] - DL control area + GP + UL area

[0328] * DL area: (i) DL data area, (ii) DL control area + DL data area

[0329] * UL area: (i) UL data area, (ii) UL data area + UL control area

[0330] PDCCH may be transmitted in the DL control domain, and PDSCH may be transmitted in the DL data domain. PUCCH may be transmitted in the UL control domain, and PUSCH may be transmitted in the UL data domain. PDCCH may transmit DCI (Downlink Control Information), such as DL data scheduling information and UL data scheduling information. PUCCH may transmit UCI (Uplink Control Information), such as ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) information for DL ​​data, CSI (Channel State Information) information, and SR (Scheduling Request). GP provides a time gap during the process of the base station and terminal switching from transmit mode to receive mode or from receive mode to transmit mode. Some symbols at the point in time when switching from DL to UL within a subframe may be set as GP.

[0331] Bandwidth Part (BWP)

[0332] In NR systems, up to 400 MHz may be supported per carrier. If a UE operating on such a wideband carrier operates with the radio frequency (RF) module attached for the entire carrier at all times, UE battery consumption may increase. Alternatively, considering various use cases operating within a single wideband carrier (e.g., eMBB, URLLC, mMTC, V2X, etc.), different numerologies (e.g., subcarrier spacing) may be supported for different frequency bands within that carrier. Alternatively, different UEs may have different capabilities for the maximum bandwidth. Taking this into consideration, a base station can instruct a UE to operate only on a portion of the wideband carrier's bandwidth rather than the entire bandwidth, and this portion of the bandwidth is referred to as the bandwidth part (BWP). In the frequency domain, BWP is a subset of contiguous common resource blocks defined for a numerology μi within a bandwidth part i on a carrier, which may have a single numerology (e.g., subcarrier interval, CP length, slot / minislot duration).

[0333] On the other hand, a base station can set one or more BWPs within a single carrier wave set in a UE. Alternatively, if UEs are concentrated in a particular BWP, some UEs may be moved to other BWPs for load balancing. Or, considering frequency domain inter-cell interference cancellation between adjacent cells, a portion of the central spectrum of the total bandwidth may be excluded, and BWPs on both sides of the cell may be set in the same slot. In other words, a base station can set at least one DL / UL BWP on a UE associated with a wideband carrier, activate at least one of the set DL / UL BWPs at a given time (by means of physical layer control signals such as L1 signaling, MAC layer control signals such as MAC control elements (CE), or RRC signaling), and instruct the UE to switch to another set DL / UL BWP (by means of L1 signaling, MAC CE, or RRC signaling), or set a timer value so that the UE switches to the specified DL / UL BWP when the timer expires. In this case, DCI format 1_1 or DCI format 0_1 ​​can be used to instruct the UE to switch to another set DL / UL BWP. The activated DL / UL BWP is specifically called an active DL / UL BWP. In situations such as when the UE is in the initial access process or before the UE's RRC connection is set up, the UE may not be able to receive configuration for the DL / UL BWP. The DL / UL BWP that the UE assumes in such situations is called the initial active DL / UL BWP.

[0334] On the other hand, DL BWP is a BWP for sending and receiving downlink signals such as PDCCH and / or PDSCH, and UL BWP is a BWP for sending and receiving uplink signals such as PUCCH and / or PUSCH.

[0335] In an NR system, the downlink channel and / or downlink signal may be transmitted and received within the active DL BWP (Downlink Bandwidth Part). Furthermore, the uplink channel and / or uplink signal may be transmitted and received within the active UL BWP (Uplink Bandwidth Part).

[0336] Before proceeding to a detailed explanation, we will describe examples of the operation of a terminal and a base station according to the embodiments of this disclosure with reference to Figures 27 and 28.

[0337] Figure 27 is a diagram illustrating an example of the operation of a terminal according to this disclosure. Referring to Figure 27, the terminal can send a first PRACH (Physical Random Access Channel) preamble in message A (S2701). Then, in response to message A, it can receive a RAR (Random Access Response) in message B related to contention resolution (S2703). At this time, the specific method by which the terminal performs the arbitrary connection process in S2701 to S2703 can be obtained based on the embodiments and features described later.

[0338] On the other hand, the terminal in Figure 27 may be any one of the various wireless devices disclosed in Figures 1 to 4. For example, the terminal in Figure 27 may be the first wireless device 100 in Figure 1 or the wireless devices 100, 200 in Figure 2. In other words, the operation process in Figure 27 may be performed by any one of the various wireless devices disclosed in Figures 1 to 4.

[0339] Figure 28 is a diagram illustrating an example of the operation of a base station according to this disclosure. Referring to Figure 28, the base station receives a first PRACH (Physical Random Access Channel) preamble in message A (S2801), and can send a RAR (Random Access Response) in message B related to contention resolution as a response to message A (S2803). At this time, the specific method by which the base station performs the arbitrary connection process in S2801 to S2803 can be obtained based on the embodiments and features described later.

[0340] On the other hand, the base station in Figure 28 may be any one of the various radio devices disclosed in Figures 1 to 4. For example, the base station in Figure 28 may be the second radio device 200 in Figure 1 or the radio devices 100, 200 in Figure 2. In other words, the operation process in Figure 28 may be performed by any one of the various radio devices disclosed in Figures 1 to 4.

