Electronics and Telecommunications Research Institute

Soongsil University

Industrial Cooperation Foundation, Korea National University of Transportation

Young Jun Chong

Jong Soo Lim

Ju Yeon Hong

Chung Sup Kim

Hyuk Joo Kim

Hyun Kyu Yu

Ho Young Kim

Eun Soo Nam

Jae Ick Choi

Myoung Sook Oh

Jun Seok Kim

Jong Ho Kim

Jae Young Kim

Dong Jin Kim

Hae Cheon Kim

Yong Tae Moon

Woo Jin Byun

Soon Ik Jeon

Cheol Mun

Dong-Uk Sim

Soon Young Eom

Kwangchun Lee

Myung Don Kim

Heon Kook Kwon

Jeong Hae Lee

Sung Woong Choi

Myoung-Won Jung

Hyeon Seok Jang

Jae Hong Park

Sung Choon Kang

Exemplary embodiments provide a method of correcting a result of a ray tracing-based propagation channel simulation. The method of correcting propagation channel simulation data, includes: determining an intensity error value of a propagation channel simulation model for a propagation path associated with each object in a space for which a three-dimensional (3D) environment map is given and storing the intensity error value in a storage device; performing a propagation channel simulation for an arbitrary pair of a transmitter position and a receiver position in the space to obtain multipath components; determining an object having influenced propagations of the multipath components in the space; and correcting an intensity of at least one of the multipath components by applying the intensity error value associated with a determined object stored in the storage device.

Propagation channel simulation method and apparatus

An operating method of a power estimation apparatus comprising a fixed antenna and a mobile antenna may comprise: a first operation of obtaining N measurement values by receiving a signal from signal sources using the fixed antenna and the mobile antenna that moves at a speed v from a first point to an Nth point; a second operation of generating a two-dimensional (2D) data collection set comprising N&#xd7;M measurement values, by repeating the first operation M times; applying an approximation singular value decomposition (SVD) algorithm to the 2D data collection set; and obtaining information of the signal sources based on an application result of the approximation SVD algorithm, wherein N and M are natural numbers.

Method and apparatus for simultaneous power estimation of multiple signal sources in communication system

Disclosed is a position estimation method for estimating a position of an interference signal source and a position estimation system for performing the method. The position estimation method may implement an indoor delay-space analysis structure by transmitting and receiving a known signal and a virtual array structure-based direction finding algorithm in an indoor environment in which a plurality of reflected waves is present and may increase an estimation probability for the position of the interference signal source.

Position estimation method for estimating position of interference signal source and position estimation system for performing the method

A method of selecting a path for transmitting a maximum power from a base station to a terminal includes simplifying a plurality of structures in an area by using OBBs, the area being an area in which beam search is to be performed; forming the plurality of simplified structures into a tree structure for ray tracing; performing the ray tracing by applying a ray tracing relation tree reduction (RRTR) algorithm for reducing an amount of computation of a GPU to the tree structure; and applying a linear regression (LR) algorithm for calculating the maximum power to be transmitted from the base station to the terminal based on a result of the ray tracing.

Apparatus and method for selecting path through beam search

A method and apparatus for calibrating a phased array antenna system is disclosed. The method includes receiving a first transmission signal transmitted from a transmitting antenna device, receiving a second transmission signal that is generated by the transmitting antenna device based on an unoccupied frequency band of a receiving array antenna system and a bandwidth of the frequency band, and generating a calibration matrix to calibrate a plurality of antenna elements included in the receiving array antenna system based on a signal magnitude and a phase difference which are calculated for each of the antenna elements using the first transmission signal and the second transmission signal.

Method and apparatus for calibrating array antenna system for phase compensation

Disclosed is a method of estimating a position of a signal source and a position estimation apparatus, the method including acquiring an environment, a frequency, and a bandwidth of the interference signal source, determining an arrangement form of the two antennas based on the environment, the frequency, and the bandwidth and arranging the two antennas, and estimating a position of the interference signal source based on an interference signal of the interference signal source and the two arranged antennas, wherein the environment includes an indoor environment and an outdoor environment.

Method of estimating position of interference signal source and apparatus thereof

A signal receiving device for measuring a characteristic of a wireless communication channel is provided. The signal receiving device includes an analog signal processor, an analog-digital converter, and a digital signal processor. The analog signal processor generates a band-limited signal by decreasing an intensity of a signal having an image frequency in a correlation operation result signal being a result of correlation operation, and generates an intermediate frequency signal by transforming the band-limited signal. The analog-digital converter converts the intermediate frequency signal into a digital signal. The digital signal processor generates a demodulated signal by performing in-phase/quadrature-phase modulation on the digital signal, the demodulated signal including a baseband signal, which includes a direct current component, and signals repeated at constant frequency intervals with a same bandwidth as the baseband signal, and generates an impulse response signal by decreasing intensities of the repeated signals in the demodulated signal.

