D2r link signal transmission of ambient IoT device

Abstract

The present document relates to a method for transmitting a device-to-reader (D2R) link signal of an ambient IoT device, a method for controlling same, and devices therefor. To this end, the method for transmitting a D2R link signal comprises: receiving, from a reader, a 0-th message including frequency information for transmitting the D2R link signal; performing line coding on the D2R link signal on the basis of the frequency information; and transmitting, to the reader, the D2R link signal to which a frequency divisional multiple access (FDMA) scheme has been applied by the line coding.

Description

D2R link signal transmission of ambient IoT devices

[0001] The following description relates to a mobile communication system that supports the Ambient Internet of Things (IoT), and more specifically, to a method for transmitting a D2R (Device-to-Reader) link signal of an ambient IoT device, a method for controlling the same, and devices therefor.

[0002] 3GPP (3rd Generation Partnership Project), which leads the technical standards for mobile communication systems rd The Generation Partnership Project (GPP) introduced various technologies to support IoT devices in LTE and 5G.

[0003] Figure 1 is a diagram briefly summarizing the requirements of IoT devices considered by 3GPP.

[0004] The drawing in Fig. 1 is data presented at the 19th GSMA 5G IoT Strategy Group Meeting (January 2022), and compares the performance of a passive IoT UE discussed in Rel-18 and being discussed as ambient IoT (hereinafter referred to simply as A-IoT) in Rel-19 with the transmission speed of general NR LTE UE, RedCap UE, LTE-M UE, and NB-IoT UE.

[0005] While other IoT UEs are all powered by batteries, A-IoT devices are being discussed assuming a large number of passive devices that secure their own power through energy harvesting, support low transmission speeds of around 10 kbps, consume very low power of 1 to 100 uW, and cost 10 to 100 times less than NB-IoT UEs. In other words, the pyramid structure of Fig. 1 can be interpreted to mean that A-IoT devices at the very bottom can be attached to more objects than other IoT devices.

[0006] Although various use cases for A-IoT are being discussed, the inventory use case as shown in Figure 2 is being studied most intensively.

[0007] Figure 2 is a drawing for explaining an example of use in an automatic warehouse as an example of the concept of an inventory use case among the use cases of A-IoT.

[0008] The concept of an automated warehouse illustrated in Figure 2 exemplifies the concept of utilizing A-IoT in the stages of checking and unloading (1), entering into inventory (2), storing in inventory (3), retrieving from inventory (4), and checking and loading (5), among which the stages of entering into inventory (2), storing in inventory (3), and retrieving from inventory (4) are used.

[0009] That is, a list of items can be secured using A-IoT at the time of receipt / delivery, and when necessary, a base station (220) or another reader can query a large number of A-IoT devices (210a-210n) in the warehouse to secure data by product group and manufacturer, and transmit this to the A-IoT server (230) (S210).

[0010]

[0011] However, as conceptualized in Fig. 1, A-IoT devices (210a-210n) assume a situation in which a large number of devices are densely deployed compared to other IoT devices, and if all A-IoT devices connect simultaneously via uplink, collisions between uplink signals may occur, so research on an efficient multiplexing method is necessary.

[0012] In addition, for certain types of A-IoT devices (210a-210n), the need to transmit multiple CW (Continuous Wave) signals is being discussed, and thus research is needed on coordination with the above-described multiplexing method.

[0013] In order to solve the above-described problem, one aspect of the present invention proposes a method for efficiently multiplexing D2R (Device-to-Reader) link signals of ambient IoT devices and devices therefor, taking into account the characteristics of ambient IoT.

[0014] In addition, considering the characteristics of A-IoT devices, which are a type of passive device as described above, we propose a method for efficiently implementing FDMA (Frequency Divisional Multiple Access) without a separate frequency shift element for D2R signal transmission, and propose a signaling means for this purpose.

[0015] In addition, we propose how to harmonize the method (mode) of multiplexing the D2R link signals of A-IoT devices in the FDMA manner and the method (mode) of transmitting the D2R link signals in the form of multiple CW (Continuous Wave).

[0016] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0017] In one aspect of the present invention for solving the above-described problem, a method for transmitting a D2R (Device-to-Reader) link signal to a reader by an ambient IoT device in a mobile communication system supporting the ambient IoT (Internet of Things) is proposed, comprising: receiving a 0th message including frequency information for transmitting the D2R link signal from the reader; performing line coding on the D2R link signal based on the frequency information; and transmitting the D2R link signal to which a Frequency Division Multiple Access (FDMA) scheme is applied by the line coding to the reader.

[0018] The above frequency information may include chip rate information of the line coding.

[0019] Additionally, the frequency information may include one or more of the chip rate, bit rate, or TBS (Transport Block Size) of the line coding.

[0020] It is assumed that the above ambient IoT device does not include a frequency shift element for center frequency shifting for the D2R link signal transmission.

[0021] Here, the frequency information may indicate one or more options available for transmitting the D2R link signal, and when there are multiple options, the ambient IoT device may select any option among the multiple options to perform line coding.

[0022] The above option may be represented in a bitmap format having multiple bits or through one or more of the maximum line coding options (R) available, and when the frequency information indicates the maximum line coding option (R), the ambient IoT device may perform line coding through an option equal to or less than the maximum line coding option (R).

[0023] The above option may also implicitly indicate bandwidth information for transmitting the D2R link signal.

[0024] The above 0 message may additionally include at least one of bandwidth information for transmitting the D2R link signal or time information (Q) for determining the timing of transmitting the D2R link signal.

[0025] At this time, the time information (Q) can be set independently for each of the multiple options when the frequency information indicates multiple options.

[0026] The bandwidth information for transmitting the above D2R link signal may indicate a bandwidth smaller than 1 PRB (Physical Resource Block), and in this case, transmitting the D2R link signal may include transmitting the D2R link signal with increased transmission power compared to transmitting the D2R link signal through 1 PRB.

[0027] Transmitting the D2R link signal to which the FDMA method is applied by the above line coding may include transmitting via a first message transmitted in a random access manner in response to the 0th message.

