Method and device for communicating in wireless communication system

Abstract

A method and a device for communicating in a wireless communication system are disclosed. The method according to one embodiment of the present disclosure may comprise steps in which a device: transmits a device-to-reader (D2R) preamble to a reader device; and repeatedly transmits, to the reader, a physical device-to-reader channel (PDRCH) subsequent to the D2R preamble.

Description

Communication method and device in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a communication method and device in a wireless communication system.

[0002] The fifth generation (5G) wireless communication system, the successor to 4G LTE (long-term evolution), is a new, clean-slate mobile communication system characterized by high performance, low latency, and high availability. 5G NR (New Radio) can utilize all available spectrum resources, from low-frequency bands below 1 GHz, to intermediate-frequency bands between 1 GHz and 10 GHz, and to high-frequency (or millimeter wave) bands above 24 GHz. 6G wireless communication systems are being developed based on the underlying technologies of 5G wireless communication.

[0003] The 6G wireless communication system is being developed with the goals of (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) reduced energy consumption of battery-free Internet of Things (IoT) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity. Considering the requirements of the 6G system, such as a peak data rate of 1 Tbps per device, an end-to-end latency of 1 ms, a maximum spectrum efficiency of 100 bps / Hz, support for mobility of 1000 km / h, satellite integration, artificial intelligence (AI), autonomous vehicles, extended reality (XR), and haptic communication, various technologies are being researched.

[0004] The technical problem of the present disclosure is to provide a communication method and device in a wireless communication system supporting the ambient internet of things (A-IoT).

[0005] In addition, an additional technical problem of the present disclosure is to provide a method and device for transmitting and receiving repetitive transmissions between a leader and an A-IoT device.

[0006] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0007] A method according to an aspect of the present disclosure may include: transmitting, by a device, a device-to-reader (D2R) preamble to a reader device; and repeatedly transmitting, by the device, a physical device-to-reader channel (PDRCH) to the reader following the D2R preamble. Based on the repeated transmission of the PDRCH, the length of a D2R midamble transmitted within the PDRCH may be determined.

[0008] A method according to an additional aspect of the present disclosure may include: receiving, by a reader, a device-to-reader (D2R) preamble from a device; and repeatedly receiving, by the reader, a physical device-to-reader channel (PDRCH) from the device following the D2R preamble. Based on the repeated transmission of the PDRCH, the length of a D2R midamble transmitted within the PDRCH may be determined.

[0009] According to an embodiment of the present disclosure, stable communication can be achieved between a leader and an A-IoT device by having a receiver perform repeated transmissions from a transmitter.

[0010] Additionally, according to an embodiment of the present disclosure, in communication between a leader and an A-IoT device, accurate time synchronization can be supported / obtained and overhead can be reduced by adding a long or short midamble when the receiver performs repeated transmission from the transmitter.

[0011] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0012] The accompanying drawings, which are incorporated in and are part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

[0013] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0014] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0015] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0016] FIG. 4 exemplarily illustrates a communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0017] FIG. 5 exemplarily illustrates a functional framework for AI / ML operations to which some examples of the present disclosure may be applied.

[0018] FIG. 6 illustrates an example of a communication procedure based on an AI / ML model between a first node and a second node to which some examples of the present disclosure may be applied.

[0019] FIG. 7 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0020] FIG. 8 exemplarily illustrates a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0021] FIG. 9 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.

[0022] Figure 10 illustrates examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0023] Figure 11 illustrates examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0024] FIG. 12 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0025] FIG. 13 illustrates four topologies for ambient IoT in a wireless communication system to which the present disclosure can be applied.

[0026] Figure 14 is a flowchart illustrating a procedure for an ambient IoT device to access a reader device.

[0027] FIG. 15 illustrates cases of topology 1 for ambient IoT to which some examples of the present disclosure may be applied.

[0028] FIG. 16 illustrates cases of topology 2 for ambient IoT to which some examples of the present disclosure may be applied.

[0029] FIG. 17 illustrates a PRDCH generation method and a PDRCH generation method to which some examples of the present disclosure can be applied.

[0030] FIG. 18 illustrates a control information and PRDCH / PDRCH transmission structure to which some examples of the present disclosure may be applied.

[0031] FIG. 19 illustrates preamble / postamble and PRDCH / PDRCH transmissions to which some examples of the present disclosure may be applied.

[0032] FIG. 20 illustrates a MAC payload structure in a PRDCH / PDRCH to which some examples of the present disclosure may be applied.

[0033] FIG. 21 illustrates repeated transmission of a PDRCH according to one embodiment of the present disclosure.

[0034] FIG. 22 illustrates a communication method according to one embodiment of the present disclosure.

[0035] FIG. 23 illustrates a communication method according to one embodiment of the present disclosure.

[0036] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0037] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0038] In the present disclosure, when a component is said to be "connected," "coupled," or "connected" to another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0039] In this disclosure, terms such as "first," "second," etc. are used only to distinguish one component from another, are not used to limit the components, and do not limit the order or importance of components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0040] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0041] In this disclosure, "A or B" can mean "only A," "only B," or "both A and B." In other words, "A or B" in this disclosure can be interpreted as "A and / or B." For example, "A, B or C" in this disclosure can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0042] As used herein, a slash ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."

[0043] In the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0044] Additionally, in the present disclosure, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0045] Additionally, parentheses used in the present disclosure may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be described as an example of "control information." In other words, "control information" in the present disclosure is not limited to "PDCCH," and "PDCCH" may be described as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be described as an example of "control information."

[0046] In the following explanation, 'when, if, in case of' can be replaced with 'based on'.

[0047] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.

[0048] In the present disclosure, a terminal or user equipment (UE) may be a portable device and may be a first node that receives a signal from a base station / second node / IAB (integrated access backhaul) node.

[0049] In the present disclosure, a base station (BS) may be a second node / IAB node / Transmission-Reception Point (TRP).

[0050] In the present disclosure, higher layer parameters may be parameters configured, pre-configured, or pre-defined for the terminal. For example, a base station or a network may transmit higher layer parameters to the terminal. For example, the higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0051] In the present disclosure, "setting or defining" may be interpreted as being set to a device through predefined signaling (e.g., SIB (system information block), MAC, RRC) from a base station or network. In the present disclosure, "setting or defining" may be interpreted as being set to a device through separate signaling or being defined in advance without separate signaling.

[0052] In the present disclosure, transmitting or receiving a channel means transmitting or receiving information or a signal through the channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through the data channel.

[0053] The technology described in the present disclosure can be used in various wireless communication systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA), LTE (long term evolution), and 5G NR.

[0054] The technology described in the present disclosure can be implemented with 6G wireless technology and applied to various 6G systems. For example, the 6G system can have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), massive machine-type communication (mMTC), artificial intelligence (AI) integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security.

[0055] Network structure

[0056] Figure 1 illustrates a flexible network topology to which some examples of the present disclosure may be applied.

[0057] To compensate for incomplete network coverage areas, a network topology that allows for more flexible and resilient split radio access networks (RANs) may be considered. For this purpose, various nodes, such as integrated access backhaul (IAB) nodes, relays, and radio frequency (RF) repeaters, as illustrated in Figure 1, may be applied, or a non-terrestrial network (NTN) may be integrated. For example, an IAB node may correspond to a node that provides wireless backhaul. For example, a relay may refer to any intermediate point, and in the case of a sidelink relay where a terminal functions as a relay, it may collectively refer to a terminal-to-network (U2N) relay and a terminal-to-terminal (U2U) relay. For example, an RF repeater may correspond to a node that simply performs the function of signal amplification and forwarding, or in the case of a network-controlled repeater, it may not only amplify and forward signals but also adjust its transmission and reception settings based on information provided by the network. For example, NTN nodes could be satellites or aircraft that provide NTN coverage that terrestrial networks struggle to provide. Beyond these examples, various intermediate points can be introduced to improve the network topology.

[0058] Referring to Figure 1, a split RAN can support the division of a base station into a centralized unit (CU) and one or more distributed units (DUs). The CU and DU can correspond to logical units. The CU can be further divided into a control plane (CP) portion and one or more user plane (UP) portions. Since a failure in the CU-CP affects not only the CU-UP but also the DUs, various intermediate points can be introduced to compensate for this.

[0059] An intermediate point may correspond to a terminal or a base station, depending on its relationship to other nodes. For example, an IAB node may include a mobile-termination (MT) portion and a unit (DU). The MT may connect the IAB node to a donor node. The unit (DU) of an IAB node may serve other terminals or connect to other IAB nodes to provide multi-hop wireless backhaul to the terminal. For example, an IAB node may correspond to a base station in its relationship to a user-side node, and to a terminal in its relationship to a network-side node.

[0060] In some examples of the present disclosure, the description of a terminal may equally apply not only to a user-side endpoint, but also to an intermediate point corresponding to a terminal in a relative relationship with a network-side endpoint. Similarly, in some examples of the present disclosure, the description of a base station may equally apply not only to a network-side endpoint, but also to an intermediate point corresponding to a base station in a relative relationship with a user-side endpoint. In most cases where there is no additional description of the operations of three or more entities, the communicating entities in the present disclosure are briefly described as terminals and / or base stations (or first nodes and / or second nodes), where the terms terminal and / or base stations (or first nodes and / or second nodes) are interpreted to include / replace any endpoint or any intermediate point in relation to other nodes.

[0061] As such, in some examples of the present disclosure, for the sake of simplicity of explanation, the subjects of the operation may be referred to as terminals and / or base stations (or first nodes and / or second nodes). In addition, the terms terminal and / or base station (or first node and / or second node) may also be interpreted / replaced as in the following examples: For example, the terminal (or first node) and the base station (or second node) may respectively correspond to the first endpoint and the second endpoint; may respectively correspond to the endpoint and the intermediate point; may respectively correspond to the intermediate point and the endpoint; or may respectively correspond to the first intermediate point and the second intermediate point.

[0062] In the present disclosure, there may be zero or more intermediate points between the base station and the terminal. If an intermediate point exists, it may correspond to an IAB node / relay / RF repeater / NTN node, or a node supporting other functions. The intermediate point may be a node with a fixed location or a node with an unfixed location.

[0063] Systems applicable to this disclosure

[0064] FIG. 2 illustrates an example of a communication system to which some examples of the present disclosure may be applied.

[0065] The communication system (100) applied to the present disclosure includes a wireless device (110), a network device (120), and a network (130). Here, the wireless device (110) refers to a device that performs communication using a wireless access technology (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G) and may be referred to as a communication / wireless / 5G / 6G device. Although not limited thereto, the wireless device (110) may include a robot (110a), a vehicle (110b-1, 110b-2), an XR (extended reality) device (110c), a hand-held device (110d), a home appliance (110e), an IoT (Internet of Things) device (110f), and an AI (artificial intelligence) device / server (110g). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle (110b-1, 110b-2) may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device (110c) includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device, and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. The portable device (110d) may include a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), a computer (e.g., a laptop, etc.), etc. The home appliance (110e) may include a TV, a refrigerator, a washing machine, etc. The IoT device (110f) may include a sensor, a smart meter, etc. The wireless device (110) may correspond to a terminal (or first node) or an intermediate point.The network device (120) may correspond to a base station (or second node) or another intermediate point. For example, the network device (120) may also be implemented as a wireless device (110), and a specific wireless device (120a) may act as a network device (120) to another wireless device (110).

[0066] Wireless devices (110a to 110f) can be connected to a network (130) via a network device (120). AI technology can be applied to the wireless devices (110a to 110f), and the wireless devices (110a to 110f) can be connected to an AI server (110g) via a network (130). The network (130) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR), or a 6G network. The wireless devices (110a to 110f) can communicate with each other via the network device (120) / network (130), but can also communicate directly (e.g., sidelink communication) without going through the network device (120) / network (130). For example, vehicles (110b-1, 110b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Additionally, an IoT device (110f) (e.g., a sensor) can communicate directly with another IoT device (e.g., a sensor) or another wireless device (110a to 110f).

[0067] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (110a to 110f) / network devices (120), network devices (120) / network devices (120). Here, the wireless communication / connection can be established through various wireless access technologies such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between network devices (150c) (e.g., relay, IAB (integrated access backhaul)). Through the wireless communication / connection (150a, 150b, 150c), the wireless device and the network device / wireless device, and the network device and the network device can transmit / receive wireless signals to each other. For example, the wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various descriptions of the present disclosure, at least some of 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., may be performed.

[0068] Device applicable to the present disclosure

[0069] FIG. 3 illustrates an example of a wireless device to which some examples of the present disclosure may be applied.

[0070] Referring to FIG. 3, the wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G). The wireless device (200) includes at least one processor (202) and at least one memory (204), and may additionally include at least one transceiver (206) and / or at least one antenna (208).

[0071] The processor (202) controls the memory (204) and / or the transceiver (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (206). In addition, the processor (202) may receive a wireless signal including second information / signal via the transceiver (206), and then store information obtained from signal processing of the second information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including instructions for performing some or all of the processes controlled by the processor (202), or for performing the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology. The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via at least one antenna (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF (radio frequency) unit. In the present disclosure, a wireless device may also mean a communication modem / circuit / chip.

[0072] Hereinafter, the hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., a functional layer such as physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), radio resource control (RRC), and service data adaptation protocol (SDAP)). At least one processor (202) may generate at least one Protocol Data Unit (PDU) and / or at least one Service Data Unit (SDU) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) may generate a message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. At least one processor (202) can generate a signal (e.g., a baseband signal) comprising a PDU, an SDU, a message, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in this document, and provide the signal to at least one transceiver (206). At least one processor (202) can receive a signal (e.g., a baseband signal) from at least one transceiver (206) and obtain the PDU, SDU, message, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document.

[0073] At least one processor (202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The at least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in the at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document may be included in the at least one processor (202), or may be stored in at least one memory (204) and driven by the at least one processor (202). The descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0074] At least one memory (204) can be connected to at least one processor (202) and can store various forms of data, signals, messages, information, programs, codes, instructions and / or commands. The at least one memory (204) can be configured as a read only memory (ROM), a random access memory (RAM), an erasable programmable read only memory (EPROM), a flash memory, a hard drive, a register, a cache memory, a computer readable storage medium and / or a combination thereof. The at least one memory (204) can be located internally and / or externally to the at least one processor (202). In addition, the at least one memory (204) can be connected to the at least one processor (202) via various technologies such as a wired or wireless connection.

[0075] At least one transceiver (206) can transmit user data, control information, wireless signals / channels, etc., mentioned in the methods and / or flowcharts of this document to at least one other device. At least one transceiver (206) can receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed in this document from at least one other device. For example, at least one transceiver (206) can be connected to at least one processor (202) and can transmit and receive wireless signals. For example, at least one processor (202) can control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Furthermore, at least one processor (202) can control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. Additionally, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document via at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using at least one processor (202).At least one transceiver (206) may convert user data, control information, wireless signals / channels, etc. processed by at least one processor (202) from a baseband signal to an RF band signal. For this purpose, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0076] The components of the wireless device described with reference to FIG. 3 may be referred to by different terms in terms of functionality. For example, the processor (202) may be referred to as a control unit, the transceiver (206) as a communication unit, and the memory (204) as a storage unit. In some cases, the communication unit may be used to mean at least a portion of the processor (202) and the transceiver (206).

