Method and apparatus for configuring transmission resource for low-power communication in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. In addition, the present disclosure relates to a low-power communication system in which a device having no battery or only a capacitor-level energy storage capability can operate. A method performed by a tag of a communication system, according to an embodiment of the present disclosure, comprises the steps of: identifying a frequency resource related to the tag; identifying a time resource related to the tag; and transmitting an uplink signal to a reader or receiving a downlink signal from the reader on the basis of the frequency resource and the time resource, wherein at least one of the frequency resource and the time resource may be identified on the basis of information pre-configured for the tag.

Description

Method and device for setting up transmission resources for low-power communication in a wireless communication system

[0001] The present disclosure relates to a terminal, a base station, and a low-power communication device in a communication system. Specifically, the present disclosure relates to a method and device for a low-power communication device to set up transmission resources for communication with a terminal or base station and to transmit and receive data with the terminal or base station through the resources.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once such 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] As described above and with the development of wireless communication systems, various services have become available, and methods for providing these services smoothly are required.

[0009] The present disclosure may be directed to providing a device and method capable of effectively providing a service in a mobile communication (or wireless communication) system.

[0010] A method performed by a tag of a communication system according to one embodiment of the present disclosure includes the steps of identifying a frequency resource associated with the tag, identifying a time resource associated with the tag, and transmitting an uplink signal to a reader or receiving a downlink signal from the reader based on the frequency resource and the time resource, wherein at least one of the frequency resource or the time resource can be identified based on information preset for the tag.

[0011] A method performed by a reader of a communication system according to one embodiment of the present disclosure includes the steps of identifying a frequency resource associated with a tag, identifying a time resource associated with the tag, and receiving an uplink signal from the tag or transmitting a downlink signal to the tag based on the frequency resource and the time resource, wherein at least one of the frequency resource or the time resource can be identified based on information preset for the tag.

[0012] A tag of a communication system according to one embodiment of the present disclosure includes a transceiver and a control unit, wherein the control unit is configured to identify a frequency resource associated with the tag, identify a time resource associated with the tag, and transmit an uplink signal to a reader based on the frequency resource and the time resource or receive a downlink signal from the reader, wherein at least one of the frequency resource or the time resource can be identified based on information preset for the tag.

[0013] A reader of a communication system according to one embodiment of the present disclosure includes a transceiver and a control unit, wherein the control unit is configured to identify a frequency resource associated with a tag, identify a time resource associated with the tag, and receive an uplink signal from the tag or transmit a downlink signal to the tag based on the frequency resource and the time resource, and at least one of the frequency resource or the time resource can be identified based on information preset for the tag.

[0014] The disclosed embodiment can provide a device and method capable of effectively providing a service in a mobile communication system.

[0015] 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 can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0016] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0017] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0018] FIG. 3A is a diagram illustrating frequency resources that can be set in a tag for low-power communication according to one embodiment of the present disclosure.

[0019] FIG. 3b is a diagram illustrating frequency resources that can be set in a tag for low-power communication according to an embodiment of the present disclosure.

[0020] FIG. 3c is a diagram illustrating frequency resources that can be set in a tag for low-power communication according to one embodiment of the present disclosure.

[0021] FIG. 4A is a diagram illustrating an example of indexing time resources in a tag for low-power communication according to one embodiment of the present disclosure.

[0022] FIG. 4b is a diagram illustrating another example of indexing time resources in a tag for low-power communication according to an embodiment of the present disclosure.

[0023] FIG. 4c is a diagram illustrating another example of indexing time resources in a tag for low-power communication according to an embodiment of the present disclosure.

[0024] FIG. 5A is a diagram illustrating a method for mapping information on frequency resources set in a tag according to an embodiment of the present disclosure into a bit string.

[0025] FIG. 5b is a diagram illustrating an example of information about frequency resources indicated by each field included in a bit string according to an embodiment of the present disclosure.

[0026] FIG. 6 is a diagram illustrating an example in which a tag receives a downlink and transmits an uplink according to available time resources set for each tag according to one embodiment of the present disclosure.

[0027] FIG. 7 is a diagram illustrating an example of a tag using fixed time and frequency resources according to one embodiment of the present disclosure.

[0028] FIG. 8 is a diagram illustrating the structure of a tag in a low-power wireless communication system according to an embodiment of the present disclosure.