[0028] In addition, transmitting the D2R link signal to which the FDMA method is applied by the line coding may additionally include transmitting via a third message transmitted in response to a second message received from the reader in response to the first message.

[0029] In one embodiment of the present invention, the line coding applied to the third message may be the same line coding as the line coding applied to the first message.

[0030] However, in another embodiment of the present invention, the line coding applied to the third message may be line coding based on frequency information of the second message.

[0031] Meanwhile, the 0th message may additionally include configuration information for transmitting the D2R link signal, and the configuration information may indicate either a first mode for transmitting the D2R link signal in an FDMA manner or a second mode for transmitting the D2R link signal in a plurality of CW (Continuous Wave) forms.

[0032] If the above configuration information includes configuration information for applying the first mode, it is preferable that the ambient IoT device is configured not to operate in the second mode.

[0033] Meanwhile, in another aspect of the present invention for solving the above-described problem, a method for controlling D2R (Device-to-Reader) link signal transmission of a plurality of ambient IoT devices by a reader in a mobile communication system supporting ambient IoT (Internet of Things) is proposed, comprising: transmitting a 0th message including frequency information for transmitting the D2R link signal to the plurality of ambient IoT devices; and receiving the D2R link signal line-coded based on the frequency information from the plurality of ambient IoT devices, wherein receiving the D2R link signal includes multiplexing the D2R link signals of the plurality of ambient IoT devices in an FDMA (Frequency Divisional Multiple Access) manner by the line coding based on the frequency information.

[0034] Receiving the D2R link signal may include receiving one or more of a first message or a third message received in a random access manner in response to the zeroth message.

[0035] Meanwhile, in another aspect of the present invention, an ambient IoT device of a mobile communication system supporting the Ambient IoT (Internet of Things) is proposed, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include receiving a 0th message including frequency information for transmitting the D2R link signal from the reader; performing line coding on the D2R link signal based on the frequency information; and transmitting the D2R link signal to which a Frequency Division Multiple Access (FDMA) scheme is applied by the line coding to the reader.

[0036] In addition, in another aspect of the present invention, a reader of a mobile communication system supporting an ambient IoT (Internet of Things) is proposed, comprising: at least one processor; and at least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, wherein the operations include transmitting a 0th message including frequency information for transmitting the D2R link signal to the plurality of ambient IoT devices; and receiving the D2R link signal line-coded based on the frequency information from the plurality of ambient IoT devices, wherein receiving the D2R link signal includes multiplexing the D2R link signals of the plurality of ambient IoT devices in an FDMA (Frequency Divisional Multiple Access) manner by the line coding based on the frequency information.

[0037] According to the embodiments of the present invention as described above, the D2R link signal of an ambient IoT device can be efficiently multiplexed in consideration of the characteristics of the ambient IoT.

[0038] Specifically, considering the characteristics of A-IoT devices, which are a type of passive device as described above, FDMA can be implemented efficiently without a separate frequency shift element for D2R signal transmission.

[0039] Additionally, by independently operating the Q value for each frequency according to the embodiment, an efficient combination of FDMA and TDMA can be implemented.

[0040] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0041] Figure 1 is a diagram briefly summarizing the requirements of IoT devices considered by 3GPP.

[0042] Figure 2 is a drawing for explaining an example of use in an automatic warehouse as an example of the concept of an inventory use case among the use cases of A-IoT.

[0043] FIGS. 3 to 6 are diagrams for explaining a method for efficiently multiplexing D2R signals of a plurality of A-IoT devices according to one embodiment of the present invention.

[0044] FIG. 7 is a diagram for explaining the concept of FDMA based on the chip rate of line coding according to one embodiment of the present invention.

[0045] FIG. 8 and FIG. 9 are diagrams for explaining a bandwidth for D2R signal transmission according to one embodiment of the present invention.

[0046] FIG. 10 is a diagram for explaining the concept of time information for distributing D2R signals of A-IoT devices in TDMA mode according to one embodiment of the present invention.

[0047] FIGS. 11 to 13 are drawings for explaining the configuration of each type of A-IoT device according to one embodiment of the present invention.

[0048] FIG. 14 is a diagram for explaining a method for efficiently multiplexing D2R signals of a plurality of A-IoT devices according to one embodiment of the present invention.

[0049] FIG. 15 is a diagram for explaining a multi-tone CW transmission method according to one embodiment of the present invention.

[0050] FIG. 16 is a diagram for explaining a problem in a case where a first mode supporting FDMA and a second mode supporting multi-tone CW transmission are simultaneously supported according to one embodiment of the present invention.

[0051] FIG. 17 is a diagram for explaining a method for simultaneously supporting FDMA and multi-tone transmission modes in one embodiment of the present invention.

[0052] Figures 18 to 20 are drawings for explaining SFS application examples according to one embodiment of the present invention.

[0053] Figure 21 illustrates a wireless device to which the present technology can be applied.

[0054] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and similar parts have been designated with similar reference numerals throughout the specification.

[0055] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0056]

[0057] As described above, in one aspect of the present invention, considering the characteristics of ambient IoT, a method for efficiently multiplexing D2R link signals of ambient IoT devices and devices therefor are proposed.

[0058] FIGS. 3 to 6 are diagrams for explaining a method for efficiently multiplexing D2R signals of a plurality of A-IoT devices according to one embodiment of the present invention.

[0059] In FIG. 3, the 'reader' is a device for securing data of A-IoT devices (210a-210n) and providing A-IoT services, and may be a base station (220) or an intermediate node (215) between the base station (220) and A-IoT devices (210a-210n). This will be described in detail with reference to FIGS. 4 to 6.