[0077] The structure of the wireless device described with reference to FIG. 3 can be understood as the structure of at least a portion of various devices. For example, the structure of the wireless device illustrated in FIG. 3 can be at least a portion of various devices described with reference to FIG. 2 (e.g., a robot (110a), a vehicle (110b-1, 110b-2), an XR device (110c), a portable device (110d), a home appliance (110e), an IoT device (110f), an AI device / server (110g)). Furthermore, according to various embodiments, in addition to the components illustrated in FIG. 3, the device may further include other components.

[0078] For example, the device may be a portable device such as a smartphone, a smart pad, a wearable device (e.g., a smart watch, smart glasses), or a portable computer (e.g., a laptop, etc.). In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an interface unit that includes at least one port for connection with another device (e.g., an audio input / output port, a video input / output port), and an input / output unit for inputting and outputting image information / signals, audio information / signals, data, and / or information input from a user.

[0079] For example, the device may be a mobile device such as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc. In this case, the device may further include at least one of a driving unit including at least one of an engine, a motor, a power train, wheels, brakes, and a steering unit of the device, a power supply unit including a wired / wireless charging circuit, a battery, etc. that supplies power, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, an autonomous driving unit that performs functions such as path maintenance, speed control, and destination setting, and a position measurement unit that obtains location information of the mobile device through a global positioning system (GPS) and various sensors.

[0080] For example, the device may be an XR device such as an HMD, a head-up display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a robot, etc. In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an input / output unit that obtains control information, data, etc. from the outside and outputs the generated XR object, and a sensor unit that senses status information, environmental information, and user information of the device or the surroundings of the device.

[0081] For example, the device may be a robot that can be classified into industrial, medical, household, military, etc. types depending on the purpose or field of use. In this case, the device may further include at least one of a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a driving unit that performs various physical actions, such as moving the robot joints.

[0082] For example, the device may be an AI device such as a TV, a projector, a smartphone, a PC, a laptop, a digital broadcasting terminal, a tablet PC, a wearable device, a set-top box (STB), a radio, a washing machine, a refrigerator, digital signage, a robot, a vehicle, etc. In this case, the device may further include at least one of an input unit that acquires various types of data from the outside, an output unit that generates output related to sight, hearing, or touch, a sensor unit that senses status information, environmental information, and user information of the device or its surroundings, and a training unit that trains a model composed of an artificial neural network using learning data.

[0083] The structure of the wireless device illustrated in FIG. 3 may be understood as a part of a terminal (or first node), or as a part of an intermediate point, or as a part of a base station (or second node). If the device illustrated in FIG. 3 is a base station (or second node), the device may further include a wired transceiver for front haul and / or back haul communications. If the front haul and / or back haul communications are based on wireless communications, at least one transceiver (206) illustrated in FIG. 3 may be used for front haul and / or back haul communications, and a wired transceiver may not be included.

[0084] Communication procedures

[0085] FIG. 4 exemplarily illustrates a communication procedure between a first node and a second node to which some examples of the present disclosure may be applied.

[0086] FIG. 4 illustrates operations of a first node (110) (e.g., a terminal) and a second node (120) (e.g., a base station) transmitting and / or receiving data and operations performed prior thereto.

[0087] In step S101, the first node (110) and the second node (120) can perform synchronization. For example, the terminal (110) performs an initial cell search operation. Specifically, the terminal (110) can detect at least one synchronization signal transmitted from the base station (120) according to a predefined rule. Here, the synchronization signal can include a plurality of synchronization signals (e.g., a primary synchronization signal, a secondary synchronization signal) classified according to a structure or purpose. Through this, the terminal (110) can confirm the boundaries of the frame, subframe, slot, and / or symbol of the base station (120) and obtain information (e.g., a cell identifier) ​​about the base station (120).

[0088] In step S103, the first node (110) can obtain system information transmitted from the second node (120). For example, the system information is information related to the properties, characteristics, and / or capabilities of the base station (120) required to access the base station (120) and use the service, and can be classified according to the content (e.g., whether it is essential for access), transmission structure (e.g., channel used, whether it is provided in an on-demand manner), etc., and can be classified into, for example, a master information block (MIB) and a system information block (SIB). If necessary, the terminal (110) can transmit a signal requesting system information before receiving the system information. Such requesting and providing of system information may be performed after a random access procedure described below.

[0089] In step S105, the first node (110) and the second node (120) can perform a random access procedure. For example, the terminal (110) can transmit and / or receive at least one message (e.g., a random access preamble, a random access response (RAR) message, etc.) for a random access procedure based on information related to a random access channel of the base station (120) obtained through system information (e.g., channel position, channel structure, structure of a supported preamble, etc.). For example, the terminal (110) may transmit a preamble (e.g., message 1 (MSG1)) over a random access channel, receive a random access response (RAR) message (e.g., message 2 (MSG2)), transmit a message (e.g., message 3 (MSG3)) including information related to the terminal (110) (e.g., identification information) using scheduling information included in the RAR message to the base station (120), and receive a message for contention resolution and / or connection establishment (e.g., message 4 (MSG4)). As another example, MSG1 and MSG3 may be transmitted and received as one message (e.g., message A (MSG A)), or MSG2 and MSG4 may be transmitted and received as one message (e.g., message B (MSG B)).

[0090] In step S107, the first node (110) and the second node (120) can perform signaling of control information. For example, the control information can be defined in various layers, such as a layer that controls a connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transmission channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (110) and the base station (120) can perform at least one of signaling for establishing a connection, signaling for determining settings related to communication, and signaling for indicating allocated resources.

[0091] In step S109, the first node (110) and the second node (120) can transmit and / or receive data. For example, the terminal (110) and the base station (120) can process, transmit, and / or receive data based on signaling of control information. For example, when transmitting data, the terminal (110) or the base station (120) can perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on information bits. For example, when receiving data, the terminal (110) or the base station (120) can perform at least one of signal extraction from resources, waveform demodulation for each antenna, signal arrangement considering layer mapping, constellation demapping, descrambling, and channel decoding.

[0092] 6G system core technologies

[0093] As core implementation technologies of the 6G system, technologies such as artificial intelligence (AI), THz (terahertz) communication, optical wireless technology, free space optics (FSO) backhaul network, massive MIMO (multiple input multiple output) technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) can be adopted.

[0094] artificial intelligence

[0095] Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0096] The following describes a functional framework for AI / ML operations.

[0097] Below, to explain AI (or AI / ML) more specifically, the terms can be defined as follows.

[0098] - Data collection: Data collected from network nodes, management entities, or terminals as a basis for AI model training, data analysis, and inference.

[0099] - AI Model: A data-driven algorithm that applies AI technology to generate a set of outputs containing predictive information and / or decision parameters based on a set of inputs.

[0100] - AI / ML Training: An online or offline process of training an AI model by learning features and patterns that best represent the data and obtain a trained AI / ML model for inference.

[0101] - AI / ML Inference: The process of making predictions or inducing decisions based on collected data and the AI ​​model using a trained AI model.

[0102] Life Cycle Management (LCM) procedures for AI / ML models (i.e., model training, model deployment, model inference, model monitoring, model updates, etc.) can be divided into functionality-based LCM and model-based LCM. In functionality-based LCM, AI / ML models may not be identified by the network, and the network can direct the activation / deactivation / fallback / switching of AI / ML functionality. In model-ID (identifier)-based LCM, AI / ML models can be identified by the network, and the network / terminal can activate / deactivate / select / switch AI / ML models based on the model ID.

[0103] FIG. 5 exemplarily illustrates a functional framework for AI / ML operations to which some examples of the present disclosure may be applied.

[0104] Figure 5 illustrates a general functional architecture relevant to both Functionality-based LCM and Model-based LCM. Some of the functions or some of the data / information / command flows (i.e., arrows) illustrated in Figure 5 may be omitted.

[0105] Referring to FIG. 5, a general functional framework can be configured to include a data collection function (10), a model training function (20), a management function (30), an inference function (40), and a model storage function (50).

[0106] The Data Collection function (10) is a function that provides input data to the Model Training function (20), Management function (30), and Inference function (40). The Data Collection function (10) can perform data preparation based on raw data and provide input data processed through data preparation. Examples of raw data may include received data / measurement data from terminals or other network entities, inference / output of AI / ML models, etc. The Data Collection function (10) may be performed by a single entity (e.g., a terminal, a network node, etc.) or may be performed by multiple entities.

[0107] Here, training data (11) refers to data required as input for the AI / ML Model Training function (20). Monitoring data (12) refers to data required as input for the Management (30) of the AI / ML model or AI / ML function. Inference data (13) refers to data required as input for the AI / ML Inference function (30).

[0108] The Model Training function (20) is a function that performs AI / ML model training, validation, and testing, which can generate model performance metrics that can be used as part of the AI / ML model testing procedure. The Model Training function (20) can perform data preparation (e.g., data pre-processing and cleaning, forming, and transformation) based on the Training Data (11) transferred from the Data Collection function (10), if necessary.

[0109] Trained / Updated Model (21): If there is a Model Storage function (50), it is used to pass a trained, validated and tested AI / ML model to the Model Storage function (50) or to pass an updated version of the model to the Model Storage function (50).

[0110] The Management function (30) is a function that supervises the operation of the AI / ML model or AI / ML function. In addition, the Management function (30) may perform decisions to ensure appropriate inference operations based on data received from the Data Collection function (10) (i.e., Monitoring Data (12)) and / or data received from the Inference function (40) (i.e., Inference Output (41)).

[0111] Management Instruction (32) is information required as input to manage the Inference function (40). The relevant information may include selection / (de)activation / switching of an AI / ML model or AI / ML-based function, and may also include fallback to non-AI / ML operations (i.e., not relying on the inference process).

[0112] A Model Transfer / Delivery Request (33) can be used to request model(s) from Model Storage (50).

[0113] A Performance Feedback / Retraining Request (31) refers to information required as input to the Model Training function (20) (e.g., for the purpose of (re)training or updating the model).

[0114] The Inference function (40) is a function that provides output from the process of applying an AI / ML model or AI / ML function using data (i.e., Inference Data (13)) provided by Data Collection (10) as input. Data preparation (e.g., data preprocessing and cleaning, formatting, and transformation) may also be performed based on the Inference Data (13) delivered by Data Collection (10). If necessary, the Inference function (40) may also perform data preparation (e.g., data preprocessing and cleaning, forming, and transformation) based on the Inference Data (13) provided by Data Collection function (10).

[0115] Inference Output (41) is data used in the Management function (30) to monitor the performance of an AI / ML model or AI / ML function. Inference Output (41) may include the inference output of the AI / ML model generated by the Inference function (30), and the details of the inference output may vary depending on the use case.

[0116] The Model Storage function (50) stores a learned / updated model that can be used to perform the Inference function (40). The Model Storage function (50) illustrated in FIG. 2 can be used as a reference point (if any) when applicable to protocol termination, model transmission / delivery, and related processes. Furthermore, the Model Storage function (50) is merely an example and is not intended to limit the storage location of actual AI / ML models, and may be omitted.

[0117] Model Transfer / Delivery (51) is used to transfer AI / ML models to inference functions.

[0118] The level of cooperation can be defined as follows depending on the capability of AI / ML functions between multiple nodes, and variations due to combination of multiple levels or separation of any one level are also possible.

[0119] Cat 0a) No collaboration framework: AI / ML algorithms are purely implementation-based and do not require any changes to the wireless interface.

[0120] Cat 0b) This level corresponds to a framework with a modified wireless interface tailored to efficient implementation-based AI / ML algorithms, but without collaboration.

[0121] Category 1) involves inter-node support to improve the AI / ML algorithms of each node. For example, this applies when a specific node receives support from another node (for training, adaptation, etc.) and vice versa. At this level, model exchange between network nodes is not required.

[0122] Category 2) Joint AI / ML tasks can be performed across multiple nodes. This level requires the exchange of AI / ML model commands or network nodes.

[0123] FIG. 5 is a diagram illustrating an overall functional framework for an AI / ML model, and not all functions and / or all data / information / command signals illustrated in FIG. 5 may be performed within a specific node, but only some of them may be performed.

[0124] AI / ML models can be divided into one-side models and two-side models depending on whether training and / or inference are performed on a single node or jointly / sequentially on multiple nodes.

[0125] A one-side model can refer to an AI / ML model in which inference is performed entirely by a single node (e.g., a terminal or network). Here, AI / ML model training can also be performed entirely by a single node. AI / ML model training and inference can be performed by the same node, or they can be performed by separate nodes.

[0126] A two-side model can refer to an AI / ML model in which joint inference is performed across multiple nodes (e.g., terminals and networks). Joint inference refers to inference being performed jointly across multiple nodes. For example, the first part of the inference may be performed by a first node, and the remaining part by a second node. Two-side models can be categorized into several types depending on the training method of the AI / ML model, as follows:

[0127] - First type: AI / ML models can be trained on a single node. In this case, joint training can be performed. The trained model can then be distributed to other nodes / objects.

[0128] - Second type: Joint training of AI / ML models can be performed on multiple nodes / entities (e.g., networks and terminals). Joint training can mean that model generation (e.g., CSI generation part) and model reconstruction (CSI compression by sub-use case) are trained in the same loop for forward activation and backward gradient. In this type, joint training can include both simultaneous training (i.e., model generation training and model reconstruction training are performed simultaneously) and sequential training (i.e., model reconstruction training is performed after model generation training).

[0129] - Third type: Separate training of AI / ML models can be performed on multiple nodes (e.g., networks and terminals). Separate training may mean that training begins sequentially on one node and continues on other nodes. In this case, the first node first performs the AI / ML model and shares the training data with the second node. The second node can then use the shared training data to perform the AI / ML model. For example, training for the CSI generation part may be performed by the terminal, while CSI reconstruction may be performed by the network.

[0130] FIG. 6 illustrates an example of a communication procedure based on an AI / ML model between a first node and a second node to which some examples of the present disclosure may be applied.

[0131] Step 1: In the description of the present disclosure described below, signaling (e.g., information / data / channel / signal, etc.) or a set of signaling between a specific node (e.g., a terminal, a network, etc.) and another node may be interpreted as the signaling or set of signaling of Step 1 used to perform an operation based on an AI / ML model, even if not otherwise mentioned. For example, it may correspond to training data for training (i.e., generation and / or reconstruction) the AI / ML model of FIG. 2, or correspond to inference data used for inference of the AI / ML model, or correspond to feedback for the AI / ML model, etc. If signaling between nodes is not required prior to an operation based on an AI / ML model in the present disclosure, Step 1 may be omitted. If a one-side model is used in the present disclosure, the unidirectional / bidirectional signaling (set) in the present disclosure may correspond to the signaling of Step 1. In addition, when a two-side model is used in the present disclosure, the one-way / two-way signaling in the present disclosure may correspond to one-stage signaling, and also, a repetitive signaling operation may correspond to one-stage signaling.

