Method for transmitting ambient IoT signals on basis of OFDM waveform, and device therefor

Abstract

A method according to an embodiment of the present specification comprises a step of transmitting signals to a second device on the basis of modulated symbols related to line coding. The modulated symbols are mapped on the basis of the number of chips related to at least one orthogonal frequency division multiplexing (OFDM) symbol.

Description

Method and device for transmitting ambient IoT signals based on OFDM waveforms

[0001] This specification relates to a method and device for transmitting an Ambient IoT signal based on an OFDM waveform.

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

[0003] The 6G (wireless) system aims to provide (i) very high data rates per device, (ii) a very large number of connected devices, (iii) global connectivity, (iv) very low latency, (v) low energy consumption for battery-free Internet of Things (IoT) devices, (vi) ultra-reliable connectivity, and (vii) connected intelligence with machine learning capabilities. The vision of the 6G system can be divided into four aspects: intelligent connectivity, deep connectivity, holographic connectivity, and ubiquitous connectivity.

[0004] Meanwhile, an R2D (Reader to Device) / D2R transmission operation based on an OFDM (Orthogonal Frequency Division Multiplexing) waveform is defined.

[0005] For example, OFDM waveform-based R2D or D2R transmission can be performed based on a method of handling a cyclic prefix (CP). Specifically, OFDM waveform-based R2D or D2R transmission can be performed based on i) Method Type 1 in which CP is removed based on an Ambient IoT device, or ii) Method Type 2 in which CP is processed so as not to cause false rising / falling edges due to CP insertion.

[0006] The purpose of this specification is to propose a data encoding method and a modulation method that take into account i) requirements different from conventional UHF (Ultra High Frequency) passive RFID, including device types, (spectrum) deployment scenarios, connectivity topology, design targets and functions, and ii) the possibility of coexistence with existing wireless communication systems, in order to support Ambient IoT in wireless communication systems.

[0007] Another purpose of this specification is to propose a method for mapping modulation symbols generated for coexistence with 4G / 5G / 6G wireless communication systems to waveforms based on Orthogonal Frequency Division Multiplexing (OFDM).

[0008] The technical problems to be achieved in this specification are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0009] To solve the above-described technical problem, a method according to one embodiment of the present specification includes a step of transmitting a signal to a second device based on codewords.

[0010] The above codewords are characterized in that they are mapped to chips within at least one OFDM (Orthogonal Frequency Division Multiplexing) symbol based on the number of chips associated with the at least one OFDM symbol.

[0011] The processing method of the cyclic prefix (CP) associated with each OFDM symbol may include i) a first method in which the CP is removed based on an ambient IoT device, and ii) a second method different from the first method.

[0012] The above codeword may be based on line coding.

[0013] The above line coding may be based on Manchester encoding.

[0014] The number of the above codewords can be determined based on i) the number of chips to which the codewords are mapped within each OFDM symbol and ii) the duration of the codeword in which one bit is encoded based on line coding.

[0015] As described above, by defining a method for mapping codewords to OFDM-based waveforms by considering CP insertion locations, the problem of false transition edges occurring due to CP insertion can be solved.

[0016] The above codewords can be mapped to the remaining chips other than the first one or more chips and the last one or more chips in each OFDM symbol.

[0017] The first one or more chips and the last one or more chips may each be mapped to a preset or defined on-off keying (OOK) value, ii) a value based on an OOK value of a chip mapped before or after the first one or more chips, iii) a value based on an OOK value of a chip mapped before or after the last one or more chips, iv) an OOK value based on a square wave starting with a value different from an OOK value of a chip mapped before the first one or more chips or a chip mapped before the last one or more chips, or v) an OOK value based on a square wave ending with a value different from an OOK value of a chip mapped after the first one or more chips or a chip mapped after the last one or more chips.

[0018] The above codewords can be mapped to the remaining chips other than the first specific chips associated with the CP within each OFDM symbol.

[0019] The above first specific chips may be i) the first 2 chips or ii) the last 2 chips.

[0020] In each of the above OFDM symbols, the bit value of the first chip and the bit value of the last chip may be the same.

[0021] Among the first two chips, a second specific chip other than the first chip or among the last two chips, a third specific chip other than the last chip may be mapped to i) a value based on an OOK value of a chip mapped before or after the second specific chip, ii) a value based on an OOK value of a chip mapped before or after the third specific chip, or iii) an arbitrary preset or defined OOK value, or iv) a bit value of the second specific chip and a bit value of the third specific chip may be mapped so that they are identical.

[0022] The above codewords can be mapped to the remaining chips other than the first chip and the last chip among the total chips based on two OFDM symbols.

[0023] The first chip may be mapped to the same value as the codeword mapped to the last chip of the first OFDM symbol, and the last chip may be mapped to the same value as the codeword mapped to the first chip of the second OFDM symbol.

[0024] The above chips may be based on the remaining chips other than one or more chips associated with CP within each OFDM symbol among the entire chips based on a plurality of OFDM symbols.

[0025] The one or more chips associated with the above CP may be i) the first one or more chips or ii) the last one or more chips.

[0026] The bit values ​​of the first one or more chips and the bit values ​​of the last one or more chips may be the same.

[0027] The above transmission of the above signal may be R2D (Reader to Device) or D2R transmission.

[0028] A first device according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0029] The instructions are characterized in that they cause the first device to perform all steps of any one of the methods based on being executed by the one or more processors.

[0030] According to another embodiment of the present disclosure, a device comprises one or more memories and one or more processors connected to the one or more memories. The one or more memories are characterized in that they store instructions that cause the device to perform all steps of any one of the above methods based on instructions executed by the one or more processors.

[0031] A non-transitory computer-readable medium according to another embodiment of the present disclosure stores instructions, the instructions being executable by one or more processors, characterized in that they cause a first device to perform all steps of any one of the above methods.

[0032] A method according to another embodiment of the present disclosure comprises receiving a signal from a first device.

[0033] The signal is characterized in that i) codewords are mapped to at least one OFDM symbol based on the number of chips associated with at least one OFDM symbol and ii) the position of the chip into which a cyclic prefix (CP) is inserted.

[0034] A second device according to another embodiment of the present disclosure comprises one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0035] The above instructions are characterized in that they cause the second device to perform all steps of the method based on being executed by the one or more processors.

[0036] In R2D / D2R transmission based on OFDM (Orthogonal Frequency Division Multiplexing) waveform, Method Type 2 of the Cyclic Prefix (CP) handling method is a CP handling method based on the case where the Ambient IoT device cannot handle the transition or change of phase / energy / value due to CP insertion. According to Method Type 2, CP must be processed so that false rising / falling edges are not caused due to CP insertion.

[0037] According to an embodiment of the present specification, by defining a method for mapping codewords or modulated symbols to chips within an OFDM symbol while considering CP insertion locations during R2D or D2R transmission based on Method Type 2, false transition edges due to CP insertion can be prevented. Accordingly, the reliability of R2D / D2R transmission of Ambient IoT based on OFDM waveform can be improved, and a wider range of IoT services can be stably supported in wireless communication systems.

[0038] The effects that can be obtained from this specification 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 technical field to which this specification belongs from the description below.

[0039] Figure 1 is an example of a topology that is directly connected between a base station and an A-IoT device.

[0040] Figure 2 is an example of a topology in which a base station and an A-IoT device are connected through an intermediate node.

[0041] Figures 3 and 4 are examples showing topologies supported by auxiliary nodes.

[0042] Figure 5 is an example of a topology that is directly connected between a terminal and an A-IoT device.

[0043] Figure 6 shows an example of power consumption and device energy status according to the operating state of an energy harvesting-based device.

[0044] Figure 7 is an example showing the combination of Deployment scenario 1 and topology 1 with various CWs.

[0045] Figure 8 is an example showing the combination of Deployment scenario 2 and topology 2 with various CWs.

[0046] Figure 9 shows an example of UHF passive RFID application.

[0047] Figure 10 is a diagram illustrating the relationship between OFDM symbols and chips in Method Type 2.

[0048] FIG. 11 is a drawing for explaining a method according to one embodiment of the present specification.

[0049] FIG. 12 is a drawing for explaining a method according to another embodiment of the present specification.

[0050] FIG. 13 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0051] As used herein, “A or B” may mean “only A,” “only B,” or “both A and B.” In other words, as used herein, “A or B” may be interpreted as “A and / or B.” For example, as used herein, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0052] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0053] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as equivalent to “at least one of A and B.”

[0054] Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.”

[0055] Additionally, parentheses used herein may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in the present disclosure is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0056] In the following explanation, ‘when, if, in case of’ can be replaced with ‘based on’.

[0057] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0058] In this specification, higher layer parameters may be parameters that are set for the terminal, preset, or predefined. For example, a base station or network may transmit higher layer parameters to the terminal. For example, higher layer parameters may be transmitted via radio resource control (RRC) signaling or medium access control (MAC) signaling.

[0059] In this specification, "configured or defined" may be interpreted as being configured or preset for a device through predefined signaling (e.g., SIB, MAC, RRC) from a base station or network. In this disclosure, "configured or defined" may be interpreted as being preset for a device.

[0060] In this specification, a user equipment (UE) may refer to a portable device, a wireless device, etc. In this disclosure, a base station (BS) may refer to a radio access network (RAN) node, a transmission reception point (TRP), a network, an integrated access and backhaul (IAB) node, a portable device, a wireless device, etc.

[0061] Hereinafter, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. A base station may be expressed as a first communication device, and a terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI system, RSU (road side unit), vehicle, robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc. In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, robot, AI module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

[0062] Ambient IoT (A-IoT)

[0063] Below, we explain Ambient IoT (A-IoT).

[0064] A-IoT may be a new device type / segment that operates solely on energy harvested from the surrounding environment. For example, A-IoT could refer to a new type of Internet of Things device that is powered by various energy sources harvested from the surrounding environment, such as radio waves, light, motion, and heat. Table 1 presents examples of A-IoT use cases. Table 2 presents IoT communication-related issues discussed in the 3GPP RAN.

[0065]

[0066]

[0067] For example, active signal generation and / or backscattering may be among the communication technologies considered to achieve low-power operation of A-IoT devices. For example, backscattering is a technique widely used in radio frequency identification (RFID), which allows devices to communicate with a network by reflecting incident waves after modulating them with information to be transmitted. For example, the device may be powered by the incident RF signal or by stored energy.

