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

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. In addition, the present disclosure relates to a low-power communication system in which an apparatus having no battery or having only a capacitor-level energy storage capability is capable of operating. The present disclosure relates to operations of a base station, a reader, and a tag in a wireless communication system. The present disclosure relates to a method and an apparatus for transmitting and receiving data between a reader and a tag, wherein the tag receives, from the reader, an indication of a frequency transmission resource to be used for signal generation, or directly and randomly determines the frequency transmission resource.

Description

Method and device for setting frequency 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 frequency 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 could serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing this technology.

[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 mobile communication (or wireless communication) system according to one embodiment of the present disclosure describes a method for setting frequency transmission resources that can be used by a low-power communication device (hereinafter referred to as a tag). This method for setting frequency transmission resources may vary depending on the modulation and frequency conversion capabilities supported by the tag. The tag may receive frequency transmission resources from a reader based on the above-described setting method. Alternatively, the tag may directly set frequency transmission resources based on the above-described setting method and use them to perform uplink transmission to the reader.

[0011] A method performed by a device of a communication system according to one embodiment of the present disclosure may include the steps of receiving information related to a frequency resource from a reader, identifying the frequency resource based on the information, and transmitting a signal to the reader based on the frequency resource. The frequency resource corresponds to a value for a frequency shift, and the value for the frequency shift may be determined based on information related to the frequency resource.

[0012] A method performed by a reader of a communication system according to one embodiment of the present disclosure may include the steps of transmitting information related to a frequency resource to a device, identifying the frequency resource based on the information, and receiving a signal from the device based on the frequency resource. The frequency resource corresponds to a value for a frequency shift, and the value for the frequency shift may be determined based on information related to the frequency resource.

[0013] According to one embodiment of the present disclosure, a device of a communication system may include at least one transceiver, at least one processor communicatively connected to the at least one transceiver, and a memory communicatively connected to the at least one processor and executable individually or in any combination by the at least one processor, the memory storing instructions that cause the device to receive information related to a frequency resource from a reader, identify the frequency resource based on the information, and transmit a signal to the reader based on the frequency resource. The frequency resource may correspond to a value for a frequency shift, and the value for the frequency shift may be determined based on information related to the frequency resource.

[0014] A reader of a communication system according to one embodiment of the present disclosure may include at least one transceiver, at least one processor communicatively connected to the at least one transceiver, and a memory communicatively connected to the at least one processor and executable individually or in any combination by the at least one processor, the memory storing instructions that cause the reader to transmit information related to a frequency resource to a device, identify the frequency resource based on the information, and receive a signal from the device based on the frequency resource. The frequency resource corresponds to a value for a frequency shift, and the value for the frequency shift may be determined based on information related to the frequency resource.

[0015] The disclosed embodiment can provide a device and method capable of effectively providing a service in a mobile communication system.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] FIG. 3 is a diagram illustrating coexistence of a band and an NR band for communication between a tag and a reader in an AIoT system according to one embodiment of the present disclosure.

[0020] FIG. 4 is a diagram showing a frequency response when tag 1 and tag 2 receive a CW and then reflect the signal by applying frequency conversion according to an embodiment of the present disclosure.

[0021] FIG. 5 is a diagram illustrating an example of a tag including an oscillator according to one embodiment of the present disclosure that utilizes the oscillator to control the switching speed of a load impedance.

[0022] FIG. 6 is a diagram showing the basic functions and state diagram of a Miller code according to an embodiment of the present disclosure.

[0023] FIG. 7 is a diagram showing the basic function of a Manchester code according to an embodiment of the present disclosure.

[0024] FIG. 8 is a diagram showing an example of a waveform that can be used when the values ​​corresponding to the sub-carrier sequence according to one embodiment of the present disclosure are M=2 and M=4, respectively.

[0025] Figure 9(a) is a diagram showing the data waveform that can be output for each data '0' and '1' when a sequence with M=2 is applied to the Manchester code.

[0026] Figure 9(b) is a diagram showing an example of a signal waveform that can be output for the data sequence '01100' when using the basic waveform without applying a subcarrier sequence to the Manchester code.

[0027] Fig. 9(c) is a diagram showing an example of a signal waveform that can be output for sequence data '01100' when a subcarrier sequence of M=2 is applied to the Manchester code.

[0028] Figure 9(d) is a diagram showing an example of a signal waveform that can be output for the data sequence '01100' when a subcarrier sequence of M=4 is applied to the Manchester code.

[0029] FIG. 10 is a diagram illustrating the spectrum of CW and reflected signals from a tag observable for different M values ​​according to one embodiment of the present disclosure.

[0030] FIG. 11 is a diagram showing a tag and a reader transmitting and receiving signals in an AIoT system according to an embodiment of the present disclosure.

[0031] FIG. 12 is a diagram illustrating an example of a spectrum of a signal reflected from a tag when the tag performs frequency conversion according to one embodiment of the present disclosure.

[0032] FIG. 13 is a diagram illustrating another example of a spectrum of a signal reflected from a tag when the tag performs frequency conversion according to an embodiment of the present disclosure.

[0033] FIG. 14 is a diagram illustrating an example of frequency conversion when a large-scale frequency converter and a small-scale frequency converter are used for frequency conversion in a tag according to one embodiment of the present disclosure.

[0034] FIG. 15 is a diagram illustrating an example in which, when a leader broadcasts a signal to induce tags to transmit information according to one embodiment of the present disclosure, multiple tags receive the signal and report their respective information back to the leader.

[0035] FIG. 16 is a diagram illustrating impedance matching for a received signal when a tag according to one embodiment of the present disclosure can have four states.

