Lg Electronics Inc.

Osong Medical Innovation Foundation, Korea University Research and Business Foundation

Byungkyu Ahn

Sangrim Lee

Hojae Lee

Jayeong Kim

Kijun Jeon

Byounghoon Kim

Bonghoe Kim

Sungjin Kim

Sunam Kim

Jun Young Heo

Kyungho Lee

Sung Sik Yoon

The present specification provides a method for estimating a quantum bit error rate (QBER) for key information, performed by a device in a quantum cryptography communication system, the method and device being characterized by: receiving a random access (RA) preamble from another device; transmitting a random access response (RAR) to the other device, in response to the RA preamble, performing a radio resource control (RRC) connection process with the other device; receiving data from the other device; and decoding the data on the basis of the key information, wherein the key information is determined on the basis of estimation of the QBER, and the device estimates the QBER on the basis of first two-dimensional parity information received from the other device through a public channel.

Method and device for estimating quantum bit error rate on basis of maximum bit group and two-dimensional parity

A method performed by means of a first wireless device in a wireless communication system, according to one embodiment of the present specification, comprises the steps of: transmitting, to a second wireless device, a first signal to which a first specific beam is applied; transmitting, to the second wireless device, a second signal to which a second specific beam is applied; receiving, from the second wireless device, feedback information generated on the basis of the first signal and the second signal; and determining, on the basis of the feedback information, a beam related to the second wireless device.

Method for controlling beam in wireless communication system, and apparatus therefor

A method performed by a first wireless device in a wireless communication system, according to one embodiment of the present specification, comprises the steps of: transmitting, to a second wireless device, a signal to which a specific beam is applied; receiving, from the second wireless device, feedback information generated on the basis of the signal; and determining, on the basis of the feedback information, a beam related to the second wireless device.

The present specification provides a method, performed by an apparatus, for transmitting at least one beam in a wireless communication system, the method comprising transmitting the at least one beam to another apparatus and receiving information about a result of measuring the at least one beam from the other apparatus, wherein the at least one beam is a beam generated on the basis of a signal synthesized from a laser signal being incident on a meta surface from a power controller, the laser signal consists of a plurality of frequency components, the synthesized signal is a signal in which power amplification is applied to each of the plurality of frequency components, and the power amplification is applied on the basis of the intensity regarding each of the plurality of frequency components.

Frequency comb power control apparatus for 4D beamforming, and method therefor

The present specification provides a method and a device, the method, performed by a device, for transmitting a first pulse train in a quantum communication system being characterized by: receiving a random access (RA) preamble from another device; transmitting an RA response (RAR) to the other device as a response to the RA preamble; performing a radio resource control (RRC) connection process with the other device; receiving data from the other device; and decoding the data on the basis of key information, wherein a first pulse train is generated in a laser diode of the device, and the key information is determined on the basis that the first pulse train passes through both a first path and a second path and is then transmitted from the device to the other device via a quantum channel.

Method and device for multi-wavelength plug-and-play quantum key distribution without time delay due to wavelength conversion

Provided is a method and device for correcting an error in a communication system, the method including: transmitting, to another device, data encrypted based on key information. The key information is obtained by: incident a detection pulse on a variable Faraday rotating mirror and a reference pulse on a first mirror, respectively, wherein the detection pulse and the reference pulse are pulses branched from a test pulse; generating a first current in a balanced photodetector (BPD) based on a first component obtained as the detection pulse is reflected from the variable Faraday rotating mirror and a second component obtained as the reference pulse is reflected from the first mirror; converting the first current into a second current; incident the second current on the variable Faraday rotating mirror; and correcting the error in the variable Faraday rotating mirror based on the incident second current.

Method and apparatus for correcting polarization distortion of faraday rotating mirror in plug-and-play quantum key distribution system

The present specification provides a method, performed by a device, for transmitting information about a pencil beam timing offset in a wireless optical communication system, in which a reference synchronization time is obtained, wherein the reference synchronization time is obtained on the basis of a cell-reference synchronization signal (C-RSS) received from another device, a peak energy time is obtained, the pencil beam timing offset is obtained on the basis of the reference synchronization time and the peak energy time, and information about the pencil beam timing offset is transmitted to the other device.

Frequency gradient metasurface device and method based on fast beam steering system

Provided are a device and a method performed by the device to correct an error in a quantum communication system. The method is characterized by comprising: transmitting a random access (RA) preamble to another device; receiving a random access response (RAR) from the other device as a response to the RA preamble; performing a radio resource control (RRC) connection procedure with the other device; and transmitting data to the other device, wherein the data is encoded on the basis of key information, the error is measured on the basis of a test pulse, and the key information is distributed to the device and the other device on the basis of the error being corrected using an improved Faraday rotator mirror of the device.

Method and device for correcting polarization distortion in plug and play quantum key distribution system

A syndrome-based decoding method and apparatus for a block turbo code are disclosed. An embodiment of the present invention provides a syndrome-based decoding method for a block turbo code that includes an extended Hamming code as a component code, where the decoding method includes: (a) generating an input information value for a next half iteration by using channel passage information and the extrinsic information and reliability factor of a previous half iteration; (b) generating a hard decision word by way of a hard decision of the input information value; (c) calculating an n number of 1-bit syndromes, which corresponds to the number of columns or rows of the block turbo code, by using the hard decision word; and (d) determining whether or not to proceed with the next half iteration by using the calculated n number of 1-bit syndromes.

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Seoul, South Korea

Byungkyu Ahn