[0341] In LTE and / or NR systems, a terminal can perform an uplink (UL) transmission via a random access procedure (RACH procedure) even if a direct uplink transmission is not scheduled from a given base station or cell. For a terminal, the random access procedure in LTE and / or systems consists of a four-step procedure: 1) sending a random access preamble, 2) receiving a message (Msg)2 corresponding to a random access response (RAR), 3) sending a message (Msg)3 including a physical uplink shared channel (PUSCH), and 4) receiving a message (Msg)4 including information on contention resolution.

[0342] Here, Msg2 is a message in which a base station that has received an arbitrary preamble allocates the UL resource that the terminal that sent the preamble will use when sending Msg3. The terminal can use Msg3 to send information such as a connection request, along with its own identification information, such as an International Mobile Subscriber Identity (IMSI) or Temporary Mobile Subscriber Identity (TMSI). Upon receiving Msg3, the base station can use Msg4 to send the terminal's identification information and the information necessary for arbitrary connection, thereby preventing collisions that may occur between different terminals during the arbitrary connection process and completing the arbitrary connection procedure for that terminal.

[0343] Unlike the existing LTE and NR Rel-15 RACH procedure, which consists of four stages as described above, the newly introduced NR Rel-16 simplifies the processing delay caused by the four stages and research is underway on a two-step RACH procedure so that the RACH procedure can be utilized even in small cells or unlicensed bandwidths. In the two-step RACH, the stage in which message 3 (Msg3) containing the Physical Uplink Shared Channel (PUSCH) is sent, and the stage in which message 4, including the contention resolution message, is sent, are omitted. Instead, in the first stage of the arbitrary connection procedure, the terminal immediately sends a message corresponding to Msg3 as Msg A along with the preamble to the base station, and in response to Msg A, the base station sends a message corresponding to Msg4 as Msg B along with the RAR to the terminal. Upon receiving Msg B, the terminal decodes Msg B, completes the arbitrary connection procedure, and then proceeds with sending and receiving data.

[0344] Figure 29 shows the basic process of two-stage RACH. Referring to Figure 29, the terminal can receive two-stage RACH-related configuration information included in the system information broadcast from the base station (S2901). Upon receiving the two-stage RACH-related configuration information, the terminal sends Msg A, which includes a RACH preamble (or PRACH preamble) and a PUSCH, based on the configuration information, in order to perform an optional connection procedure to the base station (S2903). At this time, the RACH preamble and PUSCH may be transmitted at regular intervals (gap) in the time domain or continuously, and the PUSCH contains the terminal's identifier (ID) information. The base station detects the preamble and becomes able to predict and receive the PUSCH with the gap or continuous PUSCH. Based on the terminal ID information transmitted via PUSCH, the base station, after receiving a connection request and / or response from a higher layer, sends Msg B to the terminal as a response to Msg A, containing information such as RAR and contention resolution (S2905). Subsequently, depending on whether the terminal has received Msg B, the terminal completes the connection to the base station in the same or similar manner as after receiving Msg 4 in the existing four-stage RACH procedure, and becomes able to send and receive data with the base station.

[0345] In NR, terminals can perform arbitrary connection procedures in unlicensed bands, and the Listen Before Talk (LBT) process required for signal transmission and reception in unlicensed bands may also be applied to signal transmission and reception for arbitrary connection procedures. That is, in NR-U (NR-Unlicensed spectrum) systems, LBT is always performed to check the idle or busy state of the transmission and reception channel before the base station and terminal transmit and receive signals, and this may also be performed in the procedure for transmitting and receiving Msg A and Msg B for a two-stage RACH procedure in unlicensed bands.

[0346] In particular, the transmission of Msg A in the two-stage RACH procedure includes the transmission of Msg A PUSCH along with the transmission of the Msg A PRACH preamble. Therefore, after the transmission of the Msg A PRACH preamble, the success or failure of the LBT for Msg A PUSCH may change the subsequent optional connection procedure. For example, if a terminal transmits the Msg A PRACH preamble and then successfully performs the LBT for Msg A PUSCH without any further issues, the base station may receive both the Msg A PRACH preamble and Msg A PUSCH correctly and complete the two-stage RACH procedure by transmitting Msg B, which contains conflict resolution information, to the terminal. Conversely, if the terminal fails to send the LBT for Msg A PUSCH after sending the Msg A PRACH preamble, the terminal will be unable to send Msg A PUSCH. The base station, which receives only the Msg A PRACH preamble and not Msg A PUSCH, will use Msg B to instruct a fallback to Msg3, and the terminal may switch to the 4-stage RACH procedure.

[0347] In other words, in a two-stage RACH procedure in an unlicensed band, the success or failure of the LBT for Msg A PUSCH should be considered in the transmission of Msg A PUSCH and the subsequent reception of Msg B, and in particular, it will be necessary to prevent procedure delays that occur when the LBT fails. Below, we describe how to set one or more resources for Msg A PUSCH that take LBT failure into account in order to maintain the benefits of a fast connection in a two-stage RACH procedure, and how to set the reception window (or CR timer (contention resolution timer)) for Msg B based on the set resources.

[0348] 1. When the RACH opportunity and the Msg A PUSCH opportunity have a one-to-one mapping relationship.

