Apparatus and method for performing measurement-device-independent semiquantum secure direct communication 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 therefor may comprise the steps of: acquiring system information; performing a random access procedure on the basis of the system information; transmitting, to a second device, a first signal for measurement; receiving information related to a first measurement result from the second device; generating a data signal by performing data encoding on the basis of a quantum teleportation operator determined on the basis of the first measurement result; and transmitting the data signal to the second device.

Description

Device and method for performing detector-independent anti-quantum security direct communication 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 secure direct communication (MDI SQSDC) 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 secure direct communication (MDI SQSDC) using an intermediate node in a communication system.

[0005] The present disclosure relates to an apparatus and method for performing quantum communication when there is no entanglement source at a receiving node in a communication system.

[0006] The present disclosure relates to an apparatus and method for performing quantum communication using a quantum sequence comprising a qubit generated by a transmitting node and a qubit generated by a receiving node in a communication system.

[0007] The present disclosure relates to an apparatus and method for performing a first safety inspection using a first test qubit generated by a transmitting node in a communication system.

[0008] The present disclosure relates to an apparatus and method for performing a second stability test using a second test qubit generated by a transmitting node in a communication system.

[0009] The present disclosure relates to an apparatus and method for determining a quantum teleportation operator based on measurement results of an intermediate node in a communication system.

[0010] The present disclosure relates to an apparatus and method for encoding a message based on a quantum teleportation operator in a communication system.

[0011] The present disclosure relates to an apparatus and method for performing quantum communication using a signal comprising a message qubit, a first test qubit, and a second test qubit in a communication system.

[0012] The present disclosure relates to an apparatus and method for determining a message qubit and a second test qubit in a communication system based on the basis of the qubits transmitted by the received signal.

[0013] The present disclosure relates to an apparatus and method for performing a first stability test and a second stability test based on a first test qubit and a second test qubit in a communication system.

[0014] The present disclosure relates to an apparatus and method for reducing the loss of message qubits used in quantum communication in a communication system.

[0015] 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.

[0016] 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; receiving information related to a first measurement result from the second device; generating a data signal by performing data encoding based on a quantum teleportation operator determined based on the first measurement result; and transmitting the data signal to the second device, wherein the information related to the first measurement result includes a Bell state measurement result for the first signal and a second signal for measurement transmitted by a third device, and the second signal may include at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis.

[0017] 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 second signal for measurement to a second device; receiving information related to a first measurement result from the second device; transmitting information related to a quantum teleportation operator determined based on the first measurement result to a first device; receiving information related to a second measurement result from the second device; and acquiring a message based on the information related to the second measurement result, wherein the information related to the first measurement result includes a Bell state measurement result for the second signal and the first signal for measurement transmitted by the first device, the second signal includes at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis, and the information related to the second measurement result may include the result of measuring a data signal for which data encoding is performed based on the first measurement result.

[0018] As an example of the present disclosure, the method comprises: acquiring system information; performing a random access procedure based on the system information; receiving a first signal for measurement from a first device; receiving a second signal for measurement from a third device; disclosing information related to a first measurement result including a bell state measurement result for the first signal and the second signal; receiving a data signal in which data encoding is performed based on the first measurement result; and transmitting information related to a second measurement result including a result of measuring the data signal to the third device, wherein the second signal may include at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis.

[0019] 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, receive information related to a first measurement result from the second device, generate a data signal by performing data encoding based on a quantum teleportation operator determined based on the first measurement result, and transmit the data signal to the second device, wherein the information related to the first measurement result includes a bell state measurement result for the first signal and a second signal for measurement transmitted by a third device, and the second signal may include at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis.

[0020] As an example of the present disclosure, a third device comprises: a transceiver; and a processor coupled to the transceiver, wherein the processor is configured to perform a random access procedure based on the system information, transmit a second signal for measurement to a second device, receive information related to a first measurement result from the second device, transmit information related to a quantum teleportation operator determined based on the first measurement result to a first device, receive information related to a second measurement result from the second device, and acquire a message based on the information related to the second measurement result, wherein the information related to the first measurement result includes a bell state measurement result for the second signal and the first signal for measurement transmitted by the first device, and the second signal includes at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis, and the information related to the second measurement result may include the result of measuring a data signal for which data encoding has been performed based on the first measurement result.

[0021] 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, receive a second signal for measurement from a third device, disclose information related to a first measurement result including a bell state measurement result for the first signal and the second signal, receive a data signal in which data encoding is performed based on the first measurement result, and transmit information related to a second measurement result including a result of measuring the data signal to the third device, wherein the second signal may include at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis.

[0022] 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, acquiring system information, performing a random access procedure based on the system information, transmitting a first signal for measurement to a second device, receiving information related to a first measurement result from the second device, generating a data signal by performing data encoding based on a quantum teleportation operator determined based on the first measurement result, and transmitting the data signal to the second device, wherein the information related to the first measurement result includes a Bell state measurement result for the first signal and a second signal for measurement transmitted by a third device, and the second signal may include at least one qubit generated by the transmitting node based on a first basis and at least one qubit generated by the third device based on a second basis.

[0023] 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, said at least one instruction, said at least one instruction, said 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, receives information related to a first measurement result from the second device, generates a data signal by performing data encoding based on a quantum teleportation operator determined based on said first measurement result, and transmits said data signal to the second device, wherein the information related to the first measurement result includes a Bell state measurement result for said first signal and a second signal for measurement transmitted by a third device, said second signal may include at least one qubit generated by said first device based on a first basis and at least one qubit generated by said third device based on a second basis.

[0024] 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.

[0025] The following effects may be achieved by embodiments based on the present disclosure.

[0026] According to the present disclosure, efficient quantum communication can be performed using an intermediate node.

[0027] 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.

[0028] 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.

[0029] FIG. 1 illustrates an example of a communication system applicable to the present disclosure.

[0030] FIG. 2 illustrates an example of a wireless device applicable to the present disclosure.

[0031] FIG. 3 illustrates a method for processing a transmission signal applicable to the present disclosure.

[0032] FIG. 4 illustrates a communication procedure between a terminal and a base station applicable to the present disclosure.

[0033] FIG. 5 illustrates an example of a communication structure that can be provided in a 6G (6th generation) system applicable to the present disclosure.

[0034] FIG. 6 illustrates an electromagnetic spectrum applicable to the present disclosure.

[0035] FIG. 7 illustrates a transmitter structure applicable to the present disclosure.

[0036] FIG. 8 illustrates an example of a functional framework for the application of artificial intelligence technology applicable to the present disclosure.

[0037] FIG. 9 illustrates an example of a procedure for utilizing an artificial intelligence model applicable to the present disclosure.

[0038] FIG. 10 illustrates a communication procedure based on artificial intelligence (AI) technology applicable to the present disclosure.

[0039] FIG. 11 illustrates three basic properties of quantum information that can be used in information communication applicable to the present disclosure.

[0040] FIG. 12 illustrates an example of a quantum transmission protocol according to one embodiment of the present disclosure.

[0041] FIG. 13 illustrates an example of transmitting quantum information in two-step quantum secure direct communication according to one embodiment of the present disclosure.

[0042] FIG. 14 illustrates an example in which a transmitting node transmits a data signal using the MDI SQSDC (measurement device independent semiquantum secure direct communication) protocol according to one embodiment of the present disclosure.

[0043] FIG. 15 illustrates an example in which a receiving node transmits a data signal using the MDI SQSDC protocol according to one embodiment of the present disclosure.

[0044] FIG. 16 illustrates an example in which an intermediate node transmits a data signal using the MDI SQSDC protocol according to one embodiment of the present disclosure.

[0045] FIG. 17 illustrates an example of a device for performing a first embodiment of the MDI SQSDC protocol according to one embodiment of the present disclosure.

[0046] FIG. 18 illustrates a first embodiment of signaling for performing an MDI SQSDC protocol according to one embodiment of the present disclosure.

[0047] FIGS. 19a to 19d illustrate examples in which qubits of a first embodiment are generated and transmitted according to one embodiment of the present disclosure.

[0048] FIG. 20 illustrates an example of a device performing a second embodiment of the MDI SQSDC protocol according to one embodiment of the present disclosure.

[0049] FIG. 21 illustrates a second embodiment of signaling for performing an MDI SQSDC protocol according to one embodiment of the present disclosure.

[0050] FIGS. 22a to 22d illustrate examples in which qubits of a second embodiment are generated and transmitted according to one embodiment of the present disclosure.

[0051] FIG. 23 illustrates an example of a wireless device applicable to the present disclosure.

[0052] FIG. 24 illustrates an example of a portable device applicable to the present disclosure.

[0053] FIG. 25 illustrates an example of a vehicle or autonomous vehicle applicable to the present disclosure.

[0054] FIG. 26 illustrates an example of a vehicle applicable to the present disclosure.

[0055] FIG. 27 illustrates an example of an extended reality (XR) device applicable to the present disclosure.

[0056] FIG. 28 illustrates an example of a robot applicable to the present disclosure.

[0057] FIG. 29 illustrates an example of an AI device applicable to the present disclosure.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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).

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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).

[0071] 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.

[0072] 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.

[0073] Communication systems applicable to the present disclosure

[0074] 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.

[0075] 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.

[0076] FIG. 1 illustrates an example of a communication system to which the present disclosure applies.

[0077] 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.

[0078] 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).

[0079] 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.

[0080] Devices applicable to the present disclosure

[0081] FIG. 2 illustrates an example of a wireless device that can be applied to the present disclosure.

[0082] 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).

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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).

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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).

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 6G communication systems and core implementation technologies of 6G systems

[0110] 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.

[0111] 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.

[0112] Per device peak data rate1 TbpsE2E latency1 msMaximum spectral efficiency100 bps / HzMobility supportup to 1000 km / hrSatellite integrationFullyAIFullyAutonomous vehicleFullyXRFullyHaptic CommunicationFully

[0113] 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.

[0114] - 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.

[0115] - 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).

[0116] - 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.

[0117] - 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.

[0118] Some general requirements regarding the new network characteristics of 6G mentioned above may be as follows.

[0119] - 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.

[0120] - 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.

[0121] - 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.

[0122] - 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.

[0123] - 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.

[0124] 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.

[0125] 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.

[0126] FIG. 7 illustrates a transmitter structure applicable to the present disclosure.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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).

[0133] 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'.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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).

[0138] 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.

[0139] 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).

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.).

[0152] 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.

[0153] Specific embodiments of the present disclosure

[0154] 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 a transmitting node to predetermine the locations of message qubits and test qubits and to encode the message qubits based on basis information received from a receiving node. Furthermore, the present disclosure allows the transmitting node to determine the message qubits and test qubits based on basis information received from a receiving node without first determining the locations of the message qubits and test qubits, and to perform quantum communication. By using the method proposed in the present disclosure, quantum communication can be performed even when the receiving device does not have an entanglement source.