[0068] For example, IoT devices can be classified into various device types, such as passive, semi-passive, and active, depending on how they store energy and generate transmission signals. For example, a passive device does not have an energy storage device (e.g., a capacitor) and can communicate based on backscatter communication technology. For example, a semi-passive device has an energy storage device and can communicate using backscatter communication technology with the help of the energy storage device. For example, an active device has an energy storage device and can actively generate signals using active RF components and the stored energy to communicate. For example, in the present disclosure, the following three types of IoT devices can be considered. For example, device A can be a device without energy storage and without independent signal generation (e.g., a device that supports backscatter transmission). For example, device B can be a device with energy storage and without independent signal generation (e.g., a device that supports backscatter transmission). In this case, for example, the use of stored energy may involve amplification of the reflected signal. For example, device C may be a device with energy storage and independent signal generation (e.g., a device with an active RF component for transmission).

[0069] For example, the following basic topologies may be considered to support A-IoT devices in indoor and outdoor scenarios. For example, the basic topologies may include direct connections between base stations and A-IoT devices, connections between base stations and intermediate nodes and A-IoT devices, connection support by auxiliary nodes, and / or connections between terminals and A-IoT devices. The basic topologies proposed in this disclosure are merely examples, and the proposals in this disclosure may be extended / applied to other topologies.

[0070] FIG. 1 illustrates an example of a topology in which a base station and an A-IoT device are directly connected. Specifically, FIG. 1 illustrates a topology (e.g., Topology 1) in which a base station and an A-IoT device are directly connected, according to one embodiment of the present disclosure. The embodiment of FIG. 1 may be combined with various embodiments of the present disclosure.

[0071] Referring to FIG. 1, an A-IoT device can communicate directly and bidirectionally with a base station. For example, communication between a base station and an A-IoT device may include A-IoT data and / or signals. For example, the A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel). In the embodiment of FIG. 1, the base station transmitting to the A-IoT device and the base station receiving from the A-IoT device may be different. For example, in the topology 1, a base station and an A-IoT device in a micro-cell environment may communicate directly with each other. For example, the base station may be located at a co-site with a base station equipped with an existing 3GPP technology.

[0072] FIG. 2 illustrates an example topology in which a base station and an A-IoT device are connected via an intermediate node. Specifically, FIG. 2 illustrates a topology (e.g., Topology 2) in which a base station and an A-IoT device are connected via an intermediate node, according to one embodiment of the present disclosure. The embodiment of FIG. 2 can be combined with various embodiments of the present disclosure.

[0073] Referring to FIG. 2, an A-IoT device can bidirectionally communicate with an intermediate node between the device and a base station. Here, for example, the intermediate node can be an A-IoT-capable relay, an IAB node, a terminal, a repeater, etc. For example, the intermediate node can transmit A-IoT data and / or signals between the base station and the A-IoT device. For example, the A-IoT data and / or signals can be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel). In the embodiment of FIG. 2, the intermediate node transmitting to the A-IoT device and the intermediate node receiving from the A-IoT device can be different. For example, in the topology 2, an intermediate node can exist between a base station and the A-IoT device in a macro-cell environment. For example, the base station can be located at a co-site with a base station equipped with an existing 3GPP technology. For example, intermediate nodes may be limited to terminals, and intermediate nodes may be located indoors.

[0074] FIGS. 3 and 4 illustrate examples of topologies supported by auxiliary nodes. Specifically, FIGS. 3 and 4 illustrate a topology (e.g., Topology 3) supported by an auxiliary node according to one embodiment of the present disclosure. The embodiments of FIGS. 3 and 4 may be combined with various embodiments of the present disclosure.

[0075] Referring to FIG. 3, an auxiliary node may be supported for downlink reception. For example, an A-IoT device may transmit data / signals to a base station, and the A-IoT device may receive data / signals from the auxiliary node. Referring to FIG. 4, an auxiliary node may be supported for uplink transmission. For example, an A-IoT device may receive data / signals from a base station, and the A-IoT device may transmit data / signals to an auxiliary node. Here, for example, the auxiliary node may be an A-IoT-capable relay, an IAB node, a terminal, a repeater, etc.

[0076] FIG. 5 illustrates an example of a topology in which a terminal and an A-IoT device are directly connected. Specifically, FIG. 5 illustrates a topology (e.g., Topology 4) in which a terminal and an A-IoT device are directly connected, according to one embodiment of the present disclosure. The embodiment of FIG. 5 can be combined with various embodiments of the present disclosure.

[0077] Referring to FIG. 5, the A-IoT device can communicate bidirectionally with the terminal. For example, communication between the terminal and the A-IoT device may include A-IoT data and / or signals. For example, the A-IoT data and / or signals may be transmitted or received based on a control channel and / or a data channel (e.g., a shared channel).

[0078] For example, transmission by an A-IoT device may be performed over a frequency division duplexing (FDD) spectrum (e.g., an FDD UL spectrum).

[0079] Meanwhile, a study item titled "Study on solutions for Ambient IoT (Internet of Things) in NR" has been approved for 3GPP NR Release 19. Specifically, the study item will be implemented in 3GPP NR Release 19 based on the following:

[0080] This study aims to further evaluate Ambient IoT, a new 3GPP IoT technology suitable for deployment in 3GPP systems, at the RAN WG level. It relies on ultra-low-power, ultra-low-complexity devices for very low-end IoT applications. This study must provide a clear differentiation: it must address use cases and scenarios that cannot be met by existing 3GPP LPWA IoT technologies (e.g., NB-IoT with reduced peak Tx power).

[0081] General range

[0082] The definitions given in TR 38.848 apply to this SI and are of an exclusive general scope.

[0083] A. The overall goal is to study a harmonized wireless interface design that minimizes the differences required to enable Ambient IoT to enable the following devices:

[0084] i. ~1μW peak power consumption, energy storage, initial sampling frequency offset (SFO) of up to 10X ppm, and no DL or UL amplification in the device. The device's UL transmission is backscattered from an externally supplied carrier wave.

[0085] ii. ≤ hundreds of μW peak power consumption1, energy storage, initial sampling frequency offset (SFO) of up to 10X ppm, and DL and / or UL amplification in the device. The UL transmission of the device can be generated internally or backscattered from an externally provided carrier wave.

[0086] -X is decided by WG.

[0087] - Coverage design goal: Up to 10-50 m distance with the device indoors according to TR 38.848: "...the range within which the WG can sub-select".

[0088] -No RRC state, no mobility (i.e. at least no functionality like cell selection / reselection), no HARQ, no ARQ for topologies 1 and 2 (UE as intermediate node under NW control) according to TR 38.848.

[0089] Note 1: It should be understood that "≤ hundreds of μW" means that the WG is not tasked with setting a specific value, and it is a matter for the WG to decide whether the proposed design and its power consumption meet the "≤ hundreds of μW" requirement.

[0090] B. Deployment scenarios with the following characteristics, referring to the table in clause 4.2.2 of TR 38.848:

[0091] - Deployment Scenario 1 Using Topology 1

[0092] Base Station and Coexistence Characteristics: Microcells, Co-sites

[0093] - Deployment scenario 2 using UE as an intermediate node under topology 2 and network control.

[0094] Base Station and Coexistence Characteristics: Macro Cell, Co-site

[0095] The location of the intermediate node is indoors

[0096] C. FDD's FR1 licensed spectrum.

[0097] D. In-band spectrum distribution for NR, guard bands for LTE / NR, and standalone band(s).

[0098] E. Traffic types DO-DTT, DT focusing on rUC1 (indoor inventory) and rUC4 (indoor command).

[0099] - In RAN#104, this study evaluates whether the harmonized radio interface design (see bullet 'A' above) can address Device-Initiated Autonomous (DO-A) use cases and identifies which parts of the harmonized radio interface design (see bullet 'A' above) are insufficient for DO-A use cases.

[0100] Transmissions from surrounding IoT devices (including backscattering when used) are likely to occur at least in the UL spectrum.

[0101] The following goals are set within the general range:

[0102] 1. Evaluation assumptions

[0103] a) Conclude at least the following aspects of the design objectives left to the WG in clause 5 (RAN design objectives) of TR 38.848 [RAN1]:

[0104] Article 5.3: Applicable Maximum Distance Target Value

[0105] Clause 5.6: Refines the definition of latency suitable for use in RAN WGs.

[0106] Article 5.8: 2D Distribution of Devices

[0107] b) Define additional assessment assumptions required for deployment scenarios for coverage and coexistence assessments [RAN1, RAN4].

[0108] c) Identify the basic blocks / components of a possible peripheral IoT device architecture, considering the latest implementations of low-power, low-complexity devices that meet RAN design goals for power consumption and complexity. [RAN1]

[0109] d) Define link budget calculations for coverage, including whether / how to model carrier waves at nodes inside or outside the connection topology.

[0110] Note: The evaluation performance of the design target falls within the scope of the feasibility and necessity study of the proposal, with the following objectives: For example, testing a reference implementation in the field, conducting simulations, and conducting analytical tests.

[0111] Note: RAN1 strives to minimize evaluation cases.

[0112] 2. Investigate necessary and feasible solutions for Ambient IoT, as defined in the general scope. This includes determining which functions, procedures, etc. are necessary and which are not, and ensures at least the essential functions specified in Section 6.2 of TR 38.848.

[0113] Positioning research for Rel-19 is led by RAN3 and is limited to features that have no or minimal impact on the specification (Note: This does not imply decisions regarding WI generation).

[0114] We study the feasibility and required features for proximity determination (coordination with SA3 is necessary for privacy reasons).

[0115] - RAN1 led:

[0116] For Ambient IoT DL and UL:

[0117] Frame structure, synchronization and timing, random access

[0118] Numerology, Bandwidth, and Multi-Access

[0119] Waveforms and modulation

[0120] Channel coding

[0121] Downlink channel / signal aspect

[0122] Uplink channel / signal aspect

[0123] Scheduling and Timing Relationships

[0124] We study the required characteristics of the carrier wave waveform provided to ambient IoT devices from outside, including interference handling at ambient IoT UL receivers and NR base stations.

[0125] For topology 2, there is no difference in the physical layer design from topology 1.

[0126] RAN2 led:

[0127] We study and determine the features required for an ambient IoT compact protocol stack and lightweight signaling procedures that enable DO-DTT and DT data transmission.

[0128] for example:

[0129] Paging

[0130] Random access

[0131] Data transmission including necessary radio resource control aspects that comply with general range limitations.

