Apparatus and method for performing measurement device independent semiquantum key distribution by using intermediate node in communication system

Abstract

The purpose of the present disclosure is to transmit or receive data in a quantum communication system, and a method may comprise the steps of: acquiring system information; performing a random access procedure on the basis of the system information; transmitting a first signal for measurement to a second device; transmitting a second signal for measurement to a third device; receiving information related to a measurement result from the third device; and acquiring a final key on the basis of the information related to the measurement result.

Description

Device and method for performing detector-independent anti-quantum key distribution using an intermediate node in a communication system

[0001] The present disclosure relates to a communication system, and more specifically to an apparatus and method for performing measurement device independent semiquantum key distribution (MDI SQKD) using an intermediate node in a communication system.

[0002] Wireless access systems are being widely deployed to provide various types of communication services, such as voice and data. Generally, a wireless access system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of multiple access systems include CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access) systems.

[0003] In particular, as many communication devices require large communication capacities, enhanced mobile broadband (eMBB) communication technology is being proposed as an improvement over existing radio access technology (RAT). Furthermore, communication systems are being proposed that consider not only massive machine type communications (mmTC), which connects multiple devices and objects to provide various services anytime and anywhere, but also services and user equipment (UE) that are sensitive to reliability and latency. Various technical configurations are being proposed for this purpose.

[0004] The present disclosure relates to an apparatus and method for performing measurement device independent semiquantum key distribution (MDI SQKD) using an intermediate node in a communication system.

[0005] The present disclosure relates to an apparatus and method for distributing a key for a quantum state when there is no laser device at the receiving node in a communication system.

[0006] The present disclosure relates to an apparatus and method for transmitting a sequence of qubits to an intermediate node based on qubits received by a receiving node from a transmitting node in a communication system.

[0007] The present disclosure relates to an apparatus and method for changing the positions of qubits received by a receiving node from a transmitting node in a communication system and performing a bit flip.

[0008] The present disclosure relates to an apparatus and method for a transmitting node in a communication system to derive the basis of a signal transmitted by a receiving node as location information.

[0009] The present disclosure relates to an apparatus and method for performing a first safety check based on first basis qubits generated by a transmitting node in a communication system.

[0010] The present disclosure relates to an apparatus and method for generating a raw key based on first basis qubits generated by a transmitting node in a communication system.

[0011] The present disclosure relates to an apparatus and method for performing a second stability check using at least one bit included in a source key in a communication system.

[0012] The present disclosure relates to an apparatus and method for determining an error rate based on the measurement results of base-matched qubits in a communication system.

[0013] The technical objectives to be achieved in this disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art to which the technical configuration of this disclosure applies, based on the embodiments of this disclosure described below.

[0014] As an example of the present disclosure, the method comprises the steps of acquiring system information, performing a random access procedure based on the system information, transmitting a first signal for measurement to a second device, transmitting a second signal for measurement to a third device, receiving information related to a measurement result from the third device, and acquiring a final key based on the information related to the measurement result, wherein the information related to the measurement result includes a third signal and a second signal obtained by changing the positions of qubits included in the first signal and bit flipping, and the bell state measurement result for the second signal, and the qubits included in the first signal may be generated in one of a first state of a first basis, a third state of a second basis, or a fourth state of a second basis.

[0015] As an example of the present disclosure, the method comprises the steps of acquiring system information, performing a random access procedure based on the system information, receiving a first signal for measurement from a first device, transmitting a third signal based on the first signal to a third device, receiving information related to a measurement result from the third device, and acquiring a final key based on the information related to the measurement result, wherein the information related to the measurement result includes a bell state measurement result for a second signal transmitted by the first device and the third signal, and the qubits included in the first signal may be generated in one of a first state of a first basis, a third state of a second basis, or a fourth state of a second basis.

[0016] As an example of the present disclosure, a first device comprises a transceiver and a processor coupled to the transceiver, wherein the processor is configured to acquire system information, perform a random access procedure based on the system information, transmit a first signal for measurement to a second device, transmit a second signal for measurement to a third device, receive information related to a measurement result from the third device, and acquire a final key based on the information related to the measurement result, wherein the information related to the measurement result includes a third signal and a bell state measurement result for the second signal obtained by changing the position of qubits included in the first signal and bit flipping, and the qubits included in the first signal may be generated in one of a first state of a first basis, a third state of a second basis, or a fourth state of a second basis.

[0017] As an example of the present disclosure, a second device comprises a transceiver and a processor coupled to the transceiver, wherein the processor is configured to acquire system information, perform a random access procedure based on the system information, receive a first signal for measurement from a first device, transmit a third signal based on the first signal to a third device, receive information related to a measurement result from the third device, and acquire a final key based on the information related to the measurement result, wherein the information related to the measurement result includes a bell state measurement result for a second signal transmitted by the first device and the third signal, and the qubits included in the first signal may be generated in one of a first state of a first basis, a third state of a second basis, or a fourth state of a second basis.

[0018] As an example of the present disclosure, a transmitting node comprises at least one processor and at least one computer memory connected to the at least one processor and storing instructions that direct operations as executed by the at least one processor, wherein the operations include the steps of acquiring system information, performing a random access procedure based on the system information, transmitting a first signal for measurement to a second device, transmitting a second signal for measurement to a third device, receiving information related to a measurement result from the third device, and acquiring a final key based on the information related to the measurement result, wherein the information related to the measurement result includes a third signal and a bell state measurement result for the second signal obtained by changing the position of qubits included in the first signal and bit flipping, and the qubits included in the first signal may be generated in one of a first state of a first basis, a third state of a second basis, or a fourth state of a second basis.

[0019] As an example of the present disclosure, a non-transitory computer-readable medium storing at least one instruction comprises said at least one instruction executable by a processor, said at least one instruction being configured such that a first device acquires system information, performs a random access procedure based on said system information, transmits a first signal for measurement to a second device, transmits a second signal for measurement to a third device, receives information related to a measurement result from said third device, and acquires a final key based on said information related to the measurement result, wherein the information related to the measurement result includes a third signal and a second signal obtained by changing the position of qubits included in said first signal and bit flipping, and the qubits included in said first signal may be generated in one of a first state of a first basis, a third state of a second basis, or a fourth state of said second basis.

[0020] The embodiments of the present disclosure described above are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the present disclosure can be derived and understood by those skilled in the art based on the detailed description of the present disclosure set forth below.

[0021] The following effects may be achieved by embodiments based on the present disclosure.

[0022] According to the present disclosure, an efficient quantum key distribution procedure can be performed using an intermediate node.

[0023] The effects obtainable from the embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by a person skilled in the art to which the technical configuration of the present disclosure applies from the description of the embodiments of the present disclosure below. That is, unintended effects resulting from implementing the configuration described in the present disclosure can also be derived by a person skilled in the art from the embodiments of the present disclosure.

[0024] The drawings attached below are intended to aid in understanding the present disclosure and may provide embodiments of the present disclosure together with the detailed description. However, the technical features of the present disclosure are not limited to specific drawings, and features disclosed in each drawing may be combined with one another to form new embodiments. Reference numerals in each drawing may denote structural elements.

[0025] FIG. 1 illustrates an example of a communication system applicable to the present disclosure.

[0026] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0027] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure.

[0028] FIG. 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0029] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0030] FIG. 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0031] FIG. 7 illustrates a transmitter structure applicable to the present disclosure.

[0032] FIG. 8 illustrates an example of a functional framework for the application of artificial intelligence technology applicable to the present disclosure.

[0033] FIG. 9 illustrates an example of a procedure for utilizing an artificial intelligence model applicable to the present disclosure.

[0034] FIG. 10 illustrates a communication procedure based on artificial intelligence (AI) technology applicable to the present disclosure.

[0035] FIG. 11 illustrates three basic properties of quantum information that can be used in information communication applicable to the present disclosure.

[0036] FIG. 12 illustrates an example of a quantum transmission protocol according to one embodiment of the present disclosure.

[0037] FIG. 13 illustrates an example of transmitting quantum information in two-step quantum secure direct communication according to one embodiment of the present disclosure.

[0038] FIG. 14 illustrates an example of a device performing an MDI SQKD (measurement device independent semiquantum key distribution) protocol according to one embodiment of the present disclosure.

[0039] FIG. 15 illustrates an example of signaling for performing an MDI SQKD protocol according to one embodiment of the present disclosure.

[0040] FIG. 16 illustrates an example of a device that performs an MDI SQKD protocol according to one embodiment of the present disclosure.

[0041] FIG. 17 illustrates an example of signaling for a receiving node to perform an MDI SQKD protocol that does not use a laser source, according to one embodiment of the present disclosure.

[0042] FIG. 18 illustrates an example in which a transmitting node transmits a data signal using the MDI SQKD protocol according to one embodiment of the present disclosure.

[0043] FIG. 19 illustrates an example in which a receiving node transmits a data signal using the MDI SQKD protocol according to one embodiment of the present disclosure.

[0044] FIG. 20 illustrates an example in which a transmitting node obtains a final key using the MDI SQKD protocol according to one embodiment of the present disclosure.

[0045] FIG. 21 illustrates an example in which a receiving node obtains a final key using the MDI SQKD protocol according to one embodiment of the present disclosure.

[0046] FIG. 22 illustrates an example of a wireless device applicable to the present disclosure.

[0047] FIG. 23 illustrates an example of a portable device applicable to the present disclosure.

[0048] FIG. 24 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure.

[0049] FIG. 25 illustrates an example of a vehicle applicable to the present disclosure.

[0050] FIG. 26 illustrates an example of an extended reality (XR) device applicable to the present disclosure.

[0051] FIG. 27 illustrates an example of a robot applicable to the present disclosure.

[0052] FIG. 28 illustrates an example of an AI device applicable to the present disclosure.

[0053] The following embodiments are combinations of the components and features of the present disclosure in a predetermined form. Each component or feature may be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, some components and / or features may be combined to form embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of any embodiment may be included in other embodiments, or may be replaced with corresponding components or features of other embodiments.

[0054] In the description of the drawings, procedures or steps that could obscure the gist of the present disclosure have not been described, nor have procedures or steps that are understandable to those skilled in the art been described.

[0055] Throughout the specification, when a part is described as "comprising" or "including" a component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Furthermore, terms such as "...part," "...unit," and "module" as used in the specification refer to a unit that performs at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software. Additionally, "one (a or an)," "one," "the," and similar related terms may be used in the context describing the present disclosure (particularly in the context of the following claims) in both singular and plural forms, unless otherwise indicated in the specification or clearly contradicted by the context.

[0056] In this specification, the embodiments of the present disclosure are described with a focus on the data transmission and reception relationship between a base station and a mobile station. Here, the base station refers to a terminal node of a network that communicates directly with a mobile station. Specific operations described in this document as being performed by a base station may, in some cases, be performed by an upper node of the base station.

[0057] That is, in a network consisting of multiple network nodes including a base station, various operations performed for communication with a mobile station may be performed by the base station or other network nodes other than the base station. In this case, 'base station' may be replaced by terms such as fixed station, Node B, eNB (eNode B), gNB (gNode B), ng-eNB, advanced base station (ABS), or access point.

[0058] Additionally, in embodiments of the present disclosure, the term terminal may be replaced with terms such as user equipment (UE), mobile station (MS), subscriber station (SS), mobile subscriber station (MSS), mobile terminal, or advanced mobile station (AMS).

[0059] Furthermore, the transmitting end refers to a fixed and / or mobile node that provides data or voice services, and the receiving end refers to a fixed and / or mobile node that receives data or voice services. Therefore, in the case of the uplink, a mobile station can be the transmitting end and a base station can be the receiving end. Similarly, in the case of the downlink, a mobile station can be the receiving end and a base station can be the transmitting end.

[0060] Embodiments of the present disclosure may be supported by standard documents disclosed in at least one of the wireless access systems, such as IEEE 802.xx systems, 3GPP (3rd Generation Partnership Project) systems, 3GPP LTE (Long Term Evolution) systems, 3GPP 5G (5th generation) NR (New Radio) systems and 3GPP2 systems, and in particular, embodiments of the present disclosure may be supported by 3GPP TS (technical specification) 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331 documents.

[0061] In addition, the embodiments of the present disclosure may be applied to other wireless access systems and are not limited to the systems described above. For example, they may be applicable to systems applied after the 3GPP 5G NR system and are not limited to specific systems.

[0062] That is, obvious steps or parts not described in the embodiments of the present disclosure may be described by referring to the aforementioned documents. Additionally, all terms disclosed in this document may be explained by the aforementioned standard documents.

[0063] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present disclosure and is not intended to represent the only embodiment in which the technical configuration of the present disclosure can be implemented.

[0064] Additionally, specific terms used in the embodiments of the present disclosure are provided to aid in understanding the present disclosure, and the use of such specific terms may be modified in other forms without departing from the technical spirit of the present disclosure.

[0065] The following technology can be applied to various wireless access systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access).

[0066] For the sake of clarity, the following description is based on 3GPP communication systems (e.g., LTE, NR, etc.), but the technical scope of this disclosure is not limited thereto. LTE may refer to technology from 3GPP TS 36.xxx Release 8 onwards. Specifically, LTE technology from 3GPP TS 36.xxx Release 10 onwards is referred to as LTE-A, and LTE technology from 3GPP TS 36.xxx Release 13 onwards may be referred to as LTE-A pro. 3GPP NR may refer to technology from TS 38.xxx Release 15 onwards. 3GPP 6G may refer to technology from TS Release 17 and / or Release 18 onwards. "xxx" indicates a specific standard document number. LTE / NR / 6G may be collectively referred to as 3GPP systems.

[0067] Regarding the background technology, terms, abbreviations, etc. used in this disclosure, reference may be made to standard documents published prior to this disclosure. For example, reference may be made to standard documents 36.xxx and 38.xxx.

[0068] Communication systems applicable to the present disclosure

[0069] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods, and / or flowcharts of the disclosure disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0070] Examples are provided in more detail below with reference to the drawings. In the following drawings and descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks unless otherwise described.

[0071] FIG. 1 illustrates an example of a communication system to which the present disclosure applies.

[0072] Referring to FIG. 1, the communication system (100) to which the present disclosure applies includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using wireless access technology (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (extended reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Thing) device (100f), and an AI (artificial intelligence) device / server (100g). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle (100b-1, 100b-2) may include an unmanned aerial vehicle (UAV) (e.g., a drone). The XR device (100c) includes an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. The portable device (100d) may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch, smart glasses), a computer (e.g., a laptop, etc.). The home appliance (100e) may include a TV, a refrigerator, a washing machine, etc. The IoT device (100f) may include a sensor, a smart meter, etc.For example, the base station (120) and network (130) may also be implemented as wireless devices, and a specific wireless device (120a) may act as a base station / network node to other wireless devices.

[0073] Wireless devices (100a to 100f) can be connected to a network (130) through a base station (120). AI technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (100g) through the network (130). The network (130) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, or a 6G network. The wireless devices (100a to 100f) may communicate with each other through the base station (120) / network (130), but may also communicate directly (e.g., sidelink communication) without going through the base station (120) / network (130). For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (vehicle to vehicle) / V2X (vehicle to everything) communication). Also, an IoT device (100f) (e.g., a sensor) can communicate directly with another IoT device (e.g., a sensor) or other wireless devices (100a to 100f).