Signal receiving device for measuring characteristic of wireless communication channel, and method of measuring characteristic of wireless communication channel

An apparatus for determining a received signal level of a radio wave in a ray-tracing wave propagation environment includes a reception unit configured to receive the radio wave; and an analyzing unit configured to determine the received signal level of the radio wave in the ray-tracing wave propagation environment. Further, the analyzing unit is configured to analyze a correlation of the height and altitude of a surface roughness that recognizes the surface of a surrounding obstacle depending on the length of wavelength in the course of delivery of a received signal of the radio wave and analyze precisely the scattering of the received signal depending on the surface roughness to determine the received signal level of the radio wave when determining the received signal level.

Apparatus and method for determining received signal level in ray-tracing wave propagation environment

Provided is a backward-wave oscillator in a communication system, including a waveguide formed of a metamaterial. A unit structure of the waveguide may include: a top plate; a short-circuited stub; a bottom plate separated at a predetermined gap from the top plate, and having the short-circuited stub formed in the center thereof; a first metal pillar connecting the top plate at a first port positioned on one surface based on the short-circuited stub to the bottom plate at a second port positioned on the opposite surface of the first port based on the short-circuited stub; and a second metal pillar separated from the first metal pillar, and connecting the top plate at the second port to the bottom plate at the first port.

Backward-wave oscillator in communication system

A voltage controlled oscillator includes a split ring resonator (SRR) configured to have meta-material characteristics fabricated on a board, and an energy compensation circuit configured to cause resonant oscillation of the SRR. The energy compensation circuit is fabricated in the form of an integrated circuit.

Voltage controlled oscillator

A wireless communication method and apparatus using adaptive transmission polarization control are provided. The wireless communication apparatus includes an orthogonal polarization antenna, a channel state estimator, and a transmission polarization state (TPS) selector. The orthogonal polarization antenna receives at least one reference signal. The channel state estimator estimates a wireless polarization channel on the basis of the reference signal. The TPS selector selects a TPS corresponding to the estimated wireless polarization channel from among a plurality of predefined TPSs, and feeds back the selected TPS information. Accordingly, the wireless communication apparatus feeds back information for polarization control using minimum uplink wireless resources, and maximizes a transmission capacity on the basis of the feedback information.

Wireless communication method and apparatus using adaptive transmission polarization control

A method of manufacturing a photo-detector array device integrated with a read-out integrated circuit (ROIC) monolithically integrated for a laser-radar image signal. A detector array device, a photodiode and control devices for selecting and outputting a laser-radar image signal are simultaneously formed on an InP substrate. In addition, after the photodiode and the control devices are simultaneously formed on the InP substrate, the photodiode and the control devices are electrically separated from each other using a polyamide, whereby a PN junction surface of the photodiode is buried to reduce surface leakage current and improve electrical reliability, and the structure of the control devices can be simplified to improve image signal reception characteristics.

Method of manufacturing a photo-detector array device with ROIC monolithically integrated for laser-radar image signal

A photo-detector array device integrated with a read-out integrated circuit (ROIC) monolithically integrated for a laser-radar image signal and a manufacturing method thereof are provided. According to the photo-detector array device, a photodiode and control devices for selecting and outputting a laser-radar image signal are simultaneously formed on an InP substrate, so that it is possible to simplify manufacturing processes and to greatly increasing yield. In addition, after the photodiode and the control devices are simultaneously formed on the InP substrate, the photodiode and the control devices are electrically speared from each other by using a polyimide. Therefore, a PN junction surface of the photodiode is buried, so that a surface leakage current can be reduced and an electrical reliability can be improved. In addition, a structure of the control devices can be simplified, so that image signal reception characteristics can be improved.

Photo-detector array device with ROIC monolithically integrated for laser-radar image signal and manufacturing method thereof

Provided is a signal transmission line for a millimeter-wave band. The signal transmission line includes: a dielectric substrate; an input line formed on the dielectric substrate; a pair of serial transmission lines formed on the dielectric substrate, the serial transmission lines being branched at, separated from, and electromagnetically connected in series with one end of the input line; a pair of parallel transmission lines respectively formed on the dielectric substrate at both sides of the input line and the serial transmission lines, and having both ends separated from and electromagnetically connected in parallel with one end of each of the input line and the serial transmission lines; and a pair of wires electrically connected between the other ends of the parallel transmission lines and a connection pad of a monolithic microwave integrated circuit (MMIC). An electrical signal of about 57 to 63 GHz generated from a monolithic microwave integrated circuit (MMIC) can be efficiently transferred.

Signal transmission line for millimeter-wave band

An apparatus, method and readable medium capable of automatically selecting a channel of a broadband frequency and calibrating a frequency change using approximated frequency mapping function are disclosed. The apparatus comprises a frequency band dividing part; a frequency converting part; a first controlling part; and a second controlling part. The second controlling part selects a coefficient of an approximated frequency mapping function for a channel corresponding to a channel conversion selection signal from outside from previously stored coefficients of approximated frequency mapping function for the divided frequency.

Growing community of inventors

Daejeon, South Korea

Young Jun Chong