[0132] Interaction with higher layers

[0133] Features not listed above will only be studied if deemed essential.

[0134] RAN3 led:

[0135] Identify the necessary impacts on the signals and procedures of the CN-RAN interface to enable:

[0136] Paging

[0137] Device context management

[0138] Data transfer

[0139] Identify RAN architecture aspects, including whether split architecture support is required.

[0140] Identify potential solutions for finding Ambient IoT devices that don't impact the specifications. For example, reusing existing user location reports or transmitting location information to the core network with minimal impact on the specifications.

[0141] RAN4 led:

[0142] A study on the coexistence of Ambient IoT and NR / LTE.

[0143] RF Requirements Study for Ambient IoT:

[0144] Ambient IoT BS Transmission and Reception

[0145] Ambient IoT devices, transmitting and receiving, according to general scope

[0146] Intermediate nodes (UEs) according to general range, transmitting and receiving

[0147] RAN2 and RAN3 are expected to work with SA2 to identify the RAN-CN functional split.

[0148] Note: This study targets IoT segments that are significantly lower than existing 3GPP IoT technologies (e.g., NB-IoT, eMTC, RedCap, etc.). This study does not aim to replace existing 3GPP LPWA technologies.

[0149] For example, as described above, the types of A-IoT devices can be divided into two as follows. For example, a Type 1 device has a maximum power consumption of approximately 1 uW, can store energy, has no amplification function, and can transmit by backscattering a carrier wave (CW) provided from the outside (e.g., a reader such as a base station or a terminal or a separate node). For example, a Type 2 device has a maximum power consumption of approximately several hundred uW, can store energy, has an amplification function, and can transmit by backscattering a carrier wave (CW) provided from the outside (e.g., a reader such as a base station or a terminal or a separate node) or using a signal generated internally by itself.

[0150] For example, in addition to the above-described classification methods, the type / class of A-IoT devices can be distinguished based on parameters associated with device characteristics (e.g., presence / capacity of energy storage, energy / power consumption, presence / capacity of amplification, presence / capacity of BPF (band-pass filter), supported DL / UL transmission method(s), etc.) or a combination of parameters. Here, for example, BPF capability can be distinguished by 3-dB bandwidth of supported BPF, sharpness, etc., and UL transmission methods can be distinguished by, for example, backscatter UL transmission, UL transmission by internal signal generation, etc.

[0151] In addition, the type / class of A-IoT devices can be subdivided based on parameters associated with the device characteristics (e.g., presence / capacity of energy storage, level of energy / power consumption, presence / capacity of amplification, presence / capacity of band-pass filter (BPF), supported DL / UL transmission method(s), etc.) or a combination of parameters. For example, the above-described Type 2 device can be classified into Type 2a if it performs transmission by backscattering a carrier wave (CW) provided from the outside (e.g., a reader such as a base station or terminal or a separate node), and Type 2b if it performs transmission using a signal generated internally by itself. In this case, Type 2a and 2b can be the same in that they have a maximum power consumption of approximately several hundred microwatts, are capable of energy storage, and have an amplification function.

[0152] For example, some types / classes of A-IoT devices (e.g., Device B, Device C, Type 1 devices, and / or Type 2 devices) may have energy storage capabilities (e.g., capacitors or charging batteries) for the following purposes:

[0153] - Stable energy security at the time of reception / transmission

[0154] - Operation of low-power communication modules through energy storage in low RF energy states

[0155] For example, the minimum RF reception sensitivity for operation of a low-power communication module may be -20 dBm, and the minimum reception sensitivity for energy harvesting may be -20 dBm. In this case, if the reception power of the A-IoT device ranges between -30 and -20 dBm, communication may not be possible without a capacitor, but communication may be possible after a charging time with a capacitor.

[0156] - Energy harvested from different energy sources (e.g. solar, thermal, wind, kinetic, etc.) is accumulated in a single capacitor and used to operate a low-power communication module at a desired time.

[0157] FIG. 6 illustrates examples of power consumption and device energy states according to the operating states of an energy harvesting-based device. Specifically, FIG. 6 illustrates examples of power consumption and device energy states according to the operating states of an energy harvesting-based device with energy storage capabilities, according to an embodiment of the present disclosure. The embodiment of FIG. 6 may be combined with various embodiments of the present disclosure.

[0158] Referring to (b) of Fig. 6, S1 may be a sleep state, S2 may be an active state, and P1 and P2 may be power consumption in S1 and S2, respectively. For example, the active state may mean a state in which the device consumes power to perform operations such as receiving / transmitting for communication and sensing, and the sleep state may be a state in which it is not an active state.

[0159] Figure 6 (a) may represent a device energy state corresponding to Figure 6 (b). Referring to Figure 6 (a), the E1 value and the E2 value may differ depending on the device (type / class), and the device may report information related to the E1 value and / or information related to the E2 value to R and / or the base station as capability parameters. For example, the E2 value may be defined as an energy value in a buffered state, and the E1 value may be defined as a minimum energy value required in an active state.

[0160] For example, a transition from S1 to S2 may be possible only when the device energy state value is E2 or has reached E2. For example, a transition from S1 to S2 may be possible when the device energy state value is greater than E1 (i.e., in the range between E1 and E2). The embodiment of FIG. 6 illustrates an example in which a transition from S1 to S2 is performed when the device energy state value is E2 or has reached E2.

[0161] For example, A-IoT devices may require externally provided CW for backscatter transmission. For example, CW may be used to power A-IoT devices or as CW for downlink transmission, regardless of the transmission mode (e.g., backscatter transmission or internally generated transmission).

[0162] For example, CW waveforms can be supported in various types. For example, the CW waveform type can be a single-tone CW waveform type or a more complex multi-tone CW waveform type. For example, single-tone CW can be advantageous over multi-tone CW in terms of the multiplexing capacity of tags or readers and in terms of interference because it uses fewer resources. On the other hand, multi-tone CW has advantages such as being able to transfer more energy when transmitting CW in DL, and also securing greater coverage from a single device.

[0163] Considering the advantages of these different CW waveform types, multiple CW waveform types can be supported in the A-IoT system, and the base station / IN / AN / UE can configure the CW waveform type. For example, one or more CW waveform types supported in the A-IoT communication system can be configured / defined in advance, and the base station / IN / AN / UE can select one of the one or more supported CW waveform types and transmit it to the A-IoT device. For example, the base station / IN / AN / UE can configure / instruct / indicate the selected CW waveform type to the A-IoT device in the form of a command / message transmitted as a preamble / frame-sync or payload.

[0164] For example, the present disclosure may propose at least one of the following for A-IoT communication: frame structure, synchronization and timing, random access, numerology, bandwidth, multiple access, waveforms, modulation, channel coding, channel / signal aspects, scheduling and timing relationships, and / or required characteristics of carrier waveforms for carriers provided external to the A-IoT device (including interference handling at the A-IoT device UL receiver and NR base station). For example, the present disclosure may propose at least one of the following for A-IoT communication: paging, random access, data transmission including required radio resource control aspects to comply with general range limitations, interaction with upper layers (e.g., RRC layer, non-access stratum (NAS) layer, application layer, etc.), device context management, data transmission, coexistence of A-IoT and 6G / NR / LTE, and / or RF requirements for A-IoT.

[0165] For example, technical terms used in this disclosure may be as follows:

[0166] - SSB: Synchronization Signal Block

[0167] - MIB: Master Information Block

[0168] - RMSI: Remaining Minimum System Information

[0169] - FR1: Frequency Range 1. Refers to the frequency range below 6 GHz (e.g., 450 MHz to 6000 MHz).

[0170] - FR2: Frequency Range 2. Refers to the millimeter wave (mmWave) range above 24 GHz (e.g., 24250 MHz to 52600 MHz).

[0171] - BW: Bandwidth

[0172] - BWP: Bandwidth Part

[0173] - RNTI: Radio Network Temporary Identifier

[0174] - CRC: Cyclic Redundancy Check

[0175] - SIB: System Information Block

[0176] - SIB1: SIB1 for NR devices (i.e., Remaining Minimum System Information (RMSI)). Broadcasts information necessary for NR terminals to access the cell.

[0177] - CORESET: Control Resource Set. Time / frequency resource for NR terminals to attempt candidate PDCCH decoding.

[0178] - CORESET#0: CORESET for Type0-PDCCH CSS set for NR devices (configured in MIB)

[0179] - Type0-PDCCH CSS set: a search space set in which an NR UE monitors a set of PDCCH candidates for a DCI format with CRC scrambled by a SI-RNTI

[0180] - MO: PDCCH Monitoring Occasion for Type0-PDCCH CSS set

[0181] - SIB1-R: (additional) SIB1 for reduced capability NR devices. May be limited to cases where it is generated as a separate TB from SIB1 and transmitted on a separate PDSCH.

[0182] - CORESET#0-R: CORESET#0 for reduced capability NR devices

[0183] - Type0-PDCCH-R CSS set: a search space set in which a redcap UE monitors a set of PDCCH candidates for a DCI format with CRC scrambled by a SI-RNTI

[0184] - MO-R: PDCCH Monitoring Occasion for Type0-PDCCH CSS set

[0185] - Cell defining SSB (CD-SSB): SSB containing RMSI scheduling information among NR SSBs

[0186] Non-cell defining SSB (non-CD-SSB): An SSB placed in the NR sync raster but not containing RMSI scheduling information for the corresponding cell for measurement purposes. However, it may contain information indicating the location of the cell defining SSB.

[0187] - SCS: subcarrier spacing

[0188] - SI-RNTI: System Information Radio-Network Temporary Identifier

[0189] - Camp on: "Camp on" is the UE state in which the UE stays on a cell and is ready to initiate a potential dedicated service or to receive an ongoing broadcast service.

[0190] - TB: Transport Block

[0191] - RSA (Redcap standalone): Redcap device 또는 service만 지원하는 cell.

[0192] - SIB1(-R)-PDSCH: SIB1(-R)을 전송하는 PDSCH

[0193] - SIB1(-R)-DCI: SIB1(-R)-PDSCH를 scheduling하는 DCI. DCI format 1_0 with CRC scrambled by SI-RNTI.

[0194] - SIB1(-R)-PDCCH: SIB1(-R)-DCI를 전송하는 PDCCH

[0195] - FDRA: Frequency Domain Resource Allocation

[0196] - TDRA: Time Domain Resource Allocation

[0197] - RA: Random Access

[0198] - MSGA: preamble and payload transmissions of the random access procedure for 2-step RA type.