[0349] For the transmission of Msg A, the RACH opportunity (RO) in which the Msg A PRACH preamble is sent and the PUSCH opportunity (PO) in which Msg A PUSCH is sent may be mapped one-to-one. Therefore, when a terminal transmits the Msg A PRACH preamble, there is one Msg A PUSCH opportunity corresponding to the transmitted Msg A PRACH preamble, and whether or not Msg A PUSCH is transmitted is determined for that one Msg A PUSCH opportunity based on the success or failure of the LBT.

[0350] The window or timer for the terminal to receive Msg B may be configured as follows: 1) If LBT is successful, the window may be configured or the timer may be started after the Msg A PUSCH opportunity, and if LBT fails, the window may not be configured or the timer may not be started; or 2) Regardless of the success or failure of LBT, the window may always be configured or the timer may be started after the Msg A PUSCH opportunity.

[0351] At this time, the terminal selects a Msg A PRACH preamble for the two-stage RACH procedure, and even if the LBT for Msg A PUSCH is successful, or regardless of the success or failure of the LBT, if circumstances arise such as the channel status of one Msg A PUSCH opportunity deteriorating, the terminal may predict the probability of detection error for Msg A PUSCH itself and transmit only the Msg A PRACH preamble, without transmitting Msg A PUSCH. In other words, whether or not Msg A PUSCH is transmitted may depend on the success or failure of the LBT, or on the terminal's independent judgment and selection regarding whether or not to transmit Msg A PUSCH.

[0352] In a situation where it may be determined as described above whether or not Msg A PUSCH is sent, the start time of the window or timer for receiving Msg B may be set as in the following embodiment, in which case the embodiment described below that can be used regardless of the success or failure of LBT is not limited to NR-U systems but is also applicable to licensed carriers.

[0353] (1) Example 1: When LBT is successful, set the start time of the window or timer from the first symbol one symbol after the last symbol of the PUSCH opportunity.

[0354] Example 1 is a method in which a window or timer for receiving Msg B is set only when LBT is successful and Msg A PUSCH can be sent, and if LBT fails and Msg A PUSCH cannot be sent, a window or timer for receiving Msg B is not set. In other words, even if there is a Msg A PUSCH opportunity corresponding to the Msg A PRACH preamble sent by the terminal, if LBT fails, Msg A PUSCH will not be sent at that Msg A PUSCH opportunity, and therefore the reception window or timer for Msg B will not start. On the other hand, if LBT is successful, Msg A PUSCH will be sent normally at that Msg A PUSCH opportunity, and the reception window or timer for Msg B may also start.

[0355] In this case, the start of the reception window or timer for Msg B may be one symbol after the last symbol of the Msg A PUSCH opportunity corresponding to the Msg A PRACH preamble sent by the terminal. In other words, the window or timer for receiving Msg B may be set to start at least one symbol apart from the Msg A PUSCH opportunity on a symbol-by-symbol basis. Furthermore, assuming that a resource for monitoring Msg B is configured, the start of the window or timer may be the first symbol of the resource for monitoring Msg B. Here, the resource for monitoring Msg B may be the resource corresponding to the first CORESET of the Type1-PDCCH Common Search Space set for the terminal to receive a PDCCH for Msg B.

[0356] In other words, if the terminal that sent the Msg A PRACH preamble succeeds in LBT and can send Msg A PUSCH, the window or timer set to receive Msg B starts from the first symbol of the resource for monitoring Msg B, and this starting point may be one symbol or more after the last symbol of the Msg A PUSCH opportunity.

[0357] Figure 30 shows an example of how the success or failure of the LBT for sending Msg A PUSCH configures the reception window for Msg B. In Figure 30(a), if the terminal fails the LBT for sending Msg A PUSCH to the PO that has a one-to-one correspondence with the RO associated with the Msg A PRACH preamble it sent, it does not send Msg A PUSCH and does not configure a window or timer for receiving Msg B. In contrast, in Figure 30(b), if the terminal succeeds in the LBT for sending Msg A PUSCH to the PO that has a one-to-one correspondence with the RO associated with the Msg A PRACH preamble it sent, it sends Msg A PUSCH and configures a window or timer for receiving Msg B. At this time, the window or timer set to receive Msg B starts from the first symbol of the resource for monitoring Msg B, and this starting point may be one symbol or more after the last symbol of the PUSCH opportunity.

[0358] (2) Example 2: Regardless of LBT success or failure, set the window or timer start time from the first symbol one symbol after the last symbol of the PUSCH opportunity.

[0359] Unlike Example 1, Example 2 is a method for setting a window or timer for receiving Msg B even if the terminal fails to send Msg A PUSCH due to a LBT failure. That is, if a PUSCH opportunity exists corresponding to the Msg A PRACH preamble sent by the terminal, the receiving window or timer for Msg B may be started regardless of whether the LBT is successful or unsuccessful, and the terminal can expect to receive Msg B. The method of Example 2 is applicable to both licensed and unlicensed carriers.

[0360] In Embodiment 2, the start of the reception window or timer for Msg B may be one symbol after the last symbol of the Msg A PUSCH opportunity corresponding to the Msg A PRACH preamble sent by the terminal. In other words, the window or timer for receiving Msg B may be set to start at least one symbol apart from the Msg A PUSCH opportunity on a symbol-by-symbol basis. Furthermore, assuming that a resource for monitoring Msg B is configured, the start of the window or timer may be the first symbol of the resource for monitoring Msg B. Here, the resource for monitoring Msg B may be the resource corresponding to the first CORESET of the Type1-PDCCH Common Search Space set for the terminal to receive PDCCH for Msg B.