[0074] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a to 100f) / base station (120) and between base station (120) / base station (120). Here, wireless communication / connection can be established through various wireless access technologies such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and communication between base stations (150c) (e.g., relay, IAB (integrated access backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on the various proposals of the present disclosure, at least some of the following may be performed: a process for setting various configuration information for transmitting / receiving wireless signals, a process for various signal processing (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), a resource allocation process, etc.

[0075] Devices applicable to the present disclosure

[0076] FIG. 2 illustrates an example of a wireless device that can be applied to the present disclosure.

[0077] Referring to FIG. 2, the wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, LTE-A, LTE-A pro, NR, 5G, 5G-A, 6G). The wireless device (200) includes at least one processor (202) and at least one memory (204), and may additionally include at least one transceiver (206) and / or at least one antenna (208).

[0078] The processor (202) controls the memory (204) and / or the transceiver (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or sequences of operation disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a second information / signal through the transceiver (206) and then store information obtained from the signal processing of the second information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or sequences of operations disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology. A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through at least one antenna (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with a radio frequency (RF) unit. In this disclosure, a wireless device may mean a communication modem / circuit / chip.

[0079] Hereinafter, hardware elements of the wireless device (200) will be described in more detail. Although not limited thereto, at least one protocol layer may be implemented by at least one processor (202). For example, at least one processor (202) may implement at least one layer (e.g., functional layers such as PHY (physical), MAC (media access control), RLC (radio link control), PDCP (packet data convergence protocol), RRC (radio resource control), and SDAP (service data adaptation protocol). At least one processor (202) may generate at least one PDU (Protocol Data Unit) and / or at least one SDU (service data unit) according to the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. At least one processor (202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. At least one processor (202) may generate a signal (e.g., baseband signal) including a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to at least one transceiver (206). At least one processor (202) may receive a signal (e.g., baseband signal) from at least one transceiver (206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document.

[0080] At least one processor (202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. At least one processor (202) may be implemented by hardware, firmware, software, or a combination thereof. For example, at least one application-specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one digital signal processing device (DSPD), at least one programmable logic device (PLD), or at least one field programmable gate array (FPGA) may be included in at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences 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. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be included in at least one processor (202) or stored in at least one memory (204) and driven by at least one processor (202). The descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0081] At least one memory (204) may be connected to at least one processor (202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. At least one memory (204) may be composed of ROM (read-only memory), RAM (random access memory), EPROM (erasable programmable read-only memory), flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. At least one memory (204) may be located inside and / or outside of at least one processor (202). Additionally, at least one memory (204) may be connected to at least one processor (202) via various technologies, such as wired or wireless connections.

[0082] At least one transceiver (206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc. of this document to at least one other device. At least one transceiver (206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc. disclosed in this document from at least one other device. For example, at least one transceiver (206) may be connected to at least one processor (202) and may transmit and receive wireless signals. For example, at least one processor (202) may control at least one transceiver (206) to transmit user data, control information, or wireless signals to at least one other device. Additionally, at least one processor (202) may control at least one transceiver (206) to receive user data, control information, or wireless signals from at least one other device. Additionally, at least one transceiver (206) may be connected to at least one antenna (208), and at least one transceiver (206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document through at least one antenna (208). In this document, at least one antenna may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). At least one transceiver (206) may convert the received wireless signals / channels, etc., from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc., using at least one processor (202). At least one transceiver (206) may convert the processed user data, control information, wireless signals / channels, etc., from baseband signals to RF band signals using at least one processor (202).To this end, at least one transceiver (206) may include an (analog) oscillator and / or filter.

[0083] The components of the wireless device described with reference to FIG. 2 may be referred to by other terms in terms of their function. For example, the processor (202) may be referred to as the control unit, the transceiver (206) as the communication unit, and the memory (204) as the storage unit. In some cases, the communication unit may be used to mean at least a part of the processor (202) and the transceiver (206).

[0084] The structure of the wireless device described with reference to FIG. 2 can be understood as the structure of at least part of various devices. For example, the structure of the wireless device exemplified in FIG. 2 may be at least part of the various devices described with reference to FIG. 1 (e.g., robot (100a), vehicle (100b-1, 100b-2), XR device (100c), portable device (100d), home appliance (100e), IoT device (100f), AI device / server (100g)). Furthermore, according to various embodiments, the device may include other components in addition to the components exemplified in FIG. 2.

[0085] For example, the device may be a portable device such as a smartphone, smartpad, wearable device (e.g., smart watch, smart glasses), or portable computer (e.g., laptop, etc.). In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an interface unit that includes at least one port for connection with another device (e.g., audio input / output port, video input / output port), and an input / output unit for inputting and outputting video information / signals, audio information / signals, data, and / or information input by a user.

[0086] For example, the device may be a mobile device such as a mobile robot, vehicle, train, manned / unmanned aerial vehicle (AV), or ship. In this case, the device may further include at least one of a drive unit comprising at least one of an engine, motor, power train, wheel, brake, and steering device of the device; a power supply unit that supplies power and includes a wired / wireless charging circuit, battery, etc.; a sensor unit that senses state information, environmental information, and user information of the device or its surroundings; an autonomous driving unit that performs functions such as path maintenance, speed control, and destination setting; and a position measurement unit that acquires position information of the moving body through a GPS (global positioning system) and various sensors.

[0087] For example, the device may be an XR device such as an HMD, a HUD (head-up display) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc. In this case, the device may further include at least one of a power supply unit that supplies power and includes a wired / wireless charging circuit, a battery, etc., an input / output unit that acquires control information, data, etc. from the outside and outputs a generated XR object, and a sensor unit that senses state information, environment information, and user information of the device or the surroundings of the device.

[0088] For example, the device may be a robot that can be classified into industrial, medical, household, military, etc., depending on the purpose or field of use. In this case, the device may further include at least one of a sensor unit that senses state information, environmental information, and user information of the device or its surroundings, and a drive unit that performs various physical actions, such as moving robot joints.

[0089] For example, the device may be an AI device such as a TV, projector, smartphone, PC, laptop, digital broadcasting terminal, tablet PC, wearable device, set-top box (STB), radio, washing machine, refrigerator, digital signage, robot, vehicle, etc. In this case, the device may further include at least one of an input unit that acquires various types of data from the outside, an output unit that generates output related to sight, hearing, or touch, a sensor unit that senses state information, environmental information, and user information of the device or its surroundings, and a training unit that learns a model composed of an artificial neural network using training data.

[0090] The structure of the wireless device illustrated in FIG. 2 can be understood as part of a RAN node (e.g., base station, DU, RU, RRH, etc.). That is, the device illustrated in FIG. 2 may be a RAN node. In this case, the device may further include a wired transceiver for front haul and / or back haul communication. However, if the front haul and / or back haul communication is based on wireless communication, at least one transceiver (206) illustrated in FIG. 2 is used for front haul and / or back haul communication, and the wired transceiver may not be included.

[0091] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure. For example, the transmission signal may be processed by a signal processing circuit. In this case, the signal processing circuit (300) may include scramblers (310), modulators (320), a layer mapper (330), a precoder (340), resource mappers (350), and signal generators (360). In this case, for example, the operation / function of FIG. 3 may be performed in the processor (202) and / or transceiver (206) of FIG. 2. Also, for example, the hardware elements of FIG. 3 may be implemented in the processor (202) and / or transceiver (206) of FIG. 2. For example, blocks 310 to 360 may be implemented in the processor (202) of FIG. 2. Additionally, blocks 310 to 350 may be implemented in the processor (202) of FIG. 2, and block 360 may be implemented in the transceiver (206) of FIG. 2, and are not limited to the embodiments described above.

[0092] A codeword can be converted into a wireless signal through the signal processing circuit (300) of FIG. 3. Here, the codeword is an encoded bit sequence of an information block. The information block may include a transmission block (e.g., UL-SCH transmission block, DL-SCH transmission block). Here, the information block may include AI-related data (e.g., training data, AI model data, input data, output data, etc.), and the codeword may be an encoded bit sequence corresponding to the AI-related data. The wireless signal may be transmitted through various physical channels (e.g., PUSCH, PDSCH). Specifically, the codeword may be converted into a scrambled bit sequence by scramblers (310). The scrambled sequence used for scrambling is generated based on an initialization value, which may include ID information of the wireless device, etc. The scrambled bit sequence may be modulated into a modulation symbol sequence by modulators (320). Modulation methods may include pi / 2-BPSK (pi / 2-binary phase shift keying), m-PSK (m-phase shift keying), m-QAM (m-quadrature amplitude modulation), etc.

[0093] A complex modulation symbol sequence can be mapped to at least one transmission layer by a layer mapper (330). Here, a transmission layer is a logical resource unit for mapping signals or data transmitted through spatial resources to antenna ports, and one transmission layer can correspond to one stream or one antenna port. Each complex modulation symbol included in the complex modulation symbol sequence is mapped to at least one transmission layer, thereby determining which antenna port it will be transmitted through. The modulation symbols of each transmission layer can be mapped to the corresponding antenna port(s) by a precoder (340). The output z of the precoder (340) can be obtained by multiplying the output y of the layer mapper (330) by an N×M precoding matrix W, where N is the number of antenna ports and M is the number of transmission layers. Here, the precoder (340) can perform precoding after performing transform precoding (e.g., a discrete Fourier transform (DFT)) on the complex modulation symbols. Additionally, the precoder (340) can perform precoding without performing transform precoding.

[0094] Resource mappers (350) can map the modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include multiple symbols (e.g., CP-OFDMA symbols, DFT-s-OFDMA symbols) in the time domain and multiple subcarriers in the frequency domain. Signal generators (360) generate radio signals from the mapped modulation symbols, and the generated radio signals can be transmitted to other devices through each antenna. To this end, each of the signal generators (360) may include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), a frequency uplink converter, etc.

[0095] The signal processing process for a received signal in a wireless device can be configured as the inverse of the signal processing process (310 to 360) of FIG. 3. For example, a wireless device (e.g., 200 in FIG. 2) can receive a wireless signal from the outside through an antenna port / transceiver. The received wireless signal can be converted into a baseband signal through a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Subsequently, the baseband signal can be restored into a codeword through a resource de-mapper process, a postcoding process, a demodulation process, and a de-scrambling process. The codeword can be restored into the original information block through decoding. Accordingly, a signal processing circuit (not shown) for a received signal may include a signal restorer, a resource de-mapper, a postcoder, a demodulator, a de-scrambler, and a decoder.

[0096] The signal processing circuit (300) described with reference to FIG. 3 is illustrated as including a plurality of scramblers (310), modulators (320), a plurality of resource mappers (350), and a plurality of signal generators (360). However, at least one of the scramblers, modulators, resource mappers, and signal generators may be implemented as a single integrated structure. That is, the number of at least one of the scramblers, modulators, resource mappers, and signal generators may be less than the number of layers. Furthermore, at least one of the components illustrated in FIG. 3 may be omitted.

[0097] FIG. 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure. FIG. 4 illustrates the operation of a terminal (410) and a base station (420) transmitting and / or receiving data, and the operation performed prior to this.

[0098] Referring to FIG. 4, in step 401, the terminal (410) and the base station (420) perform synchronization. For example, the terminal (410) performs an initial cell search operation. Specifically, the terminal (410) can detect at least one synchronization signal transmitted from the base station (420) according to a predefined rule. Here, the synchronization signal may include a plurality of synchronization signals (e.g., primary synchronization signal, secondary synchronization signal) classified according to structure or use. Through this, the terminal (410) can identify the boundaries of the frame, subframe, slot, and / or symbol of the base station (420) and obtain information about the base station (420) (e.g., cell identifier).

[0099] In step 403, the terminal (410) obtains system information transmitted from the base station (420). The system information is information related to the attributes, characteristics, and / or capabilities of the base station (420) required to connect to the base station (420) and use the service, and can be classified according to content (e.g., whether it is essential for connection), transmission structure (e.g., channel used, whether it is provided on-demand), etc., and can be classified, for example, into a master information block (MIB) and a system information block (SIB). If necessary, the terminal (410) may transmit a signal requesting the system information prior to receiving the system information. The system information may include information related to AI functions. For example, the system information is information required for operations performed based on AI, and may include at least one of information related to an AI model, information related to training, and information related to inference / prediction. However, the request and provision of the system information may be performed after the random access procedure described later.

[0100] In step 405, the terminal (410) and the base station (420) perform a random access procedure. The terminal (410) may transmit and / or receive at least one message for the random access procedure (e.g., random access preamble, RAR (random access response) message, etc.) based on information related to the random access channel of the base station (420) obtained through system information (e.g., channel location, channel structure, structure of supported preamble, etc.). For example, the terminal (410) may transmit a preamble (e.g., MSG1) through the random access channel, receive a RAR message (e.g., MSG2), transmit a message (e.g., MSG3) containing information related to the terminal (410) (e.g., identification information) to the base station (420) using scheduling information included in the RAR message, and receive a message (e.g., MSG4) for contention resolution and / or connection establishment. As another example, MSG1 and MSG3 can be transmitted and received as a single message, or MSG2 and MSG4 can be transmitted and received as a single message.

[0101] In step 407, the terminal (410) and the base station (420) perform signaling of control information. Here, the control information may be defined in various layers, such as a layer that controls the connection (e.g., a radio resource control (RRC) layer), a layer that handles mapping between logical channels and transmission channels (e.g., a media access control (MAC) layer), and a layer that handles physical channels (e.g., a physical (PHY) layer). For example, the terminal (410) and the base station (420) may perform at least one of signaling to establish a connection, signaling to determine settings related to communication, and signaling to indicate allocated resources. Additionally, the signaling of control information may be performed to convey information related to AI functions. For example, information related to AI functions is information necessary for operations performed based on AI, and may include at least one of information related to an AI model, information related to training, and information related to inference / prediction. More specifically, the information related to the AI ​​function signaled in step 407 can be combined and / or combined with the information related to the AI ​​function signaled in step 403, and both can be defined as having a hierarchical, mutually complementary, or substitute structure.

[0102] In step 409, the terminal (410) and the base station (420) transmit and / or receive data. That is, the terminal (410) and the base station (420) can process, transmit and / or receive data based on the signaling of control information. For example, when transmitting data, the terminal (410) or the base station (420) may perform at least one of channel encoding, rate matching, scrambling, constellation mapping, layer mapping, waveform modulation, antenna mapping, and resource mapping on the information bits. Conversely, when receiving data, the terminal (410) or the base station (420) may perform at least one of signal extraction from resources, antenna-specific waveform demodulation, signal placement considering layer mapping, constellation demapping, descrambling, and channel decoding. Here, the transmitted data is AI-related data, and may include, for example, data for AI-based operations or data generated by AI-based operations.

[0103] Steps 401 through 409 described with reference to FIG. 4 must not necessarily be performed in the order exemplified in FIG. 4, and the order of at least some of the steps may vary. Additionally, at least some of steps 401 through 409 may be combined into a single step or omitted. That is, the steps exemplified in FIG. 4 may be performed in various modified forms.