[0199] - MSGB: response to MSGA in the 2-step random access procedure. MSGB may consist of response(s) for contention resolution, fallback indication(s), and backoff indication.

[0200] - RO-N: normal UE 4-step RACH and 2-step RACH(if configured)를 위한 RO(RACH Occasion)

[0201] - RO-N1, RO-N2: When a separate RO is set for normal UE 2-step RACH, it is divided into RO-N1 (4-step) and RO-N2 (2-step).

[0202] - RO-R: RO (RACH Occasion) set separately from RO-N for redcap UE 4-step RACH and 2-step RACH (if configured)

[0203] - RO-R1, RO-R2: When separate ROs are set for redcap UE 2-step RACH, they are distinguished as RO-R1 (4-step) and RO-R2 (2-step).

[0204] - PG-R: MsgA-Preambles Group for redcap UEs

[0205] - RAR: Random Access Response

[0206] - RAR window: the time window to monitor RA response(s)

[0207] - FH: Frequency Hopping

[0208] - iBWP: initial BWP

[0209] - iBWP-DL(-UL): initial DL(UL) BWP

[0210] - iBWP-DL(-UL)-R: (separate) initial DL(UL) BWP for RedCap

[0211] - CS: Cyclic shift

[0212] - NB: Narrowband

[0213] - TO: Traffic Offloading

[0214] -mMTC; Massive Machine Type Communications

[0215] - eMBB: enhanced Mobile Broadband Communication

[0216] - URLLC: Ultra-Reliable and Low Latency Communication

[0217] - RedCap: Reduced Capability

[0218] - eRedCap: enhanced RedCap

[0219] - FDD: Frequency Division Duplex

[0220] - HD-FDD: Half-Duplex-FDD

[0221] - DRX: Discontinuous Reception

[0222] - RRC: Radio Resource Control

[0223] - RRM: Radio Resource Management

[0224] - MM: Mobility Management

[0225] - IWSN: Industrial Wireless Sensor Network

[0226] - LPWA: Low Power Wide Area

[0227] - RB: Resource Block

[0228] - CCE: Control Channel Element

[0229] - AL: Aggregation Level

[0230] - PRG: Physical Resource-block Group

[0231] - DFT-s-OFDM: DFT-spread OFDM

[0232] - PBCH: Physical Broadcast Channel

[0233] - A-PBCH: Additional PBCH

[0234] - BD: blind detection

[0235] - EPRE: Energy Per RE

[0236] - SNR: Signal-to-Noise Ratio

[0237] - TDM: Time Division Multiplexing

[0238] - FDM: Frequency Division Multiplexing

[0239] - DMRS: DeModulation Reference Signal

[0240] - TDD: Time Division Duplex

[0241] - PCI: Physical layer Cell ID

[0242] - EH: Energy Harvesting

[0243] - EH device: A device that operates based on EH. It can include all of Device A / B / C being discussed in 3GPP. In addition, although this specification primarily considers RF EH, an EH device does not necessarily have to be RF EH-based.

[0244] - ES: Energizing Signal. A signal / channel transmitted by a base station / IN / AN / UE for the purpose of supplying RF energy to a device operating on RF-based energy harvesting. (Modulated) CW, NR / LTE DL / UL signals, etc. can be ES, and a dedicated signal / channel for ES can also be designed and supported.

[0245] - ET: Energy Transfer

[0246] CW: Carrier wave. Ambient IoT devices supporting backscattering-based UL transmission transmit information by modulating and backscattering "externally provided" CW. Ambient IoT devices supporting independent signal generation-based UL transmission transmit information by modulating "internally generated" CW. Unless otherwise specified, "externally provided" CW for backscattering is assumed. CW can be used as an energizing signal (ES) for RF energy transfer.

[0247] - CWN: Carrier Wave Node. A node that provides the CW. It may be a base station / IN / AN / UE, and there may be a separate CWN for CW provision purposes.

[0248] - R: Reader / interrogator. This is a standard RFID term. In the 3GPP Ambient IoT context, readers can include gNB / eNB, intermediate / assisting nodes, and UEs, depending on the topology. Furthermore, Ambient IoT is not limited to 4G / 5G communication systems, and can include base stations, intermediate / assisting nodes, and UEs in next-generation communication systems. This can also refer to Ambient IoT readers.

[0249] - T: Tag / ambient IoT device. This is a standard RFID term. In this specification, it can be interchanged with EH device, and in the 3GPP Ambient IoT context, it mainly refers to Ambient IoT device and Device A / B / C.

[0250] - D: Ambient IoT device (may have the same meaning as T above)

[0251] - R=>T: Reader-to-Tag or Reader-to-Tag communication link. If the base station or intermediate / assisting node is the reader, it can have the same meaning as DL or forward link.

[0252] - R2D: R-to-D link (can mean the same thing as R=>T. Can also be written as R=>D.)

[0253] - CW2D: CWN-to-D link (CW node to Ambient IoT device link)

[0254] - T=>R: Tag-to-Reader or Tag-to-Reader communication link. If the base station or intermediate / assisting node is the reader, it may have the same meaning as UL or reverse / backward link.

[0255] - D2R: It can have the same meaning as T=>R. It can be written as D=>R.

[0256] - R<=>T: Includes cases where R=>T and T=>R, or R=>T or T=>R. It may be the case that both R=>T and T=>R apply.

[0257] - R<=>D: Includes R2D and D2R, or either R2D or D2R. This may apply to both R2D and D2R. (This may have the same meaning as R<=>T.)

[0258] - RF-EH: RF energy harvesting

[0259] - PRDCH: Physical R2D CHannel (may be written as PR2DCH). A physical channel for R2D communication.

[0260] - PDRCH: Physical D2R CHannel (may be denoted as PD2RCH). Physical channel for D2R communication.

[0261] - BS: Base Station

[0262] - IN: Intermediate node. In Topology 2 (BS ↔ IN ↔ Ambient IoT device), IN acts as the reader. Relay, IAB, UE, repeater, etc. can be IN.

[0263] - AN: Assisting node. It can assist DL transmission in Topology 3-1 (BS -> AN -> Ambient IoT device -> BS), or assist UL transmission in Topology 3-2 (BS -> Ambient IoT device -> AN -> BS). Relay, IAB, UE, repeater, etc. can be AN.

[0264] - UE: User Equipment. In the case of LTE, NR, or next-generation communication systems, it refers to the LTE, NR, or next-generation communication system UE / terminal, respectively. It is a general wireless communication terminal type that is distinct from Ambient IoT devices or Device A / B / C. In Topology 4 (UE ↔ Ambient IoT device), the UE acts as the reader.

[0265] - Device: Unless otherwise stated, and when used alone, refers to EH device, Ambient IoT device, or Device A / B / C indiscriminately.

[0266] - AmIoT: Ambient IoT (=A-IoT)

[0267] - F-gap: Frequency gap

[0268] - T-gap: Time gap

[0269] - TD: Time Domain

[0270] - FD: Frequency Domain

[0271] - PEI: Paging Early Indication

[0272] - LP-WUS: Low-Power Wake-Up Signal

[0273] - LP-SS: Low-Power Synchronization Signal

[0274] - RSRP: Reference Signal Received Power

[0275] - ESRP: ES Received Power. This may refer to RSRP measured using ES. It may have the same meaning as ES-RSRP.

[0276] - PRB: Physical Resource Block

[0277] - EH circuit: A circuit that performs EH operations. An EH device can be viewed as containing an EH circuit in component form.

[0278] - PHR: Power Headroom Report

[0279] - EHR: Energy Headroom Report

[0280] - BPF: Band-Pass Filter

[0281] - SM: Subcarrier Modulation

[0282] - FS: Frequency Shift. In FDD, it can be divided into small FS, which is performed within a small range (e.g., hundreds of kHz) within the DL spectrum or within the UL spectrum (mainly through baseband processing), and large FS, which is performed over a relatively large range (e.g., tens of MHz) from the DL to the UL spectrum or from the UL to the DL spectrum.

[0283] - SFO: Sampling Frequency Offset

[0284] - ASK: Amplitude Shift Keying

[0285] -DSB-ASK: Double-SideBand ASK

[0286] -SSB-ASK: Single-SideBand ASK

[0287] - PR-ASK: Phase-Reversal ASK

[0288] - OOK: On-Off Keying

[0289] - PSK: Phase-Shift Keying

[0290] - BPSK: Binary-PSK

[0291] - FSK: Frequency-Shift Keying

[0292] - B-FSK: Binary FSK

[0293] - M-FSK: M-ary FSK

[0294] - PIE: Pulse-Interval Encoding

[0295] - Ncp-ofdm, Ncp, Nu: The length of the sample unit of the CP-OFDM symbol section, CP section, and useful OFDM symbol section, respectively, in the CP-OFDM symbol. Ncp-ofdm=Ncp+Nu.

[0296] Ultra High Frequency (UHF) passive RFID communication (ISO 18000-6C) can be considered as a standardized conventional technology that uses a communication method similar to Ambient IoT communication. This UHF passive RFID supports Pulse-Interval Encoding (PIE) as a data encoding method for R=>T communication and DSB-ASK and / or SSB-ASK and / or PR-ASK as a modulation method. In addition, for T=>R communication, it supports FM0 baseband encoding and Miller modulated subcarrier as a data encoding method and ASK and / or PSK-based backscatter modulation as a modulation method.

[0297] Meanwhile, supporting Ambient IoT in wireless communication systems requires determining data encoding and modulation methods that take into account requirements different from those of conventional UHF passive RFID, such as device types, spectrum deployment scenarios, connectivity topologies, design targets, and functions. Furthermore, coexistence with efficient 4G / 5G / 6G wireless communication systems must also be considered critically.

[0298] In this specification, we propose a data encoding method, a modulation method, and a method for mapping generated modulation symbols to OFDM-based waveforms for coexistence with efficient 4G / 5G / 6G communication systems, taking into account the above-mentioned points.

[0299] The methods proposed in this specification can be applied to both topology 1 and topology 2. They can also be applied to both deployment scenario 1 and deployment scenario 2. To support Ambient IoT communication in 4G / 5G / 6G communication systems, the following combinations of topology, deployment scenario, and CW node type (CW inside topology or CW outside topology) are being considered.