[0155] Quantum Secure Direct Communication (QSDC) protocols have been studied in quantum communication scenarios where both the sender and receiver possess quantum capabilities to process quanta or photons. However, many problems can arise when transmitting quantum states in quantum communication. For example, as transmission distance increases, photon loss occurs in the quantum channel, leading to a decrease in transmission efficiency. Additionally, decoherence can occur due to interactions with the surrounding environment, potentially altering the quantum state. Consequently, intermediate nodes may be required for long-distance quantum communication. When repeaters are used as intermediate nodes, they entail significant technical challenges. Furthermore, noise and interference occurring during long-distance transmission can alter the quantum state. Therefore, methods utilizing devices other than repeaters are being proposed. Procedures for performing Measurement Device Independent Quantum Secure Direct Communication (MDI QSDC) using intermediate nodes within a communication system utilizing quantum entanglement are currently being investigated.

[0156] However, quantum communication can be considered in situations where neither the sender nor the receiver possesses all quantum capabilities. For example, through semiquantum secure direct communication (SQSDC), quantum communication can be performed between a receiver possessing all quantum capabilities and a sender lacking all quantum capabilities. In other words, the semiquantum secure direct communication technique has the advantage that not all devices participating in the communication need to possess all quantum capabilities. Therefore, this disclosure proposes MDI SQSDC (measurement device independent semiquantum secure direct communication). The basic characteristics of quantum communication are described below.

[0157] 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.

[0158] To represent qubits in quantum systems, a method to represent superimposed quantum states is required. One method that can be used to represent quantum states is Dirac notation. Dirac notation can also be referred to as bra-ket notation.

[0159] 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.

[0160] 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.

[0161] Entanglement

[0162] 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.

[0163]

[0164] 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.

[0165] 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.

[0166] For entangled qubits with M > 2 qubits or more, the GHZ state is as follows [Equation 2].

[0167]

[0168] In [Mathematical Formula 2], represents the tensor product operator.

[0169] 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.

[0170] The decay of quantum information by measurement

[0171] 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.

[0172] 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.

[0173] FIG. 11 illustrates three basic properties of quantum information applicable to 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 to an instantaneous ground state due to the influence of observation and cannot be restored to the state before measurement. Additionally, due to entanglement, if a qubit of one system is measured, information about a qubit of another system can also be known. As an example, quantum information after measurement has a probability |a| 2 A basis state A having and probability |b| 2 It decays into a ground state B that has. Therefore, the decayed information only contains information about A or B, does not contain superposition of information about A and B, and cannot return to the state before measurement.

[0174] quantum teleportation (QT)

[0175] 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.

[0176] 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.

[0177] 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.

[0178] For example, quantum information to be transmitted The quantum transfer protocol for can be represented as follows.

[0179] - Entanglement generation: Generates an entangled state of two qubits through a Bell state generator.

[0180] - 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).

[0181] - 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.

[0182] BSM Results of and Alice's QubitBob's Qubit

[0183] - 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) performs a unitary operation on the remaining qubit of the Bell state it possesses using the two classical bits received from the first device (1210) to obtain a quantum state identical to the quantum information |φ〉 that the first device (1210) intends to transmit.

[0184] Quantum Direct Communication (QDC)

[0185] Quantum Direct Communication is a method for securely transmitting classical message information. While it shares similarities with Quantum Key Distribution (QKD) technology, which is used as a 4G or 5G secure communication technology, there are also differences. Quantum Key Distribution is a method of sharing symmetric secret key information between senders and receivers by utilizing the non-cloning property of quantum mechanics to securely transmit message information sent over a classical channel. In contrast, Quantum Direct Communication is a method of sharing the classical message information to be transmitted directly over a quantum channel, rather than a secret key.

[0186] 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.

[0187] 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.

[0188]

[0189] 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.

[0190] 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.

[0191] 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.

[0192] The aforementioned QSDC protocol can directly transmit messages using quantum states. In quantum communication techniques, eavesdropping attacks are primarily carried out at the detector. To counter this, a measurement device independent (MDI) QSDC protocol has been developed.

[0193] 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.

[0194] SQSDC (semiquantum secure direct communication) protocol

[0195] For the sake of convenience of explanation, it is assumed below that qubits in the SQSDC protocol are transmitted using polarized single photons.

[0196] The first step of the SQSDC protocol is for the receiving node to transmit polarized single photons to the transmitting node. The receiving node prepares N polarized single photons as shown in [Equation 4] below and transmits them to the transmitting node.

[0197]

[0198] In [Mathematical Formula 4], It means, represents the length of the secret message M, and k is the hash function represents the length, and δ represents a fixed parameter.

[0199] A wavelength filter can be used to prevent a Trojan horse attack before N single photons are received by the sender. The wavelengths of the photons prepared by the sender and the receiver must be the same. Each photon has four polarization states. It can be determined as one of the following. In the following, the bundle of photons transmitted to the receiver will be referred to as Batch A.

[0200] The second step is the security verification step. After the sender receives batch A, the sender and receiver perform a security verification. For the security verification, the sender selects half of the photons included in batch A. Here, the selected half of the photons are designated as batch S, and the unselected half are designated as batch T. Here, each photon of batch S received by the sender is either reflected back to the receiver as is or through the Z basis or This can be measured. If the transmitter measures photons of batch S, it retransmits the same state as the measured state to the receiver.

[0201] Subsequently, the sender discloses the locations of reflected photons, the locations of measured photons, and the measurement results of the photons among the photons included in batch S. Thus, the receiver can verify the errors of the reflected photons and the errors of the measurement results. If the errors occur below a preset value, the receiver can determine that the quantum channel is safe. The receiver can then send a message instructing the sender to perform the next step. If the errors exceed the preset value, the receiver determines that the quantum channel is unsafe, and the current protocol may be discarded.

[0202] The third step is the stage of coding and retransmitting the message. The receiver informs the sender of the locations of the photons generated based on the Z basis and transmitted. For the sake of convenience in the following explanation, photons included in Batch T that are identified as having been transmitted via the Z basis will be referred to as Batch B. The reason it does not matter if they are identified as having been transmitted via the Z basis is that the sender's security is guaranteed through one-time pad encryption. Since security is guaranteed in Batch S, it implies that Batch T, which uses the same channel, is also secure; therefore, there is no security issue even if the location of the basis is revealed. Here, if the number of photons included in Batch B is not greater than m, the protocol is discarded because it consists of fewer photons than the transmitted message.

[0203] The sender, based on the secret message M as shown in [Equation 5] below, Calculate.

[0204]

[0205] In [Mathematical Formula 5], means a one-way hash function.

[0206] The sender is a secret message If α is 0, the i-th photon of batch B is not changed, If α is 1, the i-th photon of batch B is flipped. Since the transmitter, which does not possess all anti-quantum capabilities, can only flip for the Z basis, encoding is performed only for photons prepared for the Z basis. Specifically, to flip the quantum state of the photons in the Z basis, the transmitter can measure the photons in the z basis and prepare the inverse value of the measured value.

[0207] The sender transmits photons encoded with a secret message to the receiver. The receiver measures the photons. By comparing the measured values ​​with the states of the photons it transmitted, the receiver obtains the message You can obtain . If In this case, the recipient thinks the message has not been tampered with. It determines that the sender transmitted it. On the other hand, If not, the recipient determines that the message was manipulated by someone other than the sender.

[0208] Measurement device independent (MDI) quantum secure direct communication (QSDC) protocol

[0209] First, we will explain the MDI QSDC protocol. In the following , , , represents an EPR-pair composed of two qubits as in [Mathematical Equation 1], and , , means a single qubit.

[0210] The first step of the MDI QSDC is the stage where the transmitting node and the receiving node prepare a quantum sequence in an entangled state. The transmitting node is N+t oGenerate EPR-pairs and divide the generated EPR-pairs into two single qubit sequences. Here, the EPR-pairs are It is assumed that it was generated by. In the following, among the two single-qubit sequences, the sequence stored by the transmitting node is S Ah Represented as S, the sequence transmitted by the transmitting node is S At It is to be represented as such. The transmitting node additionally prepares t1 single qubits. The state of the single qubits can be determined as one of the states expressed in [Equation 6] below.

[0211]

[0212] The transmitting node prepares single qubits in sequence S At By inserting at an arbitrary position, an ordered sequence P A Creates.

[0213] The receiving node is N+t o +t1 single qubit sequence P B Generates sequence P B The state of the qubits included in [Equation 6] can be determined as one of the states expressed in [Equation 6] above. The generated EPR pairs are used for information transmission, and single qubits can be used for security verification procedures.

[0214] The second step is when the intermediate node performs the measurement and discloses the measurement results. The transmitting node sends sequence P to the intermediate node. A The receiving node transmits and sends sequence P to the intermediate node. BIt transmits. The intermediate node performs Bell-basis measurements on the received sequences and discloses the measurement results. A single qubit composed of an EPR-pair of the transmitting node can decay into one of the states as shown in [Equation 6] above after the Bell-basis measurements. Neither the transmitting node nor the intermediate node knows which state the single qubit stored by the transmitting node will decay into. However, the receiving node can infer which state the single qubit stored by the transmitting node will decay into by the following method through the initial state of the sequence and the disclosure of results by the intermediate node.

[0215] For the sake of convenience of explanation, the initial state of the EPR-pair prepared by the transmitting node below is and the state of the qubit prepared by the receiving node It is assumed that this is the case. The intermediate node that has received qubits from the transmitting node and the receiving node is It can perform Bell-basis measurements with the state as input. The intermediate node is the Bell-basis measurement result You can obtain one of the results 10, 11, 00, or 01. The results of 10, 11, 00, and 01 are respectively It means that the first two results are the transmitting node's qubits Since it means originating from, the remaining qubits of the transmitting node are It can be determined that the state prepared by the receiving node is It can also be identified in the same way.

[0216] After the intermediate node reveals the result, the receiving node and exposes the basis. The transmitting node, to the single qubit it holds By performing this, the same state as the receiving node can be obtained. The transmitted node's stored qubits and operators corresponding to the measurement result based on the receiving node's qubit state. It is as shown in [Table 3] below.

[0217] qubit state of the receiving node

[0218] In [Table 3] refers to the measurement information disclosed by the intermediate node, and the corresponding column's represents the state of the qubit stored by the transmitting node, and represents an operator for making the qubit stored by the transmitting node identical to the qubit state of the receiving node.