[0029] FIG. 9 is a diagram illustrating the structure of a leader in a wireless communication system according to an embodiment of the present disclosure.

[0030] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0031] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure may be omitted. This is to ensure that the gist of the present disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0032] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0033] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals may refer to like elements throughout the specification. In addition, when describing the present disclosure, if a specific description of a related function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description thereof may be omitted. In addition, the terms described below are terms defined in consideration of the functions of the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the specification.

[0034] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, the downlink (DL) may refer to a wireless transmission path of a signal transmitted from the base station to the terminal, and the uplink (UL) may refer to a wireless transmission path of a signal transmitted from the terminal to the base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems through some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

[0035] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment can create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0036] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0037] Here, the term '~ unit' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ unit' can perform certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Accordingly, as an example, the '~ unit' may include components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0038] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 3GPP's HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0039] As a representative example of the above broadband wireless communication system, the LTE system adopts the OFDM (Orthogonal Frequency Division Multiplexing) method in the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method in the uplink (UL). The uplink refers to a wireless link in which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B or base station (BS)), and the downlink may refer to a wireless link in which a base station transmits data or control signals to a terminal. The above multiple access method can distinguish the data or control information of each user by allocating and operating the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality.

[0040] As a future communication system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, services that simultaneously satisfy these requirements must be supported. Services being considered for 5G communication systems include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0041] eMBB may aim to provide data rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB may need to support a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems may need to provide both peak data rates and increased user-perceived data rates. To meet these requirements, improvements in various transmission and / or reception technologies, including improved multi-input, multi-output (MIMO) transmission technologies, may be required. Furthermore, while LTE transmits signals using a maximum 20 MHz of bandwidth in the 2 GHz band, 5G communication systems can meet the data rates required by 5G communication systems by using a wider bandwidth than 20 MHz in the 3-6 GHz or higher 6 GHz bands.

[0042] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the IoT, mMTC may require support for large-scale terminal connections within a cell, improved terminal coverage, improved battery life, and reduced terminal costs. The IoT, which connects various sensors and devices to provide communication functions, may require support for a large number of terminals (e.g., 1,000,000 terminals / km^2) within a cell. Furthermore, terminals supporting mMTC are likely to be located in shadow areas, such as basements, beyond cell coverage due to the nature of the service, which may require broader coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC should be comprised of low-cost terminals, and since frequent battery replacement is unlikely, very long battery lifespans, such as 10 to 15 years, may be required.

[0043] Finally, URLLC refers to cellular-based wireless communication services used for specific mission-critical purposes. Examples include remote control of robots or machinery, industrial automation, unmanned aerial vehicles (UAVs), remote health care, and emergency alerts. Therefore, URLLC communications must offer extremely low latency and high reliability. For example, URLLC-enabled services must meet air interface latency requirements of less than 0.5 milliseconds and a packet error rate (PER) of less than 10^-5. Therefore, for URLLC-enabled services, 5G systems must provide shorter Transmit Time Intervals (TTIs) than other services, while simultaneously allocating extensive resources in the frequency band to ensure communication link reliability.

[0044] The three 5G services—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. To meet the differing requirements of each service, different transmission and / or reception techniques and transmission and / or reception parameters may be used. Of course, 5G is not limited to the three services described above.

[0045] [NR time-frequency resources]

[0046] Below, the frame structure of the 5G system can be described in more detail with reference to the drawings.

[0047] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0048] Referring to FIG. 1, the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G system, is illustrated.

[0049] The horizontal axis of Figure 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and 1 subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can constitute one resource block (RB, 104). One subframe (110) on the time axis can include multiple OFDM symbols (102). For example, the length of one subframe can be 1 ms.

[0050] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0051] Referring to FIG. 2, an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202, 203) is illustrated. One frame (200) can be defined as 10 ms. One subframe (201) can be defined as 1 ms, and therefore one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In an example of FIG. 2, the cases where the subcarrier spacing setting value μ = 0 (204) and μ = 1 (205) are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of 1 slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of 2 slots (203). That is, the number of slots per 1 subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0052] [Table 1]

[0053]