[0300] Figure 7 is an example showing the combination of Deployment scenario 1 and topology 1 with various CWs.

[0301] Referring to Fig. 7, in Deployment scenario 1 with topology 1 (indoor BS + indoor AIoT device), it can be seen that i) the case where external CW is within the topology (D1T1-A), ii) the case where external CW is outside the topology (D1T1-B), and iii) the case where there is no external CW (i.e., D2R transmission using internally generated CW, D1T1-C) are considered.

[0302] D1T1-A can be considered when i) the CW2D / R2D and D2R nodes are different (D1T1-A1 in Fig. 7) and ii) the CW and R nodes for CW2D, D2R and R2D are the same (D1T1-A2 in Fig. 7).

[0303] Specifically, D1T1-A1 represents the cases where i) the CW of CW2D and the R of D2R are different, ii) the CW of CW2D and the R of R2D are the same, and iii) the R of R2D and the R of D2R are different.

[0304] D1T1-B represents the cases where i) the CW of CW2D and the R of D2R are different, ii) the CW of CW2D and the R of R2D are different, and iii) the R of R2D and the R of D2R are the same.

[0305] D1T1-C can only be considered for device 2b.

[0306] Figure 8 is an example showing the combination of Deployment scenario 2 and topology 2 with various CWs.

[0307] Referring to Fig. 8, it can be seen that in Deployment scenario 2 with topology 2 (outdoor BS + Indoor Intermediate UE + Indoor AIoT device), i) the case where external CW is within the topology (D2T2-A), ii) the case where external CW is outside the topology (D2T2-B), iii) and the case where there is no external CW (i.e., D2R transmission using internally generated CW, D2T2-C) are considered.

[0308] D2T2-A can be considered when i) the CW2D / R2D and D2R nodes are different (D2T2-A1 in Fig. 8) and ii) the CW and R nodes for CW2D, D2R and R2D are the same (D2T2-A2 in Fig. 8).

[0309] Specifically, D2T2-A1 represents the cases where i) the CW of CW2D and the R of D2R are different, ii) the CW of CW2D and the R of R2D are the same, and iii) the R of R2D and the R of D2R are different.

[0310] D2T2-B represents the cases where i) the CW of CW2D and R of D2R are different, ii) the CW of CW2D and R of R2D are different, and iii) the R of R2D and R of D2R are the same.

[0311] D2T2-C can only be considered for device 2b.

[0312] <Data encoding and modulation method>

[0313] For R2D / D2R communication, low-power / low-complexity modulation schemes such as ASK (e.g., OOK), PSK (e.g., BPSK), and FSK (e.g., B-FSK) can be considered. In addition, for efficient control of R2D / D2R communication, a chip, which is the basic unit of modulation application, can be defined, and based on this, the start and / or end points can be aligned between the transmission symbols of coexisting 4G / 5G / 6G communication systems (e.g., OFDM symbols) and AmIoT transmission symbols, or parameters for R2D / D2R communication (e.g., R2D / D2R data / chip rate, FS value) can be directed / controlled.

[0314] A chip, which is the basic unit of modulation application, can be defined as a unit of bit sequence or phase sequence of the output of a channel / baseband / data encoder. For example, when Manchester Encoding (ME) is applied to data-0, a 2-chip Manchester codeword consisting of {1, 0} is generated. At this time, ME represents an encoding method in which i) data-0 is mapped to {+phase, -phase} or {1, 0}, and data-1 is mapped to {-phase, +phase} or {0, 1}, or ii) conversely, data-0 is mapped to {-phase, +phase} or {0, 1}, and data-1 is mapped to {+phase, -phase} or {1, 0}.

[0315] Based on the definition of these chips, the codeword duration can be defined for the channel / baseband / data encoding schemes considered in AmIoT communication. As explained above, in the case of the ME codeword, the codeword duration can be 2 chips. In the case of the Extended / Repeated ME (e-ME / r-ME), the codeword duration can be defined as 4 chips, 8 chips, etc. depending on the degree of extension / repetition. For example, in the case of e-ME / r-ME, in the case of 4 chips, data-0 can be mapped to {1, 1, 0, 0} or {1, 0, 1, 0}, respectively.

[0316] Figure 9 shows an example of UHF passive RFID application.

[0317] Referring to Fig. 9, in the case of PIE, the length of the low section (PW) is set equally by R regardless of data-0 and data-1, and data-0 and data-1 are identified by the difference in the high section. R can select / determine the length of data-0 and data-1 within a certain range, and can instruct T about this selection / decision related information through R=>T preamble or frame sync. In order to support this method in Topology 2 for AmIoT communication, the base station can set / instruct IN (eg, UE) about information related to the length of data-0 and data-1. Or, it can set / instruct information related to the difference between the length of data-0, the length of data-1, and the length of data-0. IN (eg, UE) can perform R2D transmission and / or D2R reception operations using the set / instructed information.

[0318] When applying the PIE method for AmIoT communication, the chip can be defined in the following two ways.

[0319] - Method 1) A method of defining a chip based on the duration of low / off / -phase (e.g., "PW" in Fig. 9)

[0320] For example, the codeword / encoded (symbol) duration of Data-0 may be defined as 2 chips, and Data-1 may be defined as N1(>2) chips.

[0321] For example, Eg, data-0 codeword / encoded (symbol) duration can be defined in the form of {high, low} with 2 chips, data-1 codeword / encoded (symbol) duration can be defined in the form of {high, high, low} with 3 chips (N1=3), and {high, high, high, low} with 4 chips (N1=4).

[0322] For example, for the application of method 1, the data-0 codeword / encoded (symbol) duration can be restricted to twice the chip duration, and the data-1 codeword / encoded (symbol) duration can be restricted to an integer multiple of the chip duration, or method 1 can be applied only when these conditions are satisfied.

[0323] - Method 2) A method of defining a chip based on the Reference(eg, data-0) codeword / encoded (symbol) duration (eg, based on "Tari" in Fig. 9)

[0324] For example, the codeword / encoded (symbol) duration of Data-0 may be defined as 1 chip, and Data-1 may be defined as N2(>1) chips.

[0325] For example, Eg, data-0 codeword / encoded (symbol) duration can be defined as {high, low} with 1 chip, and data=1 codeword / encoded (symbol) duration can be {high, high, low} with 1.5 chip (N2=1.5), and {high, high, high, low} with 2 chip (N2=2).

[0326] For example, in order to apply method 2, the data-1 codeword / encoded (symbol) duration can be limited to X / 2 times the chip duration (where X is an integer greater than or equal to 3), or method 2 can be applied only when this condition is satisfied.

[0327] Codeword / encoded (symbol) duration, data rate, FS value, etc. can be controlled in units of chips defined above, and such control information can be transmitted / indicated through preamble / midamble / postamble / sync signals and / or payload.

[0328] The reader (or AmIoT device) can select / decide between the above method 1 and method 2, and transmit / instruct the selection / decision information to the AmIoT device (or reader) through frame sync / preamble / midamble / postamble / sync signals. Or, in Topology 2 for AmIoT communication, the base station can set / instruct the IN (e.g., UE) to one of method 1 and method 2. The IN (e.g., UE) can perform R2D transmission and / or D2R reception operations by applying the set / instructed method.

[0329] <OFDM waveform 기반의 R2D 전송 방식>

[0330] In OFDM waveform-based R2D / D2R transmission, unintended phase / energy / value transitions / changes may be detected at the R2D receiver due to CP insertion. In OFDM-based R2D reception, AmIoT devices (depending on the device type or capability) may either i) handle unintended phase / energy / value transitions / changes due to CP insertion (Assumption 1) or ii) not handle unintended phase / energy / value transitions / changes due to CP insertion (Assumption 2). For these AmIoT devices, the following CP handling methods at the R2D transmitter are being considered.

[0331] - Method Type 1: Remove CP from the device without any specified sender-side action (based on Assumption 1)

[0332] - Method Type 2: When inserting CP into an OFDM-based waveform, ensure that no false rising / falling edge occurs between the last OOK chip of the (n-1)th OFDM symbol and the first OOK chip of the (n)th OFDM symbol (based on Assumption 2).

[0333] Method Type 2 may be a method that satisfies the following conditions, for example:

[0334] - Condition 1: The values ​​of the first X chip(s) and the last X chip(s) in the OFDM symbol are the same so that false rising / falling edges do not occur even after CP insertion.

[0335] At this time, X can be 1 or 2. If the number of chips M in the OFDM symbol is less than or equal to M0, X=1, otherwise X=2. M0 is a value determined based on (Nu+Ncp) / Ncp, and can be the maximum value that satisfies the condition of "M0 < (Nu+Ncp) / Ncp" (e.g., M0=8).

[0336] - Condition 2: After CP insertion, the length of all chips is the same.

[0337] The reader (or AmIoT device) can select / decide on one of the above methods (Method Type 1 and Method Type 2), and transmit / instruct the selection / decision information to the AmIoT device (or reader) through frame sync / preamble / midamble / postamble / sync signals / R2D (or D2R) control info / payload transmitted as PRDCH (or PDRCH). Or, in Topology 2 for AmIoT communication, the base station can configure / instruct the IN (e.g., UE) to one of the above methods. The IN (e.g., UE) can perform R2D transmission and / or D2R reception operations by applying the configured / instructed method.

[0338] Whether Method Type 1 or Method Type 2 is supported and / or applied may be determined based on the number of chips M in the supported OFDM symbol. For example, Method Type 2 may be supported / applied / configured only when the M value is greater than a specific value M1 (e.g., M1=4).

[0339] Alternatively, whether Method Type 1 or Method Type 2 is supported and / or applied may be determined by other R2D / D2R transmission parameters. For example, considering that Method Type 1 is relatively easy to apply when line coding (e.g., ME, PIE) is applied, when line coding is set / applied, only Type 1 can be set / applied without any additional settings.

[0340] <Modulation Symbol Mapping Method>

[0341] Based on the above Method Type 2 and ME method, we propose methods for mapping modulation symbols for Ambient IoT R2D / D2R transmission to OFDM symbols in chip units. Fig. 10 is a diagram illustrating the relationship between OFDM symbols and chips in Method Type 2. In Fig. 10, it is assumed that there are M chips in one OFDM symbol, and the chips in the OFDM symbol are distinguished by chip index = 0, 1, 2, …, M-1.

[0342] [How to define codeword or modulation symbol mapping within one OFDM symbol]

[0343] One may consider how codewords or modulation symbols are mapped to a single OFDM symbol.

