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:
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:
In a digital broadcasting signal transmission system, a transmission frame includes a frame body and a frame header, and the frame body is divided into a plurality of sub-bands in the frequency domain and is divided into a plurality of symbols in the time domain. The frame header is provided in the former part of the transmission frame and is transmitted with a signal in the time domain. The frame body includes a plurality of services, and the services respectively receive at least one sub-band and at least one symbol. The frame header includes information on the plurality of services, and information on the plurality of services includes information on the sub-band and the symbol to which the services are allocated, information on channel encoding levels of the services, and information on digital modulation levels of the services.
Abstract:
Disclosed are a graceful degradation-forward error correction method and an apparatus for performing same. A graceful degradation-forward error correction method determines an encoding unit data group constituted by a predetermined number of time intervals for a data stream input in a time-sequential manner, determines a reference data group to be used in generating a parity frame in each time interval of the encoding unit data group, generates a parity frame using the determined at least one reference data group, and assigns the generated parity frame to at least one time interval from among a plurality of time intervals including time intervals constituting the encoding unit data group based on a predetermined rule. Thus, a lost packet can be recovered even when the packet of a continuous long interval is lost, and consequentially, a seamless service may be provided.
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:
Disclosed are a wireless communication method of improving frequency efficiency based on a channel function in a wireless communication system and an apparatus thereof. The wireless communication system using a digital modulation scheme, includes: a transmitting apparatus which modulates a data signal to generate a modulation symbol, generates a channel symbol function corresponding to the modulation symbol, combines the modulation symbol with the channel symbol function to generate a transmission symbol to transmit the generated transmission symbol through a transmission antenna; and a receiving apparatus which receives the transmission symbol through a reception antenna, estimates a channel symbol function included in the transmission symbol, and extracts the data signal based on the modulation symbol included in the transmission symbol.
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:
Provided is an apparatus and method for separating two phase-modulated signals having different amplitudes. A separation method for a phase-modulated signal may include: receiving, using a single antenna, a first received signal and a second received signal that are modulated and thereby transferred from a transmitter; calculating an attenuation level of each of the first received signal and the second received signal by dividing each of the first received signal and the second received signal into a real number portion and an imaginary number portion; calculating a difference between the first received signal and the second received signal; and separating and thereby demodulating the first received signal and the second received signal.
Abstract:
Modulation is performed on a first input signal and a second input signal to be transmitted based on symbol mapping. Phase values of the first and second modulated input signals are selectively adjusted. Angle modulation is performed on the first input signal and the second input signal having selectively adjusted phase values. The angle-modulated first and second input signals are transmitted.