[0054] Low-Power Communication: Ambient-IoT Related

[0055] The Internet of Things (IoT) has garnered significant attention in wireless communications over the past few years, with more and more objects becoming interconnected, contributing to improved productivity and convenience. Most existing IoT devices operate using batteries that require manual replacement or recharging. However, the automation and digitalization of various industries have opened up new markets, creating a need for new communication devices that do not pose the high maintenance costs, serious environmental concerns, and safety issues associated with batteries. Consequently, the need for devices without batteries or with capacitor-level energy storage has been recognized, and AIoT tags are low-power communication devices that meet these requirements. Instead of relying on batteries, AIoT tags derive their energy from light, radio waves, motion, heat, or any other power source deemed suitable. This technology is called energy harvesting. Given the size and complexity required for AIoT tags, the output power of energy harvesters typically ranges from 1uW to several hundred uW. However, current commercial communication technologies are designed for communication devices with a maximum power of 10mW or more, making it difficult to meet the requirements of AIoT device use cases. Therefore, the need for new low-power communication technologies that can be utilized in AIoT use cases is emerging.

[0056] The AIoT tag (hereinafter referred to as a tag) described below is a device that receives energy through energy harvesting. It can use two methods to generate signals. First, backscattering communication can be used to generate signals by reflecting an external RF signal for data transmission. In this case, the signal transmitted to the tag for uplink transmission from the outside can be referred to as a carrier wave (CW). The CW can be transmitted from an external node to the tag, and the tag can generate an uplink signal by reflecting the signal. When using backscattering communication, the tag does not directly generate a signal internally, which significantly reduces power consumption and device complexity. The tag can reflect the signal and encode information stored in its memory, and the reflected signal can be transmitted to the reader for decoding. Another method is to generate the signal internally. In this case, the tag must generate the signal internally, which can lead to greater power consumption and device complexity than when using backscattering communication. AIoT tags may also use amplifiers in their transmitters and receivers to improve communication performance.

[0057] In an AIoT system, tags can utilize certain frequency and time resources for transmission and reception with readers and reception of CW (Cycle Wavelet). The frequency resources of a tag may include a center frequency of the CW, a specific PRB or subcarrier number, a predefined channel number, a frequency band, and spectrum allocation information. For example, the frequency resource information of a tag may be solely the center frequency value of the CW. Alternatively, the frequency resource information of a tag may be a predefined channel number within the entire frequency band of the AIoT system. This channel number may correspond to a specific frequency value or range. If the channel number corresponds to a specific range, additional information, such as a resource block number or subcarrier number, may be provided. Alternatively, the frequency resource information of a tag may be determined by a combination of spectrum allocation information, such as in-band, guard band, or other frequency bands, and information on specific channels defined within the spectrum. Furthermore, information on frequency resources that a tag can utilize may be specified through various combinations, including specifying a center frequency or a specific frequency band. The center frequency specified at this time may be set to align with a specific subcarrier used in the NR system, or may be set independently therefrom.

[0058] FIGS. 3A, 3B, and 3C are diagrams illustrating frequency resources that can be set in a tag for low-power communication according to an embodiment of the present disclosure.

[0059] FIG. 3A illustrates a spectrum configuration that can be configured for a tag, which can be equally applied to a non-NR LTE system. The tag may be configured to operate in-band of an NR frequency band having an NR bandwidth (300) (301), within a guard band within the NR frequency band (302), or within a band other than the NR frequency band (e.g., a GSM band) (303). Additionally, the tag may be configured to operate within one of one or more bands defined within an operating spectrum. Referring to FIG. 3B, for example, three bands, Band #1 (311), Band #2 (312), and Band #3 (313), are defined within the operating spectrum, and the tag may be configured to belong to one of these bands. FIG. 3B illustrates three as an example of the number of bands defined within the operating spectrum, but this is for illustration only and does not limit the scope of the invention. Additionally, as in the example of FIG. 3c, a tag may be configured to operate on one of the predefined channels within an operating band within an operating spectrum. For example, a tag may be configured to operate on one of the predefined channels via a channel index indicating the one of the predefined channels. The channel index may indicate an actual frequency value, a PRB index, a subcarrier index, etc. FIG. 3c illustrates a total of six channel indices (#0 to #6) as channel indices for indicating one of the predefined channels, but this is for illustration only and does not limit the scope of the invention.

