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: 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: A digital spectrum analysis apparatus and method for direction finding (DF) and location is provided. The digital spectrum analysis apparatus includes: a multi-channel unit configured to convert signals inputted from antennas into digital signals, reduce a sampling rate of the digital signals by using a digital down converter (DDC), and convert the digital signals into baseband complex signals, and having a plurality of channels; a DF estimator configured to estimate the direction of the signal; a spectrum processing unit configured to map any one of a bearing and a power level of the baseband complex signal into coordinate system, and allocate different colors to one of the bearings and the power levels depending on the accumulation ratio of one of the bearing and the power level; and a display unit configured to display the power level and the bearing with colors.

Abstract: A log periodic antenna includes first and second transmission lines parallel with each other; and a plurality of broadband radiation elements having first sides electrically connected to the first and second transmission lines, a predetermined angle being defined between the first sides of the broadband radiation elements and the first and second transmission lines, and second sides not electrically connected with the first and second transmission lines, the second sides having radiation surfaces larger than radiation surfaces of the first sides. A plurality of broadband radiation elements electrically connected with the first transmission line and a plurality of broadband radiation elements electrically connected with the second transmission line are positioned to face each other with reference to the first and second transmission lines.

Abstract: Provided is a method of selecting a white Gaussian noise sub-band using singular value decomposition (SVD). The method includes selecting a first frequency band, verifying whether a signal is included in the selected first frequency band, determining the first frequency band as a target measurement frequency when the signal is not included in the selected first frequency band, and measuring a background radio noise in the determined target measurement frequency.

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: A digital spectrum analysis apparatus and method for direction finding (DF) and location is provided. The digital spectrum analysis apparatus includes: a multi-channel unit configured to convert signals inputted from antennas into digital signals, reduce a sampling rate of the digital signals by using a digital down converter (DDC), and convert the digital signals into baseband complex signals, and having a plurality of channels; a DF estimator configured to estimate the direction of the signal; a spectrum processing unit configured to map any one of a bearing and a power level of the baseband complex signal into coordinate system, and allocate different colors to one of the bearings and the power levels depending on the accumulation ratio of one of the bearing and the power level; and a display unit configured to display the power level and the bearing with colors.

Abstract: A digital spectrum analysis apparatus and method for direction finding (DF) and location is provided. The digital spectrum analysis apparatus for single-channel direction finding includes: a digital processing unit configured to receive a signal, convert the received signal into a digital signal, reduce a sampling rate of the digital signal by using a digital down converter (DDC), and convert the digital signal into a baseband complex signal; a spectrum processing unit configured to map a bearing and a power level of the baseband complex signal into coordinate system, and allocate different colors to the power levels depending on the accumulation ratio of the power levels; and a display unit configured to display the power levels with colors in order to estimate the bearing of the signal.

Abstract: A log periodic antenna includes first and second transmission lines parallel with each other; and a plurality of broadband radiation elements having first sides electrically connected to the first and second transmission lines, a predetermined angle being defined between the first sides of the broadband radiation elements and the first and second transmission lines, and second sides not electrically connected with the first and second transmission lines, the second sides having radiation surfaces larger than radiation surfaces of the first sides. A plurality of broadband radiation elements electrically connected with the first transmission line and a plurality of broadband radiation elements electrically connected with the second transmission line are positioned to face each other with reference to the first and second transmission lines.

Abstract: A digital spectrum analysis apparatus and method for direction finding (DF) and location is provided. The digital spectrum analysis apparatus for single-channel direction finding includes: a digital processing unit configured to receive a signal, convert the received signal into a digital signal, reduce a sampling rate of the digital signal by using a digital down converter (DDC), and convert the digital signal into a baseband complex signal; a spectrum processing unit configured to map a bearing and a power level of the baseband complex signal into coordinate system, and allocate different colors to the power levels depending on the accumulation ratio of the power levels; and a display unit configured to display the power levels with colors in order to estimate the bearing of the signal.

Abstract: Provided is a method of selecting a white Gaussian noise sub-band using singular value decomposition (SVD). The method includes selecting a first frequency band, verifying whether a signal is included in the selected first frequency band, determining the first frequency band as a target measurement frequency when the signal is not included in the selected first frequency band, and measuring a background radio noise in the determined target measurement frequency.