[0104]

[0105] *

[0106] 6G communication systems and core implementation technologies of 6G systems

[0107] 5G systems define various operating bands within FR1 (frequency range 1), which includes 410 MHz to 7125 MHz, and FR2 (frequency range 2), which includes 24,250 MHz to 71,000 MHz. Various frequencies are being discussed as operating bands for subsequent 6G systems, and the use of frequencies higher than those of 5G systems is also being considered for wider bandwidth and higher transmission speeds. As one example, the use of the THz (Terahertz) frequency band, which includes approximately 100 GHz to 10 THz, is being discussed. The THz frequency band is a band that possesses both the penetrability of radio waves and the directivity of optical waves, and communication using the THz frequency band is expected to play a transitional role from existing radio-based communication to optical-based communication.

[0108] As such, 6G systems utilizing the THz frequency band aim for i) very high data rates per device, ii) a very large number of connected devices, iii) global connectivity, iv) very low latency, v) reduced energy consumption of battery-free IoT devices, vi) ultra-reliable connectivity, and vii) connected intelligence with machine learning capabilities. The vision of 6G systems can be four aspects such as "intelligent connectivity," "deep connectivity," "holographic connectivity," and "ubiquitous connectivity," and 6G systems can be designed to satisfy requirements such as those shown in [Table 1] below.

[0109] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0110] At this time, the 6G system may have key factors such as enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLC), massive machine type communications (mMTC), AI integrated communication, tactile internet, high throughput, high network capacity, high energy efficiency, low backhaul and access network congestion, and enhanced data security. FIG. 5 illustrates an example of a communication structure that can be provided by a 6G system applicable to the present disclosure. Referring to FIG. 5, the 6G system is expected to have simultaneous wireless communication connectivity 50 times higher than that of a 5G wireless communication system. URLLC, a key feature of 5G, is expected to become an even more dominant technology in 6G communication by providing end-to-end latency of less than 1ms. In this case, 6G systems will have significantly superior volumetric spectral efficiency, unlike the frequently used area-spectral efficiency. Since 6G systems can provide very long battery life and advanced battery technology for energy harvesting, mobile devices in 6G systems may not need to be charged separately. New network characteristics in 6G may be as follows.

[0111] - Satellite Integrated Network: 6G is expected to be integrated with satellites to provide a global mobile population. Integrating terrestrial, satellite, and airborne networks into a single wireless communication system is crucial for 6G.

[0112] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is innovative and will update wireless evolution from "connected things" to "connected intelligence." AI can be applied at each stage of the communication process (or at each step of the signal processing described below).

[0113] - Seamless integration of wireless information and energy transfer: 6G wireless networks will transfer power to charge the batteries of devices such as smartphones and sensors. Therefore, wireless information and energy transfer (WIET) will be integrated.

[0114] - Ubiquitous Super 3D Connectivity: Connectivity to the network and core network functions of drones and very low Earth orbit satellites will create Super 3D connectivity in 6G ubiquitous.

[0115] Some general requirements regarding the new network characteristics of 6G mentioned above may be as follows.

[0116] - Small cell networks: The idea of ​​small cell networks was introduced to improve the quality of received signals in cellular systems as a result of increased throughput, energy efficiency, and spectrum efficiency. Consequently, small cell networks are an essential feature of communication systems for 5G and beyond 5G (5GB). Therefore, 6G communication systems also adopt the characteristics of small cell networks.

[0117] - Ultra-dense heterogeneous network: Ultra-dense heterogeneous networks will be another important characteristic of 6G communication systems. Multi-tier networks composed of heterogeneous networks improve overall QoS and reduce costs.

[0118] - High-capacity backhaul: Backhaul connections are characterized as high-capacity backhaul networks to support high-volume traffic. High-speed fiber optics and free-space optics (FSO) systems can be possible solutions to this problem.

[0119] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communication is one of the functions of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0120] - Softwarization and virtualization: Softwarization and virtualization are two important features that form the basis of the design process in 5GB networks to ensure flexibility, reconfigurability, and programmability. Additionally, billions of devices can be shared across a shared physical infrastructure.

[0121] To satisfy the aforementioned characteristics, technologies such as artificial intelligence (AI), THz (Terahertz) communication, optical wireless technology, FSO backhaul network, massive MIMO technology, blockchain, 3D networking, quantum communication, unmanned aerial vehicles, cell-free communication, wireless information and energy transfer (WIET), integration of sensing and communication, integration of access backhaul networks, holographic beamforming, big data analysis, and large intelligent surface (LIS) may be adopted as core implementation technologies of the 6G system.

[0122] For example, THz communication can be utilized in 6G systems. THz communication is a communication that uses a spectrum in the frequency band between 0.3 THz and 3 THz with a corresponding wavelength in the range of 0.1 mm to 1 mm as shown in Fig. 6. Referring to Fig. 6, the frequency band of the THz wave is located in the intermediate region between the infrared band and the millimeter wave band; accordingly, the THz wave can be understood as a radio wave with the shortest wavelength and, at the same time, a light wave with the longest wavelength. As a result, the THz wave shares some characteristics of infrared and microwave waves, and specifically, can simultaneously possess the penetrability of electromagnetic waves and the directivity of light waves.

[0123] FIG. 7 illustrates a transmitter structure applicable to the present disclosure.

[0124] Referring to Fig. 7, in order to modulate data onto an optical signal, the optical source of a laser can be passed through an optical wave guide to change the phase of the signal. At this time, data is loaded by changing electrical characteristics through a microwave contact, etc. Therefore, the optical modulator output is formed as a modulated waveform.

[0125] Data may be provided by a data signal generator. Here, the data may include various user data, configuration information, control information, etc. transmitted through a channel. Furthermore, the data may include data related to AI-based operations, for example, information for configuring an AI model, input / output data for tasks of an AI model, etc. To this end, components related to AI functions (e.g., an AI processing unit) may be included in the data signal generator or may interact with the data signal generator.

[0126] An O / E converter can generate THz pulses based on optical rectification by a nonlinear crystal, O / E conversion by a photoconductive antenna, emission from a bundle of relativistic electrons, etc. THz pulses generated in such a manner can have a length ranging from femtoseconds to picoseconds. The O / E converter performs down-conversion by utilizing the non-linearity of the device.

[0127] When considering the usage of the THz spectrum, it is highly likely that multiple contiguous GHz bands will be used for fixed or mobile service applications for THz systems. According to outdoor scenario criteria, available bandwidth can be classified based on an oxygen attenuation of 10^2 dB / km in the spectrum up to 1 THz. Accordingly, a framework in which the available bandwidth is composed of multiple band chunks can be considered. As an example of the above framework, if the length of the THz pulse for a single carrier is set to 50 ps, ​​the bandwidth (BW) becomes approximately 20 GHz.

[0128] Effective down-conversion from the infrared band to the THz band depends on how the nonlinearity of the photoelectric converter (O / E converter) is utilized. In other words, to achieve down-conversion to the desired THz band, it is required to design an O / E converter with the most ideal nonlinearity for transferring to that specific band. If an O / E converter that does not match the target frequency band is used, there is a high probability of errors occurring regarding the amplitude and phase of the corresponding pulse.

[0129] In a single-carrier system, a THz transceiver system can be implemented using a single photoelectric converter. Depending on the channel environment, in a multi-carrier system, as many photoelectric converters as there are carriers may be required. This phenomenon will be particularly pronounced in multi-carrier systems utilizing multiple broadbands according to the plans related to the aforementioned spectrum applications. In this regard, a frame structure for the multi-carrier system may be considered. A signal down-frequency converted based on a photoelectric converter can be transmitted in a specific resource region (e.g., a specific frame). The frequency domain of the specific resource region may include multiple chunks. Each chunk may consist of at least one component carrier (CC).

[0130] AI technology can be introduced in 6G systems. Efficient resource management and optimization are required to maintain connectivity between various services and devices. AI technology may include techniques capable of performing data analysis, pattern recognition, and predictive modeling using AI / ML (artificial intelligence / machine learning) models. Here, an AI / ML model can be understood as a set of parameter values ​​and / or weight values ​​related to mathematical formulas or algorithms generated through learning, designed to discover patterns in input data or perform predictions. To create such an AI / ML model, an AI / ML model training procedure is required to build the model by learning the relationship between input and output in a data-driven manner. Various learning algorithms, such as supervised learning, unsupervised learning, and reinforcement learning, can be utilized as training algorithms. Users can input specific data into a trained AI / ML model to generate output, and the procedure of obtaining output data by inputting input data into the AI / ML model can be referred to as AI / ML 'inference' or 'prediction'.

[0131] Network control parameters can be obtained as output through AI / ML inference using trained AI / ML models. Users can improve network efficiency by utilizing these output parameter values. For example, AI technology can be applied in various fields, such as wireless network resource allocation, traffic management, fault prediction, and Quality of Service (QoS) management. In particular, machine learning can efficiently allocate resources even in dynamically changing network environments based on real-time data. Therefore, AI technology can be utilized to provide hyper-connectivity and ultra-low latency.

[0132] In this case, AI / ML inference can be performed based on a combination of various devices. For example, the UE and the network can jointly perform AI / ML inference, and such an AI / ML model may be referred to as a two-sided AI / ML model or a two-sided model. In this case, the UE may perform the first part of the inference first, and the base station may perform the remaining inference, and vice versa. As another example, all inference may be performed by the UE, and such an AI / ML model may be referred to as a UE-side AI / ML model or a UE-side model.

[0133] In addition, life cycle management (LCM) for AI / ML models can be performed. Life cycle management may include model training, model deployment, model inference, model monitoring, and model updating. To this end, support may be required for data collection, model training, functionality / model identification, model delivery / transfer, model inference operations, functionality / model selection / enable / disable / fallback, functionality / model monitoring, model updating, and UE capabilities.

[0134] For example, AI / ML technology can be operated based on a functional framework such as FIG. 8. FIG. 8 illustrates an example of a functional framework for the application of AI / ML technology applicable to the present disclosure. First, a data collection function (810) generates training data (801), monitoring data (803), and / or inference data (805) containing processed input data by performing data preparation on input data collected from objects (e.g., UE, RAN node, network node, etc.). A model training function (820), having received the training data (801) from the data collection function (810), performs training on an AI / ML model using the training data (801) and provides the trained / updated model (813) to a model repository (840). The model repository (840) can store and retain the received trained / updated model (813).

[0135] A management function (830) may be used to control AI / ML model training. The management function (830) may control the operation of AI / ML models or AI / ML functions, or supervise their performance. To this end, the management function (830) may receive monitoring data (830) from the data collection function (810) and receive inference output (809) from the inference function (840). The management function (830) performs the role of managing the inference operation so that it can be performed efficiently based on the data received from the data collection function (810) and the inference function (840). That is, the management function (830) may transmit performance feedback or a retraining request (807) to the model training function (820) to improve the inference operation. Here, the performance feedback may be used to direct the learning goal or as a reward for reinforcement learning. Additionally, the management function (830) can provide management instructions (811) that instruct the inference function (840) to select AI / ML models or AI / ML-based functions to use, enable / disable them, or switch to non-AI / ML operations.

[0136] The inference function (840) generates an inference output (809) by performing inference and / or prediction using inference data (805) received by the data collection function (810). Here, the inference output (809) refers to the inference output of the AI / ML model used by the inference function (840), and the details of the inference output may vary depending on the use case. The AI / ML model used by the inference function (840) can be controlled by the management function (830). That is, the management function (830) can transmit a model transmission / delivery request signal (815) to the model repository function (850) to request the necessary AI / ML model, and the model repository function (850) can transmit the corresponding AI / ML model to the inference function (840) via a model transmission / delivery signal (817). Thus, the inference function (840) can perform inference using the AI / ML model (817) according to the received management instructions (811).

[0137] Additionally, the management function (830) can trigger or perform a specified task / action based on the inference output (809). Thus, the management function (830) can trigger a task / action on other objects (e.g., at least one UE, at least one RAN node, at least one network node, etc.) or on itself. Any one of the functions exemplified in FIG. 8 described above may be performed by two or more entities among the RAN, network node, network operator's OAM, or UE in collaboration. This may be referred to as a split AI operation.

[0138] To use an AI / ML model, not all of the functions (810 to 850) illustrated in FIG. 8 must be used, and the method of combining them is not limited to a specific method. Therefore, the functions (810 to 850) may be operated in an integrated manner, or some functions may be omitted. Furthermore, the functions (810 to 850) illustrated in FIG. 8 are not necessarily limited to being implemented as separate devices or apparatuses. For example, some or all of the functions (810 to 850) may be included in the processor (202) of FIG. 2. Additionally, the model storage function (850) may be included in the memory (204) of FIG. 2.

[0139] FIG. 9 illustrates an example of a procedure for utilizing an AI model applicable to the present disclosure. FIG. 9 illustrates a case where a model training function (820) is included in a network node and a model inference function (840) is included in a RAN node. Referring to FIG. 9, in step 1, RAN node 1 and RAN node 2 transmit input data (e.g., training data) for training an AI model to a network node. Here, RAN node 1 and RAN node 2 may also transmit data collected from a UE (e.g., UE measurements related to RSRP, RSRQ, SINR of a serving cell and neighboring cells, UE location, velocity, etc.) to the network node. In step 2, the network node trains the AI ​​model using the received training data. In step 3, the network node distributes / updates the AI ​​model to RAN node 1 and / or RAN node 2. RAN node 1 and / or RAN node 2 may continue to perform model training based on the received AI model. In this procedure, it is assumed that the AI ​​model is deployed / updated only to RAN Node 1. In Step 4, RAN Node 1 receives input data (e.g., inference data) for AI model inference from the UE and RAN Node 2. In Step 5, RAN Node 1 generates output data (e.g., prediction or decision) by performing AI model-based inference using the received inference data. In Step 6, if applicable, RAN Node 1 may transmit model performance feedback to the network nodes. In Step 7, RAN Node 1, RAN Node 2, and the UE (or 'RAN Node 1 and UE', or 'RAN Node 1 and RAN Node 2') perform an action based on the output data. For example, in the case of a load balancing action, the UE may move from RAN Node 1 to RAN Node 2. In Step 8, RAN Node 1 and RAN Node 2 transmit feedback information to the network nodes.

[0140] Network nodes can manage AI models based on feedback information regarding the inference results of AI models. For example, network nodes can perform additional training on AI models or generate additional information about AI models (e.g., performance information, accuracy information, etc.). If additional training is performed on AI models, network nodes can distribute the updated AI models to RAN node 1.

[0141] As explained with reference to Fig. 9, model training can be performed by network nodes, and inference using the model can be performed by RAN node 1. In other words, the model training and inference functions can be distributed. Generally, model training requires a large amount of computational resources because it involves optimization using large amounts of data and complex algorithms. In contrast, inference is a process of drawing conclusions about new data using an already trained model, and therefore requires relatively fewer computational resources compared to model training. Therefore, by using the procedure of Fig. 9, model training can be performed through network nodes if the computational resources of the UE or RAN nodes are insufficient. Additionally, security regarding the AI ​​model can be ensured because the AI ​​model is not exposed to the UE.