[0036] FIG. 17 is a diagram illustrating impedance matching for a received signal when a tag according to an embodiment of the present disclosure can have four states.

[0037] Figure 18 is a diagram showing the operation when a tag receives information about frequency resources available for uplink from a leader and selects frequency resources based on the information to transmit uplink to the leader.

[0038] Figure 19 is a diagram showing the operation when a tag randomly selects a frequency resource and then uses it to report to the leader when receiving a command to report its information from the leader.

[0039] FIG. 20 is a diagram showing the structure of a tag in a wireless communication system according to an embodiment of the present disclosure.

[0040] FIG. 21 is a diagram showing the structure of a leader in a wireless communication system according to an embodiment of the present disclosure.

[0041] FIG. 22 is a diagram illustrating an example of a sequence (or square wave) that can be considered for the frequency components of a reflected signal according to one embodiment of the present disclosure.

[0042] FIG. 23 is a diagram showing an example of an encoded signal waveform that can be observed for M=2 when using a Manchester code according to one embodiment of the present disclosure.

[0043] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] [NR time-frequency resources]

[0059] Below, the frame structure of the 5G system can be described in more detail with reference to the drawings.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] Referring to FIG. 2, an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202) 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.

[0065] [Table 1]

[0066]

[0067] Low-Power Communications: Ambient-IoT Frequency Resources

[0068] The Internet of Things (IoT) is a technology that interconnects various devices via the Internet to exchange data. It is being utilized in diverse fields such as smart homes, industrial automation, healthcare, and smart cities. Most existing IoT devices operate on batteries, requiring periodic replacement or charging. This increases maintenance costs and time for IoT systems, and can be a significant limitation, especially when deployed in large-scale or difficult-to-access locations. Ambient IoT (AIoT) is one of the next evolutionary steps in this IoT technology, a new type of IoT technology that harvests energy from the surrounding environment. AIoT tags utilize energy harvesting technology to obtain energy from light, radio waves, motion, heat, or any other suitable power source, enabling them to operate for extended periods without battery replacement or charging. Energy harvester output typically ranges from 1uW to several hundred uW, a very low level compared to the 10mW maximum power required by current commercial communication systems. Accordingly, the need for new low-power communication technologies that can be used in various use cases of AIoT is emerging.

[0069] The AIoT tag (hereinafter referred to as a tag) described below is a device that receives energy through energy harvesting, and can use the following two methods to generate a signal to be transmitted to the reader. First, backscattering communication can be used to generate a signal by reflecting an RF signal coming from the outside to transmit data. In this case, the signal transmitted to the tag for signal transmission from the tag to the reader from the outside (i.e., the uplink of the AIoT system) can be referred to as a carrier wave (hereinafter referred to as a CW). The CW can be transmitted to the tag from an external node outside the tag, and the tag can generate an uplink signal to be transmitted to the reader by reflecting the signal. When based on backscattering communication, the tag does not include a local oscillator (LO) in its internal structure, and therefore, the resulting power consumption and device complexity can be significantly reduced. The tag can reflect a signal and encode information stored in its memory, and the reflected signal can be transmitted to the reader and decoded. Generating signals directly within the tag can be another way to generate signals to be transmitted to the reader. This requires the tag to generate the signal directly using its internal LO, which can lead to greater power consumption and device complexity compared to backscattering communication. AIoT tags may also utilize amplifiers at the transceiver end to improve communication performance.

[0070] Although tags can generate signals for uplink transmission in a variety of ways, to reduce the cost and complexity of system design, it may be appropriate to aim for a harmonized design that can receive signals at the base station reception side regardless of the uplink signal generation method. For example, by designing the signals generated by reflecting CW and those generated within the tag to share similar signal shapes and transmission techniques, it may be possible to make it possible for the receiver to receive and interpret these signals using the same algorithm. Therefore, although this document describes tags that generate signals by reflecting CW, if the signal is generated directly within the tag, the generated signal can be designed to have a shape similar to that generated through CW reflection, so that the same reception technique can be applied when the signal is received at the reader side. For example, when generating a signal through CW reflection, the CW signal is a single-tone sine wave, and the tag can reflect the signal by applying a frequency shift of Δf to the sine wave. When generating signals internally, a similar signal can be generated by directly generating a sine wave with a single tone within the tag and applying the same frequency shift. Alternatively, a signal can be generated by simulating a signal with frequency shift applied from the signal generation stage. This approach allows the receiver to receive and interpret signals using the same algorithm, despite the various signal generation methods, reducing system complexity and improving overall efficiency.

[0071] Communication between tags and readers in AIoT systems can occur using specific bands, which can coexist with existing NR bands in various ways.

[0072] FIG. 3 is a diagram illustrating coexistence of a band and an NR band for communication between a tag and a reader in an AIoT system according to one embodiment of the present disclosure.

[0073] In the case of the in-band method (301), the AIoT band is included in the existing NR band (300), and NR resources can be used to provide AIoT services. In the case of the guard-band method (302), the AIoT band is included in a guard band adjacent to the NR band (300). In the case of the standalone method (303), the AIoT service is provided in an independent band that is not included in the NR band (300) or the adjacent guard band. For example, it may be possible to utilize the existing GSM frequency band. The frequency resources used by the tag to transmit a signal to the reader and the frequency resources used by the reader to transmit a signal to the tag may be included in the operating band of the AIoT system.

