Electronics and Telecommunications Research Institute

Kyu-Min Kang

Sang-In Cho

Sang-Sung Choi

Cheol-Ho Shin

Sung-Woo Choi

Kwang-Roh Park

Sunghyun Hwang

Sangsung Choi

Jae Cheol Park

Su Na Choi

Jinhyung Oh

Dong Woo Lim

Chang-Joo Kim

Sung Woo Choi

Sang In Cho

Hyung-Soo Lee

Jin-Gyun Chung

Heon-Jin Hong

Yong-Eun Kim

An identification method and an unmanned aerial vehicle (UAV) detection apparatus are provided. The identification method, as a method for preventing a collision that may occur in a process of detecting and identifying a plurality of UAVs flying in the air, detects a plurality of UAVs in the air and determines a legitimacy of flight of each of the plurality of UAVs using an identification information request message.

Identification method for detecting locations of unmanned aerial vehicles and unmanned aerial vehicle detection apparatus for performing the same

An antenna apparatus for drone identification and an operating method thereof are provided. The antenna apparatus includes: a plurality of horizontal directional antennas; a vertical directional antenna positioned at a center of an area surrounded by the plurality of horizontal directional antennas; a beamforming unit controlling beamforming of the vertical directional antenna and the plurality of horizontal antennas to transmit and receive signals in all directions; and a power supply unit for suppling power.

Antenna apparatus for identifying drone and operation method thereof

An apparatus for detecting a signal in a common frequency band includes: a signal processor configured to extract a selected band signal from received wireless signals by filtering the received wireless signal based on a frequency selection control signal, convert the extracted signal to a baseband signal, and detect a predetermined signal; a sensing signal determiner configured to determine existence of the signal, output a determination result, and outputs a frequency selection generating signal when the predetermined signal is absent; and a frequency selection controller configured to output the frequency selection control signal by selecting a target band among a plurality of previously decided bands.

Apparatus and method for detecting signal in common frequency band

Provided is an apparatus and method for detecting a packet of a zero-padded OFDM signal, which are capable of determining if a packet exists in a reception (RX) signal by comparing a cross-correlation value of an OFDM signal delayed by a predetermined sample time, e.g., a zero-padded sample time, with a power value of the RX signal, thereby increasing a packet detection probability and preventing a false alarm. The packet detecting apparatus includes: a cross-correlation calculator for calculating a cross-correlation value of a reception signal received from the outside and delaying the calculated cross-correlation value by a predetermined sample time; a power calculator for calculating a power value of the reception signal; and a packet detector for determining if a packet exists in the reception signal by comparing the delayed cross-correlation value with the calculated power value, and detecting the corresponding packet.

Apparatus and method for detecting packet of zero-padded OFDM signal

A parallel equalizer for a DS-CDMA UWB system and method thereof are provided. The parallel equalizer includes: a filter block for filtering a training input signal in a 'training mode', and filtering the plurality of input signals in parallel in a 'symbol decision mode'; a symbol decision block for obtaining a symbol error based on a output from the filter block and a training symbol in the &#x2018;training mode&#x2019;, and estimating a transmission symbol for each of the input signals in the &#x2018;symbol decision mode&#x2019;, obtaining an error of one among the estimated transmission symbols for a symbol error calculating input signal; and an weight update block for updating a filter tap coefficients of the filter block based on the training input signal or the symbol error calculating input signal and the symbol error and transmitting the updated filter tap coefficients into the filter block.

Parallel equalizer for DS-CDMA UWB system and method thereof

Provided is a method and apparatus for acquiring OFDM synchronization even when it fails to detect a plurality of symbols at an initial stage. In the method, a frequency is adjusted to a first frequency band and a cross correlation value between a received preamble symbol and a preset preamble symbol is calculated. When the calculated cross correlation value is larger than a predetermined reference value and is first detected, frequency hopping is performed to receive subsequent symbols and cross correlation values to the subsequent symbols are reexamined. When the reexamined cross correlation value larger than the predetermined reference value is detected, timing synchronization, frequency offset estimation, and frame detection are performed.

Method and apparatus for acquiring OFDM synchronization

Provided is a synchronization error tracking device and method. The method and system estimates and corrects the synchronization error generated by time and frequency offsets during the data transmission interval and uses a module designed for initial synchronization or channel estimation without adding a new correlation operator. Further, a combining mark value and a synchronization position value acquired during the synchronization process are used.

Synchronization error tracking device and method thereof

Provided is an apparatus and method for controlling a voltage gain in an ultra wideband receiving apparatus. The apparatus includes a register for storing an Automatic Gain Control (AGC) value detected in a section where an AGC operation control signal is 'ON'; and a voltage gain controller for generating a voltage gain control value by reading the AGC stored in the register during a section where a reception enable signal is 'ON', and transferring the generated voltage gain control value to a voltage gain amplifier.

