Abstract: 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×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.

Abstract: 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×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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus for calculating a reception time of a wireless communication signal is disclosed. The apparatus includes a downconverted signal generator configured to generate a downconverted signal, a baseband signal, by downconverting a frequency of a signal received from a transmission source, a modulated signal generator configured to generate a modulated signal by multiplying the downconverted signal by a randomly generated reference signal, a time difference calculator configured to calculate a time difference between the modulated signal and the reference signal by cross-correlating the modulated signal and the reference signal, and a reception time calculator configured to calculate a reception time of the signal received from the transmission source using a point in time at which the reference signal is generated and the time difference between the modulated signal and the reference signal.

Abstract: An apparatus for calculating a reception time of a wireless communication signal is disclosed. The apparatus includes a downconverted signal generator configured to generate a downconverted signal, a baseband signal, by downconverting a frequency of a signal received from a transmission source, a modulated signal generator configured to generate a modulated signal by multiplying the downconverted signal by a randomly generated reference signal, a time difference calculator configured to calculate a time difference between the modulated signal and the reference signal by cross-correlating the modulated signal and the reference signal, and a reception time calculator configured to calculate a reception time of the signal received from the transmission source using a point in time at which the reference signal is generated and the time difference between the modulated signal and the reference signal.

Abstract: An apparatus for radio direction finding, the apparatus comprising: a receiver configured to receive target signals to be subjected to the direction finding of signal sources, which are acquired by an antenna array; a channel profiler configured to produce profiles of the target signals received through the receiver; a pre-analyzer configured to preemptively process in a narrowband the wideband target signals based on the profiles that are produced by the channel profiler to produce pre-analyzed information for the wideband target signals; and a direction finder configured to perform the direction finding on the signal sources using the pre-analyzed information and the profilers of the target signals.

Abstract: Provided herein is a method and apparatus for realizing a frequency-spatial filter with variable bandwidth, the method including generating M number of FFT channel blocks having N number of channels by performing an N point FFT (Fast Fourier Transform) processing using M number of array antenna inputs; combining some of the N number of channels of each FFT channel block according to a frequency bandwidth variable parameter value; combining some of spatial response vector channels in a combined channel of each FFT channel block according to a spatial bandwidth variable parameter value; and combining all the channels and outputting the same.

Abstract: Provided herein is a method and apparatus for realizing a frequency-spatial filter with variable bandwidth, the method including generating M number of FFT channel blocks having N number of channels by performing an N point FFT (Fast Fourier Transform) processing using M number of array antenna inputs; combining some of the N number of channels of each FFT channel block according to a frequency bandwidth variable parameter value; combining some of spatial response vector channels in a combined channel of each FFT channel block according to a spatial bandwidth variable parameter value; and combining all the channels and outputting the same.

Abstract: An apparatus is used for modulation classification of unknown input signal in a wireless communication system. The apparatus includes a signal classification unit configured to classify the input signal into a PSK signal and an FSK signal and a modulation index decision unit configured to decide a modulation index for the PSK signal and the FSK signal classified by the signal classification unit.

Abstract: An apparatus for radio direction finding, the apparatus comprising: a receiver configured to receive target signals to be subjected to the direction finding of signal sources, which are acquired by an antenna array; a channel profiler configured to produce profiles of the target signals received through the receiver; a pre-analyzer configured to preemptively process in a narrowband the wideband target signals based on the profiles that are produced by the channel profiler to produce pre-analyzed information for the wideband target signals; and a direction finder configured to perform the direction finding on the signal sources using the pre-analyzed information and the profilers of the target signals.

Abstract: An apparatus is used for modulation classification of unknown input signal in a wireless communication system. The apparatus includes a signal classification unit configured to classify the input signal into a PSK signal and an FSK signal and a modulation index decision unit configured to decide a modulation index for the PSK signal and the FSK signal classified by the signal classification unit.

Abstract: Provided is a method of estimating a symbol. The method may include deriving phase components of input data, applying a second order differentiation to the phase components to obtain a second order differential phase vector, and estimating symbols corresponding to the input data using the second order differential phase vector.

Abstract: Provided is a method of estimating a symbol. The method may include deriving phase components of input data, applying a second order differentiation to the phase components to obtain a second order differential phase vector, and estimating symbols corresponding to the input data using the second order differential phase vector.