[0142] FIG. 9 illustrates a case where the model training function (820) is included in a network node and the model inference function (840) is included in a RAN node, but the present disclosure is not limited thereto. For example, if the computational resources of the RAN node are sufficient, both the model training function (820) and the model inference function (840) may be included in RAN node 1. In this case, RAN node 1 receives training data for training an AI model from the UE and RAN node 2. RAN node 1 trains the AI ​​model using the received training data. Subsequently, RAN node 1 receives inference data for AI model inference from the UE and RAN node 2. RAN node 1 generates output data by performing AI model-based inference using the received inference data. Based on the output data, the UE, RAN node 1, and RAN node 2 can perform communication-related operations (e.g., handover, cell change). Subsequently, the UE and RAN node 2 can transmit feedback regarding the operations to RAN node 1. Therefore, RAN Node 1 can train the AI ​​model and update the AI ​​model it will use through feedback information regarding the inference results of the AI ​​model. According to the aforementioned method, since signaling with the network is not required for AI model training and inference, the network load or the latency to train the AI ​​model or receive inference results can be reduced. Additionally, since the UE performs inference using the AI ​​model, the UE's personal information is not transmitted to network nodes, etc. Consequently, security regarding personal information can be enhanced.

[0143] As another example, the model training function (820) may be included in the RAN node, and the model inference function (840) may be included in the UE. The RAN node receives training data for training an AI model from the UE and trains the AI ​​model using the received training data. The RAN node distributes the trained AI model to the UE. The UE can generate output data by performing inference based on the received AI model. At this time, the data for inference can be received from the RAN node or data acquired by the UE itself can be used. The UE and the RAN node can perform communication-related operations based on the output data generated by inference. Subsequently, the UE can send feedback regarding the operation to the RAN node. Thus, through feedback information regarding the inference results of the AI ​​model, the RAN node can train the AI ​​model and distribute the updated AI model to the UE. According to the method described above, the load on the RAN node can be reduced by having the model training function (820) in the RAN node and the model inference function (840) in the UE perform inference. In addition, if the UE performs inference using data acquired independently, even if the UE loses its connection to the RAN node after receiving the AI ​​model, the UE can continue to perform inference using the received AI model and operate based on the inference results.

[0144] According to the aforementioned framework and procedure, an AI model can be trained and utilized in a wireless communication system. The model training function (820) and the model inference function (840) can be combined in various ways and are not necessarily limited to the case of FIG. 9. In the aforementioned framework and procedure, various data such as input data, training data, and inference data are introduced, and the specific details of the aforementioned data may vary depending on the task in which the AI ​​model is utilized. For example, information used in the various embodiments of the present disclosure described below may be included in the aforementioned data.

[0145] FIG. 10 illustrates an AI technology-based communication procedure applicable to the present disclosure. The detailed procedure illustrated in FIG. 10 may be combined with various embodiments of the present disclosure described below. For example, data generated according to various embodiments of the present disclosure may be used for operations (e.g., setup, training, inference, and / or data transmission / reception) in at least one of the detailed procedure illustrated in FIG. 10. As another example, the result of the inference illustrated in FIG. 10 may be used to transmit and / or receive data according to various embodiments of the present disclosure.

[0146] Referring to FIG. 10, in step S1001, at least one of the UE (1010), RAN node (1020), and network node (1030) performs an initial connection procedure. For example, in this step, at least one of an initial cell search operation, a system information acquisition operation, a random access operation, and a registration operation may be performed. In step S1003, at least one of the UE (1010), RAN node (1020), and network node (1030) performs a configuration procedure. Through the configuration procedure, parameters, resources, connections, and / or entities necessary to perform subsequent procedures at layers between the UE (1010) and the RAN node (1020) and / or at least one layer between the UE (1010) and the network node (1030) may be determined and / or created. At this time, the configuration procedure may be performed based on information, status, and / or characteristics of the AI ​​model used for subsequent training and inference.

[0147] In step S1005, at least one of the UE (1010), RAN node (1020), and network node (1030) performs a model training procedure. At least one of the UE (1010), RAN node (1020), and network node (1030) may collect training data and perform training using the training data. For example, the model training procedure may be performed as described with reference to FIG. 9. If an offline trained model is used, this step may be omitted.

[0148] In step S1007, at least one of the UE (1010), RAN node (1020), and network node (1030) performs a task using a trained model. That is, the task may be performed by the result of inference and / or prediction using the trained model. For example, the task may be a procedure belonging to a communication protocol, a preliminary operation for subsequent data transmission and / or reception, related to data transmission and / or reception, or related to data processing (e.g., encoding, decoding, etc.).

[0149] In step S1009, at least one of the UE (1010), RAN node (1020), and network node (1030) transmits and / or receives data. At this time, the result of the task performed in step S1007 may be used. In some cases, the task performed in step S1007 may include the transmission and / or reception of data, in which case this step may be omitted as it is part of step S1007.

[0150] Specific embodiments of the present disclosure

[0151] The present disclosure proposes a method for efficiently performing quantum communication through an intermediate node in quantum communication. By using the method proposed in the present disclosure, quantum communication can be performed with a device that does not possess all quantum capabilities. The present disclosure allows the receiving node to perform a key distribution procedure using a signal received from the transmitting node without using a laser source. By using the method proposed in the present disclosure, the transmitting node transmits a single state of a specific basis to the receiving node, and the receiving node performs a bit flip of that state, thereby replacing the receiving node generating the state of the corresponding basis using a laser source. Therefore, by using the method proposed in the present disclosure, quantum key distribution can be performed even when the receiving device does not have an entanglement source and a laser source.

[0152] Semiquantum key distribution (SQKD) is a protocol that sets constraints on a classical party; conventional technology sets constraints on the types of quantum states that a classical party can generate, the types of quantum states that can be measured, and the presence or absence of measurement capability. This disclosure proposes a method for configuring a measurement device-independent semiquantum key distribution (MDI SQKD) protocol under conditions where the classical party lacks a laser source. First, the basic characteristics of quantum communication are described below.

[0153] Classical computers have an internal processing unit, and the basic unit of computation is the bit, which exists in two states: 0 and 1. Meanwhile, in quantum mechanics, multiple states can be superimposed on a single quantum, and quantum computers utilizing this principle are being researched. The quantum bit used in quantum computers is referred to as a qubit (quantum bit) to distinguish it from the bits of classical computers. In other words, a single quantum can possess both a 0 state and a 1 state. However, when measuring a quantum in a superposition state, it decays into one of the superimposed states, resulting in a state of either 0 or 1.

[0154] To represent qubits in quantum systems, a method for representing superimposed quantum states is required. One method for representing quantum states is Dirac notation. Dirac notation can also be referred to as bra-ket notation.

[0155] Ket can represent the quantum state Ψ and can be expressed in the form |Ψ〉. Bra represents the complex conjugate transpose of Ket and can be expressed in the form <φ|. Therefore, <φ| and |φ〉 form a complex conjugate transpose relationship.

[0156] The inner product between two states can be calculated by combining Bra-kets. For example, the inner product between two states |Ψ〉 and |φ〉 can be expressed in the form <Ψ|φ〉. Furthermore, it can be assumed that all quantum states are normalized. That is, a set of state functions satisfying <Ψ|Ψ〉=1 can be defined. This set is defined as a Hilbert space. Additionally, two quantum states in a Hilbert space for which the Bra-ket result is 0 can be defined as orthogonal. Therefore, when <Ψ|φ〉=0, the relationship between the |Ψ〉 state and the |φ〉 state is orthogonal.

[0157] Entanglement

[0158] Entanglement is a property that plays a very important role in distinguishing quantum systems from classical information. Entanglement refers to a state where the results of different observations are closely related to each other. The entangled state in a quantum system acts more strongly than any correlation existing in classical mechanics. Two qubits can be represented in Hilbert space as a superposition of the four fundamental quantum states. Here, the four fundamental quantum states are It includes. The fundamental quantum states of two qubits can be represented through tensor operations on the fundamental states of individual qubits. When the states of two qubits cannot be represented by the tensor product of a single qubit, such qubit states are called entangled states. As representative examples of entangled qubits, there are four cases referred to as EPR (Einstein-Podolsky-Rosen) states, which are as shown in [Equation 1] below.

[0159]

[0160] In [Mathematical Formula 1] It can be used when transmitting classical information 00, and It can be written as, It can be used when transmitting classical information 10, and It can be written as, It can be used when transmitting classical information 01, and It can be written as, It can be used when transmitting classical information 11, and It can be denoted as such. The matching relationship between quantum states and classical information can be defined differently from what was previously described.

[0161] The above EPR state is also called the Bell state, and in each qubit, the measurement result of the qubit located ahead always affects the measurement of the qubit located behind. In addition, the above four pure states are all maximally entangled states and form the vertical basis of the 2-qubit Hilbert space.

[0162] For entangled qubits with M > 2 qubits or more, the GHZ state is as follows [Equation 2].

[0163]

[0164] In [Mathematical Formula 2], represents the tensor product operator.

[0165] When M=2 It becomes a bell state, and generally, the GHZ state is expressed for M=3. Sometimes, the GHZ state can be extended to be expressed as a system corresponding to d-dimension rather than 2-dimension.

[0166] The decay of quantum information by measurement

[0167] Quantum information exists probabilistically, and at the moment of measurement, it decays into the ground state and cannot be restored to its state before measurement. The quantum information after measurement by the measurement operator is probabilistic. and Depending on the, it collapses into one of the underlying states that make up the information. The collapsed information does not contain the information of 'a' or 'b' and cannot return to the state before measurement.

[0168] From the perspective of quantum error correction codes, in order to apply quantum error correction codes in a quantum information system, codewords must be generated without measuring information or without measurements that would alter the information during the process of encoding and restoring information, and information must be restored after estimating the error that occurred in the channel. In information communication, as shown in Fig. 11, three properties of quantum information—superposition, entanglement, and the influence of observation—can be utilized.

[0169] FIG. 11 illustrates three basic properties of quantum information that can be used in information communication applicable to the present disclosure. Superposition is a property in which quantum information exists probabilistically before measurement. At the moment of measurement, quantum information collapses into an instantaneous ground state due to the influence of observation and cannot be restored to the state before measurement. In addition, due to entanglement, if a qubit of one system is measured, information about a qubit of another system can also be known. For example, after measurement, quantum information collapses into a ground state A with probability |a|2 and a ground state B with probability |b|2. Therefore, the collapsed information only contains information about A or B, does not contain superposition of the information of A and B, and cannot return to the state before measurement.

[0170] quantum teleportation (QT)

[0171] Quantum teleportation is a technology that transmits quantum information from a sender at a specific location to a receiver located at a certain distance. Unlike traditional transmission, which transmits actual carriers, quantum teleportation performs the transmission of quantum information while the carriers on both sides remain fixed. For this transmission of quantum information, an entangled quantum state, or Bell state, is required. Using Bell states allows for the assumption of statistical correlations between distinct physical systems. Because the other particle undergoes the same change for every change experienced by one of the two entangled particles, the two particles can be interpreted as behaving as if they were a single quantum state.

[0172] FIG. 12 illustrates an example of a quantum transmission protocol according to one embodiment of the present disclosure. For quantum transmission, a classical channel capable of transmitting two classical bits, an entanglement state (e.g., Bell state) generating device, a quantum channel for moving two particles in an entanglement state to a transmitting and receiving device at different locations, a Bell state measuring device at the transmitting end, and a unitary computing device at the receiving end are required. As an example, the classical channel may be a wireless channel of a wireless communication system, and the bit transmitted through the wireless channel may be a classical bit. As another example, the classical channel may be a wired channel of a wired communication system. However, in the following description, to clarify the difference between the quantum channel and the existing communication channel, they are referred to as a classical channel and a classical bit, but are not limited thereto. That is, the classical channel may be any channel for transmitting data.

[0173] Additionally, the following describes a method for performing bidirectional communication between the first device (1210) and the second device (1220), and the devices may not be limited to a specific form.

[0174] For example, quantum information to be transmitted The quantum transfer protocol for can be represented as follows.

[0175] - Entanglement generation: Generates an entangled state of two qubits through a Bell state generator.

[0176] - Entanglement distribution: The generated entangled qubits are moved through a quantum channel, with one qubit going to the first transmitter device (1210) and the other qubit going to the second receiver device (1220).

[0177] - Quantum pre-processing: The first device (1210) measures the Bell state for one qubit of the Bell state it possesses and the quantum state |φ〉 to be transmitted. Thus, the first device (1210) can obtain a result corresponding to one of the Bell states. At this time, the qubit state of the second device (1220) regarding the result of the Bell state measurement by the first device (1210) is as shown in [Table 2] below.

[0178] BSM Results of and Alice's QubitBob's Qubit

[0179] - Classical Transmission: The first device (1210) encodes the Bell state measurement result into two classical bits and transmits it to the second device (1220). - Quantum Post-processing: The second device (1220) can obtain a quantum state identical to the quantum information |φ〉 that the first device (1210) intends to transmit by performing a unitary operation on the remaining qubit of the Bell state it possesses using the two classical bits received from the first device (1210). Quantum Direct Communication (QDC): Quantum direct communication is a method for securely transmitting classical message information to be transmitted. It shares similarities with, but also has differences from, the quantum key distribution (QKD) technology used as a 4G or 5G secure communication technology. Quantum key distribution technology is a method of sharing symmetric secret key information between the sender and receiver using the non-cloning characteristic of quantum mechanics to securely transmit message information transmitted over a classical channel. On the other hand, direct quantum communication is a method of sharing classical message information directly through a quantum channel without a secret key.

[0180] Among quantum direct communications, quantum secure direct communication (QSDC) is a technology that guarantees high stability as it does not generate leakage information related to transmitted information, and a 2-step quantum secure direct communication technique utilizing entangled light sources is being researched. 2-step quantum secure direct communication can be performed based on super dense coding.

[0181] Super dense coding is a technique that can safely transmit classical information using quantum communication, and is a technique that can stably transmit 2 bits of classical information using four types of single entangled photons (hereinafter EPR-pair) of [Equation 3] below.

[0182]

[0183] When using super-dense coding, the transmitter can transmit 2 bits of classical information to the receiver via a quantum channel using a single qubit. First, two qubits in an entangled state are generated. The transmitter possesses the first qubit in the entangled state, and the receiver possesses the second qubit in the entangled state. There are four possible cases for the qubit that the transmitter intends to transmit: '00', '01', '10', and '11'. For these four cases, the transmitter performs a qubit operation corresponding to each of the four cases on the entangled qubit it possesses, and then transmits the result through the quantum channel. At this time, the qubit operation can be expressed in the form of I, Z, X, and iY. Each operation performed by the transmitter can serve to change the entangled state shared by the transmitter and the receiver into a different basis form that is orthogonal to each other. Therefore, the receiver measures the qubit it possesses to recover the 2 bits of information transmitted by the transmitter.