[0219] For example, an intermediate node If it is disclosed, the receiving node's prepared qubit state Since we know that, the qubit stored by the transmitting node is It can be seen that, and the receiving node has its qubit state in a Z basis, and go I will disclose that.

[0220] Referring to [Table 3] above, when the basis of the qubits of the receiving node is the same, It is determined identically. That is, even if the receiving node exposes only the base, the sending node and the intermediate node are It can obtain. Therefore, if the receiving node exposes the base, The disclosure of can be omitted.

[0221] The third step is to check for eavesdropping. The transmitting node discloses the positions and states of t1 single qubits randomly inserted in the first step, and the receiving node discloses the state of the qubits at those positions. Since the t1 qubits with disclosed positions are states randomly selected by the transmitting and receiving nodes, if the same basis is selected and the error rate of the measurement result differs from the reference value, it can be attributed to the influence of an eavesdropper. If a different basis is selected, the error rate cannot be verified using those qubits because all possible combinations of bell states are possible.

[0222] The fourth step is the stage where the transmitting node transmits information. The receiving node bases and Since it has been disclosed, the transmitting node is the remaining N+t o Encoding operator on k qubits Can be applied. Encoding operator It is as shown in [Mathematical Formula 7] below.

[0223]

[0224] In [Equation 7], represents a quantum teleportation operator for completing quantum teleportation, and represents the message encoding operation.

[0225] is an operator disclosed by the receiving node, and can perform the role of making the qubit stored by the transmitting node the same state as the qubit generated by the receiving node. is an encoding operator, and the transmitting node transmits 0 information To use the operator and transmit 1 information The operator can be used. The sending node uses t for the integrity of the message. o Random encoding is also performed on the qubits.

[0226] The fifth step is the stage where the sending node transmits the message. The sending node sends the N+t encoded message to the intermediate node. o Transmits a sequence of single qubits. The intermediate node performs a unitary operation on the received qubits. ...is performed. Here, if the basis of the received qubit is In the case of It is set to, and the basis of the received qubit is In the case of It is set to. The intermediate node is afterwards A measurement is performed based on the baseline, and the results are disclosed. Based on the disclosed results, the receiving node can obtain the message that the transmitting node intends to send and randomly encoded numbers.

[0227] The sixth step is the step of verifying whether manipulation has occurred. The transmitting node is t o Randomly encoded numbers are disclosed to k qubits. If the error rate is lower than the threshold, it may indicate that the communication was performed safely. Conversely, if the error rate is higher than the threshold, it may indicate that the communication was manipulated by an eavesdropper or an intermediate node.

[0228] Quantum secure direct communication can be performed through an intermediate node using the MDI QSDC protocol. The present disclosure proposes a method for performing quantum secure direct communication using an intermediate node in the MDI QSDC protocol when the transmitting node and the receiving node are not both equipped with quantum capabilities.

[0229] Through the aforementioned semiquantum secure direct communication (SQSDC), quantum communication can be performed between a receiver possessing all quantum capabilities and a sender lacking all quantum capabilities. In other words, the semiquantum secure direct communication technique has the advantage that not all devices participating in the communication need to possess all quantum capabilities.

[0230] FIG. 14 illustrates an example in which a transmitting node transmits a data signal using the MDI SQSDC protocol according to one embodiment of the present disclosure. FIG. 14 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. 14, 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.

[0231] Referring to FIG. 14, in step S1401, 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.

[0232] In step S1403, the transmitting node transmits a first signal for measurement to an intermediate node. The first signal may include first test qubits for a first security check. The first signal may further include qubits selected one from each pair among a plurality of qubit pairs in an entangled state. The remaining qubits among the plurality of qubit pairs that are not included in the first signal may be stored in the transmitting node. Here, the plurality of qubit pairs in an entangled state may be used for message transmission or a second security check. Each of the qubits included in the first signal may have a quantum state among the first basis and second basis states.

[0233] In step S1405, the transmitting 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 result for the first signal and the second signal for measurement transmitted by the receiving node. Here, the second signal may include at least one qubit generated by the first device based on the first basis and at least one qubit generated by the second device based on the second basis. The information related to the first measurement result may be transmitted through a classical channel. A first security check may be performed based on the first measurement result. Specifically, if the initial quantum state of the first test qubits and the quantum state of the first test qubits measured are not identical, quantum communication may be interrupted.

[0234] In step S1407, the transmitting node may perform data encoding based on a quantum teleportation operator. The transmitting node may receive information related to the quantum teleportation operator from a third device. Encoding may be performed through an encoding operator, and the encoding operator may be determined based on the quantum teleportation operator and the message encoding operator. The qubits stored by the transmitting node may be converted through the encoding operator. At this time, the transmitted message may be converted into a codeword based on an error correction code, and then encoding may be performed to transmit the codeword.

[0235] In step S1409, the transmitting node transmits a data signal to which data encoding has been performed. The data signal may include a qubit to which an encoding operator has been applied and a second test qubit for a second security test. When the data signal is transmitted to an intermediate node, the intermediate node discloses the measurement results of the received signal to the receiving node, and the receiving node can obtain the message that the transmitting node intends to send based on the disclosed results. Additionally, a second security check may be performed by comparing the initial quantum state of the second test qubits with the measured quantum state of the second test qubits.

[0236] FIG. 15 illustrates an example in which a receiving node transmits a data signal using the MDI SQSDC protocol according to an embodiment of the present disclosure. FIG. 15 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. 15, 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. The device transmitting or receiving data through quantum communication may be the receiving node or the transmitting node. Here, the receiving node is assumed to be a semi-quantum device that cannot generate qubits based on a first basis but can generate qubits based on a second basis.

[0237] Referring to FIG. 15, in step S1501, 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.

[0238] In step S1503, the receiving node transmits a second signal for measurement to an intermediate node. The second signal may include at least one qubit generated by the transmitting node based on a first basis and at least one qubit generated by the receiving node based on a second basis. To this end, the receiving node may receive at least one qubit from the transmitting node. Here, the at least one qubit does not need to be transmitted as a single photon. For example, it may be transmitted as a pulse containing multiple states having the same information.

[0239] In step S1505, the receiving node receives information related to the first measurement result from the intermediate node. The information related to the first measurement result may include the Bell state measurement result for the first signal and the second signal for measurement transmitted by the receiving node. The first measurement result may be transmitted through a classical channel. A first security check may be performed based on the first measurement result. Specifically, if the initial quantum state of the first test qubits included in the first signal and the measured quantum state of the first test qubits are not identical, quantum communication may be interrupted. If quantum communication is interrupted, the qubits stored by the transmitting node for message transmission may be discarded.

[0240] In step S1507, the receiving node transmits information related to a quantum teleportation operator determined based on the first measurement result. The quantum teleportation operator refers to an operator that enables the qubits generated by the transmitting and receiving nodes and the qubits stored by the transmitting node to have the same quantum state. The information related to the quantum teleportation operator may include information indicating the quantum teleportation operator. In this case, the information related to the quantum teleportation operator may include information related to the basis of the qubits generated by the receiving node among the qubits included in the second signal. In this case, the transmitting node can identify the quantum teleportation operator using only the basis of the qubits prepared by the receiving node.

[0241] In step S1509, the receiving node receives information related to a second measurement result regarding the data signal from the intermediate node and decodes the data. The data signal may include a qubit to which an encoding operator is applied and a second test qubit for a second security test. Accordingly, the second measurement result may include a measurement result for the qubit to which the encoding operator is applied. Subsequently, the receiving node may perform data decoding based on the qubit to which the encoding operator is applied.

[0242] When a data signal is transmitted to an intermediate node, the intermediate node discloses the measurement results of the received signal to the receiving node, and the receiving node can obtain the message that the transmitting node intends to send based on the disclosed results. If the receiving node performs a second security check, the receiving node can receive information related to the second test qubit from the transmitting node. The receiving node can determine whether to interrupt quantum communication by comparing the initial quantum state of the second test qubits with the measured quantum state of the second test qubits.

[0243] FIG. 16 illustrates an example in which an intermediate node transmits a data signal using the MDI SQSDC protocol according to one embodiment of the present disclosure. FIG. 16 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. 16, the operating entity is referred to as the intermediate node. For convenience of explanation, the following description assumes that the 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 the receiving node or the transmitting node.

[0244] Referring to FIG. 16, in step S1601, the intermediate node performs an initial connection procedure. The intermediate node performs the initial connection procedure with the transmitting node and / or the receiving node and can establish a connection with the transmitting node and / or the receiving node. Through this procedure, the intermediate node can share information necessary for communication over a classical channel. The initial connection procedure may include a random access procedure.

[0245] In step S1603, the intermediate node receives a first signal for measurement from the transmitting node and receives a second signal for measurement from the receiving node. Each of the qubits included in the first signal may have a quantum state of one of the states of the first basis and the second basis. The second signal may include at least one qubit generated by the transmitting node based on the first basis and at least one qubit generated by the receiving node based on the second basis.

[0246] In step S1605, the intermediate node discloses information related to the first measurement result. Accordingly, the intermediate node can transmit the measurement result to the transmitting node and the intermediate node. The information related to the first measurement result may include the bell state measurement results for the first signal and the second signal received by the intermediate node. A first security check may be performed based on the first measurement result. Specifically, if the initial quantum state of the first test qubits included in the first signal and the quantum state of the first test qubits measured are not identical, quantum communication may be interrupted.

[0247] In step S1607, the intermediate node receives a data signal from the transmitting node. The data signal may include a qubit to which an encoding operator is applied and a second test qubit for a second security test. The intermediate node may perform a measurement of the received data signal. The received data signal may be measured immediately or measured after being stored in quantum memory. For example, if the order of the qubit to which the encoding operator is applied and the second test qubit for the second security test is changed by the transmitting node, the intermediate node may first store the data signal in quantum memory. Subsequently, the intermediate node may receive information regarding the qubit order from the transmitting node and perform a measurement based on the information regarding the order.

[0248] In step S1609, the intermediate node transmits information related to the second measurement result to the receiving node. After performing the measurement, the intermediate node discloses the information related to the second measurement result to the receiving node, and the receiving node can obtain the message that the transmitting node intends to send based on the disclosed information. Additionally, a second security check can be performed by comparing the initial quantum state of the second test qubits with the measured quantum state of the second test qubits.

[0249] A first embodiment of performing the MDI SQSDC protocol is described below. The first embodiment can be performed by a device such as that shown in FIG. 17.

[0250] FIG. 17 illustrates an example of an apparatus for performing a first embodiment of an MDI SQSDC protocol according to one embodiment of the present disclosure. Referring to FIG. 17, a transmitting node (1710) and a receiving node (1720) 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.