[0132] For example, in AI / ML model-based beam management (BM), if a base station predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the base station can receive quality / intensity information for multiple beams from a terminal. Furthermore, if a terminal predicts (i.e., infers) beam(s) with good quality based on an AI / ML model, the terminal can receive multiple beams from the base station.

[0133] Step 2: In the description of the present disclosure described below, an operation (e.g., calculation, selection, prediction, etc.) in a specific node (e.g., terminal, network, etc.) or a joint operation (e.g., calculation, selection, prediction, etc.) in multiple nodes (e.g., terminal, network, etc.) may correspond to a step 2 operation based on one or more functions in the functional framework of the AI / ML model, even if not mentioned separately. For example, it may correspond to training (i.e., generation and / or reconstruction) of the AI / ML model in FIG. 2, or it may correspond to inference of the AI / ML model, etc. When a one-side model is used, an operation performed by a single node in the present disclosure may correspond to a step 2 operation, and also, when a two-side model is used, a joint operation performed by multiple nodes in the present disclosure may correspond to a step 2 operation.

[0134] For example, in an AI / ML model-based BM, the base station can use quality / intensity information for multiple beams received from the terminal as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model. Furthermore, the terminal can measure multiple beams received from the base station and use the measurement results as inference data to predict (i.e., infer) beam(s) with good quality based on the AI / ML model.

[0135] Step 3: In the description of the present disclosure described below, the signaling (e.g., information / data / channel / signal, etc.) or set of signaling between a specific node (e.g., terminal, network, etc.) and another node may be interpreted as a three-step signaling or set of signaling generated due to (as a result of) an operation based on an AI / ML model, even if not otherwise mentioned. For example, it may correspond to an output resulting from inference of the AI / ML model in FIG. 2. If signaling between nodes is not required as a result of an operation based on an AI / ML model in the present disclosure, Step 3 may be omitted. If a one-side model is used in the present disclosure, the one-way / two-way signaling (set) in the present disclosure may correspond to the three-step signaling. In addition, if a two-side model is used in the present disclosure, the one-way / two-way signaling in the present disclosure may correspond to the three-step signaling, and furthermore, a repetitive signaling operation may correspond to the three-step signaling.

[0136] For example, in an AI / ML model-based BM, the base station can transmit to the terminal the beam(s) predicted based on the AI / ML model as candidates so that the terminal can determine the optimal beam. Furthermore, the terminal can report to the base station the beam(s) predicted based on the AI / ML model to request the base station to transmit the candidate beams as candidates for determining the optimal beam.

[0137] THz communication (terahertz communication)

[0138] Data transmission rates can be increased by increasing bandwidth. This can be achieved by utilizing sub-THz communications with wide bandwidths and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz, with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (the sub-THz band) is considered a key part of the THz spectrum for cellular communications. Adding the sub-THz band to the mmWave band will increase 6G cellular capacity. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF.

[0139] FIG. 7 illustrates an electromagnetic spectrum to which some examples of the present disclosure may be applied.

[0140] Key characteristics of THz communications include (i) the widely available bandwidth to support very high data rates, and (ii) the high path loss at high frequencies (which necessitates highly directional antennas). The narrow beamwidths generated by highly directional antennas reduce interference. The small wavelength of THz signals allows for a significantly larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array technologies to overcome range limitations.

[0141] Transmitting system information (e.g., MIB) in a cell in the THz frequency band can be inefficient because the beam width in high-frequency bands narrows, requiring more beam sweeps to cover the entire cell area. This method is particularly inefficient when there are only a few users within the cell.

[0142] FIG. 8 exemplarily illustrates a system information transmission / reception procedure to which some examples of the present disclosure may be applied.

[0143] The example of Fig. 8 is applicable not only to THz communication environments but also to 6G communication environments where THz communication is not applicable. Furthermore, the procedure illustrated in Fig. 8 can be combined with various embodiments of the present disclosure described below. For example, the embodiments described below can be performed based on system information acquired through the procedure illustrated in Fig. 8.

[0144] In step S810, the second node (120) (e.g., base station) can transmit system information of cell #1 through cell #2. For example, the base station provides at least two cells, cell #1 uses a THz frequency band, and cell #2 uses a frequency band other than the THz frequency band. Here, the system information may include at least one of an SFN (system frame number), a PDCCH configuration for SIB1, cell barring, cell re-selection, and subcarrier spacing generated in a higher layer, and may include at least one of an SFN, a half frame indicator, and an SSB index (synchronization signal / PBCH (physical broadcast channel) block index) generated in a physical layer. For this purpose, as an example, cell #1 and cell #2 may have a relationship of a secondary cell and a primary cell.

[0145] At step S830, the first node (110) (e.g., a terminal) can acquire synchronization for cell #1. Synchronization can be acquired by detecting a synchronization signal. Typically, synchronization is acquired before receiving system information. However, since the system information for cell #1 is received from cell #2, synchronization acquisition for cell #1 can be performed after receiving the system information. For example, the terminal can acquire synchronization based on the system information. Alternatively, synchronization acquisition can be performed before step S1010.

[0146] At step S850, the first node (110) may transmit a signal for accessing cell #1. For example, the signal may include a random access preamble. The structure of this signal and the resources (e.g., channels) for transmitting the signal may be identified through system information. Thereafter, at step S1070, the first node (110) and the second node (120) may perform an access procedure for cell #1 and communicate.

[0147] The procedure described with reference to FIG. 8 may be performed when the first node (110) initially connects to cell #1 of the second node (120). Alternatively, a similar procedure may be performed when the first node (110) performs a handover to cell #1 of the second node (120). However, in the case of a handover, the system information of cell #1 may be received from a cell of a base station other than cell #2 of the second node (120).

[0148] Communications in the THz band are expected to experience extremely severe path loss, and to overcome this, terminals and base stations may be required to use very sharp beams. The use of sharp beams means that terminals and base stations must perform beam control in addition to beamforming, and the number of beams used increases significantly. Consequently, it takes a very long time to align the transmit and receive beams between the base station and terminals. Furthermore, if the beam alignment between the base station and terminals is misaligned due to movement or movement of the terminals, frequent re-alignment is required, which can lead to link instability.

[0149] FIG. 9 illustrates an exemplary beam management procedure to which some examples of the present disclosure may be applied.

[0150] Although FIG. 9 illustrates an example of a procedure for searching and / or selecting beams for THz communication, this procedure is not limited to a THz environment and can also be applied to a 6G communication environment where THz communication is not applied.

[0151] Here, beam may be interpreted as other terms having equivalent technical meanings that can distinguish beams, such as 'spatial domain filter', 'spatial domain transmit filter', 'spatial domain receive filter', reference signal (RS) resource that distinguishes beams, SSB index, etc.

[0152] In step S910, the second node (120) (e.g., a base station) can set resources for beam management to the first node (110) (e.g., a terminal). Here, the resources may include at least one of time-frequency resources, channels, and spatial resources (e.g., antenna ports). For example, the base station may utilize a beam search signal (BSS) that is transmitted spatially separated from an existing downlink signal / channel for beam search. Here, the BSS may be transmitted based on a dedicated port for beam search. The dedicated port may be a different port from a port for transmitting an existing downlink signal / channel (e.g., SSB, PDSCH (physical downlink shared channel), etc.). BSS is a term defined for convenience of explanation, and the technical concept according to the present embodiment is not limited to the term BSS itself. For example, a signal transmitted based on a dedicated port defined / set for beam search may be included in the technical concept according to the present embodiment.

[0153] In step S930, the second node (120) (e.g., a base station) transmits measurement signals using a plurality of transmission beams. For example, the measurement signals may include at least one of a reference signal and a synchronization signal. At this time, the measurement signals may be transmitted as many times as the number of beams that require measurement, and may also be transmitted in a multi-beam transmission method that forms a plurality of beams simultaneously to reduce sweeping time. Here, the multi-beam transmission may be performed based on at least one of a multi-panel, a sub-array, and a true time delay (TTD).

[0154] At step S950, a first node (110) (e.g., a terminal) may transmit a feedback signal to a second node (120) (e.g., a base station). The feedback signal may indicate at least one beam selected by the terminal. The terminal may select at least one preferred beam based on the measurement signals received at step S1030.

[0155] In step S970, the first node (110) and the second node (120) can perform communication. For example, the second node (120) can perform transmission to the first node (110) using the reception beam of the first node (110) selected in step S1050. If channel reciprocity is established, the transmission beam of the first node (110) can also be determined through steps S1030 and S1050, so that the transmission operation from the first node (110) can also be performed using a beam that has a reciprocal relationship with the beam selected in step S1050. If channel reciprocity is not established, a procedure including transmission of measurement signal(s) by the first node (110) and transmission of feedback signal(s) by the second node (120) may be performed first to determine the transmission beam of the first node (110).

[0156] non-terrestrial networks (NTN)

[0157] Figures 10 and 11 illustrate examples of NTN scenarios to which some examples of the present disclosure may be applied.

[0158] NTN can represent a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform).

[0159] Figure 10 shows an example of a typical scenario of an NTN based on a transparent payload, and Figure 11 shows an example of a typical scenario of an NTN based on a regenerative payload.

[0160] Referring to Figure 10, a satellite (or UAS platform) can establish a service link with a terminal. The satellite (or UAS platform) can be connected to a gateway via a feeder link. The satellite can be connected to a data network via the gateway. The beam footprint can refer to the area where the signal transmitted by the satellite can be received.

[0161] Referring to Figure 11, a satellite (or UAS platform) can establish a service link with a terminal. A satellite (or UAS platform) connected to a terminal can be connected to another satellite (or UAS platform) via an inter-satellite link (ISL). The other satellite (or UAS platform) can be connected to a gateway via a feeder link. Based on the regenerated payload, the satellite can be connected to a data network through another satellite and the gateway. If an ISL does not exist between the satellite and another satellite, a feeder link between the satellite and the gateway may be required.

[0162] Figures 10 and 11 are only examples of NTN scenarios, and NTN can be implemented based on various scenarios. For example, a satellite (or UAS platform) can implement a transparent or regenerative (e.g., with onboard processing) payload. For example, a satellite (or UAS platform) can generate multiple beams across a designated service area depending on the field of view of the satellite (or UAS platform). For example, the field of view of the satellite (or UAS platform) can vary depending on the onboard antenna diagram and the minimum elevation angle.

[0163] For example, a transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may remain unchanged.

[0164] For example, a regenerative payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, a regenerative payload may be substantially equivalent to mounting all or part of a base station function on a satellite (or UAS platform).

[0165] Integrated Sensing and Communication (ISAC)

[0166] Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (or range) of an object, and thus obtain information about the characteristics of the environment and / or objects within the environment. Because radio frequency sensing does not require a networked device to connect to the object, it can provide a service for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., drones, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of wireless sensing services, such as sensing operations, may depend on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing offers an opportunity to enhance existing communication systems from a communications network to a wireless communication and sensing network.

[0167] FIG. 12 illustrates examples of sensing operations to which some examples of the present disclosure may be applied.

[0168] Specifically, Fig. 12(a) shows an example of a monostatic sensing operation using a sensing receiver and a sensing transmitter located in the same location. Fig. 12(b) shows an example of a bistatic sensing operation using a sensing receiver and a sensing transmitter located in separate locations. A sensing signal transmitted from a sensing transmitter is reflected / scattered by a sensing object, and the sensing receiver can receive the signal, and extract / obtain sensing data based on the received signal. A sensing result can be generated / determined through appropriate processing of the sensing data. The sensing result can be provided to a trusted third-party entity / service outside the 3GPP system via an entity / service within the 3GPP system.

[0169] A method for transmitting and receiving signals in a wireless communication system supporting the Ambient Internet of Things (A-IoT).

[0170] 3GPP IoT can be applied to indoor / outdoor environments, base station characteristics (e.g., macro / micro / pico cell-based deployments), connection topology (e.g., nodes that can communicate with target devices such as base stations, terminals, relay terminals, repeaters, etc.), TDD / FDD and licensed / unlicensed spectrum frequency bands, coexistence of terminals and infrastructure in frequency bands of 3GPP technologies, and assumption of device-initiated / terminated traffic.

[0171] In one embodiment of the present disclosure, three types of IoT devices may be utilized.

[0172] - Device A: A device that does not store energy and does not generate independent signals (i.e., backscattering transmission).

[0173] - Device B: A device that stores energy and does not generate an independent signal (i.e., backscattering transmission), and use of the stored energy may include amplification of the reflected signal.

[0174] - Device C: A device that stores energy and generates an independent signal (i.e., includes an active RF component for transmission).

[0175] The present disclosure relates to a signal transmission and reception method of devices A and B that perform communication through backscattering transmission among three types of devices. However, this is only one embodiment, and various embodiments of the present disclosure can also be applied to device C.

[0176] Additionally, at least one of the following four topologies may be applied as an example of the present disclosure.

[0177] FIG. 13 illustrates four topologies for ambient IoT in a wireless communication system to which the present disclosure can be applied.

[0178] - Topology (1): BS <-> Ambient IoT Device

[0179] - Topology (2): BS <-> intermediate node <-> ambient IoT device

[0180] - Topology (3): BS <-> Assisting node <-> Ambient IoT device <-> BS

[0181] - Topology (4): UE <-> Ambient IoT Device

[0182] Here, the BS may be included in or replaced by the gNB, and may be a distribution unit (gNB-DU) of the gNB. Furthermore, the ambient IoT device may be replaced by a UE, a remote UE, a device, or a tag. An intermediate node (IN) may be at least one of a relay node, an integrated access backhaul (IAB) node, a relay UE, or a repeater of the network. In the present disclosure, the gNB and the IN may be collectively referred to as a reader.

[0183] For example, for topology (1), the possibility of BS Rx and BS Tx may be included in different BSs. For topologies (2) and (3), the intermediate nodes and auxiliary nodes may be relay terminals, IAB nodes, repeaters, etc. that enable ambient IoT.

[0184] The present disclosure describes a method for transmitting and receiving signals in topologies 1 and 2, in which direct communication (i.e., mono-static communication) is performed between a base station (or / and intermediate node) and an IoT device among four topologies. However, this is only one embodiment, and the present disclosure may also be applied to topologies 3 and / or 4.

[0185] Hereinafter, in the description of the present disclosure, the direction from base station to device in topology 1 is referred to as DL or R2D (reader-to-device) or R2T (reader-to-tag), and the direction from device to base station is referred to as UL or D2R (device-to-reader) or T2R (tag-to-reader). The base station transmits an R2D (or R2T) message or data / information to the device through R2D (or R2T) signaling, and the device transmits a D2R (or T2R) message or data / information to the base station through D2R (or T2R) signaling.

[0186] In addition, in the following description of the present disclosure, in topology 2, the direction from intermediate node (IN) to device is referred to as DL or R2D (reader-to-device) or R2T (reader-to-tag), and the direction from device to IN is referred to as UL or D2R (device-to-reader) or T2R (tag-to-reader). The IN transmits an R2D (or R2T) message or data / information to the device through R2D (or R2T) signaling, and the device transmits a D2R (or T2R) message or data / information to the IN through D2R (or T2R) signaling.

[0187] In addition, in the description of the present disclosure below, transmission of an R2D signal or R2D data / information may include a physical reader-to-device channel (PRDCH), and transmission of a D2R signal or D2R data / information may include a physical device-to-reader channel (PDRCH).