[0060] Tags designed for power communication are designed for minimal power consumption, so synchronization with a reader can be challenging. The reader can be a base station, a terminal, or a separate device designed specifically for low-power tags. A reader can be a device that receives uplink signals from tags and transmits downlink signals. In this document, all of these are referred to as readers. For example, if a tag loses power due to insufficient power supply, synchronization between the tag and reader can be lost. Therefore, tags can synchronize independently from the reader. Even if they fail to achieve perfect synchronization with the reader, tags can maintain a synchronization system based on their own criteria. For example, even without precise timing synchronization with the reader, tags can define time resource indices by setting internal timers based on specific points in time. Specifically, tags can set a timer for a specific period of time based on the receipt of a timing reference signal from an external node, such as a reader or a CW node, and then define time resource indices based on the corresponding time intervals. Alternatively, the tag can define the time resource index by incrementing the time resource index whenever it receives a timing reference signal from an external node. This allows the tag to manage its time resource independently, without relying on synchronization with the leader. In this case, the timing reference signal is a signal transmitted to the tag from an external node, such as a leader or a CW node, and may be a signal designed for all tags in the system or only some tags. Such a signal may be received by the tag periodically or aperiodicly.

[0061] FIGS. 4A, 4B, and 4C are diagrams illustrating an example of indexing time resources in a tag for low-power communication according to an embodiment of the present disclosure.

[0062] FIG. 4A illustrates an example of increasing the index of a time resource at regular time intervals starting from the time point at which a tag receives a timing reference signal from an external node. Referring to FIG. 4A, a tag can operate an internal timer starting from the time point (400) at which a timing reference signal is received from an external node such as a leader or a CW node. The tag can recognize the time interval from immediately after receiving the first timing reference signal until the internal timer completes one cycle as a time resource with an index of 0 (401). The tag can recognize the time interval from immediately after the time resource with an index of 0 until the internal timer completes one cycle as time resources with indices of 1 and 2, respectively (402, 403). Referring to FIG. 4B, the tag can increase the index of the time resource every time a timing reference signal is received starting from the time point at which the tag first receives a timing reference signal from an external node such as a leader or a CW node until the tag receives the timing reference signal (410). After the tag receives the first timing reference signal, the tag can set the time interval until it receives the next timing reference signal as a time resource with an index of 0 (411), and can set the time interval until it receives the next timing reference signal as a time resource with an index of 1 (412). In the same way, the tag can set the time interval until it receives the timing reference signal again as a time resource with an index of 2 (413). In the present embodiment, the timing reference signal can be an activation signal for activating the tag. The index set by the tag can be interrupted or initialized when the tag is powered off due to lack of power or when it receives an additional signal from the reader to release the index, or the time resource index can be repeated by performing a modulo operation on a certain value. Alternatively, the tag can take the timing at which the timing reference signal is received as a starting point and operate only based on the passage of time thereafter without calculating the index of the time resource.As an example, Figure 4c illustrates a case where a tag does not calculate the index of a time resource. The tag can internally calculate the passage of time using an internal timer, etc., starting from the time at which a timing reference signal is received (420) (421). Upon receiving a new timing reference signal, the tag can reset the timer and recalculate the passage of time (422).

[0063] In AIoT systems, tags may possess information about various communication parameters for communication with the reader. To flexibly select transmission resources, tags can be allocated information about these resources from the reader. However, this process can incur additional power consumption and overhead for the tag, which can be particularly detrimental to tags that derive energy from energy harvesting. Therefore, the flexibility of the tag's transmission resources can be limited to minimize power consumption for low-power communication. Therefore, the following describes a transmission resource configuration method that reduces unnecessary overhead and minimizes power consumption for low-power communication devices. Tags do not receive separate transmission resource configuration information from the reader; instead, each tag can use only fixed transmission resources. Specifically, this transmission resource information can be hard-wired into the tag and configured separately. "Hard-wired" here means that the configuration information is physically embedded in the tag's circuitry and cannot be modified. For example, information about the transmission resources hard-wired into the tag may be displayed in the tag's global ID.