[0251] The transmitting node (1710) may include an entanglement source (ES) (1711), a laser (1712), an intensity modulator (IM) (1713), and a polarization modulator (PM) (1714).

[0252] The entanglement source (1711) is a device that generates entangled photon pairs. The entangled photons generated by the entanglement source (1711) may exhibit strong correlations in polarization, phase, or time-bin states and may be used in quantum communication protocols. The entanglement source (1711) may transmit all or part of the entangled photon pairs to an intensity modulator (1712).

[0253] A laser (1712) can generate a single photon qubit. Since the transmitting node (1710) must generate a single photon qubit set as a first test qubit as well as an entangled photon pair, the laser (1712) can be used to generate a photon qubit.

[0254] The intensity modulator (1713) can adjust the amplitude or intensity of a single qubit generated from the laser (1712), and the phase modulator (1714) can adjust the phase of the output signal of the intensity modulator (1712). At least one photon qubit generated from the entanglement source (1711) or the laser (1711) can be transmitted to an intermediate node (1730) through the intensity modulator (1713) and the phase modulator (1714). Additionally, the photon qubit generated from the laser (1712) can be transmitted to a receiving node (1720).

[0255] The receiving node (1720) may include a laser (1722), an intensity modulator (1723), and a phase modulator (1724). The laser (1722) may generate a single photon qubit. The receiving node (1720) may generate a photon qubit using the laser (1722). Here, a single qubit sequence may be formed including a single photon qubit received from the transmitting node (1710) and a single photon qubit of the receiving node (1720), and the qubit sequence may be transmitted to the intensity modulator (1723).

[0256] The intensity modulator (1723) can adjust the amplitude or intensity of a single photon qubit or sequence of qubits generated by the laser (1722). The phase modulator (1724) can adjust the phase of the output signal of the intensity modulator (1722). At least one photon qubit generated by the laser (1721) can be transmitted to an intermediate node (1730) through the intensity modulator (1723) and the phase modulator (1724).

[0257] The intermediate node (1730) may include a beam splitter (1731) and polarization beam splitters (1732, 1733). The beam splitter (1731) can split an incident optical signal into two or more paths and transmit them to two polarization beam splitters (1732, 1733). The intermediate node (1730) can use the two polarization beam splitters (1732, 1733) to split the beam according to the polarization of the optical signal received through the beam splitter (1731), and can obtain measurement results including what quantum state it has depending on which detector it was measured by.

[0258] The first embodiment can be carried out through the following Steps 1-1 to 1-6.

[0259] Step 1-1: Preparation Phase

[0260] The transmitting node is N+t o doggy An EPR pair is generated. The transmitting node separates each qubit included in the EPR pair and divides them into two single-qubit sequences. Here, sequence S Ah refers to a sequence stored by the transmitting node, and sequence S At is defined as the sequence transmitted by the transmitting node to the receiving node. The transmitting node additionally generates t1 single qubits. Here, each of the single qubits is It is generated in one of the states. The transmitting node prepares t1 single qubits and sequence S At An ordered sequence P obtained by inserting at an arbitrary position A Creates.

[0261] The transmitting node is (N+t o Generates random single qubits of (+t1) / 2 and transmits them to the receiving node. Here, (N+t o Any single qubits +t1) / 2 It is randomly generated into one of the states. At this time, N+t generated by the transmitting node.o N EPR pairs are used to transmit classical information, and t1 single qubits are used for security checks. (N+t) transmitted by the transmitting node o Since +t1) / 2 qubits are sufficient if they are in the X ground state, they do not necessarily need to have a single photon state.

[0262] The receiving node is (N+t o +t1) / 2 single qubits A sequence P that is randomly generated as one of the states and arranged in a random order with single qubits received from the transmitting node. B Creates.

[0263] Step 1-2: Measurement Step

[0264] The transmitting node sends sequence P to the intermediate node. A The receiving node transmits and sends sequence P to the intermediate node. B It transmits. The intermediate node performs Bell-basis measurements using the received qubits and publishes the measurement results. The single qubit generated by the transmitting node's EPR pair, after the Bell measurement, It collapses into one of the states. Therefore, the sequence S stored by the transmitting node Ah The single qubits included in it also collapse, and the transmitting node and the intermediate node cannot know the state in which the single qubits have collapsed. However, the receiving node, based on the initial state of the qubits it prepared and the results disclosed by the intermediate node, uses the above [Table 3] to retrieve the sequence S stored by the transmitting node. Ah The single qubits included in can be identified as follows.

[0265] If one of the qubits on which Bell-basis measurements were performed is a qubit generated by the receiving node, the receiving node can accurately know the state of the qubit stored by the transmitting node corresponding to the qubits on which Bell-basis measurements were performed.

[0266] On the other hand, if the receiving node finds that one of the qubits on which a Bell-basis measurement was performed is not a qubit generated by itself, the receiving node Only the information of can be known. Afterwards, the receiving node to the sending node It transmits the information. The transmitting node uses the received operator in the qubits it stores. By applying this, the stored qubits can be made identical to the qubits generated by the receiving node.

[0267] N+t o The initial state of the dog EPR pairs is It is set to. If the state of the qubit generated by the receiving node is In this case, the intermediate node is The result of the Bell-basis measure can be obtained for . That is, the intermediate node is If you perform a measurement on, You can obtain one of the results. The intermediate node is For each, one of the corresponding classic bits '10', '11', '00', or '01' is disclosed. If '10' or '11' is disclosed by the intermediate node, the receiving node [is] the EPR-pair prepared by the transmitting node. It can be determined that, and the qubits stored by the transmitting node are It can be seen that. Similarly, if '00' or '01' is disclosed by the intermediate node, the receiving node knows that the EPR pair prepared by the transmitting node is It can be determined that, and the qubits stored by the transmitting node are It can be seen that... In the same way, the receiving node can determine which qubits the remaining qubits stored by the transmitting node are. Subsequently, the receiving node [applies] the quantum teleportation operator to the qubits stored by the transmitting node. It can disclose.

[0268] Step 1-3: First Security Inspection Step

[0269] The transmitting node discloses the locations and states of t1 qubits, and the receiving node discloses information related to the qubits corresponding to those locations. Here, if the qubits at the corresponding locations are qubits prepared by the receiving node, the receiving node may disclose the state information of those qubits. If the qubits at the corresponding locations are qubits received from the transmitting node, the receiving node may inform the transmitting node that those qubits were received from the transmitting node. For example, the receiving node may transmit information related to the locations of the qubits received from the transmitting node. Since the quantum states of the t1 qubits disclosed by the transmitting node and their corresponding qubits are randomly selected, if an error occurs even though the basis of the qubits is the same, it can be attributed to the influence of an eavesdropper. If a different basis is selected, it is impossible to confirm that an error has occurred because all possible combinations of Bell states are possible. Therefore, the transmitting node or the receiving node can determine the presence of an eavesdropper based on the error rate and decide whether to continue quantum communication.

[0270] Step 1-4: Message Encoding Step

[0271] The transmitting node can perform encoding through the following method. The receiving node discloses information regarding the bases of the remaining N+t0 qubits to the transmitting node. Since the receiving node does not know the bases of the qubits prepared by the transmitting node, the transmitting node can determine the bases of the corresponding qubits through the qubit location information received from the transmitting node. Additionally, the transmitting node can transmit information regarding the bases of the qubits it has prepared to the receiving node.

[0272] The transmitting node is a quantum teleportation operator as in [Equation 8] and message encoding operators Encoding operator based on Determines.

[0273]

[0274] In [Equation 8], if the encoded message is 0, the message encoding operator silver It can be set to. Conversely, if the encoded message is 1, the message encoding operator silver It can be set to.

[0275] First, the transmitting node generates a codeword by encoding the message to be transmitted. Here, an error correction code may be applied to the message during codeword generation. In this case, the code rate of the error correction code can be determined by the communication operator. For example, the receiving node Since messages regarding the qubits transmitted as a basis are lost, it can be seen that an error rate occurs with an average probability of 1 / 2. Therefore, an error correction code with a code rate of 1 / 2 can be used.

[0276] The transmitting node uses an encoding operator on the encoded codeword ...can be applied. For the integrity of the message, the sending node uses t0 qubits and the received node's disclosed Arbitrary encoding can also be performed on the base position of.

[0277] Step 1-5: Message Decoding Step

[0278] The transmitting node tells the intermediate node the encoding operator Transmits a qubit sequence to which is applied. The intermediate node applies a unitary operation to the received qubit sequence Apply. Here, the unitary operator is the basis of the received qubit In the case of, It is set to, and the basis of the received qubit is In the case of, It is set to.

[0279] For the intermediate node, for the qubit sequence to which the unitary operator is applied Performs baseline measurements and discloses the results. If the receiving node Regarding the position of the qubit disclosed in the base, the measurement result is disclosed as a loss. Based on the result disclosed by the intermediate node, the receiving node can obtain the codeword encoded by the transmitting node and arbitrary encoding information. The receiving node to the transmitting node By disclosing the underlying location information and order, the sending node can transmit the initial state to the receiving node. The receiving node can estimate the codeword encoded by the sending node and decode the estimated codeword to obtain the message.

[0280] Step 1-6: Second Security Inspection Step

[0281] The transmitting node discloses a random number of t0 qubits. If the error rate is lower than a preset value, it indicates secure quantum communication. If the error rate is higher than the preset value, it can be determined that it has been manipulated by an eavesdropper or an intermediate node.

[0282] In the present disclosure, a quantum channel refers to a channel through which qubits are transmitted, and may include at least one of an EPR state generation fault, a wired or wireless photon channel, a quantum memory error channel, etc. On the other hand, a classical channel may refer to a wireless channel of a wireless communication system, and a bit transmitted through a classical channel may refer to a classical bit. A classical channel does not necessarily have to be a wireless channel and may refer to a wired channel of a wired communication system. In the following, to clarify the difference between a quantum channel and a conventional communication channel, the terms classical channel and classical bit are used, but the distinction is not limited thereto. That is, a classical channel may be any channel for transmitting data.

[0283] In the first embodiment, an example was described in which the message qubits can be restored using an error correction code when loss occurs, but encoding can be performed directly without using an error correction code. As an example, a receiving node For the position of the qubit disclosed as a base, the measurement result is determined as a loss, and the retransmission of the information bit for that position can be performed.

[0284] FIG. 18 illustrates a first embodiment of signaling for performing an MDI SQSDC protocol according to one embodiment of the present disclosure. In FIG. 18, a quantum channel refers to a channel through which qubits are transmitted. In FIG. 18, the number of qubits through which data is transmitted, N=2, and the number of test qubits, t0, is set to t0. o It is assumed that t1 is set to 2 and the number of t1 test qubits is set to 4. In the following, test qubits can be used to perform security checks. Since the t1 test qubits are measured first, they are referred to as the first test qubits, and the t0 test qubits are referred to as the second test qubits.