[0344] [Method 1] A method of mapping (M-2X) / N or floor{(M-2X) / N} codewords or modulation symbols for Ambient IoT R2D / D2R transmission, excluding the first X chip(s) and the last X chip(s) in an OFDM symbol. For example, N can be 2 for ME and N can be 4 for extended ME.

[0345] For example, X can be 1 or 2. If M is less than or equal to M0, X=1, otherwise X=2. In this case, M0 is a value determined based on (Nu+Ncp) / Ncp, and M0 can be the maximum value that satisfies the condition of "M0 < (Nu+Ncp) / Ncp". (For example, M0=8)

[0346] For example, the first X chip(s) and last X chip(s) value(s) can be filled with the following values.

[0347] i) OOK-ON. In this case, RF EH (Energy Harvesting) is effective.

[0348] ii) OOK-OFF. In this case, Tx / reader power saving is effective.

[0349] iii) The OOK value of the immediately previous / next mapped chip. In this case, false rising / edge can be minimized.

[0350] iv) The opposite value of the OOK value of the immediately previous / next mapped chip. In this case, there is the effect of clock transfer.

[0351] v) Square wave OOK values ​​starting with the opposite value of the OOK value of the immediately previous mapped chip. In this case, clock transfer is effective.

[0352] vi) Square wave OOK values ​​that end with the opposite value of the OOK value of the immediately next mapped chip. In this case, there is a clock transfer effect.

[0353] For example, chip(s) that remain unmapped after mapping by the above method can be filled with the value(s) of one of the above methods (e.g., methods i) to vi).

[0354] [Method 2] A method of mapping codewords or modulation symbols for (M-2) / N or floor{(M-2) / N} Ambient IoT R2D / D2R transmission, excluding the first or last 2 chip(s) in an OFDM symbol.

[0355] For example, N could be 2 for ME and N could be 4 for extended ME.

[0356] For example, Method 2 can only be applied when X=1, as it runs the risk of generating false rising / falling edges when X=2. Method 1 can be applied when X=2.

[0357] [Method 2-1] A method of mapping (M-2) / N or floor{(M-2) / N} codewords or modulation symbols, excluding the first 2 chips(s) in an OFDM symbol.

[0358] For example, the value of Chip 0 can be determined by the value of Chip M-1. In this case, there is an effect of maintaining the CP relationship.

[0359] For example, the value of Chip 1 can be determined in one of the following ways:

[0360] i) The OOK value of the immediately previous / next mapped chip. This has the advantage of minimizing false rising / edges.

[0361] ii) The opposite value of the OOK value of the immediately previous / next mapped chip. In this case, clock transfer is effective.

[0362] iii) OOK-ON. In this case, RF EH is effective.

[0363] iv) OOK-OFF. In this case, there is a Tx / reader power saving effect.

[0364] v) The value of Chip M-2.

[0365] [Method 2-2] A method for mapping codewords or modulation symbols for (M-2) / N or floor{(M-2) / N} Ambient IoT R2D / D2R transmission, excluding the last 2 chip(s) in the OFDM symbol.

[0366] For example, to maintain the CP relationship, the value of Chip M-1 can be determined as the value of chip 0.

[0367] For example, the value of Chip M-2 can be determined in one of the following ways:

[0368] i) The OOK value of the immediately previous / next mapped chip. This has the effect of minimizing false rising / edges.

[0369] ii) The opposite value of the OOK value of the immediately previous / next mapped chip. This has the advantage of being advantageous from a clock transfer perspective.

[0370] iii) OOK-ON. In this case, there is an RF EH effect.

[0371] iv) OOK-OFF. In this case, there is a Tx / reader power saving effect.

[0372] v) The value of Chip 1.

[0373] For example, chip(s) that remain unmapped after mapping using the above methods can be filled with the value(s) of one of the above methods.

[0374] [How to define codeword or modulation symbol mapping in units of two OFDM symbols]

[0375] A method in which codewords or modulation symbols are mapped in units of two OFDM symbols can be considered.

[0376] [Method 3] A method of mapping codewords or modulation symbols for Ambient IoT R2D / D2R transmission to (2M-2) / N or floor((2M-2) / N) chips, excluding the first and last chips (chip 0 and chip 2M-1) among 2M chips having chip indices 0, 1, 2, …, 2M-1 that constitute two OFDM symbols.

[0377] For example, the value of Chip 0 can be configured to have the value of chip M-1, and the value of chip M can be configured to have the value of chip 2M-1.

[0378] As a concrete example, chip 0 may be filled with the OOK value of chip M-1, and chip 2M-1 may be filled with the value of chip M.

[0379] - After mapping using the above method, the remaining chip(s) that are not mapped can be filled with the value(s) of one of the following methods.

[0380] i) OOK-ON. In this case, there is an RF EH effect.

[0381] ii) OOK-OFF. In this case, there is a Tx / reader power saving effect.

[0382] iii) The OOK value of the immediately previous / next mapped chip. This has the effect of minimizing false rising / edges.

[0383] iv) The opposite value of the OOK value of the immediately previous / next mapped chip. In this case, there is a clock transfer effect.

[0384] v) Square wave OOK values ​​starting with the opposite value of the OOK value of the immediately previous mapped chip. In this case, there is a clock transfer effect.

[0385] vi) Square wave OOK values ​​that end with the opposite value of the OOK value of the immediately next mapped chip. In this case, there is a clock transfer effect.

[0386] [How to map codewords or modulation symbols across OFDM symbols]

[0387] A method may be considered in which codewords or modulation symbols are mapped across multiple OFDM symbols.

[0388] [Method 4] A method of sequentially mapping codewords or modulation symbols to OFDM symbols excluding the first or last chip(s) that serve as CPs in each OFDM symbol.

[0389] [Method 4-1] A method of sequentially mapping codewords or modulation symbols to OFDM symbols except the first chip(s) of each OFDM symbol.

[0390] For example, in method 4-1, one ME codeword can be divided and mapped to chip M-1 (corresponding to the last) of OFDM symbol n and chip 1, which is the second chip of OFDM symbol n+1.

[0391] At this time, the signal mapped to chip M-1, the last chip (within the same OFDM symbol), can be mapped identically to chip 0, the first chip of each OFDM symbol.

[0392] [Method 4-2] A method of sequentially mapping codewords or modulation symbols to OFDM symbols except the last chip(s) of each OFDM symbol.

[0393] For example, in method 4-2, one ME codeword can be divided and mapped to chip M-2 (corresponding to the 2nd last) of OFDM symbol n and chip 0, which is the first chip of OFDM symbol n+1.

[0394] At this time, the signal mapped to chip 0, the first chip (within the same OFDM symbol), can be mapped identically to chip M-1, the last chip of each OFDM symbol.

[0395] - Method 4 (including Method 4-1 and Method 4-2) includes a chip that acts as a CP between ME codewords, so that the interval of 1 or 0 can be wider than that of a general ME codeword. For example, 10 can become 110 or 100. Or 01 can become 001 or 011. In this case, by using this kind of violation information, the AmIoT device can perform ME decoding by omitting the intermediate chip value, and additionally obtain synchronization information with the OFDM symbol (e.g., OFDM symbol boundary information).

[0396] For Method Type 2, the number of chips M in an OFDM symbol can be configured as the M' value (M=M' in Method Type 1) + N value (i.e., M=M'+N) to which codewords or modulation symbols can be mapped. In other words, Method Type 2 can be configured as the sum of the number M' of chips to which codewords or modulation symbols can be mapped and the number N of chips used for the CP role.

[0397] For example, if N=1, the Reader or Device can set / support M=2,3,5,9 to map codewords or modulation symbols to chips M'=1,2,4,8. Considering that the ME codeword is 2 or a multiple of 2, this method has the advantage of making codeword mapping easier.

[0398] For example, the value of N may vary depending on the value of M'.

[0399] For example, if M'=1,2,4,8,16 is supported, N can be 1 for M'=1,2,4,8, and N can be 2 for M=16. For example, the threshold of M' value at which N value changes can be determined based on the ratio of OFDM symbol period to CP period in CP-OFDM symbol ((Nu+Ncp) / Ncp value). Consequently, in this case, the M value for Method Type 2 can be M=2,3,5,9,18.

[0400] The reader (or Ambient IoT device) can select / decide on one of the above methods and transmit / instruct the selection / decision information to the Ambient IoT device (or reader) through frame sync / preamble / midamble / postamble / sync signals / R2D (or D2R) control info / payload transmitted as PRDCH (or PDRCH). Or, in Topology 2 for AmIoT communication, the base station can configure / instruct the IN (e.g., UE) to one of the above methods. The IN (e.g., UE) can perform R2D transmission and / or D2R reception operations by applying the configured / instructed method.

[0401] The various embodiments of the present disclosure (e.g., Methods 1 to 4) may be combined with each other.

[0402] In terms of implementation, the operations of the first device (e.g., Reader, BS, IN, AN, UE) / second device (e.g., Ambient IoT Device) according to the embodiments described above can be processed by the device of FIG. 13 (e.g., the processor (110, 210) of FIG. 13).

[0403] In addition, the operations of the first device (e.g., Reader, BS, IN, AN, UE) / second device (e.g., Ambient IoT Device) according to the above-described embodiment may be stored in a memory (e.g., 140, 240 of FIG. 13) in the form of a command / program (e.g., instruction, executable code) for driving at least one processor (e.g., processor (110, 210) of FIG. 13).

[0404] The embodiments described below are specifically described with reference to FIGS. 11 and 12 in terms of the operation of a first device (e.g., Reader, Base Station, Intermediate Node, Auxiliary Node, Terminal / Ambient IoT Device) and a second device (e.g., Ambient IoT Device / Reader, Base Station, Intermediate Node, Auxiliary Node, Terminal). The methods described below are distinguished only for convenience of explanation, and it goes without saying that some components of one method may be substituted for some components of another method or may be applied in combination with each other.

[0405] FIG. 11 is a flowchart illustrating a method according to one embodiment of the present specification.

[0406] Referring to FIG. 11, a method according to one embodiment of the present specification includes a step (S1110) of transmitting a signal based on codewords to a second device.

[0407] The above codewords are mapped to chips within at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol based on the number of chips associated with the at least one OFDM symbol.

[0408] At this time, the transmission of the signal may be R2D (Reader to Device) transmission or D2R transmission. The first device may be a Reader or an Ambient IoT Device.