[0184] FIG. 13 illustrates an example of transmitting quantum information in two-step quantum secure direct communication according to one embodiment of the present disclosure. In FIG. 13, SR 1 to SR 4 are optical delay lines that serve as quantum memory. CE (checking eavesdropping) 1 and CE 2 are devices that check for the presence of an eavesdropper. CM (coding message) is a device that encodes classical message information to be transmitted from the transmitting end (1310) to the receiving end (1320). EPR source is a device that generates an entangled light source in an EPR state, and bell state measurement is a device that measures entangled photon pairs. Additionally, in quantum communication, the transmitting end (1310) may be referred to as the first device (1310) or Alice, and the receiving end (1320) may be referred to as the second device (1320) or Bob, and the same notation may be used below.

[0185] In Two-Step Quantum Secure Direct Communication, unlike Superdense Coding, entangled photon pairs are not transmitted all at once to ensure security; instead, they are divided into two stages and transmitted through an upper quantum channel and a down quantum channel. For an eavesdropping session on an entangled light source, an eavesdropper must know the information from both ends of the entangled photon pair to determine the transmitted information through measurement. To prevent eavesdropping, Two-Step Quantum Secure Direct Communication utilizes a method where one side of the entangled photon pair is transmitted first, and its security against eavesdropping is verified. Once security is guaranteed, the remaining part of the photon pair, which contains the message information to be sent, is then transmitted.

[0186] For convenience of explanation, the device sending data will be referred to as the transmitting node, the device receiving data as the receiving node, and any node involved in data communication other than the transmitting and receiving nodes will be referred to as a node. In quantum communication, the transmitting node may be referred to as Alice, the receiving node as Bob, and the intermediate node as Charlie. Furthermore, in this disclosure, the meaning of a specific node disclosing information is that the information can be obtained by other nodes. The method of obtaining the information is not limited to a specific method. For example, if an intermediate node discloses information A, the intermediate node may directly transmit information A to the receiving node and the transmitting node. As another example, the intermediate node may transmit information A to the control node, and the control node may transmit information A to the transmitting node and the transmitting node. Information A does not necessarily have to be transmitted via a quantum channel and may be delivered via a classical channel. In the following, the disclosed information refers to information that, even if obtained by an eavesdropper, cannot know the message the transmitting node intends to send, and it is assumed that it is transmitted through a classical channel rather than a quantum channel.

[0187] The MDI SQKD (measurement device independent semiquantum key distribution without) protocol is a protocol that enables a key distribution protocol independent of measurement results in situations where the transmitting node possesses quantum capabilities, but the transmitting node does not possess all quantum capabilities. When using the SQKD protocol, communication devices can be implemented more easily because the devices participating in the communication do not need to possess all quantum capabilities. The MDI SQKD protocol is described below.

[0188] MDI SQKD protocol

[0189] For the sake of convenience of explanation, it is assumed below that qubits in the SQSDC protocol are transmitted using polarized single photons.

[0190] FIG. 14 illustrates an example of an apparatus for performing an MDI SQKD protocol according to one embodiment of the present disclosure. Referring to FIG. 14, a transmitting node (1410) and a receiving node (1420) can transmit a signal for measurement including a photon qubit in quantum communication. For convenience of explanation in the present disclosure, it is assumed that the quantum state is transmitted using photons.

[0191] The transmitting node (1410) may include a laser (1411), an intensity modulator (IM) (1412), and a polarization modulator (PM) (1413).

[0192] A laser (1411) can generate a single photon qubit. A transmitting node (1410) can generate a photon qubit using the laser (1411), and the photon qubit can be generated in an X-base or Z-base state.

[0193] The intensity modulator (1412) can adjust the amplitude or intensity of a single qubit generated by the laser (1411), and the phase modulator (1413) can adjust the phase of the output signal of the intensity modulator (1412). At least one photon qubit generated by the laser (1411) can be transmitted to an intermediate node (1430) through the intensity modulator (1412) and the phase modulator (1413). Additionally, the photon qubit generated by the laser (1411) can be transmitted to a receiving node (1420).

[0194] The receiving node (1420) may include a laser (1421), an intensity modulator (1422), and a phase modulator (1423). The receiving node (1420) may generate a single photon qubit using the laser (1421). Here, a single qubit sequence may be formed including a single photon qubit received from the transmitting node (1410) and a single photon qubit of the receiving node (1420), and the qubit sequence may be transmitted to the intensity modulator (1422).

[0195] The intensity modulator (1422) can adjust the amplitude or intensity of a single photon qubit or sequence of qubits generated by the laser (1421). The phase modulator (1423) can adjust the phase of the output signal of the intensity modulator (1422). At least one photon qubit generated by the laser (1421) can be transmitted to an intermediate node (1430) through the intensity modulator (1422) and the phase modulator (1423).

[0196] The intermediate node (1430) may include a beam splitter (1431) and polarization beam splitters (1432, 1433). The beam splitter (1431) can split an incident optical signal into two or more paths and transmit them to two polarization beam splitters (1432, 1433). The intermediate node (1430) and the two polarization beam splitters (1432, 1433) can split the beam according to the polarization of the optical signal received through the beam splitter (1431) and obtain measurement results including what quantum state it has depending on which detector it is measured by.

[0197] The MDI SQKD protocol may perform the process described in Step 1-1 to Step 1-6 below.

[0198] Step 1-1: Preparation Phase

[0199] The first step of the MDI SQKD protocol is that the sending node After generating single qubits, the generated qubits are transmitted to the receiving node. Here, n represents an arbitrary constant and represents the number of bits obtained as the final key. δ is a fixed parameter for redundancy and can have a value less than 1.

[0200] Each single qubit can have one of the states expressed in [Equation 4] below.

[0201]

[0202] That is, the single qubits generated by the transmitting node have one of a total of four states and can be measured as one of a total of two bases. Here and are the states of the Z basis, and , These are the states of the X basis. In the present disclosure, the Z basis may be referred to as the first basis, and the X basis may be referred to as the second basis.

[0203] The receiving node received For each of the individual qubits, either a DAP operation or a CTRL operation is performed. If a DAP operation is performed, the receiving node removes the state of the received qubit and transmits the qubit with the new state to the intermediate node. If a CTRL operation is performed, the receiving node transmits the received quantum state as is to the intermediate node. The qubit transmitted by the receiving node to the intermediate node via the DAP or CTRL operation We will refer to the single qubits as the PB batch.

[0204] Afterwards, the transmitting node 1 single qubits are randomly prepared and transmitted to the intermediate node. At this time, the single qubits can have any of the four states as shown in [Equation 4] above. In the third step, the qubits sent by the transmitting node are P A It will be referred to as a batch.

[0205] Step 1-2: Measurement Step

[0206] The intermediate node receives qubits from the transmitting node and the receiving node (i.e., P A Batch and P B Performs a bell state measurement using a batch and discloses the measurement result. The intermediate node discloses which qubit pairs were successfully measured, and if the measurement was successful, discloses the corresponding measurement result. Here, the measurement result is or It will appear as one of them.

[0207] Step 1-3: Key saving step

[0208] After the measurement results are disclosed by the intermediate node, the receiving node discloses to the transmitting node which qubits were subjected to the DAP operation. The transmitting node discloses to the receiving node which qubits share the same basis.

[0209] All measurement results regarding the qubits transmitted by the transmitting node and the receiving node can be represented as shown in [Table 3] below.

[0210] Alice to CharlieCaseBob to CharlieCharlie's resultDescription 1 or Generate raw key2 or Test errors3 Abandon the data4 Abandon the data5 Abandon the data6 Abandon the data 7 Abandon the data8 Abandon the data9 or Generate raw key10 or Test errors11 Abandon the data12 Abandon the data 13 Abandon the data14 Abandon the data15 Abandon the data16 Abandon the data17 Test errors18 Test errors 19 Abandon the data20 Abandon the data21 Abandon the data22 Abandon the data23 Test errors24 Test errors

[0211] The receiving node uses the corresponding qubit to store the raw key only in cases corresponding to case 1 and case 9 of [Table 3]. At this time, the receiving node flips and stores the state of the qubit it generated to create the same state as the transmitting node. Step 1-4: First Security Inspection Step

[0212] Check the error rate for Case 2, Case 10, Case 17, Case 18, Case 23, and Case 24 in [Table 3], and the error rate is the threshold If it is larger, discard the protocol.

[0213] Step 1-5: Second Security Inspection Phase

[0214] The transmitting node selects n bits from the raw key to be used as test bits. The transmitting node discloses the locations of the n test bits, and the receiving node discloses the values ​​of the bits at those locations. If the calculated error rate If it is larger, discard the protocol.

[0215] Step 1-6: Key Extraction Step

[0216] The transmitting and receiving nodes select n bits to be used as information bits, and through error correction code and privacy amplification (PA) processes, finally obtain a key consisting of m bits. Here, m is a number smaller than n.

[0217] FIG. 15 illustrates an example of signaling for performing an MDI SQKD protocol according to an embodiment of the present disclosure. In FIG. 15, a quantum channel refers to a channel through which qubits are transmitted. In FIG. 15, it is assumed that information transmitted to an intermediate node through a classical channel can be disclosed to a transmitting node or a receiving node.

[0218] Referring to FIG. 15, in step S1501, the transmitting node (1510) transmits single qubits to the receiving node (1520). Here, the single qubits are generated based on a first basis and a second basis. It may include qubits. The first basis may be referred to as the Z basis, and the second basis as the X basis.

[0219] In step S1503, the transmitting node (1510) transmits a PA batch to the intermediate node (1530). Here, P A The batch is generated based on the first basis and the second basis. It can include qubits.

[0220] In step S1505, the receiving node (1520) tells the intermediate node (1530) P B Transmits the batch. P B A batch can be generated by performing a DAP operation or a CTRL operation based on single qubits received from the transmitting node in step S1501. A DAP operation refers to an operation in which the receiving node (1520) removes the state of any qubit among the qubits received from the transmitting node (1510) and transmits it to the intermediate node (1530) to have a new state. A CTRL operation refers to an operation in which the receiving node (1520) transmits any qubit among the qubits received from the transmitting node (1510) to the intermediate node (1530) as is.

[0221] In step S1507, the transmitting node (1510), the intermediate node (1530), and the receiving node (1520) perform a measurement procedure. The intermediate node receives P A Batch and P B A Bell-base measurement is performed using a batch. The intermediate node (1530) can then disclose the measurement results. Thus, the intermediate node (1530) can transmit the measurement results to the transmitting node (1510) and the intermediate node (1530).

[0222] In step S1509, the receiving node (1520) transmits the location where the DAP operation was performed to the intermediate node (1530). Subsequently, the intermediate node (1530) may transmit the location where the DAP operation was performed to the transmitting node (1510).

[0223] In step S1511, the transmitting node (1510) transmits information related to the basis to the intermediate node (1530). Here, the information related to the basis may include an index indicating the qubits whose basis matches. The transmitting node (1510) can determine which qubits' basis has been measured to be in the same state based on the location where the DAP operation was performed. The intermediate node (1530) can transmit the information related to the basis to the receiving node (1520). Thus, the transmitting node (1510) can transmit an index indicating the qubits whose basis matches to the receiving node (1520).

[0224] In steps S1513 and S1515, the transmitting node (1510) and the receiving node (1520) transmit the error rate to the intermediate node (1530). The error rate can be measured based on the above [Table 3], and the error rate If the error rate is higher, the intermediate node (1530) discards or stops the protocol. Although the present disclosure exemplifies the intermediate node (1530) receiving the error rate and deciding to discard or stop the protocol, it is not limited thereto. As an example, the transmitting node (1510) may receive the error rate from the receiving node (1520) and declare the discarding or stopping of the protocol.

[0225] In step S1517, the transmitting node (1510) transmits the location of the test bits to the intermediate node. The test bits may consist of at least one bit among the bits included in the raw key. Here, the raw key may be determined by the transmitting node (1510) and the intermediate node (1530) based on [Table 3].

[0226] In step S1519, the receiving node (1520) transmits the bit values ​​of the test bits included in the raw key to the intermediate node (1530). The intermediate node (1530) transmits the bit values ​​of the test bits to the transmitting node (1510). The transmitting node (1510) can derive the error rate of the test bits by comparing the bit values ​​of the test bits, and if the derived error rate is higher than a preset value, it discards or stops the protocol.

[0227] In steps S1521 and S1523, the transmitting node (1510) and the receiving node (1520) transmit the final key to the intermediate node (1530). The final key can be obtained by performing error correction code and privacy amplification procedures using the information bits among the bits included in the raw key.

[0228] By utilizing the aforementioned MDI SQKD protocol, security keys can be shared regardless of detection results. Since detectors are the devices most susceptible to attack, the ability to perform communication independent of detection results means that communication can be conducted securely against a large number of detector attacks. Below, we will describe the MDI SQKD protocol for the case where the receiving node does not have a laser source.

[0229] FIG. 16 illustrates an example of an apparatus for performing an MDI SQKD protocol according to one embodiment of the present disclosure. Referring to FIG. 16, a transmitting node (1610) and a receiving node (1620) can transmit a signal for measurement including a photon qubit in quantum communication. For convenience of explanation in the present disclosure, it is assumed that the quantum state is transmitted using photons.

[0230] The transmitting node (1610) may include a laser (1611), an intensity modulator (IM) (1612), and a polarization modulator (PM) (1613).

[0231] A laser (1611) can generate a single photon qubit. A transmitting node (1610) can generate a photon qubit using the laser (1611), and the photon qubit can be generated in an X-base or Z-base state.

[0232] The intensity modulator (1612) can adjust the amplitude or intensity of a single qubit generated by the laser (1611), and the phase modulator (1613) can adjust the phase of the output signal of the intensity modulator (1612). At least one photon qubit generated by the laser (1611) can be transmitted to an intermediate node (1630) through the intensity modulator (1612) and the phase modulator (1613). Additionally, the photon qubit generated by the laser (1611) can be transmitted to a receiving node (1620).

[0233] The receiving node (1620) may include an intensity modulator (1622) and a phase modulator (1623). Here, a sequence of qubits with the states and order of single photon qubits received from the transmitting node (1610) may be transmitted to the intensity modulator (1622).

[0234] The intensity modulator (1622) can adjust the amplitude or intensity of a single photon qubit or sequence of qubits generated by the laser (1621). The phase modulator (1623) can adjust the phase of the output signal of the intensity modulator (1622). At least one photon qubit generated by the laser (1621) can be transmitted to an intermediate node (1630) through the intensity modulator (1622) and the phase modulator (1623).

[0235] The intermediate node (1630) may include a beam splitter (1631) and polarization beam splitters (1632, 1633). The beam splitter (1631) may split an incident optical signal into two or more paths and transmit them to two polarization beam splitters (1632, 1633). The intermediate node (1630) and the two polarization beam splitters (1632, 1633) may split the beam according to the polarization of the optical signal received through the beam splitter (1631) and obtain measurement results including what quantum state it has depending on which detector it is measured by.

[0236] MDI SQKD protocol where the receiving node does not use a laser source

[0237] The MDI SQKD protocol may perform the process described in Steps 2-1 through 2-6 below.