[0285] Referring to FIG. 18, in step S1801, the transmitting node (1810) transmits single qubits to the receiving node (1820). Here, the single qubits are generated based on the first basis (N+t o +t1) / 2 = can include 4 qubits. The 4 qubits can be measured using the X basis. It can be generated in one of the quantum states. For the sake of understanding, the following explanation will be made using FIGS. 19a through 19d. For convenience of explanation, the transmitting node (1910), receiving node (1920), and intermediate node (1930) in FIGS. 19a through 19d are assumed to be the same devices as the transmitting node (1810), receiving node (1820), and intermediate node (1830) in FIG. 18, respectively.

[0286] FIG. 19a illustrates an example in which qubits are distributed according to one embodiment of the present disclosure. In FIG. 19a, the circles represent qubits, and t o The EPR-pair of test qubits is t inside the circle o ... was indicated, and the t1 test qubits were marked with t1 inside the circle. Also, the single qubits (1923, 1924, 1926, 1928) indicated by horizontal striped circles represent four qubits generated by the transmitting node (1810) and transmitted to the receiving node (1820), and the single qubits (1921, 1922, 1925, 1927) indicated by diagonal striped circles represent four qubits generated by the receiving node (1820). Here, the four qubits (1921, 1922, 1925, 1927) generated by the receiving node (1820) can be generated based on a second basis. For example, the four qubits (1921, 1922, 1925, 1927) can be measured as a Z basis It can be generated as one of the quantum states.

[0287] In step S1803, the transmitting node (1810) tells the intermediate node (1830) P ATransmits a batch. Here, P A The placement signal may include qubits (1911-2, 1913-2, 1916-2, 1917-2) selected one by one from each of the EPR-pairs (first EPR-pair (1911-1, 1911-2), second EPR-pair (1913-1, 1913-2), third EPR-pair (1916-1, 1916-2), fourth EPR-pair (1917-1, 1917-2)) and t1 test qubits (1912, 1914, 1915, 1918). The remaining qubits (1911-1, 1913-1, 1916-1, 1917-1) not selected from the EPR-pairs are stored by the transmitting node (1810). Here, the remaining qubits (1911-1, 1913-1, 1916-1, 1917-1) stored by the transmitting node (1810) are sequence S Ah It will be referred to as [Name].

[0288] In step S1805, the receiving node (1820) tells the intermediate node (1830) P B Transmits a batch. Here, P B The batch may include single qubits (1923, 1924, 1926, 1928) received from the transmitting node (1810) and four qubits (1921, 1922, 1925, 1927) generated by the receiving node (1820).

[0289] In step S1807, the transmitting node (1810), the intermediate node (1830), and the receiving node (1820) perform a first measurement procedure. FIG. 19b illustrates single-qubit sequences of the first measurement procedure according to one embodiment of the present disclosure. Referring to FIG. 19b, the intermediate node (1830) P of FIG. 19a A Batch and P B Receive the batch, and the received P A Batch and P BBell-base measurements are performed using a batch. The intermediate node (1830) may subsequently disclose the measurement results. Thus, the intermediate node (1830) may transmit the measurement results to the transmitting node (1810) and the intermediate node (1830). Subsequently, the receiving node (1820) can identify information regarding the qubits (1911-1, 1913-1, 1916-1, 1917-1) stored by the transmitting node (1810) through the disclosed measurement results and the qubits (1921 to 1928) it has transmitted.

[0290] In step S1809, the transmitting node (1810) transmits the location and state of the first test qubits to the receiving node (1820). That is, the transmitting node (1810) discloses the location and state of the first test qubits, namely the t1 test qubits. The location and state of the qubits may be disclosed based on an index. For example, the location and state of the qubits may be disclosed in the form of a sequence pair (m,n). Here, m represents the location of the qubit, and n represents the bit value. In FIG. 19b, since the t1 test qubits are located at the 2nd, 4th, 5th, and 8th positions, m can be set to 2, 4, 5, 8. In the following, it is assumed that the transmitting node (1810) transmits (2,0), (4,0), (5,1), and (8,1) to the receiving node (1820).

[0291] In step S1811, the receiving node (1820) transmits information related to the first test qubits to the transmitting node (1810). Based on the information disclosed by the transmitting node (1810), the receiving node (1820) generates information related to the 2nd, 4th, 5th, and 8th positions. Among the 2nd, 4th, 5th, and 8th qubits, the 2nd qubit (1922) and the 5th qubit (1925) are qubits prepared by the receiving node (1820), and the 4th qubit (1924) and the 8th qubit (1928) are qubits prepared by the transmitting node (1810). Accordingly, the receiving node (1820) discloses the status of the qubits it has prepared, and provides information so that the transmitting node (1810) can identify which qubits among the qubits it has sent are the qubits it has not disclosed. For example, the transmitting node (1810) may disclose information about the qubits in the form of a pair of orders (i,j). Here, i may indicate which node generated them. For example, the qubit transmitted by the receiving node (1820) may be indicated as i=0, and the qubit transmitted by the transmitting node (1810) may be indicated as i=1. j may indicate the quantum state prepared by the receiving node (1820) when i=0, and the order received from the transmitting node (1810) when i=1. In this case, the receiving node (1820) may transmit (0,0), (1,3), (0,1), and (1,2) to the transmitting node (1810).

[0292] In step S1813, the transmitting node (1810) transmits a quantum bit error rate (QBER) to the receiving node (1820). The QBER can be derived based on information disclosed by the receiving node (1820) when the basis of the states of the qubits prepared by the transmitting node (1810) and the receiving node (1820) is the same. The receiving node (1820) can decide whether to stop quantum communication based on the received QBER. For example, if the error rate is greater than a predetermined value, quantum communication may be stopped. Although it was explained that the receiving node (1820) stops quantum communication in step S1813, step S1813 may be omitted and quantum communication may be stopped by the transmitting node (1810). In this case, an indicator to stop quantum communication, rather than the QBER, may be transmitted. As another example, if the intermediate node (1830) is a control node, the QBER is transmitted to the intermediate node (1830), and the interruption of quantum communication can be declared by the intermediate node (1830).

[0293] In step S1815, the receiving node (1820) transmits information related to quantum teleportation to the intermediate node (1830). The information related to quantum teleportation is an operator It may include information related to. Information related to quantum teleportation is P transmitted by the receiving node (1820). B It can include basis information of the qubits included in the arrangement. Quantum teleportation operator is P B Based on the basis information of the qubits included in the arrangement and the measurement results disclosed by the intermediate node (1830), it can be determined as shown in [Table 3] above. The intermediate node (1830), having received information related to quantum teleportation from the receiving node (1820), can transmit the information related to quantum teleportation to the transmitting node (1810).

[0294] In step S1817, the transmitting node (1810) transmits an encoded message to the intermediate node (1830). FIG. 19c illustrates the remaining qubits, excluding the first test qubit, according to an embodiment of the present disclosure. Since the encoded message that the transmitting node (1810) intends to transmit may be lost with a 1 / 2 probability, an error correction code having a corresponding code rate may be used. Thus, the message to be transmitted may be converted into a codeword using the error correction code. The information bits included in the converted codeword are the quantum teleportation operator received from the receiving node (1820). Message encoding can be performed using a message encoding operator determined using [Equation 8]. Here, the message encoding operator can be set in the form shown in [Equation 8] above. Here, the encoded message is encoded into N message qubits (1913-1, 1917-1) using the encoding operator This includes the applied qubits. Accordingly, the qubits (1913-1, 1917-1) containing the encoded message information are transmitted to the intermediate node (1830) as shown in FIG. 19d. For message integrity, the second test qubits (1911-1, 1916-1) are also transmitted after being encoded into test bits that are arbitrary numbers.

[0295] In step S1819, the transmitting node (1810), the intermediate node (1830), and the receiving node (1820) perform a second measurement procedure. Since the intermediate node (1830) can determine the basis of each of the received qubits (1911-1, 1913-1, 1916-1, 1917-1) based on the information related to quantum teleportation received in step S1815, the unitary operator U corresponding to the qubits (1911-1, 1913-1, 1916-1, 1917-1) based on the acquired basis B It can obtain. The intermediate node (1830) is a unitary operator U BAfter performing and measuring with the Z basis, the result is disclosed. Through the disclosed information, the receiving node (1820) can obtain the codeword of the message encoded by the transmitting node (1810) and a random number. In step S1819, the second measurement step is the unitary operator U B Although it has been described as applying and measuring with a Z basis, it is not limited thereto. For example, an intermediate node (1830) can measure with an X basis or a Z basis based on the acquired basis without applying a unitary operator.

[0296] In step S1821, the transmitting node (1810) transmits information related to the second test qubit to the receiving node (1820). Here, the information related to the second test qubit includes information related to an arbitrary number. The receiving node (1820) can calculate an error rate by comparing the arbitrary number received from the transmitting node (1810) with an arbitrary number obtained from the measurement result of the intermediate node (1830), and can determine whether there is an eavesdropper based on the error rate.

[0297] In FIG. 18, the transmission or reception of a specific signal from the transmitting node (1810) to the receiving node (1820) does not necessarily have to be delivered directly, but can be received through other nodes. For example, in step S1809, when the transmitting node (1810) transmits the location and status of the first test qubits to the receiving node (1820), the transmitting node (1810) can transmit the location and status of the first test qubits to the intermediate node (1830), and the intermediate node (1830) can transmit the location and status of the first test qubits to the receiving node (1820). As another example, the transmitting node (1810) can disclose the location and status of the first test qubits to a third node, etc., and the receiving node (1820) can receive the disclosed information.

[0298] Additionally, information transmitted by the transmitting node (1810) and the receiving node (1820) to the intermediate node (1830) may be made public. That is, information transmitted to the intermediate node (1830) via a classical channel may refer to information directly delivered to the transmitting node (1810) or the receiving node (1820). For example, as in step S1805, information related to quantum teleportation may not be transmitted from the receiving node (1820) to the intermediate node (1830) and then back to the transmitting node (1810), but rather the receiving node (1820) may directly transmit information related to quantum teleportation to the transmitting node (1810) via a classical channel. The method of transmitting the disclosed information may be broadcast or unicast. The method of transmitting information transmitted to the intermediate node may be applied identically to the procedures described below.

[0299] By utilizing the aforementioned first embodiment, secure communication can be performed regardless of the detection result. Since the detector is the equipment most susceptible to attack, the ability to perform communication regardless of the detection result means that communication can be performed safely against a large number of detector attacks.