[0074] In NR systems, base stations can allocate frequency-domain resources to terminals efficiently based on resource elements (REs) and basic resource blocks (RBs), as described above. Furthermore, frequency interference can be prevented by allocating non-overlapping REs and RBs to each terminal for frequency-domain multiple access. On the other hand, in AIoT systems, particularly for uplink transmission, tags may not include complex components such as FFTs / IFFTs, making it impossible to support RE and RB structures like those of NR systems. Furthermore, when tags generate uplink signals by reflecting CW, they may not have information about the frequency resources or specific signal formats used by the CW. For example, in certain AIoT systems, CWs may be transmitted from nodes that do not belong to the topology, and the transmission of frequency resource information of the corresponding signals to tags may not always be guaranteed. In this case, the tag may be able to transmit the signal to the reader by applying a certain frequency conversion to the signal and reflecting the signal without knowing the exact location of the frequency of the CW signal it receives. In other words, the signal reflected from the tag may be a signal that has had a certain amount of frequency conversion applied to the CW signal received by the tag. This method can enable frequency resource allocation among signals reflected from multiple tags depending on the degree of frequency shift performed by the tag. In an AIoT system, when multiple tags receive the same CW and reflect it in a backscattering manner to generate a signal to be transmitted to the reader, if each tag transmits an uplink signal by generating a different degree of frequency shift and reflecting the signal, this can provide flexibility in terms of frequency resource allocation to the tags and can enable frequency domain multiple access (FDMA) between the tags.Additionally, since frequency resources can be selected during uplink transmission in terms of a single tag, it may be possible to expect frequency diversity gains.

[0075] FIG. 4 is a diagram showing a frequency response when tag 1 and tag 2 receive a CW and then reflect the signal by applying frequency conversion according to an embodiment of the present disclosure.

[0076] Specifically, Fig. 4 is a simplified diagram of the frequency response that can be observed when CW has a center frequency of fc (401), and when tags 1 and 2 receive the CW and then reflect the signal by applying frequency conversions of f1 (402) and f2 (403), respectively. Even if the reader receives the two reflected signals simultaneously, it may be possible to receive and successfully decode both signals since the two signals can be distinguished in the frequency domain. In the figure, for convenience of explanation, CW is depicted as having a single center frequency of f c Although it is assumed to have only one sideband, a signal composed of the sum of multiple tones with a single center frequency can also be a CW signal. In the above example, both sidebands are output after frequency conversion, but depending on the implementation of the tag, it may be possible for only a single sideband to be output.

[0077] Frequency shifting in a tag can be achieved in two ways: using an actual frequency shifter or using line coding. For example, if a frequency shifter is used, one way to generate the frequency is to control the switching speed of the load impedance using an oscillator.

[0078] FIG. 5 is a diagram illustrating an example of a tag including an oscillator according to one embodiment of the present disclosure that utilizes the oscillator to control the switching speed of a load impedance.

[0079] Referring to Fig. 5, the tag's internal circuit may include an oscillator (501) for controlling the switching speed of the impedance (500). The tag's internal circuit may also include other components (e.g., a mixer) in addition to the oscillator, but these have been omitted for convenience. In this case, the tag may include an oscillator capable of operating at low power, and if a higher frequency is desired to be generated, the power consumed by the oscillator may increase. There may be various methods for actually implementing a frequency converter in a tag other than using an oscillator. In an AIoT system, it is possible to encode data using line coding when transmitting signals between a tag and a reader. This can help reduce errors in signal transmission through data modulation and maintain data synchronization between the reader and the tag. Various line coding methods, such as FM0, Miller code, and Manchester code, can be used.

[0080] FIG. 6 is a diagram illustrating the basic functions and state diagram of a Miller code according to an embodiment of the present disclosure. The Miller code has a memory characteristic in which the state of the previous bit is stored and the encoding result of the current bit changes accordingly.

[0081] FIG. 7 is a diagram illustrating the basic function of a Manchester code according to an embodiment of the present disclosure. Manchester code is a line coding method used in digital communication, and each bit can be expressed using a signal transition. Here, T represents the 'bit time' or 'bit period', which means the time required to transmit one data symbol ('0' or '1'). When a tag receives a CW signal and reflects it, if the reflected signal and the CW share the same frequency resource, the two signals may interfere with each other at the receiving end. Therefore, separating the reflected signal and the CW signal in the frequency domain can help improve signal reception performance. One method for this is to additionally consider a subcarrier sequence in line coding. When a line code and a subcarrier sequence are used for encoding, the waveform transmitted from the tag can be a form obtained by multiplying a basic function that can be transmitted when using a specific line coding by a subcarrier sequence signal in the form of a square wave. The multiplication can be performed using an XOR or XNOR operation.

[0082] FIG. 8 is a diagram illustrating an example of a waveform that can be used when the values ​​corresponding to the subcarrier sequence according to one embodiment of the present disclosure are M=2 and M=4, respectively. When M=2 is used, the waveform of FIG. 8(a) can be multiplied by the basic function when line coding is used, and when M=4 is used, the waveform of FIG. 8(b) can be multiplied by the basic function when line coding is used. As the value of M increases, the baseband link frequency of the generated signal can increase.

[0083] FIGS. 9A to 9D are diagrams illustrating examples of encoded signal waveforms that can be observed for M = 2 and 4 when using the Manchester code. FIG. 9A is a diagram showing a data waveform that can be output for each data '0' and '1' when a sequence with M = 2 is applied to the Manchester code. In this case, signal multiplication can assume the operation of XNOR. The encoded data signal waveform can be determined in a way that the sequence is multiplied with respect to the basic function. When M = 2, it can have a baseband link frequency that is twice as large as the basic function. FIG. 9B is a diagram showing an example of a signal waveform that can be output for the data sequence '01100' when using the basic waveform without applying a subcarrier sequence to the Manchester code. FIG. 9C is a diagram showing an example of a signal waveform that can be output for the sequence data '01100' when a subcarrier sequence of M = 2 is applied to the Manchester code. Figure 9d is a diagram illustrating an example of a signal waveform that can be output for the data sequence '01100' when a subcarrier sequence of M=4 is applied to the Manchester code. It can be seen that link frequencies that are double and quadruple are observed when M=2 and M=4 are applied compared to when no subcarrier sequence is applied.