[0188] AmIoT devices may require externally provided CW for backscatter transmission. For example, CW may be used to power AmIoT devices or as CW for downlink transmission, regardless of the transmission mode (e.g., backscatter transmission or internally generated transmission).

[0189] In this regard, CW waveforms can be supported in various types. For example, the CW waveform type can be a single-tone CW waveform or a more complex multi-tone CW waveform type. For example, single-tone CW can be advantageous over multi-tone CW in terms of multiplexing capacity of tags or readers and interference reduction due to its lower resource consumption. In contrast, multi-tone CW has advantages such as being able to transmit more energy when transmitting CW in DL and securing greater coverage from a single device.

[0190] Considering the advantages of these different CW waveform types, multiple CW waveform types can be supported in the AmIoT system, and the base station / IN / AN / UE can configure the CW waveform type. For example, one or more CW waveform types supported in the AmIoT communication system can be configured / defined in advance, and the base station / IN / AN / UE can select one of the one or more supported CW waveform types and transmit it to the AmIoT device. For example, the base station / IN / AN / UE can configure / instruct / indicate the selected CW waveform type to the AmIoT device in the form of a command / message transmitted as a preamble / frame-sync or payload.

[0191] Technical terms used in this disclosure may be as follows.

[0192] - EH: Energy Harvesting

[0193] - EH device: A device that operates based on EH. It can include all device types in AmIoT. In addition, although this disclosure primarily considers RF EH, an EH device does not necessarily have to be RF EH-based.

[0194] - ES: Energizing Signal. A signal / channel transmitted by a base station / IN / AN / UE to supply RF energy to devices operating on RF-based EH. ES can be (modulated) CW, NR / LTE DL / UL signals, etc., and dedicated signals / channels can be designed to support ES.

[0195] - ET: Energy Transfer

[0196] - CW: Carrier wave. AmIoT devices supporting backscattering-based UL transmission transmit information by modulating and backscattering "externally provided" CW. AmIoT devices supporting independent signal generation-based UL transmission transmit information by modulating "internal generated" CW. Unless otherwise specified, "externally provided" CW for backscattering is assumed. CW can be used as an energizing signal (ES) for RF energy transfer.

[0197] - CWN: CW Node. A node that provides CW. It can be a base station / IN / AN / UE, and there may be a separate CWN for CW provisioning purposes.

[0198] - R: Reader / Interrogator. In the AmIoT description, readers can be gNB / eNB, intermediate node (IN) / assisting node (AN), or terminals depending on the topology. Furthermore, AmIoT is not limited to 4G / 5G communication systems, and can include base stations, intermediate / assisting nodes, and terminals of next-generation communication systems. This can also mean an AmIoT leader.

[0199] - T: Tag / AmIoT device. In this disclosure, it can be interchanged with EH device, and in the AmIoT description, it mainly refers to AmIoT device, device type 1 / 2a / 2b.

[0200] - D: AmIoT device (may have the same meaning as T mentioned above)

[0201] - R=>T: Leader-to-tag or leader-to-tag communication link. When the base station or intermediate node / auxiliary node is the leader, it may have the same meaning as DL or forward link.

[0202] - R2D: Reader (R)-to-Device (D) link (can be synonymous with R=>T or AmIoT DL. Can also be written as R=>D.)

[0203] - CW2D: CWN-to-Device (D) link (CW node-to-AmIoT device link)

[0204] - T=>R: Tag-to-reader or tag-to-reader communication link. When the base station or intermediate / auxiliary node is the leader, this may be synonymous with UL or reverse / backward link.

[0205] - D2R: Device (D)-to-Reader (R) link (can be the same meaning as T=>R or AmIoT UL. Can be written as D=>R.)

[0206] - R<=>T: Includes cases where R=>T and T=>R, or R=>T or T=>R. It may be the case that both R=>T and T=>R apply.

[0207] - R<=>D: Includes R2D and D2R, or either R2D or D2R. This may apply to both R2D and D2R. (This may have the same meaning as R<=>T.)

[0208] - RF-EH: RF energy harvesting

[0209] - PRDCH: Physical R2D Channel (may be written as PR2DCH). A physical channel for R2D communications.

[0210] - PDRCH: Physical D2R Channel (may be denoted as PD2RCH). A physical channel for D2R communication.

[0211] - BS: Base Station

[0212] - IN: Intermediate node. In topology 2 (BS <-> IN <-> AmIoT device), IN acts as the leader. Relays, IABs, terminals, repeaters, etc. can be INs.

[0213] - AN: Assisting node. It can assist DL transmission in topology 3-1 (BS -> AN -> AmIoT device -> BS), or assist UL transmission in topology 3-2 (BS -> AmIoT device -> AN -> BS). ANs can be relays, IABs, terminals, repeaters, etc.

[0214] - UE: User Equipment. For LTE, NR, or next-generation communication systems, this refers to the LTE, NR, or next-generation communication system UE / terminal, respectively. It is a general wireless communication terminal type, distinct from AmIoT devices or device types 1 / 2a / 2b. In topology 4 (UE <-> AmIoT device), the UE acts as the leader.

[0215] - Device: Unless otherwise stated, and when used alone, refers to EH devices, AmIoT devices or device types 1 / 2a / 2b indiscriminately.

[0216] In describing the present disclosure, “ / ” means “and”, “or”, or “and / or”, depending on the context.

[0217] The present disclosure proposes a method for transmitting and receiving signals between a tag (e.g., an IoT device or device) and a reader (e.g., a BS, gNB, intermediate node, UE, etc.).

[0218] Figure 14 is a flowchart illustrating a procedure for an ambient IoT device to access a reader device.

[0219] Specifically, the connection procedure may consist of an MSG0 transmission / reception procedure, an MSG1 transmission / reception procedure, an MSG2 transmission / reception procedure, an MSG3 transmission / reception procedure, an MSG4 transmission / reception procedure, and an MSG5 transmission / reception procedure.

[0220] 1) MSG0 transmission and reception procedure

[0221] A leader device can transmit MSG0 (e.g., a query signal and / or PDCCH order) to an ambient IoT device. Here, one or more leader devices can transmit MSG0 according to instructions from a higher-level node. For example, multiple INs (i.e., multiple terminals) managed by the same base station can transmit MSG0 according to instructions from the base station.

[0222] For example, if MSG0 is a query signal, the terminal can determine whether to transmit MSG1 based on MSG0. MSG0 can be used as a DL sync signal, such as PSS / SSS. For example, MSG0 can be reused as a DL sync signal, such as PSS / SSS, or defined as a new sync signal.

[0223] At this time, MSG0 may include connection-related system information. For example, the connection-related system information may include a timer value for connection operations, information related to the time interval during which MSG1 transmission is possible (e.g., information related to the start time, length, window pattern, etc.). Additionally or alternatively, the connection-related system information may be transmitted via a separate MSG 0 for each specific device type, and the MSG 0 may indicate that the system information applies only to the specific device type.

[0224] Additionally or alternatively, MSG0 may include information for resolving conflicts. For example, MSG0 may include probability-based access information, UE ID-based access information, early indication-based access information, UE group / type-based access information, service / access type-based access information, etc.

[0225] 2) MSG1 transmission and reception procedure

[0226] The ambient IoT device can (re)transmit MSG1 to the reader device. For example, the ambient IoT device can (re)transmit MSG1 to the reader device using backscattering. The method described below can also be applied to transmitting and receiving messages subsequent to MSG1 (e.g., MSG 3 / 5).

[0227] As an example of the present disclosure, when MSG1 is transmitted in a slotted ALOHA manner, the ambient IoT device can transmit MSG1 at a time aligned with a specific time point (e.g., a transmission time of a DL sync signal or MSG0 transmitted by a reader device, a CW (carrier wave) transmission time, a backscattering transmission time (e.g., ambient IoT device A or B), etc.). The slotted ALOHA manner is a method of transmitting data by unit time (e.g., slot). As another example, the ambient IoT device can transmit MSG1 by selectively backscattering CW.

[0228] Additionally, MSG 1 may include a sequence for collision avoidance.

[0229] When multiple leader devices transmit MSG0, an ambient IoT device can only respond to one MSG0 transmission. For example, an ambient IoT device can transmit MSG1 in response to the first MSG0 transmission it receives, or it can only respond to the MSG0 transmission it receives with the highest intensity.

[0230] 3) MSG2 transmission and reception procedure

[0231] The ambient IoT device may receive MSG2 (from the reader device) after performing (re)transmission of MSG1. In one example of the present disclosure, MSG2 may include / indicate ACK and / or NACK information. For example, if the reader device successfully receives MSG1 and allows connection, MSG2 may include / indicate ACK. If the reader device does not successfully receive MSG1 or / and does not allow connection, MSG2 may include / indicate NACK.

[0232] For example, if MSG2 includes / indicates ACK, MSG2 may include at least one of information included in MSG1 (e.g., sequence information), transmission / reception resources of MSG1 (e.g., time / frequency resources), time / frequency for transmitting / receiving MSGs (e.g., MSG0, MSG1, MSG2, MSG3, MSG4, and / or MSG5, etc.), or CW time / frequency information for backscattering. If MSG2 includes / indicates NACK, MSG2 may include a back-off time.

[0233] 4) MSG3 transmission and reception procedure

[0234] In one embodiment of the present disclosure, when an ACK including / indicating an ACK is received, the ambient IoT device may transmit MSG3 (to the reader device). For example, the ambient IoT device may transmit MSG3 in a backscattering manner. The selection of a time interval / point in time / frequency / resource for transmitting MSG3 may be determined / selected based on at least one of the transmission / reception time interval / point in time / frequency / resource selection methods of MSG2.

[0235] MSG3 may contain at least one of UE ID, sequence, early indication, UE group / type, connection type, RRC connection / resume request message for initial connection, and C-RNTI MAC CE for UE within RRC_CONNECTED.

[0236] Here, the UE ID (e.g., C-RNTI) may be scrambled, masked, or attached to all UL messages. The sequence may be part or all of the sequence selected for MSG1. In another example, the sequence may be part or all of a newly selected sequence using at least one of the MSG1 sequence selection methods described above. The early indication may include the device type (e.g., device A, device B, or device C) and / or other processing times. The RRC connection / resume request message may include the UE ID (e.g., s-TMSI or resumption ID), etc.

[0237] 5) MSG4 transmission and reception procedure

[0238] An ambient IoT device that transmitted MSG 3 may receive MSG4 (from a reader device). MSG4 may include a UE ID (or / and contention resolution MAC CE) and / or sequence information. Here, the sequence may be selected / determined based on at least one of the MSG1 sequence selection methods described above.

[0239] If MSG4 contains the UE ID (or device ID) or sequence of the ambient IoT device, the ambient IoT device may transmit MSG5 (to the reader device).

[0240] For example, MSG5 may include terminal capability information. For example, the terminal capability information may include capability information related to device type (e.g., device type A, B, C), other processing times, early indication (e.g., device type, other processing times), terminal group / type, connection type, etc. Additionally or alternatively, MSG5 may include at least one of a UE ID, a sequence, and user data.

[0241] The methods proposed in this disclosure can be commonly applied to both topologies 1 and 2, and for convenience of explanation, the gNB and UE1 as IN are referred to as leaders. In addition, the proposed methods of this disclosure can be extended to cases where a leader receiving a backscattering signal (BSS) can directly generate a carrier wave (CW) and transmit it to a device, or where the node transmitting the CW is a separate node / device from the leader.

[0242] Additionally, the Ambient IoT base station (BS) (e.g., a leader) used in the present disclosure may be a base station (e.g., a gNB) in topology 1 and may be a specific UE in topology 2. Additionally, the Ambient IoT device (e.g., a tag) used in the present disclosure may be interpreted as an Ambient IoT device in both topology 1 and / or topology 2.

[0243] Hereinafter, in the description of the present disclosure, a preamble means something / a signal (e.g., a portion including a known sequence) transmitted at the very front of a specific D2R, R2D transmission, a midamble means something / a signal (e.g., a portion including a known sequence) transmitted in the middle of a specific D2R, R2D transmission, and a postamble means something / a signal (e.g., a portion including a known sequence) transmitted at the very back of a specific D2R, R2D transmission. Specifically, the physical channels PRDCH and PDRCH transmit a transport block (TB: Transport Block) of a higher layer (i.e., MAC PDU) and can also transmit L1 (layer 1) control information or L2 (layer 2) control information (e.g., a MAC header or a MAC control element). Here, the PRDCH or PDRCH may start transmission with a preamble and end transmission with a postamble. In other words, the PRDCH or PDRCH may be transmitted after the preamble is transmitted, and the postamble may be transmitted after the transmission of the PRDCH or PDRCH is terminated. In addition, a midamble may be included between the transmission of L1 / L2 control information or TB of the PRDCH or PDRCH. For the convenience of explanation in the present disclosure, the term x-amble means a signal known in advance to the leader and the device (e.g., a signal / portion including a known sequence in advance excluding the payload (data and control information) in a signal / transmission exchanged between the leader and the device), and may be collectively referred to as a preamble, a midamble, and a postamble.

[0244] Meanwhile, the preamble, midamble, and postamble mentioned in this specification may be transmitted together with D2R, R2D transmission (e.g., PDRCH, PRDCH) (i.e., not included in D2R, R2D transmission, but transmitted together before / middle / after D2R, R2D transmission) or may be transmitted while being included in the corresponding D2R, R2D transmission.

[0245] FIG. 15 illustrates cases of topology 1 for ambient IoT to which some examples of the present disclosure may be applied.

[0246] Referring to Fig. 15(a), different leaders, R1 node (leader 1) and R2 node (leader 2), can be responsible for transmitting the R2D channel and receiving the D2R channel, respectively. Here, the R1 node can transmit the carrier wave (CW) signal. In the present disclosure, the case of Fig. 15(a) may be referred to as the D1T1-A1 case.

[0247] Referring to Fig. 15(b), the same leader, the R node, can be responsible for both transmitting the R2D channel and receiving the D2R channel. Here, the CW signal can be transmitted by the R node. In the present disclosure, the case of Fig. 15(b) may be referred to as the D1T1-A2 case.

[0248] Referring to Fig. 15(c), the same leader R node can be responsible for both transmitting the R2D channel and receiving the D2R channel. Here, the CW signal can be transmitted by a separate CW node. In this disclosure, the case of Fig. 15(c) may be referred to as the D1T1-B case.

[0249] The R / R1 / R2 nodes in Fig. 15 may all be base stations or network nodes connected to base stations.

[0250] FIG. 16 illustrates cases of topology 2 for ambient IoT to which some examples of the present disclosure may be applied.

[0251] Referring to Fig. 16(a), different leaders, the R1 node (leader 1) and the R2 node (leader 2), can be responsible for transmitting the R2D channel and receiving the D2R channel, respectively. Here, the CW signal can be transmitted by the R1 node. In the present disclosure, the case of Fig. 16(a) may be referred to as the D2T2-A1 case.