[0361] If a terminal that has sent the Msg A PRACH preamble fails LBT and is unable to send Msg A PUSCH, or if it does not send Msg A PUSCH due to an independent judgment of the channel state, the terminal can expect to receive a fallback RAR via Msg B that includes uplink (UL) grant information for sending Msg3. The base station can also induce the terminal to send Msg3 along with a fallback to the 4-stage RACH procedure by sending the fallback RAR containing UL grant information to the terminal via Msg B. At this time, even if the RAPID (Random Access Preamble Index) contained in the detected Msg A PRACH preamble is a RAPID for the 2-stage RACH procedure, if the base station cannot decode Msg A PUSCH within a certain time, it can assume that the terminal has failed LBT and is unable to send Msg A PUSCH, and send a fallback RAR to the terminal.

[0362] A terminal that is unable to send Msg A PUSCH and expects to receive a fallback RAR may ignore a success RAR containing its RAPID and expect to receive a fallback RAR that matches its RAPID within a given window or timer interval. If the terminal does not receive a RAR by the end of the window or timer, after a certain back-off time, the terminal may perform a random access resource selection procedure up to a specified maximum number of transmissions and perform an RLF (Radio Link Failure) procedure.

[0363] In contrast, if a terminal that has sent the Msg A PRACH preamble succeeds in LBT and sends Msg A PUSCH, the terminal can expect to receive a success RAR via Msg B containing information about conflict resolution, and can expect certain values ​​such as its RAPID and Terminal Identifier (UE-ID) to be included in the content of Msg B. The base station can also inform the terminal that the terminal's two-stage RACH procedure may be successful by sending a success RAR containing information about conflict resolution in Msg B. If the terminal cannot identify its RAPID and UE-ID through Msg B, the terminal will continue blind decoding until the reception window or timer for Msg B expires. In this case, if the terminal is ultimately unable to identify RAPID and UE-ID by the time of expiration, the terminal can perform the resource selection procedure for arbitrary connections up to the specified maximum number of transmissions after a certain backoff period, and can perform the RLF (Radio Link Failure) procedure.

[0364] The above example may similarly apply to situations where multiple terminals perform a two-stage RACH procedure for a single base station. In a situation where two terminals have selected the same Msg A PRACH preamble containing the same RAPID at the same time, one terminal may send Msg A PUSCH, but the other terminal may not be able to send Msg A PUSCH. In this case, the terminal that sent Msg A PUSCH expects to receive a success RAR, as described above, and also expects its RAPID and UE-ID to be included in the Msg B content. If the terminal cannot identify its RAPID and UE-ID from Msg B, the terminal will continue blind decoding until the window or timer expires. If it still cannot identify the RAPID and UE-ID by the time the timer expires, the terminal can perform resource selection procedures for arbitrary connections and RLF (Radio Link Failure) procedures after the backoff time. In contrast, terminals that cannot send Msg A PUSCH can, as mentioned above, expect a fallback RAR in which their RAPID is matched during the window or timer period, and can ignore any success RAR that contains their RAPID. Terminals that have not received a RAR by the end of the window or timer period can perform resource selection and RLF procedures for arbitrary connections after a certain backoff period.

[0365] Figure 31 shows an example of configuring a reception window for Msg B regardless of the success or failure of the LBT for sending Msg A PUSCH. In Figure 31(a), a terminal can configure a reception window or timer for Msg B even if it fails to send Msg A PUSCH due to a failure in the LBT for sending Msg A PUSCH to a PO that has a one-to-one correspondence with the RO associated with the Msg A PRACH preamble it sent. Also, in Figure 31(b), if the terminal succeeds in the LBT for sending Msg A PUSCH to a PO that has a one-to-one correspondence with the RO associated with the Msg A PRACH preamble it sent, it sends Msg A PUSCH and configures a reception window or timer for Msg B. In this case, in Figure 31(a) or Figure 31(b), the window or timer set to receive Msg B starts from the first symbol of the resource for monitoring Msg B, and this starting point may be one symbol after the last symbol of the PUSCH opportunity.

[0366] 2. When the RACH opportunity and the Msg A PUSCH opportunity have a one-to-many mapping relationship.

[0367] For the transmission of Msg A, a RACH opportunity (RO) to which the Msg A PRACH preamble is sent may be mapped to multiple PUSCH opportunities (PO) to which Msg A PUSCH is sent. In this case, the multiple Msg A PUSCH opportunities may be allocated consecutively without a time gap in the Msg A PUSCH opportunity in the form of Time Division Multiplexing (TDM). Alternatively, the multiple Msg A PUSCH opportunities may be allocated at regular time intervals.

[0368] The one-to-many mapping relationship between RACH opportunities and Msg A PUSCH opportunities can be constructed in various ways. As a simple example, each preamble for all two-stage RACH procedure uses can be mapped to all of the multiple Msg A PUSCH opportunities.

[0369] Alternatively, as another example, a preamble for a two-stage RACH procedure can be divided into N subsets, and the number of Msg A PUSCH opportunities mapped to each preamble can be configured differently for each subset. That is, for a preamble divided into N subsets, 1) in the subset containing preambles corresponding to #0 to #A-1, each preamble can have a one-to-one mapping relationship with one Msg A PUSCH opportunity, and 2) in the subset containing preambles corresponding to #A to #B-1, each preamble can have a one-to-two mapping relationship with two Msg A PUSCH opportunities. In addition, extended settings for mapping relationships are also possible, such as 3) in the subset containing preambles corresponding to #B to #C-1, each preamble can have a one-to-three mapping relationship with three Msg A PUSCH opportunities.