[0300] A second embodiment of the MDI SQSDC protocol is described below for transmitting MDI SQSDC protocol classical information. The second embodiment may be performed by a device such as that shown in FIG. 20. FIG. 20 illustrates an example of a device for performing the second embodiment of the MDI SQSDC protocol according to one embodiment of the present disclosure.

[0301] FIG. 20 illustrates an example of an apparatus for performing a second embodiment of an MDI SQSDC protocol according to one embodiment of the present disclosure. Referring to FIG. 20, a transmitting node (2010) and a receiving node (2020) 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.

[0302] The transmitting node (2010) may include an entanglement source (ES) (2011), a laser (2012), an intensity modulator (IM) (2013), and a polarization modulator (PM) (2014).

[0303] An entanglement source (2011) is a device that generates entangled photon pairs. Entangled photons generated by the entanglement source (2011) may exhibit strong correlations in polarization, phase, or time-bin states and may be used in quantum communication protocols. The entanglement source (2011) may transmit all or part of the entangled photon pairs to an intensity modulator (2013).

[0304] A laser (2012) can generate a single photon qubit. Since the transmitting node (2010) must generate a single photon qubit set as a first test qubit as well as an entangled photon pair, the laser (2012) can be used to generate a photon qubit.

[0305] The intensity modulator (2013) can adjust the amplitude or intensity of a single qubit generated from the laser (2012), and the phase modulator (2014) can adjust the phase of the output signal of the intensity modulator (2013). At least one photon qubit generated from the entanglement source (2011) or the laser (2011) can be transmitted to an intermediate node (2030) through the intensity modulator (2013) and the phase modulator (2014). Additionally, the photon qubit generated from the laser (2012) can be transmitted to a receiving node (2020).

[0306] The receiving node (2020) may include a laser (2022), an intensity modulator (2023), and a phase modulator (2024). The laser (2022) may generate a single photon qubit. The receiving node (2020) may generate a photon qubit using the laser (2022). Here, a single qubit sequence may be formed including a single photon qubit received from the transmitting node (2010) and a single photon qubit of the receiving node (2020), and the qubit sequence may be transmitted to the intensity modulator (2023).

[0307] The intensity modulator (2023) can adjust the amplitude or intensity of a single photon qubit or sequence of qubits generated by the laser (2022). The phase modulator (2024) can adjust the phase of the output signal of the intensity modulator (2022). At least one photon qubit generated by the laser (2021) can be transmitted to an intermediate node (2030) through the intensity modulator (2023) and the phase modulator (2024).

[0308] The intermediate node (2030) may include a beam splitter (2031), a polarization beam splitter (2032, 2033), and a quantum memory (QM) (2034). The beam splitter (2031) can split an incident optical signal into two or more paths and transmit them to two polarization beam splitters (2032, 2033). The intermediate node (2030) can use the two polarization beam splitters (2032, 2033) to split the beam according to the polarization of the optical signal received through the beam splitter (2031), and can obtain measurement results including what quantum state it has depending on which detector it was measured by. In the case of the second embodiment, the intermediate node (2030) can perform measurements after storing the signals received from the transmitting node (2010) in the quantum memory (2034) and obtaining information about the order.

[0309] The second embodiment can be carried out through the following Steps 2-1 to 2-6.

[0310] Step 2-1: Preparation Phase

[0311] The transmitting nodes are N An EPR pair is generated. The transmitting node separates each qubit included in the EPR pair and divides them into two single-qubit sequences. Here, sequence S Ah refers to a sequence stored by the transmitting node, and sequence S At is defined as the sequence transmitted by the transmitting node to the receiving node. The transmitting node additionally generates t1 single qubits. Here, each of the single qubits is It is generated in one of the states. The transmitting node prepares t1 single qubits and sequence S At An ordered sequence P obtained by inserting at an arbitrary position A Creates.

[0312] The transmitting node generates (N+t1) / 2 random single qubits and transmits them to the receiving node. Here, the (N+t1) / 2 random single qubits are It is randomly generated into one of the states. In this case, the N EPR-pairs generated by the transmitting node are used to transmit classical information, and t1 single qubits are used for security checks. Here, since it is sufficient for the (N+t1) / 2 qubits transmitted by the transmitting node to be in the X ground state, they do not necessarily need to have a single photon state.

[0313] The receiving node has (N+t1) / 2 single qubits A sequence P that is randomly generated as one of the states and arranged in a random order with single qubits received from the transmitting node. B Creates.

[0314] Step 2-2: Measurement Step

[0315] The transmitting node sends sequence P to the intermediate node. A The receiving node transmits and sends sequence P to the intermediate node. B It transmits. The intermediate node performs Bell-basis measurements using the received qubits and publishes the measurement results. The single qubit generated by the transmitting node's EPR pair, after the Bell measurement, It collapses into one of the states. Therefore, the sequence S stored by the transmitting node Ah The single qubits included in it also collapse, and the transmitting node and the intermediate node cannot know the state in which the single qubits have collapsed. However, the receiving node, based on the initial state of the qubits it prepared and the results disclosed by the intermediate node, uses the above [Table 3] to retrieve the sequence S stored by the transmitting node. Ah The single qubits included in can be identified as follows.

[0316] If one of the qubits on which Bell-basis measurements were performed is a qubit generated by the receiving node, the receiving node can accurately know the state of the qubit stored by the transmitting node corresponding to the qubits on which Bell-basis measurements were performed.

[0317] On the other hand, if the receiving node finds that one of the qubits on which a Bell-basis measurement was performed is not a qubit generated by itself, the receiving node Only the information of can be known. Afterwards, the receiving node to the sending node It transmits the information. The transmitting node uses the received operator in the qubits it stores. By applying this, the stored qubits can be made identical to the qubits generated by the receiving node.

[0318] The initial state of N EPR pairs is It is set to. If the state of the qubit generated by the receiving node is In this case, the intermediate node is The result of the Bell-basis measure can be obtained for . That is, the intermediate node is If you perform a measurement on, You can obtain one of the results. The intermediate node is For each, one of the corresponding classic bits '10', '11', '00', or '01' is disclosed. If '10' or '11' is disclosed by the intermediate node, the receiving node [is] the EPR-pair prepared by the transmitting node. It can be determined that, and the qubits stored by the transmitting node are It can be seen that. Similarly, if '00' or '01' is disclosed by the intermediate node, the receiving node knows that the EPR pair prepared by the transmitting node is It can be determined that, and the qubits stored by the transmitting node are It can be seen that... In the same way, the receiving node can determine which qubits the remaining qubits stored by the transmitting node are. Subsequently, the receiving node [applies] the quantum teleportation operator to the qubits stored by the transmitting node. It can disclose.

[0319] Step 2-3: First Security Inspection Step

[0320] The transmitting node discloses the locations and states of t1 qubits, and the receiving node discloses information related to the qubits corresponding to those locations. Here, if the qubits at the corresponding locations are qubits prepared by the receiving node, the receiving node may disclose the state information of those qubits. If the qubits at the corresponding locations are qubits received from the transmitting node, the receiving node may inform the transmitting node that those qubits were received from the transmitting node. For example, the receiving node may transmit information related to the locations of the qubits received from the transmitting node. Since the quantum states of the t1 qubits disclosed by the transmitting node and their corresponding qubits are randomly selected, if an error occurs even though the basis of the qubits is the same, it can be attributed to the influence of an eavesdropper. If a different basis is selected, it is impossible to confirm that an error has occurred because all possible combinations of Bell states are possible. Therefore, the transmitting node or the receiving node can determine the presence of an eavesdropper based on the error rate and decide whether to continue quantum communication.

[0321] Step 2-4: Message Encoding Step

[0322] The transmitting node can perform encoding through the following method. The receiving node discloses information regarding the bases of the remaining N qubits to the transmitting node. Since the receiving node does not know the bases of the qubits prepared by the transmitting node, the transmitting node can determine the bases of the corresponding qubits through the location information of the qubits received from the transmitting node. Additionally, the transmitting node can transmit information regarding the bases of the qubits it has prepared to the receiving node.

[0323] The transmitting node determines the M qubits corresponding to the qubits prepared by the receiving node from among the N qubits it stores as the message qubits. (M <N) 수신 노드가 준비한 큐비트들에 대응하지 않는 나머지 N-M개의 큐비트들에 대해서는 제거하고 임의의 단일 큐비트들을 M개 생성하여 배치함으로써, 기존의 큐비트들을 대체한다. 하기에서는 메시지 큐비트들 및 대체된 임의의 단일 큐비트들로 이루어진 큐비트 시퀀스를 시퀀스 S A It will be referred to as [Name].

[0324] The transmitting node is a quantum teleportation operator as shown in [Equation 9] and message encoding operators Encoding operator based on Determines.

[0325]

[0326] In [Equation 9], when the encoded message is 0, the message encoding operator silver It can be set to. Conversely, if the encoded message is 1, the message encoding operator silver It can be set to.

[0327] The transmitting node is sequence S AEncoding can be performed by applying an encoding operator U corresponding to the encoding message to the included message qubits. Subsequently, the transmitting node sequence S A The order of the qubits is rearranged randomly. Below is the sequence S rearranged in a random order. A We will refer to it as '

[0328] Step 2-5: Message Decoding Step

[0329] The transmitting node tells the intermediate node the encoding operator Sequence S to which is applied A Transmits '. The intermediate node is sequence S A Revealing the fact of reception, and sequence S in quantum memory A The transmitting node stores '. The transmitting node is sequence S A Disclosing the order information of the qubits included in ' and the positions of t0 qubits for error checking, and the intermediate node based on the order information sequence S A Restores.

[0330] The intermediate node performs a unitary operation on the received qubit sequence Apply. Here, the unitary operator is the basis of the received qubit In the case of, It is set to, and the basis of the received qubit is In the case of, It is set to.

[0331] For the intermediate node, for the qubit sequence to which the unitary operator is applied It performs a baseline measurement and discloses the result. The receiving node can obtain an encoded message based on the disclosed result.

[0332] Step 2-6: Second Security Inspection Step

[0333] The transmitting node discloses a random number of qubit t0. If the error rate is lower than a preset value, it signifies secure quantum communication. If the error rate is higher than the preset value, it can be determined that the device has been manipulated by an eavesdropper or an intermediate node. If the intermediate node is an eavesdropper, it can determine the location of the message qubit using the sequence information disclosed by the transmitting node. Therefore, the state of the message qubit can be determined through measurement without increasing the error rate, but the value of the message cannot be determined using this method.