[0252] Referring to Fig. 16(b), the same leader R node can be responsible for both transmitting the R2D channel and receiving the D2R channel. Here, the CW signal can be transmitted by the R node. In this disclosure, the case of Fig. 16(b) may be referred to as the D2T2-A2 case.

[0253] Referring to Fig. 16(c), the same leader R node can be responsible for both transmitting the R2D channel and receiving the D2R channel. Here, the CW signal can be transmitted by a separate CW node. In this disclosure, the case of Fig. 16(c) may be referred to as the D2T2-B case.

[0254] Meanwhile, the R / R1 / R2 nodes in Fig. 16 may all be terminals that serve as intermediate nodes (IN). Alternatively, in D2T2-A1, the R1 node may be a base station and the R2 node may be a terminal, or the R1 node may be a terminal and the R2 node may be a base station.

[0255] Hereinafter, for convenience of explanation in the present disclosure, the R1 node refers to a node that performs R2D signaling / transmission, and the R2 node refers to a node that performs D2R signaling / transmission, but the R1 node and the R2 node are not necessarily limited to different nodes.

[0256] FIG. 17 illustrates a PRDCH generation method and a PDRCH generation method to which some examples of the present disclosure can be applied.

[0257] Referring to FIG. 17, the generation of PRDCH / PDRCH may consist of CRC attachment, forward error correction (FEC) encoding, TB repetitions, line code encoding, modulation, chip repetitions, and waveform generation.

[0258] Referring to (a) of FIG. 17, a PRDCH can be generated for R2D information bits through CRC attachment, line coding, and OOK (On-Off Keying)-1 / OOK-4 generation based on OFDM waveforms. Also, referring to (b) of FIG. 17, a PDRCH can be generated for D2R information bits through CRC attachment, coding, and modulation.

[0259] For example, PRDCH / PDRCH generation may be based on one or more of the seven steps described below.

[0260] - Step 1 (CRC Append): K CRC bits {c_0^CRC, c_1^CRC,..., c_(K-1)^CRC} are added to the N data bits of the original transmission block {b_0, b_1, b_2,..., b_N-1}.

[0261] - Step 2 (FEC): The (N + K) bits {b_0, b_1, b_2,..., b_N-1, c_0^CRC, c_1^CRC,..., c_(K-1)^CRC} obtained in Step 1 are encoded with a convolutional code having a code rate of, for example, 1 / 3, and a code block {c_0^FEC, c_1^FEC,..., c_(3(N+K)-1)^FEC} containing a total of 3(N+K) bits is output.

[0262] - Step 3 (TB repetition): If repeated transmission is scheduled, the code block generated in Step 2 is repeated according to the scheduled number of repetitions (e.g., 2), and bit blocks {c_0^FEC, c_1^FEC,..., c_(3(N+K)-1)^FEC, c_0^FEC, c_1^FEC,..., c_(3(N+K)-1)^FEC} containing a total of 6(N+K) bits are output.

[0263] - Step 4 (Line Code Encoding): The repeated code block in Step 3 is encoded using a line code of length 2, for example, and an encoded block {c_(0,0)^LC, c_(0,1)^LC, c_(1,0)^LC, c_(1,1)^LC,..., c_(3(N+K)-1,0)^LC, c_(3(N+K)-1,1)^FEC, c_(0,0)^LC, c_(0,1)^LC, c_(1,0)^LC, c_(1,1)^LC,..., c_(3(N+K)-1,0)^LC, c_(3(N+K)-1,1)^FEC} containing a total of 12(N+K) bits is output.

[0264] - Step 5 (Modulation): Each bit of the encoded block generated in Step 4 is mapped to 1 / 0 for OOK or +1 / -1 for BPSK (Binary Phase Shift Keying). Each OOK or BPSK symbol is considered a chip of backscatter modulation. In OOK, 1 and 0 represent high and low voltages, respectively, which are reflected in the envelope amplitude of the chip generated by the analog circuit. In BPSK, +1 and -1 represent phase shifts of 0 and 180 degrees, respectively, which are reflected in the envelope phase of the chip generated during the backscatter modulation process. The modulator outputs a chip block containing a total of 12(N+K) chips, for example, {s_0, s_1, s_2, ..., s_(12(N+K)-1)}.

[0265] - Step 6 (Chip Repetition): If a repetitive transmission is scheduled, each chip in the chip block generated in Step 5 is repeated according to the scheduled number of chip repetitions (e.g., 2), and a chip block {s_0, s_0, s_1, s_1, s_2, s_2, ..., s_(12(N+K)-1), s_(12(N+K)-1)} containing a total of 24(N+K) chips is output.

[0266] - Step 7 (Waveform Generation): A single carrier waveform is proposed for D2R transmission.

[0267] FIG. 18 illustrates a control information and PRDCH / PDRCH transmission structure to which some examples of the present disclosure may be applied.

[0268] Fig. 18 shows the transmission structure of control information and PRDCH / PDRCH in relation to R2D / D2R transmission in AmIoT communication.

[0269] Referring to FIG. 18, each transmission structure option may be transmitted immediately after the preamble. Additionally, a postamble may be transmitted immediately after the transmission of each transmission structure option.

[0270] For example, when PRDCH transmission or PDRCH transmission based on the transmission structure of option a or option b is performed including a preamble and a postamble, it may be based on a structure such as FIG. 19.

[0271] FIG. 19 illustrates preamble / postamble and PRDCH / PDRCH transmissions to which some examples of the present disclosure may be applied.

[0272] Referring to FIG. 19, R2D / D2R transmission may be performed based on the Manchester code scheme, which is an example, and may be performed based on other schemes. In addition, the preamble and postamble illustrated in FIG. 19 may also correspond to examples. As a specific example, the D2R preamble may be transmitted only as a clock acquisition part for D2R timing acquisition without a start indicator. And / or, the postamble may be transmitted at a different length while maintaining a high voltage, or may be transmitted in the form of a specific sequence composed of high voltage and low voltage. And / or, the R2D / D2R transmission may be performed by transmitting only the preamble and PRDCH / PDRCH without a postamble.

[0273] Additionally, as illustrated in FIG. 18, L1 control information of R2D transmission may be transmitted based on one or more of the following methods.

[0274] (Method 1) L1 control information may be present at the end of the R2D preamble as part of the R2D preamble. In this case, the chip duration of the L1 control information may be the same as the chip duration of the preamble. For example, L1 control information may be added immediately after the clock acquisition part of FIG. 19, and the PRDCH may be transmitted thereafter. In this case, the structure of the PRDCH transmission may be the same as option a or option b of FIG. 18. In the case of option b, the PRDCH may start with L2 control information.

[0275] (Method 2) L1 control information may exist between the R2D preamble and the PRDCH. In this case, the structure of the PRDCH transmission may be the same as option c, option d, or option e of FIG. 18. For option d, the L1 control information may be transmitted through a separate R2D control channel. For option c or option e, the L1 control information may be transmitted as a separate portion without a separate channel.

[0276] (Method 3) L1 control information may be present at the beginning of the PRDCH as part of the PRDCH. In this case, the chip duration of the L1 control information may be identical to the chip duration of the PRDCH. In this case, the structure of the PRDCH transmission may be the same as Option b of FIG. 18, and the PRDCH may begin with L1 control information.

[0277] FIG. 20 illustrates a MAC payload structure in a PRDCH / PDRCH to which some examples of the present disclosure may be applied.

[0278] The MAC payload structure illustrated in Fig. 20 may be an example of the structure of the payload (e.g., MAC payload) in Fig. 18. Here, the MAC payload may correspond to one transport block (TB).

[0279] In options a, c, and d of FIG. 20, the L2 control information may or may not be located at the very beginning of the MAC payload. In this case, whether the L2 control information is included may be indicated in the L1 control information described in FIG. 18 or the clock acquisition portion of the preamble. Alternatively, without a separate indication, the MAC payload may or may not always include the L2 control information. Alternatively, whether the L2 control information is included may be indicated in the first bit / field of the L2 control information or the bit / field immediately before the L2 control information. Alternatively, the L2 control information may be included in the MAC CE after the MAC subheader of FIG. 20. Additionally, padding may be added to the last part of the payload of FIG. 20.

[0280] When a payload (e.g., TB) is configured as shown in FIG. 20 in the MAC layer, the payload can be transmitted to the physical layer, and the physical layer can configure a PRDCH or PDRCH by adding a CRC to the payload. At this time, whether a CRC is added to the TB can be indicated in L1 control information, L2 control information, or MAC CE. And / or, in FIG. 20, the L2 control information can be classified as a specific MAC CE (always) located in front of the payload, or as a MAC header.

[0281] Additionally, for R2D / D2R transmissions, a midamble may be included in addition to the preamble and / or postamble. For example, in the case of D2R transmission, the D2R transmission may be performed in the following order: D2R preamble, PDRCH, D2R midamble, PDRCH, ..., D2R midamble, PDRCH, D2R postamble.

[0282] Hereinafter, the repetitive transmission between the A-Iot device and the reader in the present disclosure is described.

[0283] Example 1: PRDCH / PDRCH Repetitive Transmission Method

[0284] - For PDRCH (or PRDCH) that uses a fixed transport block size (TBS), R2D / D2R control information may not be required. For example, a D2R response with a fixed size, such as MSG1 for contention-based access, may not require a postamble or R2D / D2R control information.

[0285] For PDRCH (or PRDCH) using chip / bit / TB repetition of transport blocks (TB) with fixed size, the leader and / or device may perform one of the following options:

[0286] (Option 1) PDRCH (or PRDCH) repetition information (e.g., repetition count) may be indicated by R2D / D2R control information. In this case, PDRCH (or PRDCH) transmission may be repeated without a midamble and terminated without a postamble.

[0287] (Option 2) PDRCH (or PRDCH) repetition information (e.g., repetition count) may not be indicated by R2D / D2R control information. In this case, PDRCH (or PRDCH) transmissions may be repeated using a midamble and terminated using a postamble. That is, a midamble may be transmitted between consecutive PDRCHs (or PRDCHs), and a postamble may be transmitted after the last PDRCH (or PRDCH).

[0288] Here, when both a midamble and a postamble are used, the midamble sequence may not be identical to the postamble sequence.

[0289] - On the other hand, in case of a PDRCH (or PRDCH) having a variable TBS in response to R2D control information, if a TBS indication is indicated in the R2D control information, the device can generate a TB of a size up to the indicated TBS.

[0290] Here, if the actual TBS (i.e., the size of the TB that actually needs to be transmitted) does not exactly match the TBS indicated by the R2D control information (e.g., is smaller than the indicated TBS), a postamble may be added immediately after the TB.

[0291] For example, if the total size of the TB and the postamble is greater than the indicated TBS, L2 padding may be added to the TB instead of the postamble. In other words, the postamble may be added immediately after the TB only if the total size of the TB and the postamble is less than the indicated TBS.

[0292] If the actual TBS exactly matches the TBS specified in the R2D control information, no postamble or padding may be added to the TB.

[0293] If the actual required TBS (i.e., the size of the TB that actually needs to be transmitted) is larger than the specified TBS, the device may indicate the actual required TBS in the D2R L2 control information. In this case, a packet fragmented together with the D2R control information in the PDRCH (or PRDCH) may be transmitted based on the TBS indicated in the D2R L2 control information.

[0294] - For PDRCH (or PRDCH) using chip / bit / TB repetition for variable-sized TB, regardless of whether the number of PDRCH (or PRDCH) repetitions is indicated in the R2D control information, PDRCH (or PRDCH) transmission may be repeated through the midamble and terminated through the postamble. That is, the midamble may be transmitted between consecutive PDRCHs (or PRDCHs), and the postamble may be transmitted after the last PDRCH (or PRDCH).

[0295] For Topology 2, the base station (e.g., gNB) can determine whether to repeat D2R transmissions based on D2R measurements of the IN UE. The IN UE can perform measurements on D2R transmissions and report the measurement results to the base station. Based on the reports, the base station can determine whether to repeat D2R transmissions and perform one of the following:

[0296] (Option 1): The base station may transmit downlink control information (DCI) to the IN UE. The DCI may indicate chip / bit / TB unit repetition information (e.g., the number of PDRCH repetitions).

[0297] (Option 2): The base station may configure a D2R resource pool for the IN UE, which consists of D2R resources that support PDRCH repetition. The base station may also configure repetition information (e.g., the number of PDRCH repetitions) per chip / bit / TB.

[0298] In this case, the UE can autonomously select multiple PDRCH resources up to the repetition count for PDRCH repetition within the D2R resource pool set by the base station.

[0299] As described above, the PRDCH or PDRCH can be repeatedly transmitted at the chip / bit / TB level, and such repeated transmission can be indicated by control information. Specifically, for example, repeated transmission of the PRDCH or PDRCH can be indicated by a TBS indication or a specific field of L1 or L2 control information. Here, repeated transmission of the PRDCH or PDRCH can be repeated transmission of the same chip / bit / TB, or can be consecutive transmissions of different TBs. For example, whether the PRDCH or PDRCH transmission is repeated at the chip level, bit level, or TB level can be indicated by a specific field of the L1 or L2 control information in the R2D direction. Alternatively, whether the PDRCH transmission is repeated at the chip level, bit level, or TB level can be indicated by a specific field of the L1 or L2 control information in the D2R direction. When repeated transmission of the PDRCH transmission is indicated, the device repeatedly transmits the PDRCH according to the indication. Here, a specific field in the R2D direction or D2R direction can indicate / provide repetition information (e.g., number of repetitions).

[0300] If the control information does not indicate / provide PRDCH repetition or PDRCH repetition information (e.g., if the specific field is not included in the control information, or if the specific field does not indicate / provide PRDCH repetition or PDRCH repetition information), the transmitter (e.g., a reader or a device) may transmit a preamble, a midamble, or a postamble to distinguish between repetitions of the PRDCH or PDRCH (or to distinguish between repeated TBs). For example, assuming that the PRDCH or PDRCH (e.g., the same TB or different TBs) is repeatedly transmitted N times (where N is an integer greater than 1), in order to distinguish between the first transmission and the second repetition transmission of the PRDCH or PDRCH, the preamble / midamble / postamble may be transmitted immediately after the first transmission, followed by the second repetition transmission of the PRDCH or PDRCH. Then, the k-th repeated transmission of the PRDCH or PDRCH may be performed after the preamble / midamble / postamble is transmitted at the end of the k-1th repeated transmission of the PRDCH or PDRCH or at the start of the k-th repeated transmission. Afterwards, the postamble may be transmitted at the end of the last N-th repeated transmission. Here, the preamble / midamble / postamble transmitted at the end of the k-1th repeated transmission of the PRDCH or PDRCH may indicate the interval between the k-1th repeated transmission and the k-th repeated transmission or may indicate the number of repeated transmissions remaining after the k-1th repeated transmission.

[0301] In addition, if the k-1th transmission of PRDCH or PDRCH ends and the kth transmission starts immediately after each other without a gap, a midamble may be transmitted between the two consecutive transmissions. If a gap occurs between the k-1th transmission of PRDCH or PDRCH ends and the kth transmission starts, a postamble may be transmitted immediately after the k-1th transmission ends, the kth transmission may start after a predetermined gap, and the postamble may be transmitted immediately after the last Nth transmission. Here, the presence of a gap, the length of the gap, and / or the end of repeated transmission (i.e., the last transmission) may be indicated in the postamble. In addition, the initial transmission (i.e., the first transmission) may start with a preamble (i.e., the preamble is transmitted immediately before the initial transmission).

