Patent application number | Description | Published |
20080205561 | Apparatus and method for interference cancellation in broadband wireless access communication system - Provided are an apparatus and method for interference cancellation in a BWA communication system. In a receiving apparatus for the interference cancellation, a preamble correlation measurer measures a preamble correlation coefficient from a preamble of a signal received signal. A data rearranger determines a block size to divide the received signal from the preamble correlation coefficient, divides the signal according to the determined block size, and rearranges the divided signals in a Space-Time coding (STC) mode. An estimate weight calculator cross-correlates the output signals of the data rearranger, rearranges the cross-correlated signals, auto-correlates the rearranged signals, and calculates an estimate weight to perform an interpolation operation. An estimate signal decoding/combining unit detects desired signals from signals estimated by the estimate weight calculator and combines the detected signals. | 08-28-2008 |
20090086714 | Apparatus and method for estimating uplink transmission timing in wireless communication system - An apparatus and method for estimating UpLink (UL) transmission timing in a Mobile Station (MS) of a wireless communication system are provided. The method includes tracking DL timing by using a DL preamble signal received for each frame; estimating a time offset between a previous frame and a current frame by using the DL timing tracked for each frame; and estimating the UL transmission timing by using the estimated time offset. | 04-02-2009 |
20090097454 | Apparatus and method for estimating cell load in wireless communication system - An apparatus and method for estimating a cell load in a wireless communication system are provided. The apparatus includes a ranging response counter, a load estimator, an FA handover determiner, a data rate determiner, and a handover determiner. The ranging response counter counts the number of ranging response messages that are received during one period of periodic ranging. The load estimator estimates a cell load on the basis of the number of the ranging response messages. The FA handover determiner determines an FA handover on the basis of the cell load from the load estimator. The data rate determiner controls a data rate of a service on the basis of the cell load from the load estimator and requests the controlled data rate to the system. The handover determiner controls handover parameters on the basis of the cell load from the load estimator. | 04-16-2009 |
20090097579 | APPARATUS AND METHOD FOR REDUCING PAPR IN AN OFDM SYSTEM - An apparatus and method for reducing a Peak-to-Average Power Ratio (PAPR) are provided. The apparatus includes a gain processor for multiplying time signals in paths by gains set for respective paths, a delay processor for delaying gain-multiplied signals in second to last paths except for a first path by time delays set for respective second to last paths, a summer for summing the gain-multiplied signal for the first path received from the gain processor and the delayed signals received from the delay processor, a PAPR processor for measuring a PAPR of the summed signal received from the summer, for comparing the measured PAPR with a target PAPR, and for requesting one or more changes of at least one of the gain and time delay of each path, and a gain delay controller for changing the at least one of the gain and the time delay of each path according to the request received from the PAPR processor and for controlling the gain processor and the delay processor according to the change. | 04-16-2009 |
20090097583 | APPARATUS AND METHOD FOR SELECTING OPERATION MODE IN MIMO COMMUNICATION SYSTEM - An apparatus and a method for selecting an operation mode to improve a throughput in a mobile communication system are provided. The apparatus includes a Carrier to Interference and Noise Ratio (CINR) predictor for predicting a probable average and dispersion for a CINR measured using a preamble of a received pilot signal or radio signal, a metric calculator for calculating a throughput for each Modulation and Coding Scheme Level (MCS_Level) by using the probable average and dispersion for the predicted CINR and for selecting an MCS_Level having a maximum throughput, and an operation mode selector for selecting an operation mode of the selected MCS_Level having the maximum throughput. | 04-16-2009 |