[0334] FIG. 21 illustrates a second embodiment of signaling for performing an MDI SQSDC protocol according to one embodiment of the present disclosure. In FIG. 21, a quantum channel refers to a channel through which qubits are transmitted. In FIG. 21, it is assumed that the number of qubits through which data is transmitted is set to N=4, and the number of t1 test qubits is set to t1=4. In the following, test qubits may be used to perform security checks. Since the t1 test qubits are measured first, they are referred to as the first test qubits, and the t0 test qubits are referred to as the second test qubits.

[0335] Referring to FIG. 21, in step S2101, the transmitting node (2110) transmits a single qubit to the receiving node (2120). Here, the single qubit may include (N+t1) / 2 = 4 qubits generated based on a first basis. The 4 qubits can be measured as an X basis. It can be generated in one of the quantum states. For the sake of understanding, the following explanation will be made using FIGS. 22a to 22d. For convenience of explanation, the transmitting node (2210), receiving node (2220), and intermediate node (2230) in FIGS. 22a to 22d are assumed to be the same devices as the transmitting node (2110), receiving node (2120), and intermediate node (2130) in FIG. 21, respectively.

[0336] FIG. 22a illustrates an example of qubits being distributed according to one embodiment of the present disclosure. In FIG. 22a, the circles represent qubits, and the t1 test qubits are labeled t1 inside the circles. Unlike FIG. 19a, t o The positions of the test qubits are not predetermined. Additionally, the single qubits (2223, 2224, 2226, 2228) indicated by horizontal striped circles represent four qubits generated by the transmitting node (2110) and transmitted to the receiving node (2120), and the single qubits (2221, 2222, 2225, 2227) indicated by diagonal striped circles represent four qubits generated by the receiving node (2120). Here, the four qubits (2221, 2222, 2225, 2227) generated by the receiving node (2120) can be generated based on a second basis. For example, the four qubits (2221, 2222, 2225, 2227) can be measured as a Z basis. It can be generated as one of the quantum states.

[0337] In step S2103, the transmitting node (2110) tells the intermediate node (2130) P A Transmits a batch. Here, P A The placement signal may include qubits (2211-2, 2213-2, 2216-2, 2217-2) selected one by one from each of the EPR-pairs (first EPR-pair (2211-1, 2211-2), second EPR-pair (2213-1, 2213-2), third EPR-pair (2216-1, 2216-2), fourth EPR-pair (2217-1, 2217-2)) and t1 test qubits (2212, 2214, 2215, 2218). The remaining qubits (2211-1, 2213-1, 2216-1, 2217-1) not selected from the EPR-pairs are stored by the transmitting node (2110). Here, the remaining qubits (2211-1, 2213-1, 2216-1, 2217-1) stored by the transmitting node (2110) are sequence S Ah It will be referred to as [Name].

[0338] In step S2105, the receiving node (2120) tells the intermediate node (2130) P B Transmits a batch. Here, P B The batch may include single qubits (2223, 2224, 2226, 2228) received from the transmitting node (2110) and four qubits (2221, 2222, 2225, 2227) generated by the receiving node (2120).

[0339] In step S2107, the transmitting node (2110), the intermediate node (2130), and the receiving node (2120) perform a first measurement procedure. FIG. 22b illustrates single-qubit sequences of the first measurement procedure according to one embodiment of the present disclosure. Referring to FIG. 22b, the intermediate node (2130) P of FIG. 22a A Batch and P B Receive the batch, and the received P A Batch and P B Bell-base measurements are performed using a batch. The intermediate node (2130) may subsequently disclose the measurement results. Thus, the intermediate node (2130) may transmit the measurement results to the transmitting node (2110) and the intermediate node (2130). Subsequently, the receiving node (2120) can identify information regarding the qubits (2211-1, 2213-1, 2216-1, 2217-1) stored by the transmitting node (2110) through the disclosed measurement results and the qubits (2221 to 2228) it has transmitted.

[0340] In step S2109, the transmitting node (2110) transmits the location and state of the first test qubits to the receiving node (2120). That is, the transmitting node (2110) discloses the location and state of the first test qubits, namely the t1 test qubits. The location and state of the qubits may be disclosed based on an index. For example, the location and state of the qubits may be disclosed in the form of a sequence pair (m,n). Here, m represents the location of the qubit, and n represents the bit value. In FIG. 22b, since the t1 test qubits are located at the 2nd, 4th, 5th, and 8th positions, m can be set to 2, 4, 5, 8. In the following, it is assumed that the transmitting node (2110) transmits (2,0), (4,0), (5,1), and (8,1) to the receiving node (2120).

[0341] In step S2111, the receiving node (2120) transmits information related to the first test qubits to the transmitting node (2110). Based on the information disclosed by the transmitting node (2110), the receiving node (2120) generates information related to the 2nd, 4th, 5th, and 8th positions. Among the 2nd, 4th, 5th, and 8th qubits, the 2nd qubit (2222) and the 5th qubit (2225) are qubits prepared by the receiving node (2120), and the 4th qubit (2224) and the 8th qubit (2228) are qubits prepared by the transmitting node (2110). Accordingly, the receiving node (2120) discloses the status of the qubits it has prepared, and provides information so that the transmitting node (2110) can identify which qubits among the qubits it has sent are the qubits it has not disclosed. For example, the transmitting node (2110) may disclose information about the qubits in the form of a pair of orders (i,j). Here, i may indicate which node generated them. For example, the qubit transmitted by the receiving node (2120) may be indicated as i=0, and the qubit transmitted by the transmitting node (2110) may be indicated as i=1. j may indicate the quantum state prepared by the receiving node (2120) when i=0, and the order received from the transmitting node (2110) when i=1. In this case, the receiving node (2120) may transmit (0,0), (1,3), (0,1), and (1,2) to the transmitting node (2110).

[0342] In step S2113, the transmitting node (2110) transmits a quantum bit error rate (QBER) to the receiving node (2120). The QBER can be derived based on information disclosed by the receiving node (2120) when the basis of the states of the qubits prepared by the transmitting node (2110) and the receiving node (2120) is the same. The receiving node (2120) can decide whether to stop quantum communication based on the received QBER. For example, if the error rate is greater than a predetermined value, quantum communication may be stopped. Although it was explained that the receiving node (2120) stops quantum communication in step S2113, step S2113 may be omitted and quantum communication may be stopped by the transmitting node (2110). In this case, an indicator to stop quantum communication, rather than the QBER, may be transmitted. As another example, if the intermediate node (2130) is a control node, the QBER is transmitted to the intermediate node (2130), and the interruption of quantum communication can be declared by the intermediate node (2130).

[0343] In step S2115, the receiving node (2120) transmits information related to quantum teleportation to the transmitting node (2110). The information related to quantum teleportation is P transmitted by the receiving node (2120). B It can include basis information of the qubits included in the arrangement. Quantum teleportation operator is P B Based on the basis information of the qubits included in the batch and the measurement results disclosed by the intermediate node (2130), it can be determined as shown in [Table 3] above.

[0344] In step S2117, the receiving node (2120) is sequence S A Transmit ' to the intermediate node (2130). Sequence S A' may include qubits corresponding to the qubits generated by the receiving node (2120) among the qubits stored by the transmitting node (2110), and t0 test qubits. To this end, referring to FIG. 22b, the transmitting node (2110) may use the qubits (2211-1, 2217-1) corresponding to the qubits (2221 and 2227) generated by the receiving node (2120) among the qubits stored by itself as message qubits, and discard the remaining qubits (2213-1 and 2216-1). In the case as in FIG. 22b, the number of message qubits is set to M=2.

[0345] The transmitting node (2110) can generate new t0 test qubits. FIG. 22c illustrates an example of t0 test qubits generated by the transmitting node (2110) according to an embodiment of the present disclosure. Referring to FIG. 22c, sequence S in which t0 test qubits (2213-3, 2216-3) are newly inserted A t0 can be determined. The t0 test qubits (2213-3, 2216-3) can be set to any number.

[0346] The message qubits (2211-1, 2217-1) can be used for message encoding. The transmitting node (2110) receives the quantum teleportation operator. Message encoding is performed based on [Equation 9]. Here, the message encoding operator can be set in the form shown in [Equation 9] above. Subsequently, the transmitting node (2110) arranges the encoded message qubits (2211-1, 2217-1) and t0 test qubits (2213-3, 2216-3) in an arbitrary order in sequence S. A Sends ' to the intermediate node (2130).

[0347] In steps S2119 and S2121, the intermediate node (2130) is sequence S A Sends a receipt acknowledgment message to the transmitting node (2110) and the receiving node (2120). Received sequence SA ' is not measured immediately, but is stored in the quantum memory of the intermediate node (2130).

[0348] In step S2123, the transmitting node (2110) gives sequence S to the intermediate node (2130). A Transmits information related to '. Sequence S A Information related to 'sequence S A At least one of the order information of the qubits included in ' or the location of the t0 test qubits (2213-3, 2216-3) may be disclosed. The intermediate node (2130) is sequence S A Sequence S based on information related to ' A It can be restored. FIG. 22d shows that, according to one embodiment of the present disclosure, an intermediate node (2130) is sequence S A This is a drawing illustrating an example of restoring it.

[0349] In step S2125, the intermediate node (2130) performs a second measurement procedure. The intermediate node (2130) performs the unitary operator UB, measures using the Z basis, and then discloses the result. Through the disclosed information, the receiving node (2120) can obtain the codeword of the message encoded by the transmitting node (2110) and a random number.

[0350] In step S2127, the transmitting node (2110) transmits information related to the second test qubit to the receiving node (2120). Here, the information related to the second test qubit includes information related to an arbitrary number. The receiving node (2120) can calculate an error rate by comparing the arbitrary number received from the transmitting node (2110) with the arbitrary number obtained from the measurement result of the intermediate node (2130), and can determine whether there is an eavesdropper based on the error rate.

[0351] In FIG. 21, the transmission or reception of a specific signal from the transmitting node (2110) to the receiving node (2120) does not necessarily have to be delivered directly, but can be received through other nodes. For example, in step S2109, when the transmitting node (2110) transmits the location and status of the first test qubits to the receiving node (2120), the transmitting node (2110) can transmit the location and status of the first test qubits to the intermediate node (2130), and the intermediate node (2130) can transmit the location and status of the first test qubits to the receiving node (2120). As another example, the transmitting node (2110) can disclose the location and status of the first test qubits to a third node, etc., and the receiving node (2120) can receive the disclosed information.

[0352] By using the aforementioned second embodiment, secure communication independent of the detection result can be performed. Since the detector is the equipment most susceptible to attack, the ability to perform communication independent of the detection result means that communication can be performed securely against a large number of detector attacks. Unlike the first embodiment, if the intermediate node has quantum memory, the possibility of loss of message qubits can be eliminated because the location of the t0 test qubits is not determined in advance.