Apparatus and method for controlling voltage gain in ultra wideband receiving apparatus

Provided is an apparatus and method for detecting a time-frequency code in an MB-OFDM UWB system. The apparatus includes a controller for providing a band selection signal to the RF receiver and outputting a preamble selection signal at regular symbol periods to calculate a cross correlation value for a predetermined time period more than a beacon frame interval when a time-frequency code search start signal is received; and a cross correlator for storing information on preamble patterns, selecting a preamble stored depending on the preamble selection signal, and calculating a cross correlation value for a digital signal transferred through the RF receiver, wherein the controller determines a time-frequency code using a preamble where a peak occurs as a time-frequency code that is currently in use when a peak signal is inputted based on the calculated cross correlation value, and transmits the determined time-frequency code to the MAC receiver.

Apparatus and method for detecting time-frequency code in MB-OFDM UWB system

Provided are a high speed and low power fixed-point multiplier and method thereof. The multiplier includes: a partial product calculation unit for dividing input data into a plurality of bit groups, each bit group having a predetermined number of bits, generating partial products by independently multiplying a fixed coefficient for each bit group, and summing partial products included in a corresponding bit group, to thereby generate a summed partial products; and an adding unit for adding the summed partial products of each bit group generated from the partial product calculation unit.

High speed low power fixed-point multiplier and method thereof

There is provided an apparatus for detecting a preamble packet in an orthogonal frequency-division multiplexing (OFDM) system, including: a cross-correlation calculating means for calculating a cross-correlation value between a received signal and previously stored preamble pattern values for an OFDM symbol region (N-point); a delay means for delaying the calculate cross-correlation value as much as a M-point interval; a receiving power measuring means for measuring a receiving power for the guard interval; and a dividing means for calculating a final cross-correlation value by dividing the delayed cross correlation value by the measured power.

Apparatus and method for detecting preamble packet in orthogonal frequency-division multiplexing system

Provided is a method for adjusting Fast Fourier Transform (FFT) window positioning in a Multi Band Orthogonal Frequency Division Multiplexing Ultra-Wideband (MB-OFDM UWB) system. The method includes the steps of acquiring an initial FFT window position and a frequency hopping position, demodulating a received signal by using the initial FFT window position and the frequency hopping position acquired in the acquiring step, transmitting received data information to a Media Access Control (MAC) layer with a reception frame (RX frame) structure and judging at the MAC layer whether or not a packet error is occurred based on Frame Check Sequences (FCSs), and if no packet error is occurred, returning to the demodulating step, and if the packet error is occurred, changing a register map by using a predetermined interface line in a MAC-physical layer (MAC-PHY) interface to thereby adjust the FFT window position and the frequency hopping position, and then returning to the demodulating step.

Method for adjusting FFT window positioning in MB-OFDM UWB system

Provided are an apparatus and method for estimating and correcting a frequency offset in a multiband-Orthogonal Frequency Division Multiplexing Ultra-Wideband system using a time frequency hopping. The method includes the steps of: calculating a tangent input having a first value (X) and a second value (Y) by using PS symbols transferred over same frequency band with respect to one of a plurality of frequency bands used for frequency hopping; calculating tan(X/Y) using the first value (X) and the second value (Y), and calculating an index corresponding to the value of tan(X/Y) from a look-up table created by reflecting a relative frequency offset with respect to a center frequency; calculating indexes representing frequency offsets estimated with respect to remaining frequency bands used for frequency hopping from the look-up table by using the calculated index; extracting an index of a numerical controlled oscillator according to correction positions with respect to a plurality of frequency bands by using the calculated indexes; and correcting the frequency offsets estimated using the extracted indexes according to time frequency patterns by using a numerical controlled oscillator table.

Apparatus and method for estimating and correcting frequency offset in MB-OFDM UWB system using time frequency hopping

A rake receiver for DS-CDMA UWB system and a DS-CDMA receiver having the same are provided. The rake receiver includes: a channel estimator for estimating a channel having a predetermined chip duration by using a synchronization acquisition sequence; a tracking module for detecting a channel variation and adjusting a synchronization position value when the channel variation is detected; a first switch for selecting one of an output value of an analog-to-digital converter and an output value of a correlator and outputting the selected value; a second switch for selecting one of the output value of the analog-to-digital converter and the output value of the correlator; and a plurality of demodulators having a parallel processing structure to demodulate received signals by using the channel estimation value inputted from the channel estimator, the synchronization position value stored by the tracking module, and an output value of the second switch.

Rake receiver for DS-CDMA UWB system and DS-CDMA receiver having the same

Disclosed is a method for controlling power level of received signal in an ultra wide band transmission system which uses multi frequency bands, and includes a pre-gain controller (PGC) and a voltage gain amplifier (VGA). The method for controlling a power level of a received signal includes the steps of: a) at the PGCs, detecting which multi frequency band is used in a transmitter of the transmission system; b) at the PGCs, obtaining the voltage gain owing to the discrepancy in the power levels of the received signals; and c) at the PGCs, compensating for the power loss based on the voltage gain.

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Daejon, South Korea

Kyu-Min Kang