[0302] In addition, if the k-1th transmission of PRDCH or PDRCH ends and the kth transmission starts immediately after each other without a gap, a midamble may be transmitted between the two consecutive transmissions. If a gap occurs between the k-1th transmission of PRDCH or PDRCH ending and the kth transmission starting, a preamble may be transmitted immediately after the k-1th transmission ends, the kth transmission may start after a predetermined gap, and a postamble may be transmitted immediately after the last Nth transmission. Here, the presence of a gap, the length of the gap, and / or the start of a repeated transmission (i.e., a first / initial transmission) may be indicated in the preamble.

[0303] In N repeated transmissions of PRDCH or PDRCH (where N is an integer greater than 1), i) the (k-1)th transmission and the kth transmission (i.e., a part of N repeated transmissions) or ii) all individual transmissions may be transmissions of the same TB or transmissions of different TBs. Here, in the case of the same TB, it may correspond to repeated transmissions of the same TB. In the case of repeated transmissions of the same TB, the first transmission of the TB (e.g., the first PRDCH or PDRCH) may be transmitted including L1 or L2 control information, and subsequent repeated transmissions (i.e., subsequent repeated transmissions including the second transmission) may or may not include the control information. Here, whether control information is included in subsequent repeated transmissions may be indicated by the L1 or L2 control information of the first transmission. In addition, the L1 or L2 control information of the first transmission may indicate the number of repetitions and / or indicate whether the next transmission(s) is a repeated transmission of the same TB or a transmission of a new TB.

[0304] In addition, in the N-th (N is an integer greater than 1) repeated transmission of PRDCH or PDRCH, i) the k-1th transmission and the k-th transmission (i.e., a part of the N-th repeated transmission), or ii) all individual transmissions may be transmitted scrambled with the same sequence / code, or may be transmitted scrambled with different sequences / codes. In addition, in the N-th (N is an integer greater than 1) repeated transmission of PRDCH or PDRCH, i) the k-1th transmission and the k-th transmission (i.e., a part of the N-th repeated transmission), or ii) all individual transmissions may be transmitted coded with the same code rate, or may be transmitted coded with different code rates. In addition, in N (where N is an integer greater than 1) repeated transmissions of PRDCH or PDRCH, i) the (k-1)th transmission and the kth transmission (i.e., some of the N repeated transmissions) or ii) all individual transmissions may be transmitted on the same frequency resource / channel or may be transmitted by hopping / moving to different frequency resources / channels. Here, information about the code rate or frequency hopping information / pattern for R2D or D2R repeated transmission may be indicated by L1 or L2 control information of the first transmission. In addition, in case of D2R repeated transmission, information about the code rate or frequency hopping information / pattern for D2R repeated transmission may also be indicated by R2D control information.

[0305] If i) the number of repetitions for R2D or D2R repeat transmissions is fixed, or ii) the number of repetitions is indicated by a TBS instruction or L1 or L2 control information (e.g., a specific field), the transmitter may omit the postamble after the last repetition transmission, or the receiver may omit the postamble reception by stopping reception immediately after the last repetition transmission, regardless of whether the transmitter omitted the postamble.

[0306] If a midamble is transmitted between two consecutive transmissions in R2D or D2R repetitive transmissions, the midamble and the postamble may be of different sequences (i.e., they may be distinguished because they are generated based on different sequences). Alternatively, if a preamble is transmitted between two consecutive transmissions in R2D or D2R repetitive transmissions, the preamble transmitted before the first transmission and the preamble transmitted between the two consecutive transmissions may be of different sequences (i.e., they may be distinguished because they are generated based on different sequences). Alternatively, if a postamble is transmitted between two consecutive transmissions in R2D or D2R repetitive transmissions, the postamble transmitted immediately after the last repetitive transmission and the postamble transmitted between the two consecutive transmissions may be of different sequences (i.e., they may be distinguished because they are generated based on different sequences). In cases where preambles / midambles / postambles are included between repeated transmissions, control information in the R2D or D2R direction may be transmitted without including a TBS indication for the PDRCH. Furthermore, control information in the R2D direction may be transmitted without including a TBS indication for the PRDCH.

[0307] If the TB size or TB transmission length can be determined based on the command ID or TBS indication, and PRDCH or PDRCH repetition information is indicated / provided by control information (e.g., the specific field above), the transmitter can perform repeated transmission of the PRDCH or PDRCH without transmitting a preamble / midamble / postamble to distinguish PRDCH or PDRCH repetitions. For example, if the TB size or TB transmission length is determined to be 50 bits or 10 ms by the command ID or TBS indication, and N repeated transmissions are indicated by the control information, the receiver can determine that there is no preamble / midamble / postamble between two consecutive repeated transmissions of the PRDCH or PDRCH TB (i.e., between the k-1th transmission and the kth repeated transmission), and determine that the corresponding TB is repeated at every multiple of 50 bits or every multiple of 10 ms according to the determined TB size.

[0308] Alternatively, the inclusion of a midamble (or preamble / postamble) between two consecutive transmissions in R2D or D2R repeated transmissions may be indicated by the L1 / L2 control information in the R2D direction or the L1 / L2 control information in the D2R direction. For example, whether a midamble is included between two consecutive transmissions in PDRCH repeated transmissions may be indicated by a specific field of the L1 or L2 control information in the R2D direction, and if a midamble is included, at what time interval (or data size / length interval) the midamble is included may be indicated. In other words, the transmission interval of the midamble may be indicated by a specific field of the L1 or L2 control information in the R2D direction, and in this case, the transmission interval of the midamble may be indicated in units of time, bits, etc. Alternatively, a specific field in the L1 or L2 control information in the D2R direction may indicate whether a midamble is included between two consecutive transmissions in PDRCH repeat transmissions, and if so, at what time interval the midamble is included (i.e., the transmission interval of the midamble).

[0309] According to the above description, a midamble is set to be transmitted between two consecutive repeated transmissions of a PRDCH or a PDRCH, and if the receiver detects the midamble before the end point of the PRDCH or the PDRCH, it can determine that the transmission of the TB of the PRDCH or the PDRCH has ended. Then, the receiver can determine that a new TB is transmitted after the midamble, or that the repeated transmission of the TB received so far continues after the midamble, and accordingly, the receiver can continue receiving the PRDCH or the PDRCH. Additionally, if the receiver detects a midamble before the end of a repeated transmission of a PRDCH or PDRCH, it can be indicated whether the new transmission after the midamble is a repeat transmission of the previous TB or a new TB transmission by i) L1 / L2 control information transmitted within the TB received so far or immediately before the TB received so far, or ii) L1 / L2 control information or midamble transmitted within the new TB or immediately before the new TB.

[0310] FIG. 21 illustrates repeated transmission of a PDRCH according to one embodiment of the present disclosure.

[0311] Figure 21 illustrates a case where a midamble is indicated to be included between repeated transmissions of two consecutive PDRCHs by L1 / L2 control information in the R2D direction or L1 / L2 control information in the D2R direction.

[0312] Referring to FIG. 21, in repeated transmissions of PDRCH, a (D2R) preamble may be transmitted before the first PDRCH transmission begins. A (D2R) midamble may be included between two consecutive PDRCH transmissions, and a (D2R) postamble may be transmitted after the last PDRCH transmission.

[0313] Meanwhile, in Fig. 21, only the repeated transmission of PDRCH is exemplified, but the repeated transmission of PRDCH can also be performed with the same structure.

[0314] In the above-described method, when multiple PRDCHs for the same or different TBs are transmitted, the L1 / L2 R2D control information of the ith PRDCH (e.g., in chronological order) may include i) R2D control information for the i+1th or subsequent PRDCH, or ii) D2R control information of a PDRCH transmitted in response to the i+1th or subsequent PRDCH. For example, the L1 control information of the first PRDCH (e.g., in chronological order) may include i) time domain resource allocation information or frequency domain resource allocation information of the second PRDCH, or ii) time domain resource allocation information or frequency domain resource allocation information of a PDRCH transmitted in response to the second PRDCH. Additionally, the L1 control information of the first PRDCH (for example, in chronological order) may include command identifier (ID), modulation and coding scheme (MCS), TBS, repetition transmission settings such as repetition number, R2D or D2R control information such as device ID, device group ID, device type, cast type, etc. for the second PRDCH or the PDRCH transmitted in response thereto.

[0315] In the description of the present disclosure, even if not otherwise stated, chip level repetition transmission, bit level repetition transmission, and block level repetition transmission may all be applied together, or two of these methods may be applied together to transmit PRDCH or PDRCH.

[0316] Additionally, in the description of the present disclosure, in the case of block-level repetitive transmission, a cyclic redundancy check (CRC) for a block may be transmitted prior to transmission of the block. For example, when a block is repetitively transmitted three times, the CRC for the block may be transmitted first, followed by the first block, then the CRC for the block may be transmitted first, followed by the second block, and then the CRC for the last block may be transmitted first, followed by the last block, and so on. Alternatively, when a block is repetitively transmitted three times, the CRC for the block may be transmitted first, followed by the three-time repetitive transmission of the block. Alternatively, when a block is repetitively transmitted three times, the CRC may be transmitted between the first and second block transmissions, or between the second and third block transmissions.

[0317] In the description of the present disclosure, the maximum length of an R2D transmission (e.g., PRDCH) or a D2R transmission (e.g., PDRCH) may be calculated excluding or including the preamble / midamble / postamble. In addition, the maximum length of an R2D transmission (e.g., PRDCH) or a D2R transmission (e.g., PDRCH) may be calculated excluding or including the CRC.

[0318] Example 2: Maximum length-based repetitive transmission interruption method

[0319] When transmitting a PDRCH in response to a PRDCH transmission, repeated transmission of the PDRCH may be indicated through the preamble of the R2D transmission or the control information of the PRDCH, and the maximum length of the PDRCH may also be indicated. Alternatively, transmission or repeated transmission of the PDRCH may be indicated through the preamble of the D2R transmission or the control information of the PDRCH. Here, the repeated transmission indication may be indicated by one or more of chip-level repetition, bit-level repetition, or block-level repetition.

[0320] Additionally, the maximum length may be determined by a specific value indicated (or preset or predefined) through system information transmitted by the leader. Alternatively, if the maximum length is not indicated through the preamble of the R2D transmission or the control information of the PRDCH, the maximum length may be determined by a specific value indicated (or preset or predefined) through system information transmitted by the leader. Here, if there is no specific value indicated (or preset or predefined), a fixed maximum length may be determined for each device, device group, or device type.

[0321] Even if not described separately in this disclosure, system information may include information commonly applicable to multiple devices, and control information may include information applicable to a specific device.

[0322] When the maximum length of the PDRCH and the repeated transmission are indicated or determined as above, if the length of the PDRCH repeated transmission exceeds the indicated / determined maximum length, the device stops the repeated transmission. Here, the device may stop the repeated transmission in case of block-level repetition, and may not stop the repeated transmission in case of chip-level repetition or bit-level repetition.

[0323] For example, if a four-time repeat transmission is indicated through the preamble of an R2D transmission or the control information of the PRDCH, and the maximum length is indicated or determined, and if three of the repeat transmissions are within the maximum length and the fourth repeat transmission exceeds the maximum length, the device may skip only the fourth repeat transmission in its entirety, or transmit only as many bits / chips as do not exceed the maximum length in the fourth repeat transmission. Alternatively, in the above case, the device may transmit only as much of the fourth repeat transmission as the maximum length minus the postamble.

[0324] Example 3: Energy level-based repetitive transmission interruption method

[0325] When transmitting a PDRCH in response to a PRDCH transmission, transmission or repeated transmission of the PDRCH may be indicated through the preamble of the R2D transmission or the control information of the PRDCH, and the minimum power of the PDRCH may be indicated. Alternatively, transmission or repeated transmission of the PDRCH may be indicated through the preamble of the D2R transmission or the control information of the PDRCH. Here, the repeated transmission indication may be indicated by one or more of chip-level repetition, bit-level repetition, or block-level repetition.

[0326] If the minimum power of the PDRCH is not indicated through the preamble of the R2D transmission or the control information of the PRDCH, the minimum power may be determined as a specific value indicated (or preset or predefined) through system information transmitted by the leader, etc. Here, if there is no specific value indicated (or preset or predefined), a fixed minimum power may be determined for each device, device group, or device type.

[0327] When the PDRCH repeat transmission and the minimum power of the PDRCH are indicated / determined as above, if the device cannot perform all the PDRCH repeat transmissions that satisfy the minimum power due to the energy level of the device, the device stops the repeat transmission.

[0328] For example, if a four-time repeat transmission is indicated through the preamble of an R2D transmission or control information of a PRDCH, and a minimum power is indicated or determined, and all three repeat transmissions can be transmitted at or above the minimum power level, but all four repeat transmissions cannot be transmitted at or above the minimum power, the device may skip only the fourth repeat transmission entirely, or transmit the fourth repeat transmission at or below the minimum power.

[0329] Example 4: Energy level-based early termination / abortion method for D2R repeat transmission

[0330] If block-level repetition is instructed or determined and the device is repeatedly transmitting N blocks for a PDRCH with block-level repetition, the energy level may drop below a certain threshold after transmitting up to the Kth block (k < N) or while transmitting the K+1th block, or the device may not be able to transmit the PDRCH at the instructed / determined minimum power with the current energy level. In such a case, the device cannot continue performing repeated transmissions for the block before sufficient energy harvesting.

[0331] Alternatively, if block-level repetition is instructed or determined, and N blocks for PDRCH are repeatedly transmitted with block-level repetition, if the device switches to OFF / sleep state after transmitting up to K-th block (k < N) in ON state or while transmitting K+1-th block, the device will not repeatedly transmit PDRCH. In this manner, the device can determine / perform transition to OFF / sleep state (or deep sleep state) at the beginning of each block repetition (e.g., whether to transition before the transmission of the corresponding block is completed). Alternatively, the device can determine / perform transition to OFF / sleep state (or deep sleep state) immediately after each block repetition or before or after an x-amble added for each block repetition (e.g., whether to transition before the transmission of the corresponding / next block is completed).

[0332] In such a case where the device is unable to continue the repetitive transmission due to energy level / minimum power or transition to OFF / sleep state, the device can report to the leader about the early termination of the repetitive transmission (e.g., energy level / minimum power or transition to OFF / sleep state) by transmitting i) a specific pattern of D2R preamble, midamble and / or postamble, or ii) L1 / L2 control information after transmitting up to K-th block (k < N) or while transmitting K+1-th block. Thereafter, if the device becomes able to resume the repetitive transmission by satisfying the energy level / minimum power (e.g., increasing above a specific threshold) due to sufficient energy harvesting or transitioning to ON state, the device can report to the leader about the resumption of the repetitive transmission (e.g., resuming the repetitive transmission) by transmitting i) a specific pattern of D2R preamble, midamble and / or postamble, or ii) L1 / L2 control information and request the leader to instruct / approve the resumption of the remaining repetitive transmission. Thereafter, the leader may instruct the device to resume the repetitive transmission by transmitting i) a specific pattern of R2D preamble, midamble and / or postamble or ii) L1 / L2 control information, and the device may resume the repetitive transmission.