20100014476 | APPARATUS AND METHOD FOR IMPROVING HYBRID AUTOMATIC REPEAT REQUEST COMBINING GAIN IN A BROADBAND WIRELESS COMMUNICATION SYSTEM - An apparatus and method for improving a HARQ combining gain in a broadband wireless communication system are provided. The apparatus includes a seed information generator and a subcarrier allocator. The seed information generator randomly generates a seed value for changing a channel of a subcarrier and an interference pattern in a frame unit when a HARQ combining gain is not generated because an interference pattern is the same during a retransmission period. The subcarrier allocator allocates a subcarrier using the generated seed value. | 01-21-2010 |
20100128808 | CARRIER FREQUENCY ESTIMATION METHOD AND APPARATUS IN WIRELESS COMMUNICATION SYSTEM - A carrier frequency estimation method and apparatus is provided for improving frequency estimation performance in an Orthogonal Frequency Division Multiplexing (OFDM) communication system. The frequency estimation method for a wireless communication system includes summing correlations of four pairs of reference symbols transmitted at different frequency-time resource blocks in a pattern, each pair including two closest reference symbols; calculating a statistical value (E) by accumulating the summed correlation in a frequency direction; and estimating a frequency offset using an angle extracted from the statistical value (E). | 05-27-2010 |
20100322065 | APPARATUS AND METHOD FOR TRANSMITTING/RECEIVING SIGNAL IN SINGLE CARRIER FREQUENCY DIVISION MULTIPLEXING ACCESS COMMUNICATION SYSTEM - A method and apparatus for transmitting a signal in a Single Carrier-Frequency Division Multiplexing Access (SC-FDMA) communication system are provided. The method includes determining if a Bandwidth Expansion Factor (BEF) Q is an integer, the BEF being determined as N/M according to a number N of subcarriers of a system band and a number M of subcarriers of an allocated band, expanding an input signal to be transmitted Q times in a time domain when the Q is an integer, generating an SC-FDMA signal, and transmitting the SC-FDMA signal. | 12-23-2010 |
20110044186 | APPARATUS AND METHOD FOR ADAPTIVELY GENERATING CHANNEL QUALITY INDICATOR IN WIRELESS COMMUNICATION SYSTEM - An apparatus and method for generating a Channel Quality Indicator (CQI) in a wireless communication system are provided. The method includes receiving a Modulation and Coding Scheme (MCS) index and resource allocation information of a traffic channel and calculating a spectral efficiency at a particular time point, determining a temporary CQI index having a spectral efficiency closest to the calculated spectral efficiency in an index set, reading a CQI metric a time τ before the particular time point, determining, if the temporary CQI index is reported at the particular time point, an error rate based on the CQI metric, the error rate being a probability of an error occurring in a traffic channel after the time τ, receiving an error check result of the traffic channel transmitted at the particular time point and calculating a new error rate by applying a weight to the error check result and the error rate, and determining a CQI index to be fed back to a transmitter using the new error rate. Hence, the CQI index which maximizes spectral efficiency is determined and a Physical Downlink Shared CHannel (PDSCH) acknowledgement (ACK)/negative acknowledgement (NACK) probability is directly estimated adaptively according to a change in channel, thereby providing useful performance in various channel environments. | 02-24-2011 |
20110075753 | TRANSMISSION/RECEPTION APPARATUS AND METHOD FOR IMPROVING THROUGHPUT IN A MULTI-INPUT MULTI-OUTPUT COMMUNICATION SYSTEM - A method and apparatus for transmitting at least two transport blocks in a Multi-Input Multi-Output (MIMO) communication system, in which a transmitter determines whether a type of a receiver receiving the at least two transport blocks is a Successive Interference Cancellation (SIC) receiver, determines a Modulation and Coding Scheme (MCS) level for the at least two transport blocks depending on whether the type of the receiver is an SIC receiver, and transmits the at least two transport blocks using the determined MCS level. | 03-31-2011 |
20110164709 | APPARATUS AND METHOD FOR ESTIMATING CHANNEL IN BROADBAND WIRELESS COMMUNICATION SYSTEM - An apparatus and method for channel estimation decrease overhead and hardware complexity while supporting both Wiener-type channel estimation and Finite Impulse Response (FIR) filtering/Infinite Impulse