Abstract: A multi-resonant broadband antenna constructed with a dielectric substrate; a fractal radiation element having a predetermined fractal grid structure adhered on an upper surface of the dielectric substrate. A feed line adhered on the upper surface of the dielectric substrate feeds the fractal radiation element, and a ground plane positioned on a lower surface of the dielectric substrate opposite to the feed line, is physically separated by the dielectric substrate from the feed line.

Abstract: A vertical alignment method for a radar of a vehicle includes the steps of radiating radio wave to a forward ground by a radar which is installed on the vehicle; receiving reflected wave which is reflected from the ground; and determining whether or not a vertical misalignment of the radar occurs, based on the reflected wave.

Abstract: In an operating system having a first controller configured to manage one or more robots included in a first region, and a second controller configured to manage one or more robots included in a second region adjacent to the first region, a method for enabling the second controller to acquire an operation right of N robots (where N is a natural number equal to or greater than 1) operated by the first controller, the method includes: transmitting a control mapping status (CMS) containing an operation right change message to the first controller, upon reception of an operation right request signal from a user of the N robots; and checking a connection status of the N robots, upon reception of the CMS containing the operation right change message from the first controller, and acquiring an operation right by providing CMS acquisition information and control mapping information to the robots included in the second region.

Abstract: An apparatus for generating a ranging code extracts a ranging code in each ranging mode, using a ranging code table storing one period data in bytes of the PN code according to a reference UL PermBase number, and an offset table that stores byte offsets for the start positions of the PN codes of the reference UL PermBase number and the other plurality of UL PermBase numbers and bit offsets in the byte including the start positions, on the basis of the PN code according to the reference UL PermBase number.

Abstract: Provided is a transmission data frame in an orthogonal frequency division multiplexing (OFDM) burst mode transmission, and more particularly, a frequency offset estimating method and a channel equalizing method using a transmission data frame. In the transmission data frame used in the orthogonal frequency division multiplexing burst mode transmission, a length of a guard interval in a preamble area for frequency offset estimation and channel estimation varies depending on a channel environment not being limited in consideration of a size of a data symbol, and only data of ending part of the guard interval in the preamble is used to estimate frequency offset in consideration of intersymbol interference. In the frequency offset estimating method, desired frequency estimation efficiency can be satisfied with the small number of samples. Also, when channel equalization is performed, two symbols are averaged in a time area to reduce the accuracy of channel estimation due to Gaussian random noise.

Abstract: Disclosed is a method for compensating for a residual frequency offset in an orthogonal frequency division multiplexing system comprising the steps of: a) performing a fast fourier transform for an input signal to convert the input signal into a serial signal; b) detecting signal power of the serial signal to control the passthrough a signal greater than a predetermined critical value; c) selecting each section of a quadrant for each passed signal; d) estimating a phase error in each section of the quadrant for one orthogonal frequency division multiplexing symbol with respect to the selected section of the quadrant; and e) frequency-oscillating a signal based on the estimated phase error, generating the input signal by multiplying an oscillated signal by a band-passed signal, and then returning to step a).

Abstract: An approximation method and system for series expansion of functions include the steps and functions, respectively, of: expanding an input function in Taylor series up to an (N?1)-th term; expanding the input function in Taylor series up to the N-th term; multiplying the expanded result up to the (N?1)-th term by a predetermined weight ?; combining the expanded result up to the (N?1)-th term, multiplied by ?, and the expanded result up to the N-th term; and dividing the combined result by (?+1).

Abstract: Provided is a frame synchronization pattern design and synchronization method by which in a transmitter of a communications system employing an orthogonal frequency division multiplexing (OFDM), a frame synchronization pattern is inserted into the starting part of a symbol frame, and by detecting the frame synchronization pattern in a receiver, synchronization of the OFDM transmitter and receiver is performed. Also, provided are a transmitter synchronization apparatus including an OFDM symbol frame generation unit, a frame synchronization pattern insertion unit, and an OFDM transmission signal conversion unit, and a receiver synchronization apparatus comprising a frame synchronization pattern inserted OFDM symbol frame conversion unit, a frame synchronization pattern detection unit, and a source data generation unit.

Abstract: The present invention based on the LUT enables to perform a filtering at a low speed on a place where a high-speed process is necessary. Particularly, the LUT structure having a block structure is advantageous for filtering at a low speed, and for decreasing memory usage. The filter structure proposed by the present invention provides the equivalent performances to those of the traditional ones, yet conducts the filtering on an interpolation process requiring a high-speed process previously at a low speed and at a low power instead. Moreover, compared to the traditional LUT based filter, the present invention provides a new structure with a decreased memory demand. In short, the present invention provides a new filter structure that enables to implement an interpolation filter, a high-speed processor of a sending end in a wireless telecommunication system, with a low complexity and a low power consumption.

