Patent application number | Description | Published |
20110032150 | BEAMFORMING APPARATUS AND METHOD FOR MULTI-ANTENNA SYSTEM - A beamforming apparatus for a multi-antenna system includes a phase control unit including a plurality of phase shifters which respectively control the phases of signals according to a preset phase weight vector; a signal combination unit combining the signals outputted from the plurality of phase shifters; a frequency down converter down-converting the combined signal outputted from the signal combination unit into a baseband signal; an analog/digital (A/D) converter converting the baseband signal into a digital signal; and a radio frequency (RF) beamforming control unit providing a plurality of preset phase weight vectors to the phase control unit according to a preset application sequence, deciding a maximum signal-to-noise ratio (SNR) among a plurality of SNRs corresponding to the applied phase weight vectors by using the digital signal outputted from the A/D converter, and controlling the beamforming of the phase control unit by using the maximum SNR. | 02-10-2011 |
20110033015 | MULTI-ANTENNA SYSTEM USING ADAPTIVE BEAMFORMING - A multi-antenna system using adaptive beamforming includes a phase shift unit, a signal combination unit, a frequency down-converter, and an analog-to-digital (A/D) converter, and a beamforming control unit. The phase shift unit includes a plurality of phase shifters which shift the phases of signals received from a plurality of antennas. The signal combination unit combines phase-shifted signals output from the plurality of phase shifters. The frequency down-converter down-converts a signal output from the signal combination unit into a baseband signal. The A/D converter converts the baseband signal into a digital signal. The beamforming control unit searches for a weight vector higher than a preset threshold signal-to-noise ratio (SNR) when a reception SNR of the digital signal output from the A/D converter is lower than the threshold SNR, and changes a currently set weight vector into the searched weight vector to provide to the phase shift unit. | 02-10-2011 |
20110084766 | WIDEBAND ACTIVE CIRCUIT WITH FEEDBACK STRUCTURE - A broadband active circuit with a feedback structure includes: an active load unit providing a load varied according to a control voltage; an active circuit unit connected between the active load unit and a ground and outputting a signal corresponding to a pre-set bandwidth, among input signals; and a feedback circuit unit formed between an output terminal of the active circuit unit and the active load unit and providing a signal from the output terminal of the active circuit unit to the active load unit. | 04-14-2011 |
20110102219 | SUCCESSIVE APPROXIMATION ANALOG/DIGITAL CONVERTER AND TIME-INTERLEAVED SUCCESSIVE APPROXIMATION ANALOG/DIGITAL CONVERTER - A successive approximation analog/digital converter includes a sample & hold part sampling and holding an intensity of an analog input signal using a single clock cycle of a clock signal; a first comparator comparing the intensity of the analog input signal with comparison voltages determined according to estimated digital values per clock cycle following an operating clock cycle of the sample & hold part; a second comparator comparing the intensity of the analog input signal with a value equal to ½ of a preset reference voltage in the latter half of the operating clock cycle of the sample & hold part; a successive approximation register determining a value of an MSB of a digital value to be converted according to the comparison result of the second comparator and values of bits successive to the MSB according to the comparison result of the first comparator, and generating the estimated digital values by applying estimated values to undetermined bits; and a digital/analog converter generating the comparison voltages using the estimated digital values and the reference voltage. | 05-05-2011 |
20110158220 | MEDIA ACCESS CONTROL METHOD IN WIRELESS NETWORK - A media access control method in a wireless network is provided. Each of devices in the wireless network determines one of a plurality of beacon slots within a beacon period as a beacon slot of the device. The devices in the wireless network determine a data transmission order in accordance with the slot numbers of the beacon slots of the devices in a reserved period of a data transmission period. Data is transmitted in the unreserved period in accordance with the determined data transmission order. | 06-30-2011 |
20120072620 | TERMINAL AND WIRELESS COMMUNICATION METHOD THEREOF - There are provided a terminal capable of selecting a suitable wireless module among a plurality of wireless modules depending on a situation and providing an optimal image even in a state in which a display unit is separated from a main body by performing wireless communication, and a wireless communication method thereof. To enable this, the terminal includes a main body generating and transmitting image data in response to an external input; a display unit mountable on or demountable from the main body, receiving the image data from the main body and displaying an image corresponding to the image data; and a wireless communication unit provided in each of the main body and the display unit, switching a wireless communication frequency band on the basis of a transmission rate of the image data and transmitting the image data to the display unit. | 03-22-2012 |