[0060] Drawing reference numeral 410 of FIG. 4 illustrates a structure in which an A-IoT device (210a) is directly connected to a base station (220), and the A-IoT device (210a) responds to a query of the base station (220) and transmits data, and FIG. 5 conceptualizes and illustrates the protocol stacks of the A-IoT device (210a), the base station (220), and the server (230) in this structure. At this time, the server (230) can be considered as divided into functional entities such as an A-IoT function or an AMF (Access and Mobility Management Function) (231), NEF (Network Exposure Function; 232), and AF (Application Function; 233) equipped with an A-IoT function, as illustrated in FIG. 5.

[0061] Meanwhile, the drawing reference numeral 420 of FIG. 4 illustrates a structure in which an A-IoT device (210b) is not directly connected to a base station (220), but transmits data to the base station (220) via an intermediate medium (215), and FIG. 6 conceptualizes and illustrates the protocol stack of the A-IoT device (210b), the intermediate medium (215), the base station (220), and the server (230) in this structure.

[0062] The intermediate medium (215) may be a general portable user equipment (UE), such as a smartphone, that performs 5G communications or subsequent 6G communications. Fig. 4 illustrates the concept of a general UE (215) connecting to a base station (220) via a Uu interface. Furthermore, Fig. 6 conceptualizes the intermediate medium (215) as a UE reader from this perspective.

[0063] The UE as such an intermediate medium (215) can be connected to multiple A-IoT devices and transmit data of the A-IoT devices to the base station (220).

[0064] With regard to the descriptions of FIGS. 4 to 6, it can be generally seen that the base station (220) acts as a reader that collects data from A-IoT devices (210a, 210b). However, depending on the case / use case, the UE (215) may also act as a reader that collects data from A-IoT devices (210a, 210b).

[0065] For convenience of explanation, the following description assumes that the 'reader' corresponds to the base station (220), but is not limited thereto.

[0066] In addition, the 'D2R link' signal refers to a link transmitted from an A-IoT device (210) to a reader (220), and can correspond to an 'uplink' in LTE and NR communications, but is used separately to refer to a specific directional link of the above-described A-IoT system.

[0067]

[0068] Referring again to FIG. 3, the reader (220) can transmit a 0th message (Msg0) including frequency information for D2R link signal transmission to a plurality of A-IoT devices (210a - 210n) (S310a - S310n).

[0069] At this time, the frequency information may include chip rate information of line coding. However, this frequency information may correspond not only to the chip rate information of the above-described line coding, but also to information such as bit rate, TBS (Transport Block Size), or chip length, and depending on the embodiment, the frequency information for FDMA application described below may be referred to as 'information for SFS (Small Frequency Shift)'.

[0070] 'Line coding' can be performed by adjusting impedance to transmit a D2R signal after backscattering or generating the D2R signal depending on the type of A-IoT device, as described below, and for example, Manchester encoding, FM0 encoding, Miller encoding, etc. can be used.

[0071] In this way, based on the chip rate information received through the 0th message (Msg0), the A-IoT devices (210a - 210n) can perform line coding on the D2R link signal (S320). In the following description, the message numbers may be similar to the definition of messages of the random access procedure, such that the message that the A-IoT device (210) first transmits to the reader (220) according to the random access procedure may be referred to as the first message (Msg1), the message that the reader (220) transmits in response thereto may be referred to as the second message (Msg2), and the message that the A-IoT device (210) transmits in response thereto may be referred to as the third message (Msg3). The 0th message (Msg0) refers to the message preceding it.

[0072] In one embodiment of the present invention, the chip rate information as the SFS information may indicate one or more chip rate options available for D2R link signal transmission in the form of a flag. For example, if there are three chip rates that the reader can support, 1, 2, and 8, it may indicate 3-bit information, and if the chip rates applicable to the corresponding A-IoT device or A-IoT device group (210a-210n) are 1 and 8, it may be indicated in the form of a bitmap such as '101'.

[0073] In this way, when multiple chip rate candidates applicable to each A-IoT device (210) are provided, the A-IoT device (210) can perform line coding by selecting any chip rate among the multiple options.

[0074] Unlike the embodiment in which line coding options are represented in a bitmap format having multiple bits as described above, the maximum available line coding option (R) can also be represented. This line coding option (R) can also represent a chip rate as described above, and can also be simply referred to as R as an SFS factor. However, for convenience, the case in which the chip rate (R) is represented will be described below.

[0075] For example, if there are three supported chip rates (R) of 1, 2, and 8, the highest 8 can be indicated.

[0076] In this way, when the SFS information indicates a maximum line coding option (R), the A-IoT device (210) can perform line coding through an option (e.g., R=1, 2, 8) less than or equal to the maximum line coding option (R).

[0077]

[0078] The D2R link signal, which has undergone line coding in this manner, can then be transmitted to the reader (S330). Transmitting the D2R link signal in this manner (S330) involves mapping and transmitting it to different frequency domains during the line coding process described above, thereby enabling multiplexing and transmission in the FDMA manner. This will be described in more detail with reference to FIG. 7.

[0079]

[0080] FIG. 7 is a diagram for explaining the concept of FDMA based on the chip rate of line coding according to one embodiment of the present invention.

[0081] The method of implementing FDMA in this embodiment assumes a method of implementing FDMA by adjusting the chip rate of line coding without having separate hardware (e.g., a frequency shifter) for shifting the frequency when transmitting D2R signals of an A-IoT device. Accordingly, as illustrated in FIG. 7, the center frequency of the D2R signals is shown in a form fixed to CW (Continuous Wave) regardless of the chip rate.

[0082] For example, when using Manchester code as the applied line coding, the chip rate of Manchester code means the number of times it goes back and forth from 0<->1 in the same time, so a higher chip rate can mean using a higher frequency in the frequency domain, as shown in Fig. 7.

[0083] Through this, the present embodiment proposes a method of implementing FDMA using different chip rates (e.g., 1, 2, 8) while keeping the center frequency (CW) fixed.

[0084]

[0085] FIG. 8 and FIG. 9 are diagrams for explaining a bandwidth for D2R signal transmission according to one embodiment of the present invention.

[0086] The implementation of FDMA based on the chip rate of the line coding described above with respect to FIG. 7 can operate in two embodiments as shown in FIG. 8 and FIG. 9.