[0064] [Frequency Resource Indication Method]

[0065] Tags can only utilize a set of frequency resources for low-power communication. For example, the spectrum configuration of each tag can be fixed. For example, a tag can be configured to operate exclusively in the in-band spectrum, the guardband spectrum, or within a specifically defined spectrum. Alternatively, all or part of the spectrum configuration, frequency band, and predefined channel number available to each tag can be fixed. Therefore, a tag can be configured to use only fixed frequency resources corresponding to a fixed spectrum configuration, fixed frequency band number, and fixed channel number, based on hard-wired information. The level of fixed frequency resources for each tag can vary. In some cases, the spectrum can be fixed within a fixed range. That is, the tag's bandwidth usage is determined, but the specific frequency value is not fixed. In this case, flexibility in frequency resource selection within the fixed spectrum range can be guaranteed. In other cases, the frequency value itself can be completely fixed, allowing the tag to use only a specific frequency. Information about a fixed frequency value can be determined by combining information about various frequency resources. Information about the frequency value can be provided at the subcarrier, RB, or RBG level, or a lookup table can be used to set specific frequency values ​​for each index. Information corresponding to the actual frequency resource can be converted into a bit string using a formula, bitmap, or lookup table, and this can be hard-wired into the tag to become fixed information. Bit strings corresponding to the information about the frequency resource can be included, for example, as part of the tag's global ID, and the reader can utilize this information by transmitting it to the reader when necessary.

[0066] FIG. 5A is a diagram illustrating a method for mapping information on frequency resources set in a tag according to an embodiment of the present disclosure into a bit string.

[0067] FIG. 5a is a diagram illustrating a method for mapping information on frequency resources fixedly set to tag #1 (501) and tag #2 (502) according to the above embodiment into a bit string. For example, among a portion of the global ID (500) of each tag, a total of four fields A (503), B (504), C (505), and D (506) may correspond to bit strings that map frequency resource information of the tag.

[0068] FIG. 5b is a diagram illustrating an example of information about frequency resources indicated by each field included in a bit string according to an embodiment of the present disclosure.

[0069] Information about the frequency domain indicated by each field is as shown in the first table (520) of Fig. 5b. Field A (503) can indicate information about the frequency band used by the tag. Information about the frequency band used by the actual tag indicated by the bit string of field A can refer to the second table (521) of Fig. 5b. Field B (504) can indicate information about the spectrum used by the tag. Information about the spectrum used by the actual tag indicated by the bit string of field B can refer to the third table (522) of Fig. 5b. In the case of tag #1 and tag #2, fields A and B both indicate band #1 and in-band operation. Therefore, both tags can be tags that communicate with the reader in-band within band #1. The bit string of field C can indicate information about the channel set to the tag. In this case, the channel can also be used to indicate the relative location of the resource block in the frequency domain. For example, a bit string representing a channel can indicate the location of a specific frequency by corresponding to the relative position of a PRB within a specific bandwidth. Alternatively, a channel may correspond to an absolute frequency value itself. For example, a frequency value of a channel corresponding to a bit string value representing a channel may be defined in a reference table. Such a reference table may be defined in advance for each frequency band, and the reader may know this information in advance. Alternatively, for the start frequency and frequency offset values ​​that can be set for each specific band, the frequency value corresponding to the channel can be calculated as start frequency + (frequency offset) * (channel bit string value). When channel information defined in advance for each frequency band is used, information about the frequency band is set together, and when the relative frequency position can be used, information about the frequency band may not be set but may be set flexibly.In this embodiment, as an example for explanation, it can be assumed that there are 4 channels (CH#0, CH#1, CH#2, CH#3) defined in advance for the in-band spectrum of band #1. The frequency values ​​corresponding to the channels are defined in a reference table, so that the index of each channel can represent the frequency value corresponding to each channel. The value of field C of tag #1 corresponds to 1, the value of field C of tag #2 corresponds to 7, and in the example of FIG. 5a, field C (505) has a size of 3 bits and can represent 8 values, while the number of defined channels is 4, which is less than the number of values ​​that field C can represent, 8. Therefore, the channel index corresponding to each tag can be determined by performing a modulo operation based on 4, which is the number of channels, on the value of field C. Accordingly, the result value of performing a mod 4 operation on the values ​​of fields C of tag #1 and tag #2 can indicate the index of the channel of each tag. In this case, tag #1 may have a value corresponding to CH #1 (510), tag #2 may have a value corresponding to CH #3 (511), and when the tags communicate with the reader, tag #1 may use the frequency band corresponding to CH #1 (510), and tag #2 may use the frequency band corresponding to CH #3 (511). It depends on the size and value of the dividend field C of the modulo operation, and the divisor may depend on the total number of channels defined within the operating spectrum and operating band. In this example, the number of defined channels is less than the number of values ​​that the associated fields can represent, but this is an example, and in reality, there may be no restrictions on their values. Field D (506) can be used to indicate information about additional frequency axes, such as the frequency bandwidth that each tag can use. The above examples are only some examples of how to indicate information about frequency resources as a bit string, and various other methods can be used to provide information about frequency resources.As another example, a bit string of length 4 can be used to indicate channel information in a bitmap manner. In this case, tag #1 may have a bit string of '0100' to indicate CH#1, tag #2 may have a bit string of '0001' to indicate CH#3. The field indicating information about frequency resources in the tag ID can be transmitted when the reader wants to obtain information about the resources used by the tag, and can be used to provide specific information about this. As in the above embodiment, the determined frequency resources can be used when the tag performs both uplink transmission and downlink reception. Alternatively, separate frequency resources for uplink transmission and downlink reception can be set separately. Each piece of information can be hard-wired into the tag and included in the tag's global ID.