[0409] As an example of R2D (Reader to Device), a signal transmitted from a first device (Reader) to a second device (Ambient IoT Device) may be based on a physical channel. The physical channel may be referred to as an R2D channel or a Physical Reader-to-Device CHannel (PRDCH). As a specific example, the PRDCH may carry i) all higher-layer payloads (e.g., higher-layer payload including system information, higher-layer payload including settings / information other than system information) and / or ii) R2D control information.

[0410] As an example of D2R (Device to Reader), the signal transmitted from a second device (Ambient IoT Device) to a first device (Reader) may be based on a physical channel. The physical channel may be referred to as a D2R channel or a Physical Device-to-Reader Channel (PDRCH). As a specific example, the PDRCH may carry i) any higher-layer payload, ii) a response transmitted from the Ambient IoT Device to the Reader during a contention-based access procedure, and / or iii) D2R control information.

[0411] According to one embodiment, the handling method of a cyclic prefix (CP) associated with each OFDM symbol may include i) Method Type 1 in which the CP is removed based on an ambient Internet of Things (IoT) device, and ii) Method Type 2, which is different from Method Type 1. For convenience of explanation in this specification, Method Type 1 may be expressed as a first method, and Method Type 2 may be expressed as a second method.

[0412] Specifically, the first method may refer to a method for removing CP from a device without explicit transmitter-side operation. The first method may be a method based on the assumption that an Ambient IoT device can handle unintended phase / energy / value transitions / changes due to CP insertion when receiving OFDM-based R2D.

[0413] The second method may refer to a method that ensures that no false rising / falling edge occurs between the last OOK chip of the (n-1)th OFDM symbol and the first OOK chip of the (n)th OFDM symbol when a CP is inserted into an OFDM-based waveform. The second method may be a method based on the assumption that an Ambient IoT device cannot handle unintended phase / energy / value transitions / changes due to CP insertion when receiving OFDM-based R2D.

[0414] For example, the second method may be a method that satisfies the following two conditions.

[0415] Condition 1) The values ​​of the first X chip(s) and the last X chip(s) in the OFDM symbol are the same so that false rising / falling edges do not occur even after CP insertion.

[0416] For example, in the above condition 1, X can be 1 or 2. As a specific example, if the number of chips M in the OFDM symbol is less than or equal to M0, X can be 1, and if M is greater than M0, X can be 2. In this case, M0 can be a value determined based on (Nu+Ncp) / Ncp. As a specific example, M0 can be the maximum value satisfying "M0 < (Nu+Ncp) / Ncp" (for example, M0=8).

[0417] Condition 2) After CP insertion, the length of all chips is the same.

[0418] In one embodiment, the signal may be a signal mapped based on the second method.

[0419] In one embodiment, the line coding may be based on Manchester encoding.

[0420] In one embodiment, the number of codewords may be determined based on i) the number of chips to which the codewords are mapped within each OFDM symbol and ii) the duration of a codeword in which one bit is encoded based on line coding.

[0421] As a concrete example, in the case of Manchester encoding, i) data-1 (bit {1}) can be line coded with a codeword of {1, 0} and data-0 (bit {0}) can be line coded with a codeword of {0, 1}, or ii) data-1 can be line coded with a codeword of {0, 1} and data-0 can be line coded with a codeword of {1, 0}.

[0422] For example, codewords mapped to a chip associated with at least one OFDM symbol may be modulated into a modulated symbol based on a modulation method (e.g., an On-Off Keying (OOK) method) and then mapped to the chip.

[0423] In one embodiment, a method for mapping codewords / modulation symbols for one OFDM can be considered.

[0424] For example, the codewords may be mapped to chips other than the first one or more chips and the last one or more chips within each OFDM symbol.

[0425] For example, the number of the first one or more chips and the number of the last one or more chips may be the same and may be 1 or 2.

[0426] As a specific example, the number of the first one or more chips (=the number of the last one or more chips) may be 1 if i) the number of chips M in each OFDM is less than or equal to M0, or ii) 2 if M is greater than M0. In this case, M0 may be a value determined based on (Nu+Ncp) / Ncp. As a more specific example, M0 may be a maximum value that satisfies the condition of "M0 < (Nu+Ncp) / Ncp".

[0427] For example, the first one or more chips and the last one or more chips may each be mapped to: i) a preset or defined on-off keying (OOK) value (e.g., an OOK-ON value or an OOK-OFF value), ii) a value based on an OOK value of a chip mapped before or after the first one or more chips (e.g., an OOK value of a previous / next mapped chip or an opposite value of an OOK value of a previous / next mapped chip), iii) a value based on an OOK value of a chip mapped before or after the last one or more chips, iv) an OOK value based on a square wave starting with a value different from an OOK value of a chip mapped before the first one or more chips or a chip mapped before the last one or more chips, or v) an OOK value based on a square wave ending with a value different from an OOK value of a chip mapped after the first one or more chips or a chip mapped after the last one or more chips.

[0428] For example, after mapping is performed using the above method, the remaining chip(s) that have not yet been mapped can be mapped to any one of the values ​​i) to v). This embodiment may be based on Method 1.

[0429] In one embodiment, the codewords may be mapped to chips other than those associated with the CP within each OFDM symbol. For convenience of explanation herein, the chips associated with the CP may be referred to as first specific chips.

[0430] For example, the first chips may be i) the first 2 chips or ii) the last 2 chips.

[0431] For example, the bit value of the first chip and the bit value of the last chip in each OFDM symbol may be the same.

[0432] For example, among the first two chips, a chip other than the first chip (hereinafter, “the second specific chip”) or among the last two chips, a chip other than the last chip (hereinafter, “the third specific chip”) may be mapped to i) a value based on an OOK value of a chip mapped before or after the second specific chip, ii) a value based on an OOK value of a chip mapped before or after the third specific chip, or iii) a preset or defined OOK value (e.g., an OOK-ON value or an OOK-OFF value), or iv) a bit value of the second specific chip and a bit value of the third specific chip may be mapped to be the same.

[0433] For example, after mapping is performed according to the above embodiment, each chip(s) that remains unmapped may be mapped to any one of the values ​​i) to iv). This embodiment may be based on Method 2.

[0434] In one embodiment, a method for mapping codewords / modulation symbols for two OFDMs may be considered.

[0435] In one embodiment, the codewords may be mapped to the remaining chips other than the first chip and the last chip among the total chips based on two OFDM symbols.

[0436] As a specific example, the above codewords can be mapped to 2M-2 chips, excluding the first chip (chip 0) and the last chip (chip 2M-1), among the 2M chips of two OFDM symbols.

[0437] For example, the first chip may be mapped to the same value as the codeword mapped to the last chip of the first OFDM symbol. As a specific example, the value of chip 0 may be set to have the value of chip M-1.

[0438] For example, the last chip may be mapped to the same value as the codeword mapped to the first chip of the second OFDM symbol. As a specific example, the value of chip 2M-1 may be set to have the value of chip M.

[0439] For example, after mapping is performed according to the above embodiment, the remaining chip(s) that are not yet mapped may be mapped to i) a preset or defined OOK value (e.g., an OOK-ON value or an OOK-OFF value), ii) a value based on the OOK value of the chip mapped immediately before or after the remaining chip(s) (e.g., the OOK value of the immediately before / after mapped chip or the opposite value of the OOK value of the immediately before / after mapped chip), iii) OOK values ​​in the form of a square wave starting with a value different from the OOK value of the chip mapped before the remaining chip(s), or iv) OOK values ​​in the form of a square wave ending with a value different from the OOK value of the chip mapped after the remaining chip(s). The present embodiment may be based on Method 3.

[0440] In one embodiment, a method for mapping codewords / modulation symbols across multiple OFDMs may be considered.

[0441] In one embodiment, the chips may be based on the remaining chips other than one or more chips associated with a CP within each OFDM symbol among the entire chips based on a plurality of OFDM symbols.

[0442] For example, the one or more chips associated with the CP may be i) the first one or more chips or ii) the last one or more chips. Accordingly, the chips to which the codeword is mapped may be i) the remaining chips after excluding the first one or more chips or ii) the remaining chips after excluding the last one or more chips, among all chips based on a plurality of OFDM symbols.

[0443] For example, the bit values ​​of the first one or more chips and the bit values ​​of the last one or more chips may be the same.

[0444] As a concrete example, codewords or modulation symbols may be time-sequentially mapped to the remaining chips within OFDM symbols, excluding the first chip(s) that serve as CPs within each OFDM symbol.

[0445] As a more specific example, one codeword (e.g., ME codeword) can be mapped to chip M-1, which is the last chip of the nth OFDM symbol, and chip 1, which is the second chip of the n+1th OFDM symbol. In other words, when the ME codeword is {1, 0}, a codeword of "1" can be mapped to chip M-1 of OFDM n, and a codeword of "0" can be mapped to chip 1 of OFDM n+1. At this time, the signal / bit mapped to chip M-1, which is the last chip of the same OFDM symbol, can be identically mapped to chip 0, which is the first chip of each OFDM symbol.

[0446] As another concrete example, codewords or modulation symbols may be time-sequentially mapped to chips within OFDM symbols except for the last chip(s) that serve as CPs within each OFDM symbol.

[0447] As a more specific example, one codeword (e.g., ME codeword) may be mapped to chip M-2, which is the second-to-last chip of the nth OFDM symbol, and chip 0, which is the first chip of the n+1th OFDM symbol. In other words, when the ME codeword is {1, 0}, a codeword of "1" may be mapped to chip M-2 of OFDM n, and a codeword of "0" may be mapped to chip 0 of OFDM n+1. At this time, the signal / bit mapped to chip 0, which is the first chip in the same OFDM symbol, may be identically mapped to chip M-1, which is the last chip of each OFDM symbol. This embodiment may be based on Method 4.

[0448] In the case of the above method 4, a chip acting as a CP may be included between one codeword (e.g., {1, 0} or {0, 1} in which bit 1 is encoded in the case of an ME codeword), so that the interval of 1 or 0 may be wider than that of a general codeword. For example, i) codeword 10 may be expressed as 110 or 100, or ii) 01 may be expressed as 001 or 011. An Ambient IoT device may perform ME decoding by omitting the value of the intermediate chip (= chip acting as a CP) by utilizing information in cases where the interval between 1 and 0 in one codeword as above is wide. In addition, the Ambient IoT device may additionally obtain synchronization information with an OFDM symbol (e.g., OFDM symbol boundary information).