[0238] Step 2-1: Preparation Phase

[0239] The transmitting node After generating single qubits, the generated qubits are transmitted to the receiving node. Here, n represents an arbitrary constant and represents the number of bits obtained as the final key. δ is a fixed parameter for redundancy and can have a value less than 1.

[0240] Each single qubit can have one of the states expressed in [Equation 5] below.

[0241]

[0242] Unlike the aforementioned Step 1-1, the single qubits generated by the transmitting node have one of a total of three states and can be measured as one of a total of two bases. Here, are the states of the Z basis, and , These are the states of the X basis. In the present disclosure, the Z basis may be referred to as the first basis, and the X basis may be referred to as the second basis.

[0243] The receiving node from the transmitting node Receives single qubits. Here, the single qubits received from the transmitting node are P B ' It will be referred to as a batch.

[0244] The receiving node is P B ' Arrange the qubits included in the batch in an arbitrary order, and perform a bit flip on the qubits at arbitrary positions. P B ' Sequence P after the qubits of the arrangement are arranged in a random order and a random bit flip is performed. B It will be referred to as a batch.

[0245] Afterwards, the transmitting node 1 single qubits are randomly prepared and transmitted to the intermediate node. At this time, the single qubits can have any of the four states as shown in [Equation 4] above. The qubits transmitted by the transmitting node to the intermediate node are P A It will be referred to as a batch.

[0246] Step 2-2: Measurement Step

[0247] The intermediate node receives qubits from the transmitting node and the receiving node (i.e., P A Batch and P B Performs a bell state measurement using a batch and discloses the measurement result. The intermediate node discloses which qubit pairs were successfully measured, and if the measurement was successful, discloses the corresponding measurement result. Here, the measurement result is or It will appear as one of them.

[0248] Step 2-3: Key saving step

[0249] After the measurement results were disclosed by the intermediate node, the transmitting node sent P to the receiving node. B 'The basis of the qubits in the batch is disclosed. The receiving node discloses to the transmitting node the order in which the received qubits were arranged. Based on the disclosed order of the qubits, the transmitting node can determine which qubits share the same basis and discloses which qubits share the same basis.

[0250] All measurement results regarding the qubits transmitted by the transmitting node and the receiving node can be represented as shown in [Table 4] below.

[0251] Alice to CharlieCaseBob to CharlieCharlie's resultDescription 1 or Generate raw key2 Abandon the data3 Abandon the data4 Abandon the data 5 Abandon the data6 or Generate raw key7 Abandon the data8 Abandon the data 9 Abandon the data10 Abandon the data11 Test errors12 Test errors 13 Abandon the data14 Abandon the data15 Test errors16 Test errors

[0252] The receiving node uses the corresponding qubit to store the raw key only in cases 1 and 6 of [Table 4]. At this time, the receiving node flips the state of the qubit it generated to create the same state as the transmitting node and stores it.

[0253] Step 2-4: First Security Inspection Step

[0254] Check the error rate for Cases 11, 12, 15, and 16 in [Table 4], and the error rate is at the threshold If it is larger, discard the protocol.

[0255] Step 2-5: Second Security Inspection Phase

[0256] The transmitting node selects n bits from the raw key to be used as test bits. The transmitting node discloses the locations of the n test bits, and the receiving node discloses the values ​​of the bits at those locations. If the calculated error rate If it is larger, discard the protocol.

[0257] Step 2-6: Key Extraction Step

[0258] The transmitting and receiving nodes select n bits to be used as information bits, and through error correction code and privacy amplification (PA) processes, finally obtain a key consisting of m bits. Here, m is a number smaller than n.

[0259] FIG. 17 illustrates an example of signaling for a receiving node to perform an MDI SQKD protocol that does not use a laser source, according to one embodiment of the present disclosure. In FIG. 17, a quantum channel refers to a channel through which qubits are transmitted. In FIG. 17, it is assumed that information transmitted to an intermediate node through a classical channel can be disclosed to a transmitting node or a receiving node.

[0260] Referring to FIG. 17, in step S1701, the transmitting node (1710) transmits single qubits to the receiving node (1720). Here, the single qubits are generated based on a first basis and a second basis. It may include qubits. The first basis may be referred to as the Z basis, and the second basis as the X basis. Here, when transmitted as the second basis, or It can be transmitted as, but in the case of transmission to the first basis, Transmitted in Roman. The qubits transmitted in step S1701 are P B It will be referred to as 'arrangement'.

[0261] In step S1703, the transmitting node (1710) tells the intermediate node (1730) P A Transmits a batch. Here, P A The batch is generated based on the first basis and the second basis. It can include qubits.

[0262] In step S1705, the receiving node (1720) tells the intermediate node (1730) P B Transmits the batch. P B A batch can be generated by randomly changing the order of single qubits received from the transmitting node in step S1701 and performing random bit flips.

[0263] In step S1707, the transmitting node (1710), the intermediate node (1730), and the receiving node (1720) perform a measurement procedure. The intermediate node receives P A Batch and P B Bell-base measurements are performed using a batch. The intermediate node (1730) can subsequently disclose the measurement results. Thus, the intermediate node (1730) can transmit the measurement results to the transmitting node (1710) and the intermediate node (1730).

[0264] In step S1709, the transmitting node (1710) tells the intermediate node (1730) P B Transmits information related to the basis of the arrangement. Subsequently, the intermediate node (1730) sends P to the receiving node (1720). B It can convey information related to the basis of the arrangement.

[0265] In step S1711, the receiving node (1720) tells the intermediate node (1730) P B Information related to the order of placement is transmitted. Subsequently, the intermediate node (1730) can transmit the location where the DAP operation was performed to the transmitting node (1710). P B Transmits information related to the order of placement.

[0266] In step S1713, the transmitting node (1710) transmits information related to the basis to the intermediate node (1730). Here, the information related to the basis may include an index indicating the qubits that match the basis. The transmitting node (1710) receives P from the receiving node. B Based on information related to the order of placement, it can be determined which qubits' basis has been measured to be in the same state. Subsequently, the intermediate node (1730) can transmit information related to the basis to the receiving node (1720).

[0267] In steps S1715 and S1717, the transmitting node (1710) and the receiving node (1720) transmit the error rate to the intermediate node (1730). The error rate can be measured based on the above [Table 4], and the error rate If the error rate is higher, the intermediate node (1730) discards or stops the protocol. Although the present disclosure exemplifies the intermediate node (1730) receiving the error rate and deciding to discard or stop the protocol, it is not limited thereto. As an example, the transmitting node (1710) may receive the error rate from the receiving node (1720) and declare the discarding or stopping of the protocol.

[0268] In step S1719, the transmitting node (1710) transmits the location of the test bits to the intermediate node. The test bits may consist of at least one bit among the bits included in the raw key. Here, the raw key may be determined by the transmitting node (1710) and the intermediate node (1730) based on [Table 4].

[0269] In step S1721, the receiving node (1720) transmits the bit values ​​of the test bits included in the raw key to the intermediate node (1730). The intermediate node (1730) transmits the bit values ​​of the test bits to the transmitting node (1710). The transmitting node (1710) can derive the error rate of the test bits by comparing the bit values ​​of the test bits, and if the derived error rate is higher than a preset value, it discards or stops the protocol.

[0270] In steps S1723 and S1725, the transmitting node (1710) and the receiving node (1720) transmit the final key to the intermediate node (1730). The final key can be obtained by performing error correction code and privacy amplification procedures using the information bits among the bits included in the raw key.

[0271] In FIG. 17, the transmission node (1710) and the reception node (1720) transmitting or receiving a specific signal do not necessarily have to be transmitted directly, but can be received through other nodes. For example, in step S1709, the transmission node (1710) sends P to the reception node (1720). B When transmitting information related to the basis of the arrangement, the transmitting node (1710) sends P to the intermediate node (1730). B Transmits information related to the basis of the arrangement, and the intermediate node (1730) sends P to the receiving node (1720). B Information related to the basis of the arrangement can be transmitted. As another example, the transmitting node (1710) discloses the location and status of the first test qubits to the third node, etc., and the receiving node (1720) can receive the disclosed information.

[0272] Additionally, information transmitted by the transmitting node (1710) and the receiving node (1720) to the intermediate node (1730) may be made public. That is, information transmitted to the intermediate node (1730) via a classical channel may refer to information directly delivered to the transmitting node (1710) or the receiving node (1720). For example, information related to the order, such as in step S1711, may not be transmitted from the receiving node (1720) to the intermediate node (1730) and then back to the transmitting node (1710), but rather the receiving node (1720) may directly transmit the information related to the order to the transmitting node (1710) via a classical channel. The method of transmitting the disclosed information may be a broadcast or unicast method, etc. The method of transmitting information transmitted to the intermediate node may be applied identically to the procedures described in this disclosure.

[0273] FIG. 18 illustrates an example in which a transmitting node transmits a data signal using the MDI SQKD protocol according to one embodiment of the present disclosure. FIG. 18 illustrates a method performed by a device that performs wireless communication (e.g., the UE (1110), RAN node (1020), network node (1030) of FIG. 10, the first device (1210), and the second device (1220) of FIG. 12). In the description with reference to FIG. 18, the operating entity is referred to as the transmitting node. For convenience of explanation, the following description assumes that an intermediate node performs the role of a base station, and the transmitting node and receiving node perform the role of a terminal, but is not limited thereto. As an example, the transmitting node may perform the role of a terminal, the receiving node may perform the role of a base station, and the intermediate node may perform the role of a repeater. The device transmitting or receiving data through quantum communication may be a receiving node or a transmitting node. Here, the receiving node may be an anti-quantum device that does not operate a laser source.

[0274] Referring to FIG. 18, in step S1801, the transmitting node performs an initial connection procedure. The transmitting node performs the initial connection procedure with the receiving node and / or intermediate node and can establish a connection with the receiving node and / or intermediate node. For convenience of explanation, the initial connection procedure between the transmitting node and the intermediate node is described, but the same method may be used for the initial connection procedure between the transmitting node and the receiving node. To perform the initial connection procedure, the transmitting node may receive system information from the intermediate node. The system information may be transmitted via the master information block (MIB) and the system information block (SIB). The initial connection procedure may include a random access procedure. Based on the system information, the transmitting node transmits a signal for initial connection (e.g., a random access preamble) to the base station and receives a response signal for the signal for initial connection from the base station.

[0275] In step S1803, the transmitting node transmits a first signal for measurement to the receiving node. The first signal may include a plurality of qubits. Each of the qubits included in the first signal may have one of the states of the first basis and the second basis. For convenience of explanation, the quantum states that can be measured by the first basis will be referred to as the first state and the second state, and the quantum states that can be measured by the second basis will be referred to as the third state and the fourth state. If a qubit included in the first signal has a state of the first basis, it may be generated to have only the first state, and if it has a state of the second basis, it may be generated to have both the third state and the fourth state.

[0276] After receiving the first signal, the receiving node arbitrarily changes the order of the qubits of the first signal and performs a bit flip on any of the qubits of the first signal. Thus, the qubits of the first signal may all remain the same, or a bit flip may be performed on at least one of the qubits of the first signal. The transmitting node transmits the first signal, on which the position change of the qubits and the bit flip have been arbitrarily performed, to the intermediate node. For convenience of explanation, the signal obtained by the position change of the qubits and the bit flip of the first signal will be referred to as the third signal below.

[0277] In step S1805, the transmitting node transmits a second signal for measurement to an intermediate node. The second signal for measurement may include the same number of qubits as the number of qubits included in the first signal. The qubits included in the second signal may have one of a first state, a second state, a third state, or a fourth state.

[0278] In step S1807, the transmitting node receives information related to the measurement results from the intermediate node. The information related to the measurement results may include the bell state measurement results for the second signal and the third signal. The information related to the measurement results may be transmitted through a classical channel.

[0279] In step S1809, the transmitting node obtains a final key based on the measurement results. The final key may include at least one bit among the bits included in the raw key. Here, the raw key may include bit values ​​corresponding to the qubits transmitted by the transmitting node. For example, if the qubit of the first state transmitted by the transmitting node and the qubit of the second state transmitted by the receiving node are successfully measured, or if the qubit of the second state transmitted by the transmitting node and the qubit of the first state transmitted by the receiving node are successfully measured, the bit values ​​of the corresponding qubits may be included in the raw key.

[0280] FIG. 19 illustrates an example in which a receiving node transmits a data signal using the MDI SQKD protocol according to one embodiment of the present disclosure. FIG. 19 illustrates a method performed by a device that performs wireless communication (e.g., the UE (1110), RAN node (1020), network node (1030) of FIG. 10, the first device (1210), and the second device (1220) of FIG. 12). In the description with reference to FIG. 19, the operating entity is referred to as the receiving node. For convenience of explanation, the following description assumes that an intermediate node performs the role of a base station and a transmitting node and a receiving node perform the role of a terminal, but is not limited thereto. As an example, the transmitting node may perform the role of a terminal, the receiving node may perform the role of a base station, and the intermediate node may perform the role of a repeater. A device that transmits or receives data through quantum communication may be a receiving node or a transmitting node. Here, the receiving node may be an anti-quantum device that does not operate a laser source.

[0281] Referring to FIG. 19, in step S1901, the receiving node performs an initial connection procedure. The receiving node performs the initial connection procedure with the transmitting node and / or intermediate node and can establish a connection with the transmitting node and / or intermediate node. Through this procedure, the receiving node can share information necessary for communication over a classical channel. The initial connection procedure may include a random access procedure.

[0282] In step S1903, the receiving node receives a first signal for measurement. The first signal may include a plurality of qubits. Each of the qubits included in the first signal may have one of the states of the first basis and the second basis. For convenience of explanation, the quantum states that can be measured by the first basis will be referred to as the first state and the second state, and the quantum states that can be measured by the second basis will be referred to as the third state and the fourth state. If a qubit included in the first signal has a state of the first basis, it may be generated to have only the first state, and if it has a state of the second basis, it may be generated to have both the third state and the fourth state.

[0283] In step S1905, the receiving node transmits a third signal to the intermediate node, which is obtained by position change and bit flipping for the qubits included in the first signal. Thus, all qubits of the third signal remain the same as the initial state, or a bit flip may be performed on at least one of the qubits of the third signal.

[0284] In step S1907, the receiving node receives information related to the first measurement result from the intermediate node. The information related to the measurement result may include the bell state measurement results for the second signal and the third signal. The information related to the measurement result may be transmitted through a classical channel. Here, the second signal is a signal transmitted by the transmitting node to the intermediate node. The qubits included in the second signal may have one of the first state, the second state, the third state, or the fourth state.

[0285] In step S1909, the transmitting node receives information related to the measurement results from the intermediate node. The information related to the measurement results may include the bell state measurement results for the second signal and the third signal. The information related to the measurement results may be transmitted through a classical channel.

[0286] In step S1911, the receiving node obtains a final key based on the measurement results. The final key may include at least one bit among the bits included in the raw key. Here, the raw key may include bit values ​​corresponding to the qubits transmitted by the transmitting node. For example, if the qubit of the first state transmitted by the transmitting node and the qubit of the second state transmitted by the receiving node are successfully measured, or if the qubit of the second state transmitted by the transmitting node and the qubit of the first state transmitted by the receiving node are successfully measured, the bit values ​​of the corresponding qubits may be included in the raw key.