[0070] [How to direct time resources]

[0071] To reduce low-power communication complexity, tags can only use fixed time resources. For example, interference between tags can be reduced by pre-allocating fixed time resources so that each tag can use different time resources. If a tag uses a timing reference signal to index time resources, the index of the time resources available to the tag is fixed, and this information can be hard-wired into the tag, for example, included as part of the tag's global ID. Accordingly, a specific tag can use this fixed time resource index to determine the actual timing of uplink transmission or the expected timing of downlink transmission. If a tag does not index time resources, the absolute time value is fixed for each tag, and this information can be hard-wired into the tag, for example, included as part of the tag's global ID. In this case, time resources can be configured to initially provide broad information, and then gradually narrow the range to provide more precise information. For example, a broad range can be initially specified, and then a more detailed time resource range can be gradually provided in subsequent steps. All of this sequential information can be hard-wired into the tag and, specifically, recorded as part of the tag's global ID, reported to the reader when needed. The fixed time resource can be unique for each tag, or some tag groups may share the same time resource information. In this case, additional interference reduction can be expected by randomly staggering uplink transmissions within tag groups sharing the same time resource information.

[0072] FIG. 6 is a diagram illustrating an example in which a tag receives a downlink and transmits an uplink according to available time resources set for each tag according to one embodiment of the present disclosure.

[0073] Both tag #1 (501) and tag #2 (502) can internally operate a timer of a certain length of time starting from the time point (600) when the timing reference signal is first received. The tag can increase the virtual time resource index by 1 each time the timer completes the set time (601, 602, 603, 604). Tag #1 (501) can expect to receive a downlink at time resource index #1 (602) and can attempt to transmit an uplink at time resource index #2 (603). Tag #2 (502) can expect to receive a downlink at time resource index #1 (602) and can attempt to transmit an uplink at time resource index #3 (604). When a tag can expect to receive a downlink, the tag can be said to be in RX (Reception) mode. When a tag can attempt to transmit an uplink, the tag can be said to be in TX (Transmission) mode. At time resource index #1, both tags are converted to RX mode and expect downlink reception (610). At this time, the downlink transmission may actually occur from the leader and be received by the tag, or such reception may not occur due to the leader's judgment or channel influence. At time resource index #2, tag #1 may attempt uplink transmission (611). At time resource index #3, tag #2 may attempt uplink transmission (612). In this embodiment, for convenience, an example is described limited to two terminals, but more tags can set time resources in the same manner. In addition, by setting the same time resource index for each tag group, it can be expected that only transmission or reception of the corresponding tag group will occur during a certain period of time. Within a tag group that shares time resources for a certain period of time by being set the same time resource, each tag can additionally prevent collisions between tags by utilizing a method that delays uplink transmission by a random amount of time, such as a random backoff.If a tag does not perform time resource indexing and only considers the passage of time starting from the reception of a timing reference signal, the tag may be configured with a value for a specific time or a specific value that can correspond to a specific time. In this case, the tag may attempt to perform the configured transmission or reception operation at the moment when the specified time elapses from the timing reference signal.

[0074] Each tag can be configured with fixed frequency and time resource information. This fixed frequency and time resource information can be hard-wired into the tag and stored. For example, it can be entered into the tag's global ID, allowing the tag to transmit this information to the reader when needed.

[0075] FIG. 7 is a diagram illustrating an example of a tag using fixed time and frequency resources according to one embodiment of the present disclosure.