[0087] First, FIG. 8 illustrates an embodiment in which an A-IoT device transmits a D2R signal while maintaining a bandwidth of 1 PRB (Physical Resource Block).

[0088] This approach aims to accommodate multiple A-IoT devices. It can simultaneously accommodate multiple A-IoT devices using multiple frequencies while maintaining the transmission speed of each device.

[0089] Since one PRB is used per A-IoT device, more PRBs in the D2R link must be allocated for A-IoT, but unlike the method in Fig. 9, there are limitations in amplifying the transmission power, so it may be difficult to expect an effect of increasing coverage.

[0090] Meanwhile, FIG. 9 illustrates an embodiment in which an A-IoT device transmits a D2R signal using a bandwidth smaller than 1 PRB.

[0091] Although this method can accommodate multiple A-IoT devices simultaneously, its main purpose is to increase D2R coverage.

[0092] This means that each A-IoT device can increase transmission power density by reducing the bandwidth it uses, thereby enhancing coverage. Furthermore, by systematically using only one PRB for A-IoT, bandwidth can be preserved for other cellular communications (e.g., LTE, NR).

[0093] However, as described above, there may be a disadvantage in that the D2R transmission speed of the A-IoT device decreases as the bandwidth used decreases.

[0094] As in the embodiments of FIGS. 8 and 9, the bandwidth for D2R link signal transmission of A-IoT devices can be implemented in various ways. In one embodiment of the present invention, the reader (220) can additionally indicate bandwidth information in the 0th message (e.g., query message, paging-like message) transmitted to the A-IoT device (210).

[0095] Additionally, this bandwidth information can be set to be implicitly indicated through an indicator for the chip rate information of the above-described line coding.

[0096] For example, when sending a query command (message 0), the line code option can be notified in the form of a flag as described above. For example, if the available chip rates are 2, 4, and 8, and 2 and 8 will be used in this round, the available chip rates can be notified by sending '101' in the query message.

[0097] When the chip rate is indicated in this way using a flag (bitmap), the A-IoT device can estimate the D2R link signal transmission bandwidth through the number of bits in the flag (bitmap). When the chip rate applicable to line coding is indicated using 3 bits as in the example described above, the bandwidth for D2R link signal transmission of the A-IoT device can be estimated through the existing bandwidth / bit number.

[0098]

[0099] In addition, in one embodiment of the present invention, in addition to the chip rate-based FDMA used for line coding as described above in D2R link signal transmission, time information (Q) for determining D2R link signal transmission timing is provided to implement TDMA, thereby reducing the probability of collision between D2R signals in a dense A-IoT deployment situation as described above with respect to FIGS. 1 and 2.

[0100] FIG. 10 is a diagram for explaining the concept of time information for distributing D2R signals of A-IoT devices in TDMA mode according to one embodiment of the present invention.

[0101] As described above with reference to FIG. 3, the reader (220) can transmit chip rate information when transmitting the 0th message, and in the present embodiment, in addition to the chip rate information, it is proposed to provide time information (Q) for determining the D2R link signal transmission time of A-IoT devices. In one embodiment of the present invention, this time information (Q) can be transmitted on a physical layer control channel for transmitting the 0th message.

[0102] In this case, the A-IoT device (210) can calculate a counter to determine the timing at which the A-IoT device (210) can transmit a D2R link signal (transmit a random access preamble) based on the Q value.

[0103] For example, A-IoT devices are [0 ~ 2 Q -1] A random value can be selected from the range and set as a counter, and the counter can be counted (e.g., counter value -1) for each random access preamble transmission opportunity (e.g., for each slot), and the point in time when the counter reaches 0 can be determined as the random access preamble transmission timing.

[0104] Specifically, FIG. 10 shows a procedure in which a tag responds to a query from an interrogator in a random access manner by indicating an A-IoT device (210) as a tag and a reader (220) as an interrogator, and distinguishes between scenario A in which the random access of the tag succeeds and scenario B in which the random access of the tag fails due to a collision or other reasons.

[0105]

[0106] In scenarios A and B, the reader (220) can also be used by setting a counter based on the Q value, like the A-IoT device (210).

[0107] Specifically, in scenario A, the A-IoT device (210) that received the 0th message corresponding to the query from the reader (220) can transmit a random access preamble starting from the A-IoT device (210) whose set counter value reaches 0 if the group ID of the 0th message corresponds to its tag ID. At this time, the A-IoT device (210) can generate an arbitrary number of a length (e.g., 16 bits) determined according to the length of the tag ID and use it as a preamble.

[0108] When the A-IoT device (210) that performed random access receives an ACK for random access from the reader (220), the A-IoT device (210) can transmit data including a tag ID, and when transmission of the final data is completed, the A-IoT device (210) can notify the reader (220) that the random access is complete.

[0109] Meanwhile, in scenario B, the random access preamble transmitted by the A-IoT device (210) may collide with a random access preamble transmitted by another A-IoT device (210) (S710), there may be no response from the reader (220) for a predetermined period of time (S720), or there may be a response from the reader (220) but it may be an invalid response (S730) (for example, if the received response is an ACK for the random access preamble of another A-IoT device).

[0110] As illustrated in Scenario B, if the random access via the random access preamble of the A-IoT device (210) is not successful, the A-IoT device (210) may retransmit the random access preamble, and at this time, the A-IoT device (210) may count a retransmission counter. For example, the retransmission counter may be increased by 1 for each retransmission, or alternatively, the retransmission counter may be deducted by 1 from a preset maximum number of retransmissions.

[0111] This retransmission counter can be included in the data transmitted upon successful receipt of an ACK from the reader (220) so that the reader (220) can then use it to set a subsequent Q value.

[0112]

[0113] Based on the concept of the above-described time information (Q), one embodiment of the present invention proposes that the reader (220) additionally transmits a Q value to the 0th message transmitted to the A-IoT device (210), and independently sets and notifies the Q value for each line coding chip rate option. Since the size of the round may be different for each D2R frequency, the reader (220) can take this into account and set the Q value for each D2R frequency and provide it to the A-IoT device (210).