[0370] In the above example, where the number of Msg A PUSCH opportunities mapped to preambles differs for each subset, the preambles included in subset 1) have a one-to-one mapping relationship with the Msg A PUSCH opportunity, so there is one PUSCH opportunity corresponding to the transmitted PRACH preamble, and whether or not Msg A PUSCH is transmitted based on the success or failure of the LBT is determined for that one PUSCH opportunity. The preambles included in subset 2) have a one-to-two mapping relationship with the Msg A PUSCH opportunity, so there are two PUSCH opportunities corresponding to the transmitted PRACH preamble, and whether or not Msg A PUSCH is transmitted based on the success or failure of the LBT is determined for those two PUSCH opportunities. Similarly, since the preambles included in the subset of 3) have a one-to-three mapping relationship with the Msg A PUSCH opportunity, there are three PUSCH opportunities corresponding to the transmitted PRACH preamble, and whether or not Msg A PUSCH is transmitted is determined for these three PUSCH opportunities based on the success or failure of the LBT.

[0371] The more PUSCH opportunity resources corresponding to the transmitted PRACH preamble there are, the more LBT attempts can be made, thus increasing the probability of transmitting Msg A PUSCH despite LBT failures. In other words, the probability of transmitting Msg A PUSCH may vary depending on the subset, and the terminal can select a subset containing preambles with relatively high or low Msg A PUSCH transmission probabilities, taking into account factors such as channel status or the priority of the signals that must be transmitted. For example, the terminal can select a subset based on the Reference Signal Received Power (RSRP) of the received SSB (Synchronization Signal Block) or CSI-RS (Channel State Information-Reference Signal), or based on priority criteria such as the size of the Msg A PUSCH that must be transmitted. Based on the selected subset, the terminal can perform LBT on the PUSCH opportunities corresponding to the preambles included in the subset, attempt to transmit Msg A PUSCH, and configure a window or timer for receiving Msg B.

[0372] In this case, a preamble with a one-to-one mapping relationship can transmit Msg A PUSCH according to the above-described Example 1 or Example 2, and configure the reception window or timer for Msg B. When multiple PUSCH opportunities are mapped to a single preamble that does not have a one-to-one mapping relationship, the NR system needs to be able to consider the possibility of collisions between multiple Msg A PUSCH due to multiple PUSCH opportunities. For example, to reduce the possibility of collisions between multiple Msg A PUSCH, Msg A PUSCH can be transmitted using one Msg A PUSCH opportunity determined by applying modulo operation to the UE-ID based on the total number (M) of multiple Msg A PUSCH opportunities corresponding to the preamble. Here, the modulo operation is (UE-ID)mod(M), and each preamble is sequentially mapped to a PUSCH opportunity according to the result of (UE-ID)mod(M) based on the UE-ID it contains, and the terminal can send Msg A PUSCH based on the mapped Msg A PUSCH opportunity. At this time, the window or timer for receiving Msg B may start after one mapped PUSCH opportunity.

[0373] Another method for sending Msg A PUSCH when multiple PUSCH opportunities are mapped to a single preamble is for the terminal to send Msg A PUSCH on all Msg A PUSCH opportunities corresponding to the preamble, in order to increase the diversity and transmission probability of Msg A PUSCH, even if there is a possibility of collisions between multiple Msg A PUSCHs. In this case, the terminal will attempt to send Msg A PUSCH on multiple PUSCH opportunities corresponding to the preamble, and in this case, LBT will be performed on all of the multiple PUSCH opportunities. Therefore, it is necessary to set which of the multiple PUSCH opportunities the window or timer for receiving Msg B is based on, and the following embodiment may be used for this purpose.

[0374] Here, as in Example 1 or Example 2, if the terminal succeeds in LBT, or regardless of the success or failure of LBT, if circumstances such as the channel status of the one PUSCH opportunity deteriorate occur, the terminal may predict the probability of detection error for Msg A PUSCH itself and send only the Msg A PRACH preamble, and not send Msg A PUSCH. In other words, among the embodiments referred to in the following disclosure, those that can be used regardless of the success or failure of LBT are not limited to NR-U systems but are also applicable to licensed carriers.

[0375] (1) Example 3: Among multiple PUSCH opportunities, set the window or timer start time from the first symbol one symbol after the last symbol of a PUSCH opportunity that successfully completed LBT.

[0376] Embodiment 3 is a method in which a terminal performs LBT for multiple PUSCH opportunities and sets a window or timer for receiving Msg B based on the PUSCH opportunities for which LBT was successful. Embodiment 3 is the same as Embodiment 1 in that it sets a window or timer for receiving Msg B based on the PUSCH opportunities for which LBT was successful. In Embodiment 3, if the terminal fails to perform LBT for all of the multiple PUSCH opportunities, the window or timer for receiving Msg B is not set. That is, if the terminal cannot send Msg A PUSCH, the window or timer for receiving Msg B is not started.