[0076] In this embodiment, for the convenience of diagramming time and frequency resources, they are diagrammed using a grid method, but actual frequency resources and time resources can be determined according to the embodiment described above. On the grid, a time domain resource area can be determined according to information (702) about time resources set to a tag, and on the grid, a frequency domain resource area can be determined according to information (701) about frequency resources set to a tag. Accordingly, a tag can expect uplink transmission or downlink reception in a resource (710) corresponding to a portion where the time domain resource area and the frequency domain resource area overlap in the grid. This information can be converted into a corresponding bit string using a method such as a formula, a bitmap, or a reference table. The bit string can be included in a part of the tag's global ID.

[0077] In low-power communication systems, dynamic resource management of tags can entail the overhead and complexity required for resource configuration. Specifically, for frequency resources, tags must incorporate a frequency converter to dynamically change frequency resources. However, tags in low-power communication systems typically may not be able to supply sufficient power to the frequency converter. Furthermore, the performance of the frequency converter may be significantly degraded due to low-power limitations. For these reasons, tags with dynamic resource management systems may not be suitable for low-power communications. By utilizing such a fixed resource management system, tags can reduce the overhead and complexity associated with resource management, significantly reducing the tag's complexity and power consumption.

[0078] The fixed resource management system of the above tag can be used to mitigate interference between tags by enabling frequency division multiple access (FDM) between tags. More specifically, a base station or a reader can instruct a CW source to emit a CW corresponding to a specific center frequency. At this time, among multiple tags or tag groups, only a tag or tag group that uses the same frequency resource as the CW can receive the CW and attempt uplink transmission by reflecting it. Similarly, a reader can attempt downlink transmission only on a specific center frequency. In this case, only tags using the corresponding frequency resource can receive the corresponding downlink information and sequentially perform operations accordingly.

[0079] FIG. 8 is a diagram illustrating the structure of a tag in a low-power wireless communication system according to an embodiment of the present disclosure.

[0080] Referring to FIG. 8, the tag may include a transceiver, which refers to a tag receiving unit (800) and a tag transmitting unit (810), a memory (not shown), and a tag processing unit (805, or tag control unit or processor). Depending on the communication method of the tag described above, the tag transmitting and receiving units (800, 810), the memory, and the tag processing unit (805) may operate. The tag processing unit (1705, or processor) may control the operation of the tag according to each of the above-described embodiments as well as a combination of at least one embodiment.

[0081] However, the tag's components are not limited to the examples described above. For example, the tag may include more or fewer components than the aforementioned components. Furthermore, the transceiver, memory, and processor may be implemented in a single chip.

[0082] The transceiver can transmit and receive signals with the reader. The signals may include control information and data. To this end, the transceiver may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0083] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

[0084] Memory can store programs and data necessary for the tag's operation. Furthermore, memory can store control information or data included in signals transmitted and received by the tag. Memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0085] Additionally, the processor can control a series of processes to enable tag operation according to the aforementioned embodiments. For example, there may be multiple processors, and the processors can perform component control operations of the tag by executing programs stored in memory.

[0086] FIG. 9 is a diagram illustrating the structure of a leader in a wireless communication system according to one embodiment of the present disclosure. The leader may be a device designed solely for a base station, terminal, or low-power communication device in a wireless communication system.

[0087] Referring to FIG. 9, the reader may include a transceiver, which refers to a reader receiver (900) and a reader transmitter (910), a memory (not shown), and a reader processing unit (905, or a reader control unit or processor). According to the communication method of the reader described above, the transceiver units (900, 910), the memory, and the reader processing unit (905) of the reader may operate. The reader processing unit (905, or processor) may control the operation of the reader according to each of the above-described embodiments as well as a combination of at least one embodiment. However, the components of the reader are not limited to the examples described above. For example, the reader may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0088] The transceiver can transmit and receive signals to and from tags. The signals may include control information and data. If the reader is a base station, the transceiver can transmit signals to a CW source. The signals may include control information and data. To this end, the transceiver may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0089] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through the wireless channel.

[0090] Memory can store programs and data necessary for the reader's operation. Furthermore, memory can store control information or data included in signals transmitted and received by the reader. Memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0091] The processor can control a series of processes to enable the reader to operate according to the embodiments of the present disclosure described above. There may be multiple processors, and the processors can perform component control operations of the reader by executing programs stored in memory.