[0114]

[0115] Meanwhile, in one embodiment of the present invention, the chip rate, bandwidth, and Q value can all be notified through the 0 message of FIG. 3.

[0116] For example, the reader (220) can inform the A-IoT device (210) of the bandwidth options to be used (e.g., whether to use multiple PRBs), chip rate options in the form of flags through a query message, and can inform the reader of the Q value to be used at each frequency.

[0117] At this time, the bandwidth option may be a 1-bit flag, and in such a system, A-IoT devices may be required to reduce the bandwidth they use by using only 1 PRB.

[0118] There are two ways to specify the bandwidth to use.

[0119] 1) Fixed values ​​specified in the standard

[0120] 2) Determine by looking at the number of flag bits of the chip rate option (bandwidth to use = base bandwidth / number of flag bits of the chip rate option)

[0121] For example, if the chip rate option flag is 3 bits, the bandwidth used can correspond to 1 / 3 of the basic bandwidth.

[0122] In such a situation, the Q value can be individually signaled according to the number of chip rate options to be used. For example, if the chip rate option flag is "101," two Q values ​​can be transmitted to control the use of each chip rate, allowing efficient implementation of FDMA + TDMA.

[0123] The Q value was previously reported as only one value, but in cases where multiple D2R frequencies are used as in the embodiments described above, since the number of A-IoT devices in each D2R frequency is different, it is desirable to report different Q values ​​for efficient communication.

[0124] Each D2R frequency can operate independently without time synchronization between different frequencies by using a separate Q value.

[0125] The A-IoT device (210) can determine the bandwidth to be used by looking at the query message from the reader (220), and can arbitrarily determine the chip rate to be used by looking at the chip rate option. Then, it applies the Q value to be used at the chip rate to be used. For example, if “101” is sent down as the chip rate option in the query, the A-IoT device (210) can arbitrarily select one of chip rates 1 and 8, and use the Q value of the selected chip rate to determine the D2R signal transmission time.

[0126]

[0127] Meanwhile, to examine in detail how A-IoT devices transmit D2R link signals, the configuration of A-IoT devices is described.

[0128] FIGS. 11 to 13 are drawings for explaining the configuration of each type of A-IoT device according to one embodiment of the present invention.

[0129] A-IoT devices can have various types, and the types of A-IoT devices currently being discussed in 3GPP standardization are as follows.

[0130] Device Type 1 (Fig. 11): 1uW power consumption, energy storage, and backscattering support.

[0131] Device Type 2a (Fig. 12): 100 uW power consumption, energy storage, backscattering, DL and / or UL amplifier support

[0132] Device Type 2b (Fig. 13): Power consumption of 100 uW, energy storage, active signal generation, DL and / or UL amplifier support.

[0133] At this time, device type 1 / 2a transmits the transmission signal by backscattering it, and device type 2b transmits the signal by amplifying it through a power amplifier.

[0134]

[0135] Specifically, the composition of each type is as follows.

[0136] Figure 11 illustrates an example of a type 1 device among the types of A-IoT devices described above.

[0137] The A-IoT device illustrated in FIG. 11 may include a matching network (510), an RF energy harvester (520: harvester), a PMU (531: Power Management Unit), and an energy storage module (532) to support an energy storage function. In brief, the RF energy harvester (520) extracts energy from a received RF signal and stores it in the energy storage module (532), thereby supporting the operation of a low-power consumption A-IoT device.

[0138] Meanwhile, for processing the signal received by DL, an RF BPF (541: Band Pass Filter), an RF energy envelope detector (542), a BB LPF (543: BaseBand Low Pass Filter), a comparator / 1-bit ADC (552), and a clock generator (551) may be included.

[0139] It is currently under discussion whether the frequency band of the DL signal of the A-IoT device will be used fixedly or variably, and accordingly, the RF BPF (541) is indicated by a dotted line in the structure of Fig. 11.

[0140] Processing of the received DL signal and generation of the UL signal can be performed by the BB logic (553) including a decoder, a controller, and an encoder, as illustrated in FIG. 11. The necessary information is stored by the memory (560), and the stored information can be reused by the BB logic (553).

[0141] The UL signal transmission of an A-IoT device can be transmitted through a backscatter modulator (570). Roughly speaking, an A-IoT device with a simple, low-power transmission structure transmits a UL signal by backscatter-ing the signal, and can perform line coding by adjusting the impedance to Z1 or Z2 as illustrated in FIG. 11.

[0142] Meanwhile, the A-IoT devices of type 2a and type 2b exemplarily illustrated in FIGS. 12 and 13 may include a matching network (610, 731), an RF energy harvester (620, 732), a PMU (631, 733), and an energy storage module (632, 734) to support an energy storage function, similar to the type 1 device of FIG. 11. In addition, the type 2a and type 2b devices illustrated in FIGS. 12 and 13 indicate that the energy harvester (630, 735) may be included separately as a module other than the RF unit.

[0143] In addition, for processing the signal received by DL, it includes the same RF BPF (641, 740: Band Pass Filter), BB LPF (643, 743: BaseBand Low Pass Filter), comparator / 1-bit ADC (652, 751), and clock generator (651) as the type 1 device, but in the case of the type 2a device of FIG. 12 and the type 2b device of FIG. 13, it is characterized in that it can additionally include an amplifier configuration such as an LNA (Low Noise Amplifier; 642, 741), a BB amplifier (643, 743), and an RF envelope detector (645, 742) for signal amplification.

[0144] Likewise, it is currently under discussion whether the frequency band of the DL signal of the A-IoT device will be used fixedly or variably, and accordingly, the LNA (642, 741) in the structures of FIGS. 12 and 13 is indicated by a dotted line.

[0145] Processing of the received DL signal and generation of the UL signal can be performed by the BB logic (653, 752) including a decoder, a controller, and an encoder as shown in FIGS. 12 and 13, and the necessary information is stored by the memory (660, 760), and the stored information can be reused in the BB logic (653, 752).