[0353] Hereinafter, examples of wireless device applications to which various embodiments of the present disclosure are applied will be described.

[0354] FIG. 23 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).

[0355] Referring to FIG. 23, 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).

[0356] 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.

[0357] In FIG. 23, various elements, components, units / parts, and / or modules within the wireless device (200) may be entirely interconnected via a wired interface, or at least partially connected via a communication unit (210). For example, within the wireless device (200), the control unit (220) and the communication unit (210) may be connected via a wire, and the control unit (220) and the first unit (e.g., 230, 240) may be connected wirelessly 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.

[0358] Hereinafter, an implementation example of FIG. 23 will be described in more detail with reference to the drawings.

[0359] FIG. 24 illustrates an example of a portable device applicable to the present disclosure. A 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). A 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).

[0360] Referring to FIG. 24, 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. 24 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0361] 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.

[0362] 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).

[0363] FIG. 25 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.

[0364] Referring to FIG. 25, 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. 25 correspond to blocks 210 / 230 / 240 of FIG. 23, respectively.

[0365] 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.

[0366] 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).

[0367] FIG. 26 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. 26, 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. 23, respectively.

[0368] 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.

[0369] 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).

[0370] FIG. 27 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.

[0371] Referring to FIG. 27, 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. 27 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0372] 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 control the components of the XR device (200a) to perform various operations. 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.

[0373] 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).

[0374] 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).

[0375] FIG. 28 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.

[0376] Referring to FIG. 28, 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. 28 correspond to blocks 210 to 230 / 240 of FIG. 23, respectively.

[0377] 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.

[0378] FIG. 29 illustrates an example of an AI device applicable to the present disclosure.

[0379] 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.

[0380] Referring to FIG. 29, 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. 29 correspond to blocks 210 to 230 / 140 of FIG. 23, respectively.

[0381] 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 this end, 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).

[0382] 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.

[0383] 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).

[0384] 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.

[0385] 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).

[0386]

[0387] 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).

[0388] 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.

[0389] 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.

[0390] 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.

[0391] 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 receiving information related to a first measurement result from the second device; A step of generating a data signal by performing data encoding based on a quantum teleportation operator determined based on the first measurement result; and The method includes the step of transmitting the above data signal to the second device, The information related to the first measurement result above includes the bell state measurement result for the first signal and the second signal for measurement transmitted by the third device, and A method in which the second signal comprises at least one qubit generated by a first device based on a first basis and at least one qubit generated by a third device based on a second basis.

2. In Paragraph 1, The first signal above includes a first qubit, a second qubit, and a third qubit, and A method in which the fourth qubit entangled with the second qubit and the fifth qubit entangled with the third qubit are stored by the first device.

3. In Paragraph 2, A step of transmitting the position and state of the first qubit to the third device; A step of receiving information related to a sixth qubit existing at the same position as the first qubit among the qubits included in the second signal from the third device; and A method for determining whether to use the fourth qubit and the fifth qubit based on measurement results related to the first qubit and the sixth qubit among the first measurement results.

4. In Paragraph 3, The first qubit and the sixth qubit are generated on the same basis, and A method in which the fourth qubit and the fifth qubit are discarded when the measurement results related to the first qubit and the sixth qubit and the initial quantum states of the first qubit and the sixth qubit are not identical.

5. In Paragraph 2, The method further includes the step of receiving information related to the quantum teleportation operator from the third device, wherein A method in which the second signal includes a seventh qubit existing at the same location as the second qubit and an eighth qubit existing at the same location as the third qubit.

6. In Paragraph 5, The information related to the above quantum teleportation operator includes the basis information of the 7th qubit and the basis information of the 8th qubit, and The quantum teleportation operator for the fourth qubit is determined based on the basis information of the seventh qubit and the measurement results of the second qubit and the seventh qubit, and A method in which a quantum teleportation operator for the fifth qubit is determined based on the basis information of the eighth qubit and the measurement results of the third qubit and the eighth qubit.

7. In Paragraph 6, The above fourth qubit is set as a message qubit for the data encoding, and The above fifth qubit is set as a second test qubit.

8. In Paragraph 7, A step of converting a transmitted message into a codeword based on an error correction code; A step of determining a message encoding operator based on information bits included in the above codeword; A step of determining an encoding operator based on the quantum teleportation operator for the fourth qubit and the message encoding operator; and The method further includes the step of performing data encoding by applying the encoding operator to the fourth qubit, The above data signal is a method including the fourth qubit to which the above encoding operator is applied.

9. In Paragraph 8, When the above 7th qubit is generated as the above 2nd basis, the information bit transmitted to the above 4th qubit to which the above encoding operator is applied is determined to be a successful transmission, and A method in which, when the above-mentioned seventh qubit is generated with the above-mentioned first basis, the information bit transmitted to the above-mentioned fourth qubit to which the above-mentioned encoding operator is applied is determined to be a transmission failure.

10. In Paragraph 8, A step of determining a test bit for the fifth qubit; A step of determining an encoding operator based on the quantum teleportation operator for the fifth qubit and the test bit; and The method further includes the step of performing encoding by applying the encoding operator to the fifth qubit, The above data signal is a method including the fifth qubit to which the above encoding operator is applied.

11. In Paragraph 10, The step of disclosing information related to the above test bit is further included, A method for determining whether to stop quantum communication based on the measurement result of the fifth qubit to which the above encoding operator is applied and the above test bit.

12. In Paragraph 6, The method further includes the step of receiving information regarding the bases of the seventh qubit and the eighth qubit from the third device, wherein If the basis of the above 7th qubit is generated as the above 1st basis, the above 4th qubit is discarded, and If the basis of the above 7th qubit is generated as the above 2nd basis, the above 4th qubit is set as a message qubit, and If the basis of the above 8th qubit is generated as the above 1st basis, the above 5th qubit is discarded, and A method in which the 5th qubit is set as a message qubit when the basis of the 8th qubit is generated as the 2nd basis.

13. In Paragraph 12, A step of determining a message encoding operator based on a transmitted message; A step of determining an encoding operator based on a quantum teleportation operator for the seventh qubit set as the message qubit and the message encoding operator; A step of performing data encoding by applying the encoding operator to the seventh qubit set as the message qubit; and The above data signal is a method including the seventh qubit to which the above encoding operator is applied.

14. In Paragraph 13, If the above eighth qubit is discarded, the data signal further includes a second test qubit indicating an arbitrary bit, and A method for determining whether to use the fourth qubit and the fifth qubit based on the measurement result of the second test qubit and the arbitrary bit.

15. In Paragraph 14, A step of changing the order of qubits included in the above data signal; and A method further comprising the step of transmitting information regarding the order of changed qubits to the second node.

16. 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 second signal for measurement to a second device; A step of receiving information related to a first measurement result from the second device; A step of transmitting information related to a quantum teleportation operator determined based on the first measurement result to the first device; A step of receiving information related to a second measurement result from the second device; and The method includes the step of obtaining a message based on information related to the second measurement result, The information related to the first measurement result above includes the bell state measurement result for the second signal and the first signal for measurement transmitted by the first device, and The second signal comprises at least one qubit generated by a first device based on a first basis and at least one qubit generated by a third device based on a second basis, and Information related to the second measurement result above includes a method comprising the result of measuring a data signal in which data encoding is performed based on the first measurement result above.

17. In Paragraph 15, A method in which information related to the above quantum teleportation operator includes information related to the basis of a qubit generated by the third device among the qubits included in the second signal.

18. 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 receiving a second signal for measurement from a third device; A step of disclosing information related to a first measurement result, including a bell state measurement result for the first signal and the second signal; A step of receiving a data signal for which data encoding has been performed based on the first measurement result above; The method includes the step of transmitting information related to a second measurement result, including the result of measuring the data signal, to the third device, wherein A method in which the second signal comprises at least one qubit generated by a first device based on a first basis and at least one qubit generated by a third device based on a second basis.

19. In Paragraph 18, A step of storing the above data signal in a quantum memory; A step of receiving information regarding the order of changed qubits from the first node; and A method further comprising the step of measuring a data signal stored in a quantum memory based on information regarding the above sequence.

20. 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 Receive information related to the first measurement result from the second device, and A data signal is generated by performing data encoding based on a quantum teleportation operator determined based on the first measurement result above, and Configured to transmit the above data signal to the second device, The information related to the first measurement result above includes the bell state measurement result for the first signal and the second signal for measurement transmitted by the third device, and The second signal is a first device comprising at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis.

21. In the third device, Transmitter / receiver; and It includes a processor coupled to the above-mentioned transmitter and receiver, The above processor is, Based on the above system information, a random access procedure is performed, and Transmitting a second signal for measurement to a second device, Receive information related to the first measurement result from the second device, and Transmitting information related to a quantum teleportation operator determined based on the first measurement result to the first device, and Receive information related to the second measurement result from the second device, and Configured to acquire a message based on information related to the second measurement result above, The information related to the first measurement result above includes the bell state measurement result for the second signal and the first signal for measurement transmitted by the first device, and The second signal comprises at least one qubit generated by a first device based on a first basis and at least one qubit generated by a third device based on a second basis, and Information related to the second measurement result above includes a third device comprising the result of measuring a data signal for which data encoding has been performed based on the first measurement result.

22. 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 A first device receives a first signal for measurement, and A third device receives a second signal for measurement, and Disclosing information related to a first measurement result including a bell state measurement result for the first signal and the second signal, and Receive a data signal for which data encoding has been performed based on the first measurement result above, and The third device is configured to transmit information related to a second measurement result, including the result of measuring the data signal, to the third device, The second signal comprises a second device including at least one qubit generated by a first device based on a first basis and at least one qubit generated by a third device based on a second basis.

23. 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; 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 receiving information related to a first measurement result from the second device; A step of generating a data signal by performing data encoding based on a quantum teleportation operator determined based on the first measurement result; and The method includes the step of transmitting the above data signal to the second device, The information related to the first measurement result above includes the bell state measurement result for the first signal and the second signal for measurement transmitted by the third device, and The second signal is a transmitting node comprising at least one qubit generated by the transmitting node based on a first basis and at least one qubit generated by the third device based on a second basis.

24. 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 Receive information related to the first measurement result from the second device, and A data signal is generated by performing data encoding based on a quantum teleportation operator determined based on the first measurement result above, and Configured to transmit the above data signal to the second device, The information related to the first measurement result above includes the bell state measurement result for the first signal and the second signal for measurement transmitted by the third device, and The second signal is a computer-readable medium comprising at least one qubit generated by the first device based on a first basis and at least one qubit generated by the third device based on a second basis.

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