Patent application number | Description | Published |
20090102571 | CASCODE AMPLIFIER AND DIFFERENTIAL CASCODE VOLTAGE-CONTROLLED OSCILLATOR USING THE SAME - Provided is a differential cascode voltage-controlled oscillator that can reduce a phase noise by the use of a quality factor enhancement technique with negative conductance and can mitigate a ground-caused noise effect by the use of a cascode connection technique. The differential cascode voltage-controlled oscillator includes an AC signal generator, and first through fourth cascode amplifiers. The AC signal generator generates an AC signal with a certain frequency according to a control voltage. The first cascode amplifier is connected in a cascode configuration, and amplifies the AC signal to output the resulting signal to a first output terminal. The second cascode amplifier is connected in a cascode configuration and connected to the first cascode amplifier in a cross-coupled configuration, to amplify the AC signal to output the resulting signal to a second output terminal. The third cascode amplifier is connected in a cascode configuration to amplify the AC signal to output the resulting signal to the first output terminal. The fourth cascode amplifier is connected in a cascode configuration and connected to the third cascode amplifier in a cross-coupled configuration, to amplify the AC signal to output the resulting signal to the second output terminal. Herein, the first and second cascode amplifiers and the third and fourth cascode amplifiers are symmetrically connected to differentially amplify the AC signal. | 04-23-2009 |
20090154529 | METHOD AND APPARATUS FOR ACQUIRING OFDM SYNCHRONIZATION - 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. | 06-18-2009 |
20090154532 | APPARATUS AND METHOD FOR RECEIVING SIGNAL FOR EXTENT LIMITATION OF TIMING SYNCHRONIZATION IN MB-OFDM UWB SYSTEM - The present invention relates to an apparatus and a method for receiving signal for extent of timing synchronization in MB-OFDM UWB System. The invention divides the digital samples completed of sampling twice as much as minimum sampling clock required to restore the MB-OFDM received signal into ODD data path and EVEN data path, executes the packet detection and timing synchronization for each of divided path and selects the data of path with larger cross correlation value at the timing synchronization point to secure the stable receiving performance in system environment with severe frequency offset and prevent the FTT window shift within preamble section through adding minimum hardware and structural change without increasing the system clock. | 06-18-2009 |
20090158131 | VITERBI DECODING APPARATUS AND METHOD - A Viterbi decoding apparatus receives a plurality of block data in time order, and transmits a block data group including the plurality of block data. Then, the Viterbi decoding apparatus applies a Viterbi decoding algorithm to the block data group and outputs some block data of the block data group. In this way, it is possible to provide a Viterbi decoding apparatus that can operate at a high speed and improve a data transmission rate. | 06-18-2009 |
20100054306 | SIGNAL TRANSMITTING METHOD AND DEVICE AND INFORMATION DETECTING DEVICE - A signal transmitting device detects information on respective frequencies of a plurality of subcarriers configuring an interference signal and information on respective voltage values of the subcarrier from the received interference signal, and modulates data according to the ultra-wideband scheme through subcarriers of part of predetermined bandwidths based on frequency information and voltage value information to generate ultra-wideband signals. Accordingly, signal interference with a heterogeneous communication device can be reduced by detecting an interference signal when an absolute value of the interference signal is small or noise power of the interference signal is large. | 03-04-2010 |
20110002416 | METHOD OF COMMUNICATING FOR SMART UTILITY NETWORK USING TV WHITE SPACE AND APPARATUS FOR THE SAME - There are disclosed a method of communicating for a smart utility network using a TV white space and an apparatus for the same. The method of communicating for a smart utility network using a TV white space according to the present invention includes: generating a time domain sequence repeated every predetermined number of samples; generating an OFDM symbol having a cyclic prefix length corresponding to an FFT size divided by a natural number of 2 or more and including samples of a number corresponding to the sum of the FFT size and the cyclic prefix length; and generating an SUN packet to be transmitted through a TV channel band selected in the TV white space by using the time domain sequence and the OFDM symbol. Accordingly, it is possible to satisfy all requirements required by the IEEE 802.15.4g SUN standardization group. | 01-06-2011 |
20110149958 | MULTI-HOP COMMUNICATION METHOD BASED ON DISTRIBUTED MEDIUM ACCESS CONTROL - Disclosed herein is a multi-hop communication method based on distributed medium access control. In the multi-hop communication method based on distributed medium access control according to the present invention, a beacon frame which includes a first multi-hop information element is generated and transmitted to a neighboring device so as to search for a route to an external device which does not belong to a beacon group. A third multi-hop information element, which is generated based on a second multi-hop information element generated by the external device, is received from the neighboring device. A multi-hop route to the external device is set up in accordance with the third multi-hop information element, and data is transmitted to the external device. Therefore, a multi-hop route between devices in the extended beacon group can be efficiently set up. | 06-23-2011 |