[0146] In addition, in the case of a Type 2a device, UL signal transmission can be transmitted through a backscatter modulator (670), and in the case of a Type 2a device illustrated in FIG. 12, unlike the Type 1 device of FIG. 11, a large frequency shifter (661) and a reflection amplifier (680) are additionally included, so that a signal can be amplified and transmitted.

[0147] In addition, for a type 2b device, a UL signal can be actively transmitted through a Tx modulator (761), a DAC (762), an LPF (770), and a PA (780) without using a backscatter modulator as shown in FIG. 13.

[0148]

[0149] Relationship between FDMA and multi-tone transmission

[0150] FIG. 14 is a diagram for explaining a method for efficiently multiplexing D2R signals of a plurality of A-IoT devices according to one embodiment of the present invention.

[0151] In FIG. 14, the 'reader' is a device for securing data of A-IoT devices (210a-210n) and providing A-IoT services, and may be a base station (220) or an intermediate node (215) between the base station (220) and A-IoT devices (210a-210n), as described above with reference to FIGS. 4 to 6.

[0152] In addition, the 'D2R link' signal refers to a link transmitted from an A-IoT device (210) to a reader (220), and can correspond to an 'uplink' in LTE and NR communications, but is used separately to refer to a specific directional link of the above-described A-IoT system.

[0153]

[0154] Referring back to FIG. 14, the reader (220) can transmit a message including configuration information for transmitting a D2R link signal to a plurality of A-IoT devices (210a - 210n) (S1410a - S1410n). At this time, the message including the configuration information may correspond to the 0th message of FIG. 3, but need not be limited thereto. Based on such configuration information, the plurality of A-IoT devices (210a - 210n) can transmit a D2R link signal to the reader (220) (S1420).

[0155] At this time, one embodiment of the present invention proposes performing the operation in at least one of a first mode for transmitting a D2R link signal in an FDMA manner, or a second mode for transmitting a D2R link signal in a plurality of CW forms.

[0156] Below, transmission according to the above-described FDMA method and transmission in multiple CW formats are described in detail.

[0157]

[0158] Among the various types of A-IoT devices described above with reference to FIGS. 11 to 13, one embodiment of the present invention will examine multi-tone CW transmission that can be applied to a device type that transmits a D2R link signal in a backscattering manner.

[0159] FIG. 15 is a diagram for explaining a multi-tone CW transmission method according to one embodiment of the present invention.

[0160] CW can be viewed as the signal used by A-IoT devices when transmitting D2R link signals. Specifically, when a base station or external node transmits a CW signal, which is an unmodulated, pure sine signal, the A-IoT device changes its impedance and backscattering the signal.

[0161] When backscattering is performed, the D2R link signal is frequency shifted relative to CW, and the reader demodulates the signal by removing the CW signal.

[0162] In RFID, which can be compared to A-IoT, the CW transmission described above only considers single-tone CW. However, since multi-tone CW, as illustrated in FIG. 15, can have diversity gain by considering multiple CWs with different frequencies, one embodiment of the present invention proposes to support a method (mode) for transmitting a D2R signal in such a multi-tone CW format.

[0163] Figure 15 shows a form in which two CWs are transmitted at positions F1 and F2, and in which two tones shifted by the BLF (Backscatter Link Frequency) in each CW are represented with a specific bandwidth (BW).

[0164]

[0165] Embodiment 1 - Exclusive application of FDMA and multi-tone transmission

[0166] FIG. 16 is a diagram for explaining a problem in a case where a first mode supporting FDMA and a second mode supporting multi-tone CW transmission are simultaneously supported according to one embodiment of the present invention.

[0167] In the embodiment illustrated in FIG. 16, the first A-IoT device (UE 1) and the second A-IoT device (UE 2) can transmit D2R link signals to distinct locations in the frequency domain centered on CW in the FDMA manner as described above with respect to FIG. 7. In addition, the first A-IoT device (UE 1) and the second A-IoT device (UE 2) can perform multi-tone transmission with CW 1 and CW 2, respectively, as described above with respect to FIG. 15.

[0168] However, Fig. 16 illustrates a problem in which collisions occur between signals in the frequency domain when two modes are used simultaneously, because both transmission modes use multiple frequencies.

[0169] Therefore, in a preferred embodiment of the present invention, it is proposed to control that if one of D2R FDMA and multi-tone CW is configured and / or activated, the other function is not configured and / or activated.

[0170] That is, when either the first mode for FDMA transmission or the second mode for multi-tone transmission is applied to a specific A-IoT device, it can be set so that neither the first mode nor the second mode is applied to the A-IoT device.

[0171] Additionally, such a restriction may also be implemented through configuration information transmitted by the reader to the A-IoT device in the embodiment of FIG. 14. That is, if the configuration information transmitted to the A-IoT device includes configuration information for applying FDMA transmission (first mode), the A-IoT device may be configured not to perform multi-tone CW transmission (second mode).

[0172] In addition, in one embodiment of the present invention, the exclusive application of the first mode and the second mode may be commonly applied to all of a plurality of A-IoT devices serviced by the same reader. That is, if there is an A-IoT device to which the second mode (multi-tone CW transmission) is applied among a plurality of A-IoT devices serviced by a single reader, the first mode (FDMA multiplexing) may be configured not to be applied to all of the plurality of ambient IoT devices.

[0173]

[0174] Embodiment 2 - Simultaneous application of FDMA and multi-tone transmission

[0175] However, in some cases, for example, when there are many A-IoT devices multiplexed by a single reader, FDMA application is required, and frequency domain diversity gain is required, there may be cases where multiplexing through FDMA and multi-tone transmission mode are required to be set simultaneously.

[0176] Accordingly, in another embodiment of the present invention, a method for simultaneously supporting FDMA and multi-tone transmission modes while preventing frequency domain collisions as described above with respect to FIG. 16 is described.