[0287] FIG. 20 illustrates an example in which a transmitting node obtains a final key using the MDI SQKD protocol according to one embodiment of the present disclosure. FIG. 20 illustrates a method performed by a device performing wireless communication (e.g., the UE (1110), RAN node (1020), network node (1030) of FIG. 10, the first device (1210), and the second device (1220) of FIG. 12). In the description with reference to FIG. 20, the operating entity is referred to as the transmitting node. For convenience of explanation, the following description assumes that an intermediate node performs the role of a base station, and the transmitting node and receiving node perform the role of a terminal, but is not limited thereto. As an example, the transmitting node may perform the role of a terminal, the receiving node may perform the role of a base station, and the intermediate node may perform the role of a repeater. A device that transmits or receives data through quantum communication may be a receiving node or a transmitting node. Here, the receiving node may be an anti-quantum device that does not operate a laser source. In FIG. 20, it is assumed that the transmitting node transmits a first signal containing a plurality of qubits to a receiving node and transmits a second signal containing a plurality of qubits to an intermediate node. Here, it is assumed that the qubits included in the first signal are generated in one of the first state of the first basis, the third state of the second basis, or the fourth state of the second basis, and are not generated in the second state of the first basis.

[0288] Referring to FIG. 20, in step S2001, the transmitting node transmits information regarding the basis of the qubits included in the first signal to the receiving node. The information regarding the basis can be transmitted through index values ​​in the order of the qubits included in the first signal.

[0289] In step S2003, the transmitting node receives information from the receiving node regarding the order of the qubits included in the third signal. The information regarding the order of the qubits included in the third signal may indicate information regarding the order in which the receiving node arranged the qubits of the first signal. Since the transmitting node generated the first signal, it can determine the states of the qubits of the third signal even if it only receives information regarding the order.

[0290] In step S2005, the transmitting node transmits information related to qubits with matching bases. The transmitting node can determine the bases of the qubits included in the third signal transmitted by the receiving node based on information related to the order. If two qubits of the same base are measured through bell state measurement, they may be considered validly measured. Therefore, information related to qubits with matching bases can be transmitted for the qubits included in the second signal transmitted by the transmitting node to the intermediate node and the third signal transmitted by the receiving node to the intermediate node. Here, information related to qubits with matching bases can be indicated by an index value.

[0291] In step S2007, the transmitting node performs a first security check and obtains a raw key. Among the qubits that successfully measured, the qubits with matching bases may be used for the first security check or as a raw key.

[0292] Specifically, among the qubits with matching bases that have been successfully measured, the qubits generated from the second basis can be used for security verification. Therefore, a first security verification can be performed by comparing the measurement error rate of the qubits generated from the second basis with a preset error rate. If the first security verification is not passed, the currently running quantum protocol may be terminated. If the first security verification is passed, the transmitting node can obtain the raw key using the qubits generated from the first basis among the qubits with the same basis that have been successfully measured.

[0293] In step S2009, the transmitting node performs a second security check. The second security check may be performed based on the error rate of the test bits. In this case, the test bits may include at least one bit among the bits included in the raw key obtained in step S2007. The transmitting node and the receiving node can determine the error rate and determine whether the second security check is satisfied by comparing the test bits. Information regarding the test bits may be transmitted in various ways. For example, the transmitting node transmits information related to the location of the test bits to the receiving node, and the receiving node transmits the bit values ​​of the test bits at the corresponding locations in the raw key it holds to the transmitting node. Subsequently, the transmitting node measures the error rate of the test bits by comparing the received bit values.

[0294] In step S2011, the transmitting node obtains the final key. After the second security check is passed, the transmitting node can obtain the final key based on the remaining bits of the raw key, excluding the test bits.

[0295] FIG. 21 illustrates an example in which a receiving node obtains a final key using the MDI SQKD protocol according to one embodiment of the present disclosure. FIG. 21 illustrates a method performed by a device performing wireless communication (e.g., the UE (1110), RAN node (1020), network node (1030) of FIG. 10, the first device (1210), and the second device (1220) of FIG. 12). In the description with reference to FIG. 21, the operating entity is referred to as the receiving node. For convenience of explanation, the following description assumes that an intermediate node performs the role of a base station and the transmitting node and receiving node perform the role of a terminal, but is not limited thereto. As an example, the transmitting node may perform the role of a terminal, the receiving node may perform the role of a base station, and the intermediate node may perform the role of a repeater. A device that transmits or receives data through quantum communication may be the receiving node or the transmitting node. Here, the receiving node may be an anti-quantum device that does not operate a laser source. In FIG. 21, it is assumed that the transmitting node transmits a first signal containing multiple qubits to the receiving node and transmits a second signal containing multiple qubits to the intermediate node. Additionally, it is assumed that the receiving node transmits a third signal obtained by changing the positions of the qubits included in the first signal and by bit flipping to the intermediate node.

[0296] Referring to FIG. 21, in step S2101, the receiving node receives information regarding the basis of the qubits included in the first signal from the transmitting node. The information regarding the basis may be transmitted through index values ​​in the order of the qubits included in the first signal. The receiving node can determine the basis of the qubits included in the third signal based on the information regarding the order of the qubits included in the first signal.

[0297] In step S2103, the receiving node transmits information regarding the order of the qubits included in the third signal. The information regarding the order of the qubits included in the third signal may indicate information regarding the order in which the receiving node arranged the qubits of the first signal. Since the transmitting node generated the first signal, it can determine the states of the qubits of the third signal even if it only receives the information regarding the order.

[0298] In step S2105, the receiving node receives information related to the qubits with matching bases. Here, the information related to the qubits with matching bases can be indicated by index values.

[0299] In step S2107, the receiving node performs a first security check and obtains a raw key. Among the qubits that successfully measured, the qubits with matching bases can be used for the first security check or as the raw key.

[0300] Specifically, among the qubits with matching bases that have been successfully measured, the qubits generated from the second basis can be used for security verification. Therefore, a first security verification can be performed by comparing the measurement error rate of the qubits generated from the second basis with a preset error rate. If the first security verification is not passed, the currently running quantum protocol may be terminated. If the first security verification is passed, the receiving node can obtain the raw key using the qubits generated from the first basis among the qubits with the same basis that have been successfully measured.

[0301] In step S2109, the receiving node performs a second security check. The second security check may be performed based on the error rate of the test bits. In this case, the test bits may include at least one bit among the bits included in the raw key obtained in step S2107. The transmitting node and the receiving node can determine the error rate and determine whether the second security check is satisfied by comparing the test bits. Information regarding the test bits can be transmitted in various ways. For example, the transmitting node transmits information related to the location of the test bits to the receiving node, and the receiving node transmits the bit values ​​of the test bits at the corresponding locations in the raw key it holds to the transmitting node. Subsequently, the transmitting node can measure the error rate of the test bits by comparing the received bit values ​​and then transmit to the receiving node whether the second security check has been passed.

[0302] In step S2111, the receiving node obtains the final key. After the second security check is passed, the receiving node can obtain the final key based on the remaining bits of the raw key, excluding the test bits.

[0303] By utilizing the aforementioned MDI SQKD protocol, secure communication can be performed regardless of detection results. Since detectors are the equipment most susceptible to attacks, the ability to perform communication independent of detection results means that communication can be safely conducted against a large number of detector attacks. Furthermore, because the laser source of the receiving node is not used, the laser source of the receiving node can be omitted, thereby reducing the complexity of device implementation regarding the receiving node.

[0304] Hereinafter, examples of wireless device applications to which various embodiments of the present disclosure are applied will be described.

[0305] FIG. 22 illustrates an example of a wireless device applicable to the present disclosure. The wireless device may be implemented in various forms depending on the use—example / service (see FIG. 1).

[0306] Referring to FIG. 22, the wireless device (200) corresponds to the wireless device (200) of FIG. 2 and may be composed of various elements, components, units / parts, and / or modules. For example, the wireless device (200) may include a communication unit (210), a control unit (220), a memory unit (230), and additional elements (240). The communication unit may include a communication circuit (212) and transceiver(s) (214). For example, the communication circuit (212) may include one or more processors (202) and / or one or more memories (204) of FIG. 2. For example, the transceiver(s) (214) may include one or more transceivers (206) and / or one or more antennas (208) of FIG. 2. The control unit (220) is electrically connected to the communication unit (210), the memory unit (230), and additional elements (240) and controls the overall operation of the wireless device. For example, the control unit (220) can control the electrical / mechanical operation of the wireless device based on a program / code / command / information stored in the memory unit (230). Additionally, the control unit (220) can transmit information stored in the memory unit (230) to an external entity (e.g., another communication device) via a wireless / wired interface through the communication unit (210), or store information received from an external entity (e.g., another communication device) via a wireless / wired interface through the communication unit (210) in the memory unit (230).

[0307] The additional element (240) may be configured in various ways depending on the type of wireless device. For example, the additional element (240) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 1, 100a), a vehicle (Fig. 1, 100b-1, 100b-2), an XR device (Fig. 1, 100c), a portable device (Fig. 1, 100d), a home appliance (Fig. 1, 100e), an IoT device (Fig. 1, 100f), a digital broadcasting terminal, a holographic device, a public safety device, an MTC device, a medical device, a fintech device (or financial device), a security device, a climate / environment device, an AI server / device (Fig. 1, 400), a base station (Fig. 1, 200), a network node, etc. Depending on the use—e.g., service—the wireless device may be movable or used in a fixed location.

[0308] In FIG. 22, various elements, components, units / parts, and / or modules within the wireless device (200) may be entirely interconnected via a wired interface, or at least some of them may be wirelessly connected via a communication unit (210). For example, within the wireless device (200), the control unit (220) and the communication unit (210) may be wired, and the control unit (220) and the first unit (e.g., 230, 240) may be wirelessly connected via the communication unit (210). Additionally, each element, component, unit / part, and / or module within the wireless device (200) may include one or more additional elements. For example, the control unit (220) may be composed of one or more sets of processors. For example, the control unit (220) may be composed of a set of a communication control processor, an application processor, an Electronic Control Unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory and / or a combination thereof.

[0309] Hereinafter, an implementation example of FIG. 22 will be described in more detail with reference to the drawings.

[0310] FIG. 23 illustrates an example of a portable device applicable to the present disclosure. The portable device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch, smart glasses), or a portable computer (e.g., a laptop). The portable device may be referred to as a Mobile Station (MS), a User Terminal (UT), a Mobile Subscriber Station (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), or a Wireless Terminal (WT).

[0311] Referring to FIG. 23, the portable device (200) may include an antenna unit (208), a communication unit (210), a control unit (220), a memory unit (230), a power supply unit (240a), an interface unit (240b), and an input / output unit (240c). The antenna unit (208) may be configured as part of the communication unit (210). Blocks 210 to 230 / 240a to 240c of FIG. 23 correspond to blocks 210 to 230 / 240 of FIG. 22, respectively.

[0312] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other wireless devices and base stations. The control unit (220) can control the components of the portable device (200) to perform various operations. The control unit (220) may include an AP (Application Processor). The memory unit (230) can store data / parameters / programs / code / commands required for the operation of the portable device (200). Additionally, the memory unit (230) can store input / output data / information, etc. The power supply unit (240a) supplies power to the portable device (200) and may include wired / wireless charging circuits, batteries, etc. The interface unit (240b) can support the connection between the portable device (200) and other external devices. The interface unit (240b) may include various ports (e.g., audio input / output ports, video input / output ports) for connection with external devices. The input / output unit (240c) can receive or output video information / signals, audio information / signals, data, and / or information input by a user. The input / output unit (240c) may include a camera, a microphone, a user input unit, a display unit (240d), a speaker and / or a haptic module, etc.

[0313] For example, in the case of data communication, the input / output unit (240c) acquires information / signals (e.g., touch, text, voice, image, video) input by the user, and the acquired information / signals can be stored in the memory unit (230). The communication unit (210) converts the information / signals stored in the memory into wireless signals and can directly transmit the converted wireless signals to another wireless device or to a base station. Additionally, the communication unit (210) can receive wireless signals from another wireless device or base station and then restore the received wireless signals to their original information / signals. The restored information / signals are stored in the memory unit (230) and then can be output in various forms (e.g., text, voice, image, video, haptic) through the input / output unit (240c).

[0314] FIG. 24 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), a ship, etc.

[0315] Referring to FIG. 24, a vehicle or autonomous vehicle (200-1) may include an antenna unit (208-1), a communication unit (210-1), a control unit (220-1), a driving unit (240a-1), a power supply unit (240b-1), a sensor unit (240c-1), and an autonomous driving unit (240d-1). The antenna unit (208-1) may be configured as part of the communication unit (210-1). Blocks 210-1 / 230-1 / 240a-1 to 240d-1 of FIG. 24 correspond to blocks 210 / 230 / 240 of FIG. 22, respectively.

[0316] The communication unit (210-1) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (Road Side Unit), etc.), and servers. The control unit (220-1) can perform various operations by controlling elements of the vehicle or autonomous vehicle (200-1). The control unit (220-1) may include an Electronic Control Unit (ECU). The driving unit (240a-1) can drive the vehicle or autonomous vehicle (200-1) on the ground. The driving unit (240a-1) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (240b-1) supplies power to the vehicle or autonomous vehicle (200-1) and may include wired / wireless charging circuits, batteries, etc. The sensor unit (240c-1) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (240c-1) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (240d-1) may implement technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0317] For example, the communication unit (210-1) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (240d-1) can generate an autonomous driving path and a driving plan based on the acquired data. The control unit (220-1) can control the drive unit (240a-1) so that the vehicle or the autonomous vehicle (200-1) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (210-1) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, during autonomous driving, the sensor unit (240c-1) can acquire vehicle status and surrounding environment information. The autonomous driving unit (240d-1) can update the autonomous driving path and the driving plan based on the newly acquired data / information. The communication unit (210-1) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles. If the device (220-2) is an autonomous vehicle, it can perform the same procedure as the vehicle or autonomous vehicle (200-1). In addition, if the device (220-2) is a base station or a roadside base station, the device (220-2) can transmit data and control signals to the vehicle or autonomous vehicle (200-1) through the communication unit (210-2).

[0318] FIG. 25 illustrates an example of a vehicle applicable to the present disclosure. The vehicle may be implemented as a means of transport, a train, an aircraft, a ship, etc. Referring to FIG. 25, the vehicle (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), and a position measurement unit (240b). Here, blocks 210 to 230 / 240a to 240b correspond to blocks 210 to 230 / 240 of FIG. 22, respectively.

[0319] The communication unit (210) can transmit and receive signals (e.g., data, control signals, etc.) with other vehicles or external devices such as base stations. The control unit (220) can control the components of the vehicle (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the vehicle (100). The input / output unit (240a) can output AR / VR objects based on information within the memory unit (230). The input / output unit (240a) may include a HUD. The position measurement unit (240b) can acquire position information of the vehicle (200). The position information may include absolute position information of the vehicle (200), position information within the driving line, acceleration information, position information relative to surrounding vehicles, etc. The position measurement unit (240b) may include GPS and various sensors.