[0333] Alternatively, the device may report to the leader about the resumption of repetitive transmission by transmitting i) a specific pattern of D2R preamble, midamble and / or postamble, or ii) L1 / L2 control information (e.g., resuming repetitive transmission, or additionally a gap length), and then immediately or after a specific gap, resuming repetitive transmission.

[0334] Here, in the above-described method, the device may report to the leader an energy level / minimum power, transition to an OFF / sleep state, or resumption of repeated transmission. Additionally, the report may include the length of a specific gap.

[0335] In the above-described method, if the leader that has received up to the Kth block fails to successfully decode the TB and no PDRCH repeated transmission is detected after the Kth block, the leader may transmit an R2D preamble, midamble and / or postamble, or transmit R2D control information to indicate block-level repeated transmission from the K+1th block. For example, the leader may indicate the resumption of repeated transmission through a pattern of the preamble, midamble and / or postamble, or a specific field of the R2D control information, or may indicate the Kth repetition received so far or the K+1th repetition to be received in the future.

[0336] Meanwhile, in the above-described repetitive transmission method, a preamble, a midamble, and / or a postamble may be transmitted between blocks that are repeatedly transmitted, or the preamble, midamble, and / or postamble may be repeatedly transmitted M times. Here, M and N may be the same or different. Alternatively, in the above-described repetitive transmission method, a gap may be set between blocks that are repeatedly transmitted. For this purpose, the presence or absence of a gap and the length of the gap may be indicated through the preamble of R2D transmission or the control information of the PRDCH, or the preamble of D2R transmission or the control information of the PDRCH. If there is a gap, the leader may also instruct to stop the repetitive transmission of the block after the gap during the gap.

[0337] An example of the above method is as follows. The reader can perform R2D / D2R transmission with a specific device by setting a duty cycle. Here, each repetitive transmission can be transmitted during the ON period of the duty cycle, and the remaining time can be used for charging and the repetitive transmission can be continued as follows. For example, if the duty cycle is 50 ms, the device can perform the first repetitive transmission for 5 ms, and not perform transmission in the OFF / sleep state while harvesting energy for the remaining 45 ms. Then, when the device receives a trigger signal from the reader indicating that the ON period begins in the next duty cycle (i.e., the R2R preamble, midamble and / or postamble of the specific pattern, or L1 / L2 control information), the device can perform the second repetitive transmission again for 5 ms. Here, if the leader successfully receives the data with only two repetitions, the leader may inform the device that no more repeated transmissions are needed in the ON period of the next duty cycle, and the device receiving this may stop the repeated transmissions.

[0338] Example 5: Repeated transmission of x-amble (i.e., preamble / midamble / postamble)

[0339] When repeatedly transmitting a PRDCH / PDRCH (for example, repeated transmission according to at least one embodiment among embodiments 1 to 4), repeated transmission may be applied to at least one (i.e., one, some, or all) of a preamble, a midamble, and a postamble transmitted together with the PRDCH / PDRCH.

[0340] Here, repeated transmission of x-amble can be performed by applying at least one (i.e., one, some, or all) of the following options.

[0341] 1) Option 1: x-amble and its PRDCH / PDRCH transmission can be transmitted repeatedly in the same manner.

[0342] For example, if x-amble is bit-level repetitive transmission, the PRDCH / PDRCH transmission for it is also transmitted as bit-level repetitive transmission, if x-amble is chip-level repetitive transmission, the PRDCH / PDRCH transmission for it is also transmitted as chip-level repetitive transmission, and if x-amble is block-level repetitive transmission, the PRDCH / PDRCH transmission for it can also be transmitted as block-level repetitive transmission.

[0343] 2) Option 2: The x-amble and its PRDCH / PDRCH transmissions can be repeated in a different manner.

[0344] For example, if x-amble is a bit-level repetitive transmission, the PRDCH / PDRCH transmission for it can be transmitted as a chip-level or block-level repetitive transmission. Or, if x-amble is a chip-level repetitive transmission, the PRDCH / PDRCH transmission for it can be transmitted as a block-level or bit-level repetitive transmission. Or, if x-amble is a block-level repetitive transmission, the PRDCH / PDRCH transmission for it can be transmitted as a chip-level / bit-level repetitive transmission.

[0345] Alternatively, x-amble can increase the chip duration or symbol duration by k times, and the PRDCH / PDRCH transmission for this can be transmitted as N chip-level / bit-level / block-level repeated transmissions, where N can be equal to or different from k. Alternatively, k can be a multiple or divisor of N.

[0346] 3) Option 3: x-amble can be transmitted repeatedly according to the PRDCH / PDRCH repetition number.

[0347] For example, in case of N repeated PRDCH / PDRCH transmissions, the x-amble for this may also be repeatedly transmitted N times.

[0348] Alternatively, in case of N repeated PRDCH / PDRCH transmissions, the corresponding x-amble may be transmitted K times repeatedly. Here, K may be a multiple of N or a divisor of N. Alternatively, a specific N value may be set or defined to be mapped to a specific K value. In this case, the mapping between N and K may be set by system information or control information transmitted by the leader, or may be fixed (i.e., predefined) in the specification.

[0349] Here, the repetition transmission method of x-amble and PRDCH / PDRCH transmission for it may be the same or different.

[0350] For example, if N PRDCH / PDRCHs are block-level repeated transmissions, the x-amble for them can be transmitted as N or K bit-level or block-level repeated transmissions.

[0351] 4) Option 4: The transmission length of x-amble can be adjusted / determined according to the PRDCH / PDRCH repetition number.

[0352] The chip duration or symbol duration of the x-amble or the entire x-amble length can be adjusted / determined according to the PRDCH / PDRCH repetition number. For example, the chip duration or symbol duration or the entire x-amble duration for the x-amble can be increased by k times, and the PRDCH / PDRCH transmission for this can be transmitted by N times chip-level / bit-level / block-level repetition transmission. Here, N can be equal to or different from k. Alternatively, k can be a multiple or divisor of N.

[0353] For example, let's assume that x-amble is transmitted only at a high voltage level. In this case, if repeated transmission for x-amble is not applied, x-amble can be transmitted at a high voltage level with a length of X1, and if repeated transmission for x-amble is applied, x-amble can be transmitted at a high voltage level with a length of X2. Here, X2 can be determined according to the number of PRDCH / PDRCH repetitions N. The mapping relationship between N and X2 can be set as system information or control information transmitted by the leader, or can be fixed in the specification (i.e., the mapping relationship is predefined). For example, as the value of N increases, the length of X2 can increase proportionally to a multiple of the length of X1 (e.g., X2 = N * X1), and this method can be suitable for the postamble.

[0354] 5) Option 5: A long sequence dedicated to repeated transmission can be configured separately and transmitted.

[0355] If PRDCH / PDRCH repetitive transmission is not applied, the x-amble for this can be transmitted using a sequence of S1 pattern. On the other hand, if N-time repetitive transmission is applied to PRDCH / PDRCH, the x-amble for this can be transmitted using a sequence of SN pattern corresponding to the N value.

[0356] For example, when PRDCH / PDRCH transmission is not repeated, x-amble can be transmitted in a sequence of S1 pattern, when PRDCH / PDRCH transmission is repeated twice, x-amble can be transmitted in a sequence of S2 pattern, and when PRDCH / PDRCH transmission is repeated N times, x-amble can be transmitted in a sequence of SN pattern.

[0357] Here, the pattern of the sequence can be fixed as a specification (i.e., predefined) or set as system information or control information transmitted by the leader.

[0358] Here, the mapping between the number of repetitions of PRDCH / PDRCH transmission and the pattern may be set / defined one-to-one, or may be set / defined as a mapping between the range of the number of repetitions of PRDCH / PDRCH transmission and the pattern.

[0359] 6) Option 6: How to apply gaps between repeated transmissions

[0360] In the proposed method of the present disclosure, when x-amble is repeatedly transmitted, it can be transmitted without a gap between repeated transmissions or with a gap.

[0361] Here, the gap can be set to the length of the bit / chip / repeat / sequence or its divisor / multiplier (i.e., dynamically set) or fixed in the specification (i.e., predefined). If it is set to the length of the bit / chip / repeat / sequence or its divisor / multiplier, the leader can set it via system information or control information.

[0362] The settings for the operations of the above options 1 to 6 may be set by system information transmitted by the leader or by R2D / D2R control information. For example, the repeated transmission of D2R x-amble may be set / instructed by R2D or D2R control information, and the repeated transmission of R2D x-amble may be set / instructed by R2D control information. Alternatively, the settings for the operations of the above options 1 to 6 may be predefined in the specification.

[0363] Example 6: Repetitive transmission structure of x-amble and PRDCH / PDRCH

[0364] - When the preamble is also transmitted K times during N PRDCH / PDRCH repetition transmission, it can be transmitted with one of the following options. Here, N and K can be the same or different.

[0365] i) Option A1: Structure in which the preamble is repeatedly transmitted K times and then the PRDCH or PDRCH is repeatedly transmitted N times.

[0366] This method is applicable to chip-level / bit-level / block-level iterative transmission.

[0367] ii) Option A2: Structure that repeatedly transmits {preamble + PRDCH} or {preamble + PDRCH} N times.

[0368] Here, if N = K, {preamble + PRDCH} or {preamble + PDRCH} can be repeatedly transmitted N times.

[0369] Additionally, if N > K, after {preamble + PRDCH} or {preamble + PDRCH} is repeatedly transmitted K times, PRDCH or PDRCH can be repeatedly transmitted (NK) times.

[0370] Additionally, if N < K, after the preamble is repeatedly transmitted (KN) times, {preamble + PRDCH} or {preamble + PDRCH} may be repeatedly transmitted N times.

[0371] This method can be broadly applied to block-level iterative transmission methods.

[0372] - When the midamble is also repeatedly transmitted K times during N PRDCH / PDRCH repetition transmission, it can be transmitted with one of the following options. Here, N and K can be the same or different. This method can be generally applied to the block-level repetition transmission method.

[0373] When N = K, the PRDCH or PDRCH including the midamble can be repeatedly transmitted N times.

[0374] If N > K,

[0375] i) Option B1: After the PRDCH or PDRCH including the midamble is repeatedly transmitted K times, the PRDCH or PDRCH without the midamble can be repeatedly transmitted (NK) times.

[0376] ii) Option B2: After the PRDCH or PDRCH without the midamble is repeatedly transmitted (NK) times, the PRDCH or PDRCH including the midamble can be repeatedly transmitted K times.

[0377] If N < K,

[0378] i) Option B1: After the PRDCH or PDRCH including the midamble is repeatedly transmitted N times, the PRDCH or PDRCH without the midamble can be repeatedly transmitted (KN) times.

[0379] ii) Option B2: After the PRDCH or PDRCH without the midamble is repeatedly transmitted (KN) times, the PRDCH or PDRCH including the midamble can be repeatedly transmitted N times.

[0380] - When the postamble is also transmitted K times during N PRDCH / PDRCH repetition transmission, it can be transmitted with one of the following options. Here, N and K can be the same or different.

[0381] i) Option C1: A structure in which the postamble is repeatedly transmitted K times after the PRDCH or PDRCH is repeatedly transmitted N times.

[0382] This method is applicable to chip-level / bit-level / block-level iterative transmission.

[0383] ii) Option C2: Structure in which {PRDCH + postamble} or {PDRCH + postamble} is repeatedly transmitted N times.

[0384] If N = K, {PRDCH + postamble} or {PDRCH + postamble} is repeatedly transmitted N times.

[0385] If N > K, after PRDCH or PDRCH is repeatedly transmitted (NK) times, {PRDCH + postamble} or {PDRCH + postamble} may be repeatedly transmitted K times.

[0386] If N < K, after {PRDCH + postamble} or {PDRCH + postamble} is repeatedly transmitted N times, the postamble can be repeatedly transmitted (KN) times.

[0387] This method can be broadly applied to block-level iterative transmission methods.

[0388] When the preamble and postamble are transmitted together with the PRDCH or PDRCH, or when the preamble, midamble, and postamble are all transmitted together with the PRDCH or PDRCH, or when the preamble and midamble are transmitted together with the PRDCH or PDRCH, the transmission structure can be determined by combining the above-described options. For example, it can be transmitted in a structure of option A1+B1+C1, a structure of option A1+B2+C2, or a structure of option A2+B1+C1 or option A2+B2+C2.

[0389] The above options can be configured as system information transmitted by the leader or as R2D / D2R control information. For example, repeated transmission of D2R x-amble can be configured / instructed by R2D or D2R control information, and repeated transmission of R2D x-amble can be configured / instructed by R2D control information. Alternatively, the settings can be fixed (i.e., predefined) by the specification.

[0390] Example 7: Early termination / stop instruction method for D2R repeat transmission

[0391] When transmitting a PDRCH in response to a PRDCH transmission, transmission or repeated transmission of the PDRCH may be indicated through the preamble of the R2D transmission or the control information of the PRDCH. Alternatively, transmission or repeated transmission of the PDRCH may be indicated through the preamble of the D2R transmission or the control information of the PDRCH. Here, the repeated transmission indication may be indicated by one or more of chip-level repetition, bit-level repetition, or block-level repetition.

[0392] If block-level repetition is indicated or determined, and N blocks are repeatedly transmitted on the PDRCH with block-level repetition, a leader that has received up to the Kth block (k < N) can successfully decode the TB. In this case, the leader can instruct the device to stop repeated transmission after the Kth block by transmitting an R2D preamble, midamble, or postamble, or by transmitting R2D control information. For example, the leader can instruct the device to stop repeated transmission through a specific pattern of the R2D preamble, midamble, or postamble, or a specific field of the L1 or L2 control information of the PRDCH.

[0393] A device that successfully receives an instruction to stop the above-described repetitive transmission can terminate the PDRCH repetitive transmission by stopping the repetitive transmission after the Kth block. In this case, the device can notify the leader of the termination of the PDRCH repetitive transmission by transmitting a postamble after the Kth block. Alternatively, a device that successfully receives an instruction to stop the above-described repetitive transmission can terminate the PDRCH repetitive transmission by stopping the repetitive transmission after the block that has been or is currently being transmitted. In this case, the device can notify the leader of the termination of the PDRCH repetitive transmission by transmitting a postamble after the block that has been or is currently being transmitted.

[0394] If the R2D transmission that instructs the leader to stop the repetitive transmission fails (e.g., the leader does not receive a D2R response to the R2D transmission instructing to stop the repetitive transmission, or the device continues the repetitive transmission after being instructed to stop the repetitive transmission), the leader may re-instruct to stop the repetitive transmission by retransmitting the R2D preamble, midamble, or postamble, or by retransmitting the R2D control information.

[0395] A device that successfully receives an R2D retransmission instructing it to stop repeat transmissions may terminate the PDRCH repeat transmissions by stopping repeat transmissions after the currently transmitted or currently transmitting block. Here, the device may notify the leader of the termination of the PDRCH repeat transmissions by transmitting a postamble after the currently transmitted or currently transmitting block.