[0377] In Example 3, if LBT is successful for a specific PUSCH opportunity, the transmission of Msg A PUSCH for that PUSCH opportunity is performed normally, and the reception window or timer for Msg B may also be started. At this time, the point in time when the reception window or timer for Msg B is started may be one symbol after the last symbol of the PUSCH opportunity corresponding to the Msg A PRACH preamble transmitted by the terminal. In other words, the window or timer for receiving Msg B may be set to start at least one symbol apart from the PUSCH opportunity on a symbol-by-symbol basis. Furthermore, assuming that a resource for monitoring Msg B is configured, the start time of the window or timer may be the first symbol of the resource for monitoring Msg B. Here, the resource for monitoring Msg B may be the resource corresponding to the first CORESET of the Type 1 PDCCH common search space set for the terminal to receive PDCCH for Msg B.

[0378] In other words, if the terminal that sent the Msg A PRACH preamble succeeds in LBT and can send Msg A PUSCH, the window or timer set to receive Msg B starts from the first symbol of the resource for monitoring Msg B, and this starting point may be one symbol or more after the last symbol of the PUSCH opportunity.

[0379] Figure 32 shows an example of how a reception window for Msg B is configured based on successful LBT (Likely Blind Test) opportunities among multiple PUSCH opportunities. In Figure 32, if a terminal fails to perform LBT on a particular PO (Point of Presence) that corresponds to an RO (Region of Presence) associated with the Msg A PRACH preamble it sent, it does not configure a window or timer for receiving Msg B based on that PO. Instead, the terminal performs LBT until it finds a PO that successfully performs LBT, and sends Msg A PUSCH at the PO that successfully performs LBT, but can configure a window or timer for receiving Msg B one symbol after the last symbol of that PO. In this case, the POs shown in Figure 32 are one-to-many correspondences to a single Msg A PRACH preamble and may be resources that are overlappingly allocated in a TDM (Time Delivery Mission) configuration.

[0380] (2) Example 4: Regardless of whether the LBT is successful or unsuccessful, set the window or timer start time from the first symbol one symbol after the last symbol of the last PUSCH opportunity among multiple PUSCH opportunities.

[0381] Embodiment 4 is a method for setting a window or timer for receiving Msg B for multiple push opportunities corresponding to the Msg A PRACH preamble, regardless of the success or failure of LBT for each push opportunity, always with respect to the last push opportunity among the multiple push opportunities. That is, in preparation for the failure of LBT for all of the corresponding multiple push opportunities, and in order to expect the reception of a fallback RAR, the start time of the window or timer for receiving Msg B is always set from one symbol after the last symbol of the last push opportunity among the multiple TDM push opportunities. The method of Embodiment 4 is applicable regardless of whether the carrier is licensed or unlicensed, and the operation of the terminal and base station related to Embodiment 4 may be the same as that described in Embodiment 2.

[0382] In Example 4, if LBT is successful for a specific Msg A PUSCH opportunity, the transmission of Msg A PUSCH for that opportunity will be performed normally, and the reception window or timer for Msg B may also be started based on the Msg A PUSCH opportunity for which LBT was successful. In this case, the terminal can expect to receive a success RAR by transmitting Msg A PUSCH, and can even expect to successfully complete the two-stage RACH procedure.

[0383] However, if LBT continues to fail, regardless of whether LBT succeeds or fails for the last Msg A PUSCH opportunity, the start time of the window or timer for receiving Msg B is set relative to the last Msg A PUSCH opportunity. If the terminal is unable to send Msg A PUSCH even during the last Msg A PUSCH opportunity, the terminal can expect to receive a fallback RAR and fall back to the 4-stage RACH procedure to send Msg3.

[0384] In this case, the start time of the reception window or timer for Msg B may be one symbol after the last symbol of the last Msg A PUSCH opportunity, as described above. In other words, the window or timer for receiving Msg B may be set to start at least one symbol apart from the Msg A PUSCH opportunity on a symbol-by-symbol basis. Furthermore, assuming that a resource for monitoring Msg B is configured, the start time of the window or timer may be the first symbol of the resource for monitoring Msg B. Here, the resource for monitoring Msg B may be the resource corresponding to the first CORESET of the type 1 PDCCH common search space set for the terminal to receive a PDCCH for Msg B.

[0385] Figure 33 illustrates an example of how the reception window for Msg B is configured based on the last Msg A PUSCH opportunity, regardless of the success or failure of the LBT (Letter Blind Test) among multiple Msg A PUSCH opportunities. In Figure 33, even if the terminal fails to perform LBT on all three POs (Points of Presence) that correspond to the RO (Role of Presence) associated with the Msg A PRACH preamble it sent, it can still configure a window or timer for receiving Msg B based on the last PO. In particular, the terminal can configure a window or timer for receiving Msg B at a point one symbol after the last symbol of the last PO. In this case, the POs shown in Figure 33 are one-to-many correspondences to a single Msg A PRACH preamble and may be resources that are overlappingly allocated in a TDM (Time Delivery Mission) configuration.

[0386] (3) Example 5: Regardless of whether the LBT is successful or unsuccessful, set the window or timer start time from one symbol after the last symbol of the first PUSCH opportunity among multiple PUSCH opportunities.