20120076074 | APPARATUS AND METHOD FOR ESTABLISHING CONTENTION WINDOW IN WIMEDIA WIRELESS NETWORK - There are provided an apparatus and a method for establishing a contention window in a WiMedia wireless network. The contention window establishing apparatus includes: a parsing unit extracting the number of devices that intend to transmit data from a beacon received during a beacon period and an access category (AC) of each device; a calculation unit calculating a transmission probability of each access category (AC) on the basis of the extracted number of devices; and a contention window establishing unit establishing a contention window for each access category (AC) on the basis of the calculated transmission probability, to reduce contentions among the devices and decrease data transmission latency time, thereby maximizing efficiency in data transmission latency time. | 03-29-2012 |
20120200459 | BEAM FORMING METHOD AND MULTIPLE ANTENNA SYSTEM USING THE SAME - Disclosed are a beam forming method and a multiple antenna system using the same. There is provided a multiple antenna system which forms optimal beam patterns through a transmission of a training sequence between a transmitter and a receiver, each including a plurality of antennas, the multiple antenna system comprising: a transmitter selecting antennas to be activated according to a level and transmitting the training sequence to a receiver through the selected antennas; a receiver selecting the antennas to be activated according to the level and transmitting to the transmitter an index of an optimal transmission weight vector significantly reducing a cost function based on the training sequence transmitted from the transmitter, wherein the transmitter selects antennas so that the beam patterns formed by the antennas selected at a q-th level (q: the index of the level) include the beam patterns formed by the antennas selected at a q+1-th level. As a result, the transmission frequency of the training sequence may be reduced. | 08-09-2012 |
20120201314 | APPARATUS AND METHOD FOR REDUCING PEAK TO AVERAGE POWER RATIO THROUGH RECOMBINATION OF ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYMBOL - There are provided an apparatus and a method for reducing a peak to average power ratio (PAPR) through the recombination of an orthogonal frequency division multiplexing (OFDM) symbol. The apparatus includes an orthogonal frequency division multiplexing (OFDM) symbol transforming unit sequentially transforming an OFDM symbol in a time domain obtained through an inverse fast Fourier transform (IFFT) to generate a plurality of OFDM symbols; a peak power measuring unit measuring peak powers of each of the OFDM symbol and the plurality of OFDM symbols generated therefrom; and an OFDM symbol selecting unit selecting an OFDM symbol having a minimum value among the measured peak powers as a candidate OFDM symbol to be transmitted and transmitting the selected candidate OFDM symbol, wherein the OFDM symbol transforming unit generates the plurality of OFDM symbols by (a) performing a process of rotating the OFDM symbol by a predetermined angle in a complex plane and performing cyclical shifting with respect to the rotated OFDM symbol and (b) repetitively performing process (a) with respect to the cyclically shifted OFDM symbol. Therefore, diversity is secured, whereby the PAPR may be reduced. | 08-09-2012 |
20120242158 | WIRELESS POWER TRANSMITTER AND WIRELESS POWER TRANSCEIVER - Disclosed are a wireless power transmitter capable of transmitting power wirelessly according to an impedance of an output side and a wireless power transceiver. There are provided a wireless power transmitter and a wireless power transceiver including: a wireless power transmitting unit converting input power into a preset transmission power and transmitting the converted input power wirelessly; and a controlling unit controlling a transmission of the transmission power according to a level of output impedance of the transmission power output from the wireless power transmitting unit. | 09-27-2012 |
20120250495 | METHOD OF REDUCING RETRANSMISSION OF DATA FRAME AND RECEIVING NODE THEREFOR - A method of reducing a retransmission of a data frame and a receiving node therefor continuously receiving N data frames generated by encoding K source data packets by erasure coding. Errors in the received N data frames are checked, and an ACK message transmitted informing that the source data packets are capable of being restored, when the number (R) of data frames not containing errors is equal to or greater than the number (K) of source data packets. An ACK message including the number (X) of data frames for which retransmission is to be requested is transmitted when the number (R) of data frames not containing errors is less than the number (K) of source data packets, as a result of checking for errors in the received N data frames. Despite errors in some of the data frames, data may be restored without requesting the retransmission of data frames. | 10-04-2012 |
20140003412 | APPARATUS AND METHOD FOR ESTABLISHING CONTENTION WINDOW IN WIMEDIA WIRELESS NETWORK | 01-02-2014 |
20140333147 | WIRELESS POWER TRANSMISSION/RECEPTION APPARATUS AND METHOD - A wireless power transmission/reception apparatus includes a wireless power transmission unit. The transmission unit is configured to generate a wireless power signal to be transmitted, transmit the wireless power signal using magnetic resonance, receive a reflected wireless power signal from a wireless power reception unit, determine whether a load device is present, and transmit a further wireless power signal when it is determined that the load device is present in such a way that impedance and output power depending on variation in a distance to the load device are tracked, and wireless power is supplied to the load device in an optimized state. Accordingly, a separate transceiver module is not provided for the purpose of performing communication between a transmitting end and a receiving end, and a reception environment is automatically detected, thus enabling wireless power to be transmitted in an optimal wireless power transmission state. | 11-13-2014 |