[0084] The sequence that can be considered to shift the frequency component of the reflected signal is not limited to the example of Fig. 8. For example, any square wave satisfying M = T / (2*chip length) within the time interval T associated with one information bit can be used as the sequence. In this case, a chip may correspond to the minimum time length that constitutes a modulation signal. In the present disclosure, the chip length (T) c ) may correspond to the length of one symbol of the modulation signal.

[0085] FIG. 22 is a diagram illustrating an example of a sequence (or square wave) that can be considered for the frequency components of a reflected signal according to one embodiment of the present disclosure.

[0086] Figure 22 (a) shows the case where M = 2, and when M = 2, the chip length (T c ) can correspond to a 1 / 4 interval of T. Therefore, when M=2, there can be a total of 4 chips within the T interval.

[0087] Figure 22 (b) shows the case where M = 4, and when M = 4, the chip length can correspond to 1 / 8 of the section T. Therefore, when M = 4, a total of 8 chips can exist within the section T.

[0088] FIG. 23 is a diagram showing an example of an encoded signal waveform that can be observed for M=2 when using a Manchester code according to an embodiment of the present disclosure. Specifically, FIG. 23 is a diagram showing a data waveform that can be output for each data '0' and '1' when a sequence with M=2 defined in (a) of FIG. 22 is applied to the Manchester code. At this time, it can be assumed that the multiplication of the signal is performed based on the XNOR operation. The encoded data signal waveform can be determined in a manner in which the sequence is multiplied by the basic function. At this time, when a square wave such as the sequence defined in (a) of FIG. 22 is used, the signal after the multiplication is applied can output the same waveform as when the data symbol is repeated M times within the same section with respect to the signal before the multiplication. That is, the waveform corresponding to one data symbol before multiplying the square wave can be output by repeating M times within the same section, and even in this case, the frequency of the signal can change.

[0089] Depending on the type of sequence selected for square wave generation, differences in frequency shifting capabilities may occur, and when attempting frequency domain multiple access between multiple devices, frequency interference effects between devices may occur differently.

[0090] The present disclosure is not limited to the type of sequence for generating a square wave of this embodiment and the method of multiplying the square wave. For example, multiplication of the sequence can be performed by selecting one of the operations of XOR or XNOR. In the present disclosure, a case in which multiplication of the sequence is performed based on XOR will be described as an example, but when multiplication of the sequence is performed based on XNOR, the same output waveform as that of the present disclosure can be obtained by inverting 0 and 1 of the sequence. The M value in the following description can be understood as an indicator indicating the degree of frequency shift and can be a value associated with the number of chips included in a sequence that can be defined within one information bit interval.

[0091] In the present disclosure, the sequence can also be represented as a combination of 0 and 1. For example, the signals in FIG. 8(a) and FIG. 8(b) can be interpreted as square waves having the sequences of (1, 0, 1, 0) and (1, 0, 1, 0, 1, 0, 1, 0), respectively. The signals in FIG. 22(a) and FIG. 22(b) can be interpreted as square waves having the sequences of (1, 0, 0, 1) and (1, 0, 1, 0, 0, 1, 0 1), respectively. In this case, each 0 and 1 is T c = T / (2*M) may be a signal that persists for an interval of M = T / (2*T c) when defining a value for frequency transition, as in the sequence of Fig. 8, a sequence in which (1, 0) is repeated throughout the entire section can be generalized into a sequence having 2M chips following (1, 0, 1, 0,…). A sequence in which (1, 0) is repeated for the preceding T / 2 time and (0, 1) is repeated for the remaining time, as in the sequence of Fig. 22, can be generalized into a sequence having M chips following (1, 0, 1, 0,… and M chips following (0, 1, 0, 1,…). Depending on the selection of XOR or XNOR for signal multiplication, 0 and 1 can be inverted and defined.

[0092] FIG. 10 is a diagram illustrating the spectrum of CW and reflected signals from a tag observable for different M values ​​according to one embodiment of the present disclosure.

[0093] Referring to Fig. 10, examples of the spectrum (1003, 1004, 1005) of CW (1002) and signals reflected from tags that can be observed for M values ​​of 2, 4, and 8 on the AIot channel (1001) are schematically illustrated. As the M value increases, the center frequency of the signal reflected from the tag increases relative to the center frequency f of CW. ccan be further from. Therefore, appropriately selecting the M value of the line code used in the encoding process in the tag can help not only to distinguish between CW and reflected signals at the reader side, but also to distinguish signals between tags that use different M values. This subcarrier sequence can also be applied to cases where the amplitude of the signal does not change, such as FSK and PSK, but other characteristics of the signal (e.g., frequency or phase) change according to the data. In such cases, it is possible to consider only the subcarrier sequence without applying the line coding. For example, when using binary phase shift keying (BPSK), applying a subcarrier sequence to the basic function representing each data (0 and 1) may still allow changing the frequency of the output signal according to the M value.

[0094] [Example 1: AIoT system frequency resource indication method using subcarrier sequence values ​​of line codes]

[0095] FIG. 11 is a diagram showing a tag and a reader transmitting and receiving signals in an AIoT system according to an embodiment of the present disclosure.