[0396] Example 8: MCS change method based on maximum length

[0397] When transmitting a PDRCH in response to a PRDCH transmission, repeated transmission of the PDRCH may be indicated through the preamble of the R2D transmission or the control information of the PRDCH, and the maximum length of the PDRCH may be indicated. Alternatively, transmission or repeated transmission of the PDRCH may be indicated through the preamble of the D2R transmission or the control information of the PDRCH. Here, the repeated transmission indication may be indicated by one or more of chip-level repetition, bit-level repetition, or block-level repetition.

[0398] If the maximum length is not indicated through the preamble of the R2D transmission or the control information of the PRDCH, the maximum length may be determined by a specific value indicated by the system information transmitted by the leader. Alternatively, if the maximum length is not indicated through the preamble of the R2D transmission or the control information of the PRDCH (or is not additionally indicated by the system information), the maximum length may be determined as a fixed maximum length for each device, device group, or device type.

[0399] If the PDRCH is transmitted repeatedly or not repeatedly, and if the maximum length of the PDRCH is indicated / determined, and if the PDRCH transmission or repeated transmission does not satisfy the maximum length, the device may stop the PDRCH transmission or change the MCS to satisfy the maximum length of the PDRCH and transmit. For example, if there is no power to transmit one TB with a 1 / 3 coding rate, one TB may be transmitted or repeatedly transmitted with a 1 / 2 coding rate within the maximum length if a 1 / 2 coding rate satisfies the maximum length. In this case, the device may indicate a 1 / 2 coding rate with the L1 control information of the PDRCH.

[0400] FIG. 22 illustrates a communication method according to one embodiment of the present disclosure.

[0401] FIG. 22 illustrates the operation of a device (e.g., an Ambient-IoT device or tag) based on the proposed methods in the embodiments described above. The example in FIG. 22 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some of the step(s) illustrated in FIG. 22 may be omitted depending on the situation and / or setting. In addition, the device in FIG. 22 is only an example and may be implemented as the device illustrated in FIG. 3. For example, the processor (202) in FIG. 3 may control the transceiver (206) to transmit and receive channels / signals / data / information, etc., and may also control the processor (202) in FIG. 3 to store the channels / signals / data / information to be transmitted or received in the memory (204).

[0402] Additionally, the operation of FIG. 22 may be processed by one or more processors (202) of FIG. 3. Additionally, the operation of FIG. 22 may be stored in a memory (e.g., one or more memories (204) of FIG. 3) in the form of a command / program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 202) of FIG. 3.

[0403] In FIG. 22, the device may be a device that transmits a backscattered signal to the leader based on a carrier wave for energy harvesting or backscattering from the leader or from a CW node, and the leader may be a device that receives the backscattered signal from the device.

[0404] Referring to FIG. 22, the device transmits a D2R (device-to-reader) preamble to the reader (S2201).

[0405] The device repeatedly transmits a physical device-to-reader channel (PDRCH) followed by a D2R preamble to the leader (S2202).

[0406] Based on the repeated transmission of the above PDRCH, the length of the D2R midamble transmitted within the above PDRCH can be determined.

[0407] Here, the entire D2R transmission may include at least one D2R preamble, at least one PDRCH, and at least one D2R midamble.

[0408] Transmitting the PDRCH after the D2R preamble may mean that the PDRCH bits are arranged / positioned after the D2R preamble bits in the overall D2R transmission. Additionally, transmitting the D2R midamble within the PDRCH may mean that the bits of the D2R midamble are arranged / positioned in the middle of the overall PDRCH bits.

[0409] Additionally, the pattern of the midamble sequence can be determined based on the length of the D2R midamble.

[0410] Additionally, the length of the D2R midamble may be determined based on the number of repetitions of the repeated transmission of the PDRCH. For example, the length of the D2R midamble may be determined based on the number of repetitions of the repeated transmission of the PDRCH, and accordingly, the pattern of the midamble sequence may be determined.

[0411] For example, the length of the D2R midamble may be determined as a multiple of the D2R midamble transmitted within a non-repeated PDRCH in proportion to the number of repetitions of the repeated transmission of the PDRCH.

[0412] Here, the mapping between the number of repetitions of the repeated transmission of the PDRCH and the length of the D2R midamble may be set by system information received from the leader or control information of the PRDCH or may be predefined (e.g., in the specification).

[0413] Although not shown in FIG. 22, the device can receive a physical reader-to-device channel (PRDCH) from the reader.

[0414] Here, repeated transmission of the PDRCH may be indicated by a preamble related to the PRDCH or control information of the PRDCH.

[0415] For example, the maximum length of the PDRCH may be further indicated by a preamble associated with the PRDCH or control information of the PRDCH. In this case, the repetitive transmission of the PDRCH may be stopped based on the length of the repetitive transmission of the PDRCH exceeding the maximum length.

[0416] As another example, the minimum power of the PDRCH may be further indicated by a preamble related to the PRDCH or control information of the PRDCH. In this case, the repeated transmission of the PDRCH may be stopped based on the determination that the kth (k is an integer greater than 0) repetition of the repeated transmission of the PDRCH cannot be completed beyond the minimum power depending on the energy level of the device.

[0417] As another example, the repetitive transmission of the PDRCH may be discontinued based on the energy level of the device dropping below a specific threshold during the repetitive transmission of the PDRCH or the device switching to an OFF or sleep state. In this case, the discontinuation of the repetitive transmission of the PDRCH may be reported to the leader through a specific pattern of D2R preamble, midamble and / or postamble, or L1 / L2 control information by the device. Furthermore, the resumption of the repetitive transmission of the PDRCH may be reported to the leader through a specific pattern of D2R preamble, midamble and / or postamble, or L1 / L2 control information by the device based on the energy level of the device rising above a specific threshold or the device switching to an ON state after the discontinuation of the repetitive transmission of the PDRCH.

[0418] FIG. 23 illustrates a communication method according to one embodiment of the present disclosure.

[0419] FIG. 23 illustrates the operation of a leader (i.e., a base station, a UE, or an intermediate node) based on the proposed methods in the embodiments described above. The example in FIG. 23 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some of the step(s) illustrated in FIG. 23 may be omitted depending on the situation and / or setting. In addition, the device in FIG. 23 is only an example and may be implemented as the device illustrated in FIG. 3. For example, the processor (202) in FIG. 3 may control the transceiver (206) to transmit and receive channels / signals / data / information, etc., and may also control the processor (202) in FIG. 3 to store the channels / signals / data / information to be transmitted or received in the memory (204).

[0420] Additionally, the operation of FIG. 23 may be processed by one or more processors (202) of FIG. 3. Additionally, the operation of FIG. 23 may be stored in a memory (e.g., one or more memories (204) of FIG. 3) in the form of a command / program (e.g., an instruction, an executable code) for driving at least one processor (e.g., 202) of FIG. 3.

[0421] In FIG. 23, the device may be a device that transmits a backscattered signal to the leader based on a carrier wave for energy harvesting or backscattering from the leader or from a CW node, and the leader may be a device that receives the backscattered signal from the device.

[0422] Referring to FIG. 23, the reader receives a D2R (device-to-reader) preamble from the device (S2301).

[0423] The leader repeatedly receives a physical device-to-reader channel (PDRCH) following a D2R preamble from the device (S2302).

[0424] Based on the repeated transmission of the above PDRCH, the length of the D2R midamble transmitted within the above PDRCH can be determined.

[0425] Here, the entire D2R transmission may include at least one D2R preamble, at least one PDRCH, and at least one D2R midamble.

[0426] Transmitting the PDRCH after the D2R preamble may mean that the PDRCH bits are placed / positioned after the D2R preamble bits in the overall D2R transmission. Additionally, transmitting the D2R midamble within the PDRCH may mean that the bits of the D2R midamble are placed / positioned in the middle of the overall PDRCH bits.

[0427] Additionally, the pattern of the midamble sequence can be determined based on the length of the D2R midamble.

[0428] Additionally, the length of the D2R midamble may be determined based on the number of repetitions of the repeated transmission of the PDRCH. For example, the length of the D2R midamble may be determined based on the number of repetitions of the repeated transmission of the PDRCH, and accordingly, the pattern of the midamble sequence may be determined.

[0429] For example, the length of the D2R midamble may be determined as a multiple of the D2R midamble transmitted within a non-repeated PDRCH in proportion to the number of repetitions of the repeated transmission of the PDRCH.

[0430] Here, the mapping between the number of repetitions of the repeated transmission of the PDRCH and the length of the D2R midamble may be set by system information received from the leader or control information of the PRDCH or may be predefined (e.g., in the specification).

[0431] Although not shown in FIG. 23, the leader may transmit a physical reader-to-device channel (PRDCH) to the device.

[0432] Here, repeated transmission of the PDRCH may be indicated by a preamble related to the PRDCH or control information of the PRDCH.

[0433] For example, the maximum length of the PDRCH may be further indicated by a preamble associated with the PRDCH or control information of the PRDCH. In this case, the repetitive transmission of the PDRCH may be stopped based on the length of the repetitive transmission of the PDRCH exceeding the maximum length.

[0434] As another example, the minimum power of the PDRCH may be further indicated by a preamble related to the PRDCH or control information of the PRDCH. In this case, the repeated transmission of the PDRCH may be stopped based on the determination that the kth (k is an integer greater than 0) repetition of the repeated transmission of the PDRCH cannot be completed beyond the minimum power depending on the energy level of the device.

[0435] As another example, the repetitive transmission of the PDRCH may be discontinued based on the energy level of the device dropping below a specific threshold during the repetitive transmission of the PDRCH or the device switching to an OFF or sleep state. In this case, the discontinuation of the repetitive transmission of the PDRCH may be reported to the leader through a specific pattern of D2R preamble, midamble and / or postamble, or L1 / L2 control information by the device. Furthermore, the resumption of the repetitive transmission of the PDRCH may be reported to the leader through a specific pattern of D2R preamble, midamble and / or postamble, or L1 / L2 control information by the device based on the energy level of the device rising above a specific threshold or the device switching to an ON state after the discontinuation of the repetitive transmission of the PDRCH.

[0436] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

[0437] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics of the present disclosure. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0438] The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on / in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices remotely located from the processor(s). The memory or, alternatively, the non-volatile memory device(s) within the memory comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and / or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0439] Here, the wireless communication technology implemented in the device of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PAN) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0440] The method proposed in this disclosure is explained with a focus on examples applied to 3GPP LTE / LTE-A, 5G, and 6G systems, but can be applied to various wireless communication systems in addition to 3GPP LTE / LTE-A, 5G, and 6G systems.

Claims

1. A step of transmitting a D2R (device-to-reader) preamble to a reader device by a device; and By the above device, a step of repeatedly transmitting a physical device-to-reader channel (PDRCH) following the D2R preamble to the leader is included, A method in which the length of a D2R midamble transmitted within the PDRCH is determined based on repeated transmission of the PDRCH.

2. In paragraph 1, A method in which a pattern of a midamble sequence is determined based on the length of the above D2R midamble.

3. In paragraph 1, A method in which the length of the D2R midamble is determined based on the number of repetitions of the repeated transmission of the PDRCH.

4. In paragraph 3, A method wherein the length of the above D2R midamble is determined as a multiple of the D2R midamble transmitted within a PDRCH without repetition in proportion to the number of repetitions of the repeated transmission of the PDRCH.

5. In paragraph 3, A method in which the mapping between the number of repetitions of the repeated transmission of the PDRCH and the length of the D2R midamble is set or predefined by system information received from the leader or control information of a physical reader-to-device channel (PRDCH).

6. In paragraph 1, Further comprising a step of receiving a physical reader-to-device channel (PRDCH) from the reader by the device, A method in which repeated transmission of the PDRCH is indicated by a preamble related to the PRDCH or control information of the PRDCH.

7. In paragraph 6, The maximum length of the PDRCH is further indicated by the preamble related to the PRDCH or the control information of the PRDCH, A method in which the repeated transmission of the PDRCH is stopped based on the length of the repeated transmission of the PDRCH exceeding the maximum length.

8. In paragraph 6, The minimum power of the PDRCH is further indicated by the preamble related to the PRDCH or the control information of the PRDCH, A method in which the repetitive transmission of the PDRCH is stopped based on the determination that the kth (k is an integer greater than 0) repetition of the repetitive transmission of the PDRCH cannot be completed beyond the minimum power depending on the energy level of the device.

9. In paragraph 6, A method in which the repetitive transmission of the PDRCH is stopped based on the energy level of the device falling below a specific threshold or the device switching to an OFF or sleep state during the repetitive transmission of the PDRCH.

10. In paragraph 9, A method in which the leader is reported about the cessation of repetitive transmission of the PDRCH through a specific pattern of D2R preamble, midamble and / or postamble, or L1 / L2 control information by the device.

11. In paragraph 10, A method in which the resumption of the repeated transmission of the PDRCH is reported to the leader through a specific pattern of D2R preamble, midamble and / or postamble, or L1 / L2 control information by the device based on the energy level of the device rising above a specific threshold or the device switching to the ON state after the cessation of the repeated transmission of the PDRCH.

12. The device: One or more transceivers for transmitting and receiving wireless signals; and comprising one or more processors controlling one or more of the above transceivers, One or more of the above processors: Transmit a D2R (device-to-reader) preamble to the leader; and The above leader is configured to repeatedly transmit the PDRCH (physical device-to-reader channel) following the D2R preamble, A device in which the length of a D2R midamble transmitted within the PDRCH is determined based on repeated transmission of the PDRCH.

13. One or more non-transitory computer-readable media storing one or more instructions, The one or more instructions are executed by one or more processors, so that the device: Transmit a D2R (device-to-reader) preamble to the leader; and Control the above leader to repeatedly transmit the PDRCH (physical device-to-reader channel) following the D2R preamble, A computer-readable medium in which the length of a D2R midamble transmitted within the PDRCH is determined based on repeated transmission of the PDRCH.

14. In a processing device configured to control a device, the processing device: one or more processors; and One or more computer memories operatively connected to said one or more processors and storing instructions that perform operations based on being executed by said one or more processors, The above actions are: A step of transmitting a D2R (device-to-reader) preamble to the leader; and A step of repeatedly transmitting a physical device-to-reader channel (PDRCH) following the D2R preamble to the above leader, A processing device in which the length of a D2R midamble transmitted within the PDRCH is determined based on repeated transmission of the PDRCH.

15. A step of receiving a D2R (device-to-reader) preamble from a device by a reader; and A step of repeatedly receiving, by the above leader, a physical device-to-reader channel (PDRCH) following the D2R preamble from the above device, A method in which the length of a D2R midamble transmitted within the PDRCH is determined based on repeated transmission of the PDRCH.

16. The leader: One or more transceivers for transmitting and receiving wireless signals; and comprising one or more processors controlling one or more of the above transceivers, One or more of the above processors: Receive a device-to-reader (D2R) preamble from the device; and It is set to repeatedly receive a PDRCH (physical device-to-reader channel) following the D2R preamble from the above device, A leader in which the length of a D2R midamble transmitted within the PDRCH is determined based on repeated transmission of the PDRCH.

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