[0177] FIG. 17 is a diagram for explaining a method for simultaneously supporting FDMA and multi-tone transmission modes in one embodiment of the present invention.

[0178] In order to avoid the frequency domain collision problem described above with respect to FIG. 16, the embodiment of FIG. 17 proposes that the spacing between CWs is controlled through configuration information for multi-tone CW transmission so as to secure sufficient frequency space for FDMA application. In this case, the configuration information may be an RRC message transmitted by the base station to A-IoT devices, but is not limited thereto, and may also be transmitted in the form of a MAC (Medium Access Control) CE (Control Element) and / or DCI (Downlink Control Information).

[0179]

[0180] The configuration information that the reader transmits to A-IoT devices for D2R FDMA may include one or more of the number of channels to be used for FDMA, BLF, bandwidth to be used, and slot counter to be used in each FDMA channel.

[0181] Meanwhile, there is no need to separately transmit configuration information for multi-tone CW transmission to A-IoT devices. This is because A-IoT devices can perform backscattering through impedance switching even without knowing the configuration information for multi-tone CW transmission.

[0182] However, in the topology considering the intermediate node described above in FIG. 14 and FIG. 4, it is desirable that the base station can transmit configuration information for multi-tone transmission to the intermediate node through an RRC configuration or reconfiguration message.

[0183]

[0184] As described above, it is not necessarily required to transmit separate configuration information to the A-IoT device for multi-tone transmission in general, but in one embodiment of the present invention, in order to prevent a frequency domain collision problem that may occur when FDMA and multi-tone transmission are applied simultaneously, as shown in FIG. 16, the reader provides the A-IoT device with configuration information for multi-tone transmission, thereby preventing a frequency domain collision problem.

[0185] Configuration information for such multi-tone transmission may include the power of CW, the number of CWs, frequency resource location (e.g., PRB index), etc.

[0186] At this time, the frequency resource location information can be set based on the interval (G; 1610) in the frequency domain of multiple CWs and the frequency domain (1620) occupied by the channels to be used for the FDMA.

[0187] At this time, the frequency range (1620) occupied by the channels to be used for FDMA can be determined based on the number of channels to be used for FDMA, BLF, and bandwidth (BW) of one tone, as shown in FIG. 17.

[0188] Specifically, in one embodiment of the present invention, it is proposed that the interval (G; 1610) in the frequency domain of a plurality of CWs is set to satisfy the following mathematical equation.

[0189] [Mathematical Formula 1]

[0190] G ≥ 2 * (number of channels to use for FDMA * BLF + BW / 2) + guard region

[0191]

[0192] Transfer mode control

[0193] Considering the first and second embodiments described above, the base station can operate as follows.

[0194] Multi-tone CW can be seen as a function to increase coverage, and FDMA can be seen as a function required to increase capacity. Base stations / intermediate nodes can determine whether to activate the two functions by assessing the current situation.

[0195] At this time, the criteria for determining the operation at the base station / intermediate node include D2R reception signal strength, data collision rate, etc.

[0196] For example, by changing the multi-tone CW and FDMA configurations at the intermediate node, the intermediate node can transmit information such as D2R reception signal strength, data collision rate, etc. to the base station via RRC messages, and the base station can then transmit the changed configuration back to the intermediate node. In addition, if there is a separate CW transmitter, the intermediate node can request a CW configuration change via UCI (Uplink Control Information).

[0197]

[0198] Line coding related signaling

[0199] In the above description, it was mentioned that the method of applying FDMA to D2R link signal transmission by line coding can be referred to as SFS (Small Frequency Shift).

[0200] Figures 18 to 20 are drawings for explaining SFS application examples according to one embodiment of the present invention.

[0201] B in Figs. 18 to 20 tx,D2R represents the transmission bandwidth and can be viewed as a frequency resource allocated by the reader for D2R link signal transmission from one A-IoT device.

[0202] B occ,D2R represents the Occupied Bandwidth, which can correspond to the combined transmission band and potential associated intra A-IoT guard band.

[0203] Accordingly, B tx,D2R >= B occ,D2R It is desirable to satisfy the relationship.

[0204]

[0205] Specifically, FIG. 18 shows B for 2SB (Double Sideband) transmission using Option 1 Manchester line code when D2R line code is not used (i.e., when a square wave corresponding to SFS is used). tx,D2R and B occ,D2R This is a drawing showing .

[0206] Also, Fig. 19 shows B for 1SB (Single Sideband) transmission using Option 1 Manchester line code when D2R line code is not used (i.e., when a square wave corresponding to SFS is used). tx,D2R and B occ,D2R This is a drawing showing .

[0207] In FIGS. 18 and 19, Fc represents the carrier frequency, and FSx exemplarily represents the amount of SFS.

[0208] As shown in Fig. 18, in 2SB transmission, both -FSx and +FSx are included, and as shown in Fig. 19, in 1SB transmission, only one of -FSx and +FSx can be included.

[0209]

[0210] There are two factors that can influence these SFSs.

[0211] First, when generating an OFDM signal using OOK-4, nine M values ​​are defined as shown in Fig. 20. Fig. 20 shows the minimum B associated with the possible M values. tx,D2R It shows the relationship between values.

[0212] Secondly, the required information may vary depending on whether 2SB is used as in Fig. 18 or 1SB as in Fig. 19. When 1SB is used, selection of (+) and (-) frequencies as in Fig. 19 may be required.

[0213]

[0214] Based on the above, one embodiment of the present invention proposes to transmit 6-bit channel information as the 'frequency information' of FIG. 3, and preferably, the 6-bit channel information is proposed in a manner that includes (4 bits of M value index) + (1 bit for whether it is DSB or SSB) + (+ / - 1 bit of channel index).

[0215]

[0216] Figure 21 illustrates a wireless device to which the present technology can be applied.

[0217] Referring to FIG. 21, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals via various wireless access technologies (e.g., LTE, NR). Here, the first wireless device (100) and the second wireless device (200) can correspond to the A-IoT devices (210a-210n) and readers (215, 220) of FIG. 3, respectively.