[0096] As shown in FIG. 11, when a tag (1102) transmits a signal to a reader (1101) in an AIoT system (1104), information about frequency resources to be used by the tag can be indicated by the reader (1103). When the tag generates a signal to be transmitted to the reader by reflecting the received CW, information about frequency resources used by the tag can be information about frequency shift based on the center frequency of the CW. For example, the degree of frequency shift can be varied by changing M, which is a subcarrier sequence value for a line code used by the tag when generating a signal to be transmitted to the reader. Specifically, it may be possible for the M value to be indicated by the reader. For example, it may be possible for information about the M value to be directly or indirectly included in the information bits of a signal transmitted from the reader. Table 2 shows an example in which the reader indicates to the tag that the number of M available to the tag is 8 with a 3-bit indicator N. That is, the reader can use the indicator N to instruct the tag to select one of the eight M values, and this can be included as an information bit in the data that the reader transmits to the tag. The tag can receive data from the reader, interpret the N value, determine the M value, and apply it as the M value of the line code that the tag will use when generating a signal to transmit to the reader. The reader can transmit the value of N=1 to the tag by including it as an information bit called '001'. The tag can receive the information and use the value of M=8 as the subcarrier sequence value of the configured line code. At this time, the type of line code used by the tag may be a code determined by receiving configuration information from the reader, or a code that has already been agreed upon between the tag and the reader and is fixedly used by the tag. Alternatively, it may be possible to not use a line code but to be instructed only with the M value and use it for the basic function of the signal.The M value indicated by the indicator in Table 2 is only an example and does not limit the scope of the present invention, and the M value that the actual indicator can indicate to the tag may be another combination agreed upon between the reader and the tag.

[0097] [Table 2]

[0098]

[0099] Alternatively, a signal transmitted by a reader to a tag may trigger the operation of an impedance matching switch within the tag, thereby determining the M value of the line coding that the tag uses for signal transmission. For example, a tag may be capable of having one of four different impedance states corresponding to a specific M value: {State1, State2, State3, State4}. The reader transmits a signal to the tag to match one of these four impedance states, and when the tag receives the signal, it can check the impedance matching for the four states and determine the M value corresponding to the state to which the received signal matches. The number of impedance states that a tag can have and the M value corresponding to each impedance state may vary depending on the design.

[0100] FIG. 16 is a diagram illustrating impedance matching for a received signal when a tag according to an embodiment of the present disclosure can have four states. The tag can receive (1602) a signal transmitted from a reader, and this signal can be set to match one of the four states (1603) that the tag can have when generated from the reader. The receiving end (1601) of the tag can receive this signal and perform impedance matching (1600). After confirming which of the four states matches the received signal, the M value corresponding to the state can be confirmed, thereby using it for line coding. The tag can perform line coding using a subcarrier sequence using the confirmed M value, and can use it when generating an uplink signal.

[0101] When a reader indicates M-related information to a tag in various ways, the M value can be associated with the number of repetitions of the information transmitted by the tag to the reader. For example, if the channel condition between the tag and the reader is expected to be good, such as when the signal strength from the tag received by the reader is strong or the signal-to-noise ratio (SNR) is high, the tag can be instructed to use a larger M value and a smaller number of repetitions. Conversely, if the channel condition between the tag and the reader is expected to be poor, such as when the signal strength is weak or the SNR is low, the tag can be instructed to use a smaller M value and a larger number of repetitions. This is expected to increase the efficiency of multiple accesses between tags and reduce interference between tags by allowing the tag to expend more energy for frequency shifting when the channel condition between the tag and the reader is expected to be good. Conversely, this can reduce the additional energy consumption due to repeated transmissions, thereby conserving transmission resources. Conversely, if the channel condition between the tag and the reader is expected to be poor, the tag can reduce the M value to reduce the energy consumed for frequency shifting and instead increase the number of repeated transmissions, which is expected to improve transmission reliability.

[0102] [Example 2: AIoT system frequency resource indication method using input values ​​of a frequency converter]

[0103] When a tag reflects a signal by applying a frequency shift based on the center frequency of the received CW, the reader may indicate information about the input value of the frequency converter contained within the tag. For example, the tag may indicate the input information for the frequency converter as a single offset value (f offset) or a single offset value and its multiple value (k). When a single offset value is instructed from the reader, the tag sets the set offset value as the input of the frequency converter, and the frequency converter can convert the frequency of the signal coming in as the input by the corresponding offset and output it. When a single offset value and its multiple value are instructed from the reader, the tag sets the multiple of the set offset value as the input of the frequency converter (i.e. f offset* k), the frequency converter can convert the frequency of the signal input as an input and output it by the corresponding value. At this time, the single offset value is a value predetermined between the tag and the reader, so that separate information transmission from the reader is not required, or it is shared with the tag at the initial stage of connection, and information about the multiple value can be transmitted from the reader later. This method of using a multiple for a single offset can be used to simply adjust the frequency interval between tags according to the size of the offset when using the same offset value between tags when allocating different frequency resources between tags using a frequency converter. In addition, when using individual offset values ​​between different tag groups, it can be helpful in distinguishing the frequency resources used between tag groups according to the difference in the size of the two offsets. Specifically, it may be possible for the offset value or the multiple value to be directly or indirectly included in the information bits of the signal transmitted from the reader. If a tag can use a total of eight offset values, the reader can instruct the tag which offset value to apply with a 3-bit indicator N. At this time, the eight offset values ​​may be values ​​preset for the tag or information preset by the reader. The reader can instruct the tag to select one of the eight offset values ​​using the indicator N, which can be included as an information bit in the data transmitted from the reader to the tag. The tag can receive this, interpret the N value, and determine the offset value corresponding to the N value. This offset value can be set as the frequency conversion value of the frequency converter when the tag generates a signal to be transmitted to the reader. The same instruction method can be similarly applied to the multiplier value (k). When a multiplier value is set to the tag, the tag can set the preset offset value or a value that is a multiple of the offset value instructed by the reader as the input of the frequency converter.Alternatively, the signal transmitted by the reader to the tag may trigger the operation of an impedance matching switch within the tag, thereby determining the offset value that the tag uses as an input to the frequency converter. For example, the tag may be capable of having one of four different impedance states corresponding to a specific offset value: {State1, State2, State3, State4}. The reader transmits a signal to the tag to match one of these four impedance states, and when the tag receives the signal, it can check the impedance matching for the four states and check the offset value corresponding to the state to which the received signal matches. The tag can use the checked offset value to set the input value of the frequency converter and use it when generating a signal to be transmitted to the reader. When the tag reflects the signal received, the frequency converter converts the frequency of the received signal by the offset value set as the input.