Abstract: A transmitter of a Diagonal Bell Laboratories Layered Space-Time (DBLAST) system includes an interleaver for performing interleaving for all sub-streams in a stream of a transmission signal, thereby generating an interleaved signal, a symbol repeater for generating a reverse-arranged signal rearranged in a reverse order to the interleaved signal, and a DBLAST transmit unit for transmitting the interleaved signal and the reverse-arranged signal through multiple transmit antennas. A receiver of a DBLAST system includes a DBLAST receive unit for receiving signals through multiple transmit antennas, a repeating symbol combiner for generating a combined signal; a deinterleaver for generating a deinterleaved signal; and a decoder for decoding the deinterleaved signal.

Abstract: Disclosed is a digital sampling rate converter for compensating for a drop of an in-band signal, the digital sampling rate converter including a CIC (Cascaded Integrator-Comb) decimator for performing a decimation operation at a first decimation ratio based on an overall decimation ratio, for an input signal; a sub-decimator for performing a decimation operation at a second decimation ratio for a signal output from the CIC decimator; and a compensation unit for performing at least two multiplication operations and two addition operations with respect to a signal output from the sub-decimator using a lowest operation clock frequency in an assigned band.

Abstract: Disclosed is a digital sampling rate converter for compensating for a drop of an in-band signal, the digital sampling rate converter including a CIC (Cascaded Integrator-Comb) decimator for performing a decimation operation at a first decimation ratio based on an overall decimation ratio, for an input signal; a sub-decimator for performing a decimation operation at a second decimation ratio for a signal output from the CIC decimator; and a compensation unit for performing at least two multiplication operations and two addition operations with respect to a signal output from the sub-decimator using a lowest operation clock frequency in an assigned band.

Abstract: Disclosed is a method for compensating for a residual frequency offset in an orthogonal frequency division multiplexing system comprising the steps of: a) performing a fast fourier transform for an input signal to convert the input signal into a serial signal; b) detecting signal power of the serial signal to control the passthrough a signal greater than a predetermined critical value; c) selecting each section of a quadrant for each passed signal; d) estimating a phase error in each section of the quadrant for one orthogonal frequency division multiplexing symbol with respect to the selected section of the quadrant; and e) frequency-oscillating a signal based on the estimated phase error, generating the input signal by multiplying an oscillated signal by a band-passed signal, and then returning to step a).

Abstract: An antenna is located at the end of a wireless communication system, or other radio system, and more particularly, a wideband planar antenna with linear and circular polarization uses different polarization for transmission or reception to increase the isolation between the transmission and reception by suggestion and using a type of radiation element. The disclosed antenna is more efficient than other similar antennas that can transmit/receive linear or circular polarization. The disclosed invention makes it possible to pr vide an antenna having dual polarization, which has an orthogonal characteristic in both linear and circular polarization, and which can lower the height of the antenna by embodying a micro strip planar antenna which has linear and circular polarization that has high gain over a wide frequency band, and which transmits/receives linear or circular polarization.

Abstract: The present invention relates to measurement of cross-inertia-moment in a limited angular rotatory axis, and more specifically, to a measuring device and method of cross-inertia-moment in a limited angular rotatory axis. The measuring device includes a base plate; a pair of first supporters, each end portion being secured on the base plate through a load cell, for supporting a first rotatory axis; a second supporter installed inbetween the pair of first supporters to be able to rotate round the first rotatory axis, for supporting a second rotatory axis that is orthogonal to the first rotatory axis; and a roller installed at the inside of the second supporter, being rotatable round the second rotatory axis. Therefore, the present invention enables to measure and amend the cross-inertia-moment of multiple axis LOS (line of sight) stabilizer as well as low speed rotatory machinery.

Abstract: A tunable filter circuit using a phase locked loop for filtering signals by varying a center frequency of the tunable filter circuit. The tunable filter circuit includes a phase locked loop and a resonance circuit. The phase locked loop includes: a voltage controlled oscillator having a resonance circuit, of which center frequency is varied in correspondence to an inputted control voltage level, for oscillating a frequency signal corresponding to the inputted control voltage level; a PPL controller for generating an error voltage signal corresponding to a phase difference by comparing a reference frequency signal to a signal phase that is oscillated by the voltage controlled oscillator, in correspondence to frequency control data for variably setting a resonance frequency of the voltage controlled oscillator; and a loop filter for loop filtering the error voltage signal and for outputting the loop filtered signal to the voltage controlled oscillator as the control voltage.

Abstract: Disclosed is an apparatus for measuring an absolute rotation angle and a method thereof. In particular, the apparatus is available for a measurement and servo system in which high precision is required in rotation drive and absolute rotation angle measurement.

Abstract: A multi-access conference call apparatus and method in an exchange system.

Abstract: Disclosed is an apparatus for measuring an absolute rotation angle and a method thereof. In particular, the apparatus is available for a measurement and servo system in which high precision is required in rotation drive and absolute rotation angle measurement.