[0218] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0219] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code including commands for performing some or all of the processes controlled by the processor (202) or performing the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE E-UTRA, 5G NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0220] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0221] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0222] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0223] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0224]

[0225] The detailed description of the preferred embodiments of the present invention disclosed above has been provided to enable those skilled in the art to implement and practice the present invention. While the above description has been made with reference to preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the scope of the present invention. For example, those skilled in the art can utilize the individual components described in the above-described embodiments in combination with each other.

[0226] Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0227] The D2R link signal transmission of an ambient IoT device and the devices therefor according to the embodiments of the present invention as described above are suitable for use in a 3GPP-based mobile communication environment, but as described above, they can also be widely used in communication methods other than 3GPP to efficiently multiplex D2R link signals in an ambient IoT environment.

Claims

1. In a mobile communication system supporting Ambient IoT (Internet of Things), a method for transmitting a D2R (Device-to-Reader) link signal from an Ambient IoT device to a reader, Receive a 0th message including frequency information for transmitting the D2R link signal from the reader; Based on the above frequency information, line coding is performed on the D2R link signal; and A D2R link signal transmission method, comprising transmitting the D2R link signal to which the FDMA (Frequency Divisional Multiple Access) method is applied by the line coding to the reader.

2. In paragraph 1, The above frequency information is, A D2R link signal transmission method including chip rate information of the above line coding.

3. In paragraph 1, The above frequency information is, A method for transmitting a D2R link signal, comprising at least one of a chip rate, a bit rate or a Transport Block Size (TBS) of the above line coding.

4. In paragraph 1, A method for transmitting a D2R link signal, wherein the above ambient IoT device does not include a center frequency shift element for transmitting the D2R link signal.

5. In paragraph 1, The above frequency information indicates one or more options available for transmitting the D2R link signal, A D2R link signal transmission method in which, when there are multiple options, the ambient IoT device selects any option among the multiple options and performs line coding.

6. In paragraph 5, The above options are represented by a bitmap format with multiple bits or by one or more of the available maximum line coding options (R). A D2R link signal transmission method, wherein, when the frequency information indicates the maximum line coding option (R), the ambient IoT device performs line coding using an option lower than the maximum line coding option (R).

7. In paragraph 5, A D2R link signal transmission method, wherein the above option implicitly indicates bandwidth information for the D2R link signal transmission.

8. In paragraph 1, The above 0 message is, A D2R link signal transmission method, further comprising at least one of bandwidth information for transmitting the D2R link signal or time information (Q) for determining the timing of transmitting the D2R link signal.

9. In paragraph 8, The above time information (Q) is, A D2R link signal transmission method, wherein the frequency information indicates multiple options, and is independently set for each of the multiple options.

10. In paragraph 8, The bandwidth information for the above D2R link signal transmission indicates a bandwidth smaller than 1 PRB (Physical Resource Block). Transmitting the above D2R link signal is: A method for transmitting a D2R link signal, comprising transmitting the D2R link signal by increasing transmission power compared to transmitting the D2R link signal through 1 PRB.

11. In paragraph 1, Transmitting the D2R link signal to which the FDMA method is applied by the above line coding is as follows: A method for transmitting a D2R link signal, comprising transmitting a first message transmitted in a random access manner in response to the above-mentioned 0 message.

12. In paragraph 11, Transmitting the D2R link signal to which the FDMA method is applied by the above line coding is as follows: A D2R link signal transmission method, further comprising transmitting a third message transmitted in response to a second message received from the reader in response to the first message.

13. In paragraph 12, The line coding applied to the above third message is: A method for transmitting a D2R link signal, applying the same line coding as that applied to the first message.

14. In paragraph 12, The line coding applied to the above third message is: A D2R link signal transmission method applying line coding based on frequency information of the second message.

15. In paragraph 1, The above 0 message additionally includes configuration information for transmitting the D2R link signal, The above configuration information is A first mode for transmitting the D2R link signal in FDMA mode, or A second mode for transmitting the above D2R link signal in the form of multiple CW (Continuous Wave) Indicates one of the modes, D2R link signal transmission method.

16. In paragraph 15, If the above configuration information includes configuration information for applying the first mode, the ambient IoT device is configured not to operate in the second mode. D2R link signal transmission method.

17. In a mobile communication system supporting ambient IoT (Internet of Things), a method for controlling D2R (Device-to-Reader) link signal transmission of multiple ambient IoT devices by a reader, Transmitting a 0th message including frequency information for transmitting the D2R link signal to the plurality of ambient IoT devices; and Including receiving the D2R link signal line-coded based on the frequency information from the plurality of ambient IoT devices, Receiving the above D2R link signal, A D2R link signal transmission control method comprising multiplexing D2R link signals of the plurality of ambient IoT devices in an FDMA (Frequency Divisional Multiple Access) manner by the line coding based on the frequency information.

18. In paragraph 17, Receiving the above D2R link signal, A method for controlling transmission of a D2R link signal, comprising receiving at least one of a first message or a third message received in a random access manner in response to the above-mentioned 0 message.

19. In an ambient IoT device of a mobile communication system supporting the Ambient IoT (Internet of Things), at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, Receive a 0th message including frequency information for transmitting the D2R link signal from the reader; Based on the above frequency information, line coding is performed on the D2R link signal; and An ambient IoT device comprising transmitting the D2R link signal to which the FDMA (Frequency Divisional Multiple Access) method is applied by the line coding to the reader.

20. In a reader of a mobile communication system supporting Ambient IoT (Internet of Things), at least one processor; and At least one computer memory operably connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations; The above actions are, Transmitting a 0th message including frequency information for transmitting the D2R link signal to the plurality of ambient IoT devices; and Including receiving the D2R link signal line-coded based on the frequency information from the plurality of ambient IoT devices, Receiving the above D2R link signal, A reader comprising multiplexing D2R link signals of the plurality of ambient IoT devices in an FDMA (Frequency Divisional Multiple Access) manner by the line coding based on the frequency information.

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