[0104] FIG. 17 is a diagram illustrating impedance matching for a received signal when a tag according to an embodiment of the present disclosure can have four states. The tag can receive (1702) a signal transmitted from a reader, and this signal can be set to match one of the four states (1703) that the tag can have when generated from the reader. The receiving end (1701) of the tag can receive this signal and perform impedance matching (1700). After confirming which of the four states matches the received signal, it is possible to use the offset value corresponding to the state for line coding. The tag can input the confirmed offset value as a frequency conversion value of a frequency converter and use it when generating an uplink signal.

[0105] [Example 3: Integrated Frequency Resource Indication Method for AIoT Systems]

[0106] Tags in AIoT systems may or may not include a frequency converter, depending on the implementation. Furthermore, some tags may include a frequency converter capable of relatively large frequency conversions, while others may only include a frequency converter capable of relatively small frequency conversions. Some tags may not include a frequency converter at all. Therefore, depending on the implementation, tags may apply frequency conversion values ​​to received CW signals when generating uplink signals. When a tag reflects the received CW and generates a signal transmitted to a reader, and indicates the frequency resources to be used by the tag for multiple accesses in the frequency domain, defining different indication methods depending on the tag implementation can increase system complexity and be inefficient. Therefore, system complexity can be reduced by using a single, unified indication method in the reader, regardless of tag implementation. The reader can indicate the frequency resources to be used by all tags using the same frequency resource indication method. Each tag can interpret the received frequency resource indication information differently depending on its supported frequency conversion capabilities. Table 3 shows an example of how each tag can interpret information about frequency resources when the reader uses a 3-bit indicator to instruct the tag. For example, when the tag transmits frequency resource information to the tag using the indicator of '011', a tag (A) with a small frequency shifter capable of only a relatively small level of frequency conversion can receive a specific offset value for the received CW. The tag (B) with a large frequency shifter capable of performing a relatively high level of frequency conversion can perform an F corresponding to a specific offset value for the received CW. d It is possible to perform an operation of reflecting through backscatter by performing a frequency conversion in the negative direction equivalent to twice the frequency of . At this time, for a large-scale frequency converter, it is assumed that only the spectrum corresponding to the single sideband is output after frequency conversion through the implementation of the tag. In other words, if the center frequency of the signal received from the frequency converter is f0, the frequency of the signal reflected by the tag that received the indicator of '011' is f0-2F. d It can be.

[0107] Fig. 12 is a diagram showing an example of a spectrum of a signal reflected from a tag when a tag performs frequency conversion according to an embodiment of the present disclosure. Referring to Fig. 12, the tag uses a small frequency converter for frequency conversion, and receives an indicator of '000' from a reader and transmits it on an AIoT channel (1201). (1203) as the center frequency f c The spectrum of the signal reflected from the tag when performing frequency conversion at (1202) is shown.

[0108] FIG. 13 is a diagram illustrating another example of a spectrum of a signal reflected from a tag when the tag performs frequency conversion according to an embodiment of the present disclosure. Referring to FIG. 13, the tag uses a large-scale frequency converter for frequency conversion, and receives an indicator of '000' from a reader and transmits F on an AIoT channel (1301). d (1304) as the center frequency f c The spectrum of the signal reflected from the tag when performing frequency conversion at (1303) is shown in this figure.

[0109] FIG. 14 is a diagram illustrating an example of frequency conversion when a large-scale frequency converter and a small-scale frequency converter are used for frequency conversion in a tag according to an embodiment of the present disclosure. Referring to FIG. 14, when a large-scale frequency converter and a small-scale frequency converter are used, the center frequency f of CW on the AIoT channel (1401) c An example of a frequency conversion that can be applied based on (1403) is shown. Compared to a small-scale frequency converter, a large-scale frequency converter can maintain a frequency interval in larger units, and there may be no overlap between the frequency resources that can be selected using the two frequency converters. In addition, if the tag selects the frequency resource of the signal reflected from the tag by using M, the value of the subcarrier sequence of the line coding, without using a frequency converter (C), the tag can interpret the indicator received from the reader to determine the value of M and apply it to the line code when the signal is reflected from the tag. For example, if the value of the indicator received by the tag is '011', the tag can set the frequency resource of the reflected signal based on the information transmitted from the base station by using M=16 during the line code encoding process. In this example, information about the tag's implementation, such as which type of frequency converter the tag can use, may be reported directly by the tag to the reader, or may already be fixedly set in the tag so that the reader knows it in advance. Additionally, if a tag can interpret a frequency resource indicator in more than one way, the reader can pre-set how it will interpret it, or interpret it based on priorities. The offset values ​​in Table 3 correspond to and F dThe value of offset is preset to the tag at the stage of initial connection, etc., and the reader can use the multiple value of offset as the input of the frequency conversion value of the frequency converter by indicating a multiple value (e.g., 1, 2, 4, …128) to the tag. Alternatively, the values ​​corresponding to each indicator may not use a common offset and may not consider the multiple, and the offset values ​​corresponding to each indicator may be set differently. For example, if the indicator is 000, F d,1 If the value of the indicator is 001, F d,2 The value of can be used as an input for the frequency conversion value of the frequency converter. If the tag uses a frequency converter, the reader can instruct the tag with the input value for the frequency conversion in various ways according to Example 2 and is not limited to this example.