[0320] For example, the communication unit (210) of the vehicle (200) can receive map information, traffic information, etc. from an external server and store it in the memory unit (230). The location measurement unit (240b) can acquire vehicle location information through GPS and various sensors and store it in the memory unit (230). The control unit (220) creates a virtual object based on map information, traffic information, and vehicle location information, etc., and the input / output unit (240a) can display the created virtual object on the glass window inside the vehicle (240a-1, 240a-2). In addition, the control unit (220) can determine whether the vehicle (200) is operating normally within the driving line based on the vehicle location information. If the vehicle (200) deviates abnormally from the driving line, the control unit (220) can display a warning on the glass window inside the vehicle through the input / output unit (240a). Additionally, the control unit (220) can broadcast a warning message regarding a driving abnormality to surrounding vehicles through the communication unit (210). Depending on the situation, the control unit (220) can transmit the vehicle's location information and information regarding the driving / vehicle abnormality to relevant authorities through the communication unit (210).

[0321] FIG. 26 illustrates an example of an XR device applicable to the present disclosure. The XR device may be implemented as an HMD, a Head-Up Display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc.

[0322] Referring to FIG. 26, the XR device (200a) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a power supply unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 26 correspond to blocks 210 to 230 / 240 of FIG. 22, respectively.

[0323] The communication unit (210) can transmit and receive signals (e.g., media data, control signals, etc.) with external devices such as other wireless devices, mobile devices, or media servers. The media data may include video, images, sound, etc. The control unit (220) can perform various operations by controlling the components of the XR device (200a). For example, the control unit (220) may be configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, metadata generation, and processing. The memory unit (230) may store data / parameters / programs / code / commands required for driving the XR device (200a) or creating an XR object. The input / output unit (240a) acquires control information, data, etc. from the outside and can output the created XR object. The input / output unit (240a) may include a camera, microphone, user input unit, display unit, speaker and / or haptic module, etc. The sensor unit (240b) can obtain XR device status, surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and / or radar, etc. The power supply unit (240c) supplies power to the XR device (200a) and may include a wired / wireless charging circuit, a battery, etc.

[0324] For example, the memory unit (230) of the XR device (200a) may contain information (e.g., data, etc.) necessary for creating an XR object (e.g., AR / VR / MR object). The input / output unit (240a) may receive a command to operate the XR device (200a) from the user, and the control unit (220) may operate the XR device (200a) according to the user's operation command. For example, if the user intends to watch movies, news, etc. through the XR device (200a), the control unit (220) may transmit content request information to another device (e.g., mobile device (200b)) or a media server through the communication unit (230). The communication unit (230) may download / stream content such as movies, news, etc. from another device (e.g., mobile device (200b)) or a media server to the memory unit (230). The control unit (220) controls and / or performs procedures such as video / image acquisition, (video / image) encoding, and metadata generation / processing for the content, and can generate / output an XR object based on information about the surrounding space or real object acquired through the input / output unit (240a) / sensor unit (240b).

[0325] Additionally, the XR device (200a) is wirelessly connected to the mobile device (200b) through the communication unit (210), and the operation of the XR device (200a) can be controlled by the mobile device (200b). For example, the mobile device (200b) can act as a controller for the XR device (200a). To this end, the XR device (200a) can acquire three-dimensional position information of the mobile device (200b), and then generate and output an XR object corresponding to the mobile device (200b).

[0326] FIG. 27 illustrates an example of a robot applicable to the present disclosure. Robots may be classified into industrial, medical, domestic, military, etc., depending on the purpose or field of use.

[0327] Referring to FIG. 27, the robot (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a), a sensor unit (240b), and a driving unit (240c). Here, blocks 210 to 230 / 240a to 240c of FIG. 27 correspond to blocks 210 to 230 / 240 of FIG. 22, respectively.

[0328] The communication unit (210) can transmit and receive signals (e.g., driving information, control signals, etc.) with external devices such as other wireless devices, other robots, or control servers. The control unit (220) can control the components of the robot (200) to perform various operations. The memory unit (230) can store data / parameters / programs / codes / commands that support various functions of the robot (200). The input / output unit (240a) can acquire information from outside the robot (200) and output information to outside the robot (200). The input / output unit (240a) may include a camera, microphone, user input unit, display unit, speaker and / or haptic module, etc. The sensor unit (240b) can obtain internal information of the robot (200), surrounding environment information, user information, etc. The sensor unit (240b) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, a radar, etc. The driving unit (240c) may perform various physical movements, such as moving robot joints. Additionally, the driving unit (240c) may enable the robot (200) to travel on the ground or fly in the air. The driving unit (240c) may include an actuator, a motor, a wheel, a brake, a propeller, etc.

[0329] FIG. 28 illustrates an example of an AI device applicable to the present disclosure.

[0330] AI devices can be implemented as stationary devices or mobile devices, such as TVs, projectors, smartphones, PCs, laptops, digital broadcasting terminals, tablet PCs, wearable devices, set-top boxes (STBs), radios, washing machines, refrigerators, digital signage, robots, vehicles, etc.

[0331] Referring to FIG. 28, the AI ​​device (200) may include a communication unit (210), a control unit (220), a memory unit (230), an input / output unit (240a / 240b), a learning processor unit (240c), and a sensor unit (240d). Blocks 210 to 230 / 240a to 240d of FIG. 28 correspond to blocks 210 to 230 / 140 of FIG. 22, respectively.

[0332] The communication unit (210) can transmit and receive wired and wireless signals (e.g., sensor information, user input, learning model, control signal, etc.) with external devices such as other AI devices (e.g., 100a to 100f, 120 in FIG. 1) or AI servers (e.g., 100g in FIG. 1) using wired and wireless communication technology. To do this, the communication unit (210) can transmit information within the memory unit (230) to an external device or transmit signals received from an external device to the memory unit (230).

[0333] The control unit (220) can determine at least one executable operation of the AI ​​device (200) based on information determined or generated using a data analysis algorithm or a machine learning algorithm. The control unit (220) can perform the determined operation by controlling the components of the AI ​​device (200). For example, the control unit (220) can request, search, receive, or utilize data from the learning processor unit (240c) or the memory unit (230), and can control the components of the AI ​​device (200) to execute a predicted operation or an operation determined to be desirable among at least one executable operation. Additionally, the control unit (220) can collect historical information, including the operation content of the AI ​​device (200) or user feedback regarding the operation, and store it in the memory unit (230) or the learning processor unit (240c), or transmit it to an external device such as an AI server (Fig. 1, 100g). The collected historical information can be used to update the learning model.

[0334] The memory unit (230) can store data that supports various functions of the AI ​​device (200). For example, the memory unit (230) can store data obtained from the input unit (240a), data obtained from the communication unit (210), output data from the learning processor unit (240c), and data obtained from the sensing unit (140). Additionally, the memory unit (230) can store control information and / or software code required for the operation / execution of the control unit (220).

[0335] The input unit (240a) can acquire various types of data from outside the AI ​​device (200). For example, the input unit (220) can acquire training data for model training and input data to which the training model is applied. The input unit (240a) may include a camera, a microphone and / or a user input unit, etc. The output unit (240b) can generate output related to visual, auditory, or tactile senses, etc. The output unit (240b) may include a display unit, a speaker and / or a haptic module, etc. The sensing unit (140d) can obtain at least one of internal information of the AI ​​device (200), surrounding environment information of the AI ​​device (200), and user information using various sensors. The sensing unit (140d) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and / or radar, etc.

[0336] The learning processor unit (240c) can train a model composed of an artificial neural network using training data. The learning processor unit (240c) can perform AI processing together with the learning processor unit of the AI ​​server (Fig. 1, 100g). The learning processor unit (240c) can process information received from an external device through the communication unit (210) and / or information stored in the memory unit (230). Additionally, the output value of the learning processor unit (240c) can be transmitted to an external device through the communication unit (210) and / or stored in the memory unit (230).

[0337]

[0338] The proposed methods described above may be implemented independently, but they may also be implemented in the form of a combination (or merger) of some of the proposed methods. Rules may be defined so that the base station informs the terminal of the application status of the proposed methods (or information regarding the rules of the proposed methods) through a predefined signal (e.g., a physical layer signal or an upper layer signal).

[0339] The present disclosure may be embodied in other specific forms without departing from the technical ideas and essential features described herein. Accordingly, the above detailed description should not be interpreted restrictively in all respects and should be considered illustrative. The scope of the present disclosure shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included within the scope of the present disclosure. Furthermore, embodiments may be constructed by combining claims that are not explicitly related in the claims, or new claims may be included by amendments made after filing.

[0340] One embodiment can be applied to various wireless access systems. Examples of various wireless access systems include the 3GPP (3rd Generation Partnership Project) or 3GPP2 system.

[0341] One embodiment can be applied not only to the various wireless access systems mentioned above, but also to all technical fields utilizing the various wireless access systems. Furthermore, the proposed method can be applied to mmWave and THz communication systems utilizing the ultra-high frequency band.

[0342] Additionally, some embodiments may be applied to various applications such as autonomous vehicles and drones.

Claims

1. Regarding the method, Step of acquiring system information; A step of performing a random access procedure based on the above system information; A step of transmitting a first signal for measurement to a second device; A step of transmitting a second signal for measurement to a third device; A step of receiving information related to the measurement result from the third device; and The method includes a step of obtaining a final key based on information related to the above measurement results, The information related to the above measurement result includes a third signal obtained by changing the positions of qubits included in the first signal and bit flipping, and a bell state measurement result for the second signal. A method in which qubits included in the first signal are generated into one of the first state of the first basis, the third state of the second basis, or the fourth state of the second basis.

2. In Paragraph 1, A step of transmitting information regarding the basis of the qubits included in the first signal to the second device; A step of receiving information related to the order of qubits included in the third signal from the second device; and A method further comprising the step of transmitting information related to qubits whose basis matches to the second device.

3. In Paragraph 1, The step of performing a first security inspection based on the above measurement results is further included, A method in which the pass or fail of the first security test is determined based on the error rate measured using the qubits generated from the second basis among the qubits that the third device successfully measured.

4. In Paragraph 1, It further includes a step of determining a raw key based on the above measurement results, but, The above raw key is determined based on the qubits generated from the first basis among the qubits that the third device has successfully measured.

5. In Paragraph 4, A step of selecting at least one test bit among the bits included in the above raw key; A step of transmitting information related to the position of the at least one test bit to the second device; A step of receiving at least one bit value corresponding to the position from the second device; and A method further comprising the step of performing a second security check based on at least one bit value.

6. In Paragraph 5, A method in which the above final key is determined based on the remaining bits, excluding at least one test bit among the bits included in the above raw key.

7. Regarding the method, Step of acquiring system information; A step of performing a random access procedure based on the above system information; A step of receiving a first signal for measurement from a first device; A step of transmitting a third signal to a third device based on the first signal; A step of receiving information related to the measurement result from the third device; and The method includes a step of obtaining a final key based on information related to the above measurement results, The information related to the above measurement result includes the bell state measurement result for the second signal and the third signal transmitted by the first device, and A method in which qubits included in the first signal are generated into one of the first state of the first basis, the third state of the second basis, or the fourth state of the second basis.

8. In Paragraph 7, The step of transmitting the third signal is, A step of generating a fourth signal by changing the order of at least one qubit among the qubits included in the first signal; A method comprising the step of generating the third signal by performing a bit flip on at least one qubit among the qubits included in the fourth signal.

9. In Paragraph 7, A step of receiving information regarding the basis of the qubits included in the first signal from the first device; A step of transmitting information related to the order of qubits included in the second signal to the first device; and A method further comprising the step of receiving information related to base-matched qubits from the first device.

10. In Paragraph 7, The step of performing a first security inspection based on the above measurement results is further included, A method in which the pass or fail of the first security test is determined based on the error rate measured using the qubits generated from the second basis among the qubits that the third device successfully measured.

11. In Paragraph 7, It further includes a step of determining a raw key based on the above measurement results, but, The above raw key is determined based on the qubits generated from the first basis among the qubits that the third device has successfully measured.

12. In Paragraph 11, A step of selecting at least one test bit among the bits included in the above raw key; A step of receiving information related to the position of at least one test bit from the first device; A step of transmitting at least one bit value corresponding to the position to the first device; and A method further comprising the step of receiving the result of a second security check determined based on at least one bit value.

13. In Paragraph 12, A method in which the above final key is determined based on the remaining bits, excluding at least one test bit among the bits included in the above raw key.

14. In the first device, Transmitter / receiver; and It includes a processor coupled to the above-mentioned transmitter and receiver, The above processor is, Acquire system information, and Based on the above system information, a random access procedure is performed, and Transmitting a first signal for measurement to a second device, and Transmitting a second signal for measurement to a third device, and Receive information related to the measurement result from the third device, and Configured to obtain the final key based on information related to the above measurement results, The information related to the above measurement result includes a third signal obtained by changing the positions of qubits included in the first signal and bit flipping, and a bell state measurement result for the second signal. A first device in which qubits included in the first signal are generated in one of the first state of the first basis, the third state of the second basis, or the fourth state of the second basis.

15. In the second device, Transmitter / receiver; and It includes a processor coupled to the above-mentioned transmitter and receiver, The above processor is, Acquire system information, and Based on the above system information, a random access procedure is performed, and Receive a first signal for measurement from a first device, and Transmitting a third signal to a third device based on the first signal, and Receive information related to the measurement result from the third device, and Configured to obtain the final key based on information related to the above measurement results, The information related to the above measurement result includes the bell state measurement result for the second signal and the third signal transmitted by the first device, and A second device in which the qubits included in the first signal are generated in one of the first state of the first basis, the third state of the second basis, or the fourth state of the second basis.

16. In the transmitting node, At least one processor; It includes at least one computer memory connected to the at least one processor and storing instructions that direct operations as they are executed by the at least one processor, The above operations are, Step of acquiring system information; A step of performing a random access procedure based on the above system information; A step of transmitting a first signal for measurement to a second device; A step of transmitting a second signal for measurement to a third device; A step of receiving information related to the measurement result from the third device; and The method includes a step of obtaining a final key based on information related to the above measurement results, The information related to the above measurement result includes a third signal obtained by changing the positions of qubits included in the first signal and bit flipping, and a bell state measurement result for the second signal. The qubits included in the first signal are a transmitting node generated in one of the first state of the first basis, the third state of the second basis, or the fourth state of the second basis.

17. In a non-transitory computer-readable medium storing at least one instruction, It includes at least one instruction executable by a processor, The above at least one instruction is, the first device, Acquire system information, and Based on the above system information, a random access procedure is performed, and Transmitting a first signal for measurement to a second device, and Transmitting a second signal for measurement to a third device, and Receive information related to the measurement result from the third device, and Configured to obtain the final key based on information related to the above measurement results, The information related to the above measurement result includes a third signal obtained by changing the positions of qubits included in the first signal and bit flipping, and a bell state measurement result for the second signal. A computer-readable medium in which qubits included in the first signal are generated in one of the first state of the first basis, the third state of the second basis, or the fourth state of the second basis.

Images