[0449] According to one embodiment, the number M of chips in an OFDM symbol based on Method Type 2 (the second method) among CP handling methods can be expressed as the sum of i) the number M' of chips to which codewords or modulation symbols can be mapped (M = M' in Method Type 1) and ii) the number N of chips that serve as CPs (M = M' + N).

[0450] For example, when the number N of chips acting as CP is 1, the total number M of chips in an OFDM symbol can be set / supported as 2, 3, 4, or 9. Accordingly, the number M' of chips to which codewords or modulation symbols can be mapped can be 1, 2, 4, or 8. The above method has the advantage of facilitating codeword mapping when considering that the ME codeword is 2 or a multiple of 2 (e.g., extended ME).

[0451] For example, the value of N may vary based on the value of M'.

[0452] As a specific example, i) when M' is supported / set to 1, 2, 4, 8 or 16, N can be determined as 1 when M' is 1, 2, 4 or 8, and ii) when M' is supported / set to 16, N can be determined as 2. The threshold of the M' value at which the N value changes can be determined based on the ratio of the OFDM symbol period to the CP period in the CP-OFDM symbol ((Nu+Ncp) / Ncp). Consequently, if the above method is followed, the M value can be 2, 3, 5, 9 or 18.

[0453] The reader (or AmIoT device) can select / decide on one of the above methods and transmit / instruct the selection / decision information to the AmIoT device (or reader) through frame sync / preamble / midamble / postamble / sync signals / R2D (or D2R) control info / payload transmitted as PRDCH (or PDRCH). Or, in Topology 2 for AmIoT communication, the base station can configure / instruct the IN (e.g., UE) to one of the above methods. The IN (e.g., UE) can perform R2D transmission and / or D2R reception operations by applying the configured / instructed method.

[0454] The various embodiments of the present disclosure (e.g., Methods 1 to 4) may be combined with each other.

[0455] The embodiments described below are specifically described in terms of the operation of the second device.

[0456] S1210, described below, corresponds to S1110, described in FIG. 11. Considering the above correspondence, redundant descriptions are omitted. The detailed description of the second device operation described below may be replaced with the corresponding description / example of FIG. 11.

[0457] FIG. 12 is a flowchart illustrating a method according to another embodiment of the present specification.

[0458] Referring to FIG. 12, a method according to another embodiment of the present specification includes a step (S1210) of receiving a signal based on codewords from a first device.

[0459] The above codewords are mapped to chips within at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol based on the number of chips associated with the at least one OFDM symbol.

[0460] According to one embodiment, the reception of the signal may be R2D (Reader to Device) or D2R reception.

[0461] The operation based on S1210 described above can be implemented by the device of FIG. 13. For example, referring to FIG. 13, the second device (100) can control one or more transceivers (130) and / or one or more memories (140) to perform the operation based on S1210.

[0462] The operations / terms based on the embodiments described above have been described assuming a 5G system. However, this is for convenience of explanation and is not intended to limit the scope of application of the technical problems and problem-solving means to be solved by this specification to a specific system. The technical problems / technical issues / problems mentioned in this specification may equally exist in other systems (e.g., 6G systems). It is self-evident that the embodiments of this specification can be expanded and applied to solve problems equally existing in the other systems. Therefore, for the expanded application of the embodiments of this specification to other systems, the terms defined / described based on the 5G system may be replaced / changed with terms defined in the other systems (or generalized terms not specific to one system). For example, PRACH, PUSCH, PUCCH, or SRS may be replaced / changed with uplink signals (or uplink channels). For example, SSB, CSI-RS, PDSCH, and PDCCH may be replaced / changed with downlink signals (or downlink channels).

[0463] Hereinafter, a device to which an embodiment of the present specification can be applied (a device that implements a method / operation according to an embodiment of the present specification) is described with reference to FIG. 13.

[0464] FIG. 13 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0465] The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

[0466] The processor (110) performs baseband-related signal processing and may include a higher layer processing unit (111) and a physical layer processing unit (115). The higher layer processing unit (111) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (115) may process operations of a PHY layer. For example, when the first device (100) is a base station device in base station-terminal communication, the physical layer processing unit (115) may perform uplink reception signal processing, downlink transmission signal processing, etc. For example, when the first device (100) is a first terminal device in terminal-to-terminal communication, the physical layer processing unit (115) may perform downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc. In addition to performing baseband-related signal processing, the processor (110) may also control the overall operation of the first device (100).

[0467] The antenna unit (120) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (130) may include an RF (Radio Frequency) transmitter and an RF receiver. The memory (140) may store information processed by the processor (110), and software, an operating system, applications, etc. related to the operation of the first device (100), and may also include components such as a buffer.

[0468] The processor (110) of the first device (100) may be configured to implement the operation of the base station in the base station-to-terminal communication (or the operation of the first terminal device in the terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0469] The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

[0470] The processor (210) performs baseband-related signal processing and may include a higher layer processing unit (211) and a physical layer processing unit (215). The higher layer processing unit (211) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (215) may process operations of a PHY layer. For example, when the second device (200) is a terminal device in base station-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, etc. For example, when the second device (200) is a second terminal device in terminal-to-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, sidelink reception signal processing, etc. In addition to performing baseband-related signal processing, the processor (210) may also control the overall operation of the second device (210).

[0471] The antenna unit (220) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (230) may include an RF transmitter and an RF receiver. The memory (240) may store information processed by the processor (210), software, an operating system, applications, etc. related to the operation of the second device (200), and may also include components such as a buffer.

[0472] The processor (210) of the second device (200) may be configured to implement operations of the terminal in base station-to-terminal communication (or operations of the second terminal device in terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0473] In the operation of the first device (100) and the second device (200), the same explanations given for the base station and the terminal (or the first terminal and the second terminal in the terminal-to-terminal communication) in the examples of the present disclosure may be applied, and redundant explanations are omitted.

[0474] Here, the wireless communication technology implemented in the device of the present disclosure may include LTE, NR, and 6G, as well as Narrowband Internet of Things (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names.

[0475] Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names.

[0476] Additionally or alternatively, the wireless communication technology implemented in the device of the present disclosure may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN), which take low-power communication into account, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be called by various names.

Claims

1. In a method performed by a first device, A step of transmitting a signal based on codewords to a second device; comprising: A method characterized in that the above codewords are mapped to chips within at least one OFDM (Orthogonal Frequency Division Multiplexing) symbol based on the number of chips associated with the at least one OFDM symbol.

2. In paragraph 1, A method for processing a cyclic prefix (CP) associated with each OFDM symbol, characterized in that the method includes i) a first method in which the CP is removed based on an ambient Internet of Things (IoT) device, and ii) a second method different from the first method.

3. In paragraph 1, The above codewords are based on line coding, A method characterized in that the above line coding is based on Manchester encoding.

4. In paragraph 1, A method characterized in that the number of the above codewords is determined based on i) the number of chips to which the codewords are mapped within each OFDM symbol and ii) the length (duration) of the codeword.

5. In paragraph 1, A method characterized in that the above codewords are mapped to the remaining chips other than the first one or more chips and the last one or more chips in each OFDM symbol.

6. In paragraph 5, A method characterized in that the first one or more chips and the last one or more chips are each mapped to i) a preset or defined on-off keying (OOK) value, ii) a value based on an OOK value of a chip mapped before or after the first one or more chips, iii) a value based on an OOK value of a chip mapped before or after the last one or more chips, iv) an OOK value based on a square wave starting with a value different from an OOK value of a chip mapped before the first one or more chips or a chip mapped before the last one or more chips, or v) an OOK value based on a square wave ending with a value different from an OOK value of a chip mapped after the first one or more chips or a chip mapped after the last one or more chips.

7. In paragraph 1, The above codewords are mapped to the remaining chips other than the first specific chips associated with the CP within each OFDM symbol, A method, characterized in that the first specific chips are i) first 2 chips or ii) last 2 chips.

8. In paragraph 7, A method characterized in that the bit value of the first chip and the bit value of the last chip in each OFDM symbol are the same.

9. In paragraph 8, A method characterized in that a second specific chip other than the first chip among the first two chips or a third specific chip other than the last chip among the last two chips is mapped to i) a value based on an OOK value of a chip mapped before or after the second specific chip, ii) a value based on an OOK value of a chip mapped before or after the third specific chip, or iii) a preset or defined OOK value, or iv) a bit value of the second specific chip and a bit value of the third specific chip are mapped to be the same.

10. In paragraph 1, A method characterized in that the above codewords are mapped to the remaining chips other than the first chip and the last chip among the entire chips based on two OFDM symbols.

11. In paragraph 10, The first chip above is mapped to the same value as the codeword mapped to the last chip of the first OFDM symbol, A method characterized in that the last chip is mapped to the same value as the codeword mapped to the first chip of the second OFDM symbol.

12. In paragraph 1, The above chips are based on the remaining chips other than one or more chips associated with CP within each OFDM symbol among the entire chips based on multiple OFDM symbols, A method, characterized in that one or more chips associated with the CP are i) the first one or more chips or ii) the last one or more chips.

13. In paragraph 12, A method, characterized in that the bit values ​​of the first one or more chips and the bit values ​​of the last one or more chips are the same.

14. In paragraph 1, A method, characterized in that the transmission of the signal is R2D (Reader to Device) transmission or D2R transmission.

15. In the first device, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A first device characterized in that the instructions, based on being executed by the one or more processors, cause the first device to perform all steps of the method according to any one of claims 1 to 14.

16. In a device comprising one or more memories and one or more processors connected to the one or more memories, A device characterized in that said one or more memories store instructions that cause said device to perform all steps of a method according to any one of claims 1 to 14, based on being executed by said one or more processors.

17. In a non-transitory computer-readable medium storing instructions, A non-transitory computer-readable medium characterized in that the instructions executable by one or more processors cause a first device to perform all steps of a method according to any one of claims 1 to 14.

18. In a method performed by a second device, A step of receiving a signal based on codewords from a first device; comprising: A method characterized in that the above codewords are mapped to chips within at least one OFDM (Orthogonal Frequency Division Multiplexing) symbol based on the number of chips associated with the at least one OFDM symbol.

19. In the second device, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A second device characterized in that said instructions, based on being executed by said one or more processors, cause said second device to perform all steps of the method according to claim 18.

Images