[0110] [Table 3]

[0111]

[0112] [Example 4: Frequency Resource Allocation for a Competition-Based Access to AIoT Systems]

[0113] In an AIoT system, a reader can broadcast a command to gather information from scattered tags, prompting them to transmit their own information. A tag receiving the command can report back to the reader by transmitting the collected information or its own unique information. Since the reader transmits the command to all tags, if multiple tags receive the command and attempt to transmit information, collisions between the tags' signals can occur, making it difficult for the receiver to accurately receive the signal. Therefore, in such cases, selecting frequency resources so that tags can use available frequency resources without overlapping can help reduce contention and improve signal reception. For example, upon receiving the command, each tag can randomly select the M value of the line code and use it to generate a signal to the reader. The M value can be included in the signal transmitted by the tag and reported to the reader, or the reader can determine the location of the frequency resources used by the tag that transmitted the signal. Alternatively, after receiving a data transmission command from the reader, a tag can randomly select a frequency conversion offset value and use this as the frequency conversion input value of a frequency converter. Alternatively, the same offset value can be used between tags, and a multiple value for the offset value can be randomly selected for each tag. In this case, the tag can use the value obtained by multiplying the fixed offset value by the selected multiple as the input for the frequency conversion value of the frequency converter. Information about the offset value that the tag can use can be information that is preset by the reader or preset by the tag. Information about the M value and frequency offset or multiple that the tag can use can be agreed upon in advance between the tag and the reader, or can be included in the information that the tag receives from the reader at the beginning of the connection. In this case, the beginning of the connection can include receiving information from the reader that occurs before the current time.As described in Examples 1 to 3, tags and readers may be able to indicate frequency resources using a common method. Based on this indication method, the tag may select an M value, a frequency offset, or a multiplier value, and then encode data containing this information and transmit it to the reader.

[0114] Additionally, it may be possible to attempt to reduce contention during multiple access by having tags perform frequency conversion in different ways for each implementation. Specifically, when tag A can select a frequency resource by converting the M value of the line code, and tag B can select a frequency resource by modifying the input offset value of the frequency converter, tag A can randomly set the M value to generate an uplink signal, and then report information about the M value to the reader. At this time, tag A may also report to the reader that the value it reports is information about the M value, or the reader may already know this information, or the reader may be able to infer this information from the frequency resource location of the reported signal. Tag B may randomly select one of the available offset values ​​and use it to generate an uplink signal. Tag B may report information about the used offset value to the reader. At this time, tag B may also report to the reader that the value it reports is an offset value for the frequency conversion input value of the frequency converter, or the reader may already know this information, or the reader may be able to infer this information from the frequency resource location of the reported signal. At this time, the information reported by the tag may include information about the frequency resources it has used, as described in Examples 1 to 3, and may be encoded as a bit string and transmitted to the reader.

[0115] FIG. 15 is a diagram illustrating an example in which, when a leader broadcasts a signal to induce tags to transmit information according to one embodiment of the present disclosure, multiple tags receive the signal and report their respective information back to the leader.

[0116] Referring to FIG. 15, the reader (1501) can broadcast a signal (1510) to induce the tags to transmit a signal. If all three tags can select a frequency resource by setting the M value of the line code, for example, tag #1 (1502) can generate an uplink signal (1511) using M=2 and report information about it to the reader (1501). Tag #2 (1503) can generate an uplink signal (1512) using M=4 and report information about it to the reader (1501). Tag #3 (1504) can generate an uplink signal (1513) using M=8 and report information about it to the reader (1501). As another example, tag #1 can select a frequency resource by setting the M value of the line code, generate an uplink signal using M=8 and report information about it to the reader. Tag #2 selects frequency resources using small frequency converters. By inputting the offset of the frequency converter and applying frequency conversion to the received signal, an uplink signal can be generated. This information can be reported to the leader. Tag #3 selects frequency resources using a large-scale frequency converter and 2F d By inputting the offset of the frequency converter and applying frequency conversion to the received signal, an uplink signal can be generated. Information about this can be reported to the reader. At this time, each piece of information can be converted into information bits according to specific encoding rules and reported to the reader. The three tags can help increase the reliability of uplink reception at the reader by using different frequency resources during the multiple access stage.

[0117] Embodiments 1 to 4 of the present disclosure described above can be implemented through a combination of one or more embodiments as needed.

[0118] When generating signals internally within the tag to be transmitted to the reader, the tag may not receive CW. Even in such cases, to achieve a unified design, the tag can still receive information from the reader about the degree of frequency shift relative to the CW center frequency. Therefore, the tag may be able to receive additional information about the CW center frequency. This information may be transmitted from the reader during the initial connection phase or included in the scheduled signal.

[0119] Figure 18 is a diagram showing the operation when a tag receives information about frequency resources available for uplink from a leader and selects frequency resources based on the information to transmit uplink to the leader.

[0120] Referring to FIG. 18, a tag may receive an AIoT uplink frequency domain indicator from a reader (1801). The tag may select a frequency resource for uplink signal transmission based on the received indicator and / or the tag's implementation (1802). Based on the selected frequency resource, the tag may transmit an AIoT uplink resource to the reader (1803). Each step illustrated in FIG. 18 may be performed based on any one or a combination of one or more of Embodiments 1 to 3 of the present disclosure described above. In addition, although not illustrated, the reader may perform operations to support the operation of the tag described in FIG. 18 according to embodiments of the present disclosure.

[0121] Figure 19 is a diagram showing the operation when a tag randomly selects a frequency resource and then uses it to report to the reader when receiving a command to transmit a signal from the reader.

[0122] Referring to FIG. 19, a tag may receive an AIoT command requesting signal transmission from a reader (1901). The tag receiving the AIoT command may randomly select a frequency resource according to the tag's implementation (1902). Based on the selected frequency resource, the tag may transmit a report regarding the command to the reader (1903). Each step illustrated in FIG. 19 may be performed based on Embodiment 4 of the present disclosure described above. In addition, although not illustrated, the reader may perform operations to support the operation of the tag described in FIG. 19 according to the embodiment of the present disclosure.

[0123] FIG. 20 is a diagram showing the structure of a tag in a wireless communication system according to an embodiment of the present disclosure.

[0124] Referring to FIG. 20, the tag may include a transceiver, which refers to a tag receiving unit (2000) and a tag transmitting unit (2010), a memory (not shown), and a tag processing unit (2005, or a tag control unit or processor). Depending on the communication method of the tag described above, the tag transmitting and receiving units (2000, 2010), the memory, and the tag processing unit (2005) may operate. The tag processing unit (2005, 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] FIG. 21 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.

[0131] Referring to FIG. 21, the reader may include a transceiver, which refers to a reader receiver (2100) and a reader transmitter (2110), a memory (not shown), and a reader processing unit (2105, or a reader control unit or processor). According to the communication method of the reader described above, the transceiver units (2100, 2110), the memory, and the reader processing unit (2105) of the reader may operate. The reader processing unit (2105, 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 above-described examples. For example, the reader may include more or fewer components than the above-described components. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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 aid in 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 modified examples 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 device of a communication system, A step of receiving information related to frequency resources from a reader; a step of identifying the frequency resource based on the above information; and A step of transmitting a signal to the leader based on the above frequency resource is included, The above frequency resource corresponds to a value for frequency shift, A method characterized in that the value for the above frequency shift is determined based on information related to the frequency resource.

2. In paragraph 1, Information related to the above frequency resources indicates a set of values ​​for available frequency shifts, A method characterized in that the value for the frequency shift corresponding to the frequency resource is determined as one of the values ​​for the available frequency shift.

3. In paragraph 2, A method characterized in that the value for the frequency shift corresponding to the frequency resource is randomly selected from among the values ​​for the available frequency shift.

4. In paragraph 1, The time resource associated with the above signal is T c Contains a plurality of chips having a length of , The above T c is T c =T b / (2*M) is satisfied, The above T c is the length of the above chip, The above T b is the length of the bit period corresponding to each bit, A method characterized in that the above M is a value for the above frequency shift.

5. In a method performed by a reader of a communication system, A step of transmitting information related to frequency resources to a device; a step of identifying the frequency resource based on the above information; and A step of receiving a signal from the device based on the frequency resource, The above frequency resource corresponds to a value for frequency shift, A method characterized in that the value for the above frequency shift is determined based on information related to the frequency resource.

6. In paragraph 5, Information related to the above frequency resources indicates a set of values ​​for available frequency shifts, A method characterized in that the value for the frequency shift corresponding to the frequency resource is determined as one of the values ​​for the available frequency shift.

7. In paragraph 6, A method characterized in that the value for the frequency shift corresponding to the frequency resource is randomly selected from among the values ​​for the available frequency shift.

8. In paragraph 5, The time resource associated with the above signal is T c Contains a plurality of chips having a length of , The above T c is T c =T b / (2*M) is satisfied, The above T c is the length of the above chip, The above T b is the length of the bit period corresponding to each bit, A method characterized in that the above M is a value for the above frequency shift.

9. In the device of the communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, wherein said device, Receive information related to frequency resources from the reader, Identify the frequency resource based on the above information, A memory storing a command to transmit a signal to the leader based on the above frequency resources; Including, The above frequency resource corresponds to a value for frequency shift, A device characterized in that the value for the above frequency shift is determined based on information related to the frequency resource.

10. In paragraph 9, Information related to the above frequency resources indicates a set of values ​​for available frequency shifts, A device characterized in that the value for the frequency shift corresponding to the frequency resource is determined as one of the values ​​for the available frequency shift.

11. In paragraph 10, A device characterized in that the value for the frequency shift corresponding to the frequency resource is randomly selected from among the values ​​for the available frequency shift.

12. In paragraph 9, The time resource associated with the above signal is T c Contains a plurality of chips having a length of , The above T c is T c =T b / (2*M) is satisfied, The above T c is the length of the above chip, The above T b is the length of the bit period corresponding to each bit, A device characterized in that the above M is a value for the above frequency shift.

13. In the reader of the communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, such that said leader, Transmits information related to frequency resources to a device, Identify the frequency resource based on the above information, A memory storing a command to receive a signal from the device based on the frequency resource; Including. The above frequency resource corresponds to a value for frequency shift, A leader characterized in that the value for the above frequency shift is determined based on information related to the frequency resource.

14. In paragraph 13, Information related to the above frequency resources indicates a set of values ​​for available frequency shifts, A leader characterized in that the value for the frequency shift corresponding to the frequency resource is determined as one of the values ​​for the available frequency shift.

15. In paragraph 14, A leader characterized in that the value for the frequency shift corresponding to the frequency resource is randomly selected from among the values ​​for the available frequency shift.

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