[0092] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0093] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0094] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0095] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0096] In the specific embodiments of the present disclosure described above, components included in the invention are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0097] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples presented to easily explain the technical content of the present disclosure and facilitate understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art to which the present disclosure pertains that other modifications based on the technical concept of the present disclosure are possible. Furthermore, the above-described embodiments may be combined and operated as needed.

Claims

1. In a method performed by a tag of a communication system, A step of identifying a frequency resource associated with the above tag; A step of identifying a time resource associated with the above tag; and A step of transmitting an uplink signal to a reader or receiving a downlink signal from the reader based on the frequency resource and the time resource is included. A method characterized in that at least one of the frequency resource or the time resource is identified based on preset information for the tag.

2. In paragraph 1, The above frequency resource is identified based on first information preset for the tag, The above first information is, Frequency bands associated with the above frequency resources; The operating spectrum associated with the above frequency band; a channel index within the above operating spectrum; or A method characterized by comprising at least one of the frequency bandwidths.

3. In paragraph 1, The above time resource is identified based on second information preset for the above tag, The above second information is, A first time resource index for transmission of the above uplink signal; or A second time resource index for receiving the above downlink signal; Contains at least one of: A method characterized in that the first time resource index and the second time resource index are determined based on a timing reference signal.

4. In paragraph 1, A method characterized in that the preset information for the above tag is included in the global ID (identifier) of the above tag.

5. In a method performed by a reader of a communication system, A step of identifying a frequency resource associated with a tag; A step of identifying a time resource associated with the above tag; and A step of receiving an uplink signal from the tag or transmitting a downlink signal to the tag based on the frequency resource and the time resource is included. A method characterized in that at least one of the frequency resource or the time resource is identified based on preset information for the tag.

6. In paragraph 5, The above frequency resource is identified based on first information preset for the tag, The above first information is, Frequency bands associated with the above frequency resources; The operating spectrum associated with the above frequency band; a channel index within the above operating spectrum; or A method characterized by comprising at least one of the frequency bandwidths.

7. In paragraph 5, The above time resource is identified based on second information preset for the above tag, The above second information is, A first time resource index for transmission of the above uplink signal; or A second time resource index for receiving the above downlink signal; Contains at least one of: A method characterized in that the first time resource index and the second time resource index are determined based on a timing reference signal.

8. In paragraph 5, A method characterized in that the preset information for the above tag is included in the global ID (identifier) of the above tag.

9. In the tag of the communication system, Includes a transmitter / receiver and a control unit, The above control unit, Identify the frequency resource associated with the above tag, Identify the time resource associated with the above tag, It is configured to transmit an uplink signal to a reader or receive a downlink signal from the reader based on the above frequency resource and the above time resource, A tag characterized in that at least one of the frequency resource or the time resource is identified based on preset information for the tag.

10. In paragraph 9, The above frequency resource is identified based on first information preset for the tag, The above first information is, Frequency bands associated with the above frequency resources; The operating spectrum associated with the above frequency band; a channel index within the above operating spectrum; or A tag characterized by comprising at least one of the frequency bandwidths.

11. In paragraph 9, The above time resource is identified based on second information preset for the above tag, The above second information is, A first time resource index for transmission of the above uplink signal; or A second time resource index for receiving the above downlink signal; Contains at least one of: A tag characterized in that the first time resource index and the second time resource index are determined based on a timing reference signal.

12. In paragraph 9, A tag characterized in that the preset information for the tag is included in the global ID (identifier) of the tag.

13. In the reader of the communication system, Includes a transmitter / receiver and a control unit, The above control unit, Identify the frequency resources associated with the tag, Identify the time resource associated with the above tag, It is configured to receive an uplink signal from the tag or transmit a downlink signal to the tag based on the frequency resource and the time resource, A reader characterized in that at least one of the frequency resource or the time resource is identified based on preset information for the tag.

14. In paragraph 13, The above frequency resource is identified based on first information preset for the tag, The above first information is, Frequency bands associated with the above frequency resources; The operating spectrum associated with the above frequency band; a channel index within the above operating spectrum; or A leader characterized by comprising at least one of the frequency bandwidths.

15. In paragraph 13, The above time resource is identified based on second information preset for the above tag, The above second information is, A first time resource index for transmission of the above uplink signal; or A second time resource index for receiving the above downlink signal; Contains at least one of: A leader characterized in that the first time resource index and the second time resource index are determined based on a timing reference signal.

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