[0387] Embodiment 5 is a method for setting a window or timer for receiving Msg B for multiple Msg A PUSCH opportunities corresponding to a Msg A PRACH preamble, always based on the first Msg A PUSCH opportunity among the multiple Msg A PUSCH opportunities, regardless of the success or failure of LBT for each Msg A PUSCH opportunity. That is, the start time of the window or timer for receiving Msg B is set from one symbol after the last symbol of the first Msg A PUSCH opportunity among the multiple TDM-decoded Msg A PUSCH opportunities. In this case, the operation of the terminal and base station after the reception window or timer for Msg B based on the first Msg A PUSCH opportunity according to Embodiment 5 is activated may be the same as that described in Embodiment 2, and the terminal can simultaneously perform LBT for the remaining multiple Msg A PUSCH opportunities.

[0388] The terminal sets a receiving window or timer for Msg B after the first Msg A PUSCH opportunity and expects to receive Msg B, while simultaneously performing LBT for subsequent Msg A PUSCH opportunities. Therefore, depending on which Msg A PUSCH opportunity the terminal successfully sends Msg A PUSCH, the time when Msg B is received may be before or after the time when Msg A PUSCH is sent. For example, if the terminal successfully performs LBT for the first PUSCH opportunity and sends Msg A PUSCH during the first Msg A PUSCH opportunity, the time when Msg B is received may be after the time when Msg A PUSCH is sent. However, if the terminal fails to send Msg A PUSCH on multiple Msg A PUSCH opportunities, including the first one, and only sends Msg A PUSCH on a Msg A PUSCH opportunity after the window or timer for receiving Msg B has expired, then the time of receiving Msg B will be before the time of sending Msg A PUSCH.

[0389] Therefore, the subsequent actions of a terminal performing LBT for multiple Msg A PUSCH opportunities may vary as follows, depending on whether the terminal performing LBT ultimately succeeds in LBT but receives Msg B before or after sending Msg A PUSCH. In this case, the following terminal actions may differ depending on whether the terminal sent Msg A PUSCH or failed to send it, and the target object signal that each terminal attempts to receive, such as a success RAR or a fallback RAR, may change. Similarly, the problem of duplicate transmission of success RARs or fallback RARs can also be solved by applying a method similar to that in Example 2.

[0390] First, if the terminal receives Msg B from the base station before sending Msg A PUSCH, the base station receives the Msg A PRACH preamble and fails to receive Msg A PUSCH. Therefore, the Msg B sent by the base station includes a fallback RAR containing information about the fallback and the transmission of Msg3. In this case, if there are still configured Msg A PUSCH opportunities, the terminal can expect to send Msg A PUSCH by saving the fallback RAR and performing LBT on the remaining Msg A PUSCH opportunities. If the terminal fails to perform LBT on all Msg A PUSCH opportunities and ultimately fails to send Msg A PUSCH, the terminal falls back to the four-stage RACH procedure using the information contained in the previously received fallback RAR and sends Msg3. Here, the transmission information such as a grant for Msg3 sent in the fallback RAR of Msg B may indicate subsequent resources considering that the base station was initially allocated multiple Msg A PUSCH opportunities.

[0391] On the other hand, if a terminal receives Msg B from a base station after successfully performing LBT and sending Msg A PUSCH, the terminal's subsequent actions depend on the content of Msg B sent by the base station. Since the terminal has already sent Msg A PUSCH, if Msg B contains a fallback RAR, the terminal can ignore it and expect to receive a success RAR. If a success RAR is not received within the reception window or timer period for Msg B, the terminal can fall back to the 4-stage RACH procedure based on the previously received fallback RAR and send Msg 3. Alternatively, if a success RAR is not received within the reception window or timer period for Msg B, the terminal can perform a resource selection procedure for arbitrary connections after a set backoff time to avoid collisions with duplicated RAPID messages.

[0392] In the embodiments described in this disclosure above, the terminal can recognize the operation after the reception window or timer for the configured Msg B has expired as an operation resulting from the failure to resolve the conflict. In this case, after a pre-configured backoff time, the terminal can again select a two-stage RACH procedure or a four-stage RACH procedure depending on the channel state and perform a resource selection procedure for an arbitrary connection.

[0393] Without limiting itself, the various descriptions, functions, procedures, suggestions, methods and / or operation diagrams of the present invention disclosed herein may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0394] The following will provide more specific examples with reference to the drawings. In the following drawings / descriptions, unless otherwise specified, the same reference numerals in the drawings may represent the same or corresponding hardware block, software block, or functional block.

[0395] Figure 34 illustrates a communication system 1 to which the present invention is applied.

[0396] Referring to Figure 34, the communication system 1 to which the present invention applies includes wireless equipment, a base station, and a network. Here, wireless equipment means equipment that communicates using wireless connectivity technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)), and can be called communication / wireless / 5G equipment. Although not limited thereto, wireless equipment can include robots 100a, vehicles 100b-1, 100b-2, XR (eXtended Reality) equipment 100c, handheld devices 100d, home appliances 100e, IoT (Internet of Things) equipment 100f, and AI equipment / servers 400. For example, vehicles can include vehicles with wireless communication capabilities, autonomous vehicles, and vehicles capable of vehicle-to-vehicle communication. Here, vehicles can include UAVs (Unmanned Aerial Vehicles) (e.g., drones). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and may be embodied in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) installed in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smart pads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, 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 embodied as wireless devices, and specific wireless device 200a may operate as a base station / network node for other wireless devices.

[0397] Wireless devices 100a to 100f may be connected to network 300 via base station 200. Artificial Intelligence (AI) technology may be applied to wireless devices 100a to 100f, and wireless devices 100a to 100f may be connected to AI server 400 via network 300. Network 300 may be configured using a 3G network, 4G (e.g., LTE) network, or 5G (e.g., NR) network. Wireless devices 100a to 100f can communicate with each other via base station 200 / network 300, but they can also communicate directly without going through base station / network (e.g., sidelink communication). For example, vehicles 100b-1 and 100b-2 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Furthermore, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0398] Wireless communication / connection 150a, 150b, and 150c may be performed between wireless devices 100a to 100f and base stations 200, and between base stations 200. Here, wireless communication / connection may be performed by various wireless connectivity technologies such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication), and inter-base station communication 150c (e.g., relay, IAB (Integrated Access Backhaul) (e.g., 5G NR)). Wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals from each other via wireless communication / connection 150a, 150b, 150c. For example, wireless communication / connection 150a, 150b, 150c can transmit / receive signals through various physical channels. To this end, at least some of the following may be performed based on various proposals of the present invention: various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc.

[0399] The embodiments described above are combinations of the components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless otherwise explicitly mentioned. Each component or feature may be implemented in a form that does not combine with other components or features. It is also possible to combine some components and / or features to constitute embodiments of the present invention. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in other embodiments, or replaced with corresponding components or features of other embodiments. It is obvious that claims that do not have an explicit reference relationship in the claims may be combined to constitute embodiments or incorporated into new claims by amendment after filing.

[0400] In this document, certain operations described as being performed by a base station may, in some cases, be performed by its upper node. That is, it is self-evident that various operations performed for communication with a terminal in a network consisting of multiple network nodes, including a base station, may be performed by the base station or other network nodes. The term "base station" may be replaced with terms such as "fixed station," "gNode B (gNB)," "Node B," "eNode B (eNB)," or "access point."

[0401] It will be obvious to those skilled in the art that the present invention can be embodied in other specific forms without departing from the features of the invention. Therefore, the above detailed description should not be constrained in any way as restrictive, but should be considered illustrative. The scope of the invention must be determined by a reasonable interpretation of the appended claims, and any modifications within the equivalent scope of the invention are included within the scope of the invention. [Industrial applicability]

[0402] The method and apparatus for receiving downlink signals in the unlicensed band based on an arbitrary connection process, as described above, were primarily explained in the context of a 5-household NR (NewRAT) system, but they are applicable to various other wireless communication systems as well.

Claims

1. The stage in which the terminal sends message A to the network, The terminal includes the step of receiving a RAR (Random Access Response) in message B from the network during the window, Based on the fact that the PRACH (Physical Random Access Channel) preamble maps to a valid PUSCH (Physical Uplink Shared Channel) opportunity, i) In response to the transmission of PRACH only without PUSCH in message A, and, ii) In response to the transmission of PRACH and PUSCH in message A, A method wherein the window for detecting the message B begins at least one symbol after the last symbol of the PUSCH opportunity corresponding to the transmission of the PRACH.

2. The method according to claim 1, wherein, based on the fact that message B includes a fallback RAR, the fallback RAR includes UL (uplink) grant information.

3. The UL grant information is processed, and a PUSCH transmission is performed. The method according to claim 2, wherein once the PUSCH is transmitted, information related to conflict resolution is received.

4. The method according to claim 1, wherein the window starts with the first symbol of the resource associated with the reception of message B.

5. At least one processor, The system comprises at least one memory that is operably connected to the at least one processor and stores instructions that operate based on being executed by the at least one processor, The aforementioned operation is, Sending message A and This includes receiving a RAR (Random Access Response) in message B during the window, Based on the fact that the PRACH (Physical Random Access Channel) preamble maps to a valid PUSCH (Physical Uplink Shared Channel) opportunity, i) In response to the transmission of PRACH only without PUSCH in message A, and, ii) In response to the transmission of PRACH and PUSCH in message A, The window for detecting message B begins at least one symbol after the last symbol of the PUSCH opportunity corresponding to the transmission of PRACH, in the device.

6. The device according to claim 5, wherein, based on the fact that message B includes a fallback RAR, the fallback RAR includes UL (uplink) grant information.

7. The UL grant information is processed, and a PUSCH transmission is performed. The device according to claim 6, wherein once the PUSCH is transmitted, information related to conflict resolution is received.

8. The apparatus according to claim 5, wherein the window starts with the first symbol of the resource associated with the reception of message B.

9. At least one transceiver and a receiver, At least one processor, The system comprises at least one memory that is operably connected to the at least one processor and stores instructions that operate based on being executed by the at least one processor, The aforementioned operation is, Sending message A and This includes receiving a RAR (Random Access Response) in message B during the window, Based on the fact that the PRACH (Physical Random Access Channel) preamble maps to a valid PUSCH (Physical Uplink Shared Channel) opportunity, i) In response to the transmission of PRACH only without PUSCH in message A, and, ii) In response to the transmission of PRACH and PUSCH in message A, The window for detecting message B begins at least one symbol after the last symbol of the PUSCH opportunity corresponding to the transmission of PRACH at the terminal.

10. The terminal according to claim 9, wherein, based on the fact that message B includes a fallback RAR, the fallback RAR includes UL (uplink) grant information.

11. The UL grant information is processed, and a PUSCH transmission is performed. The terminal according to claim 10, wherein once the PUSCH is transmitted, information related to conflict resolution is received.

12. The terminal according to claim 9, wherein the window starts with the first symbol of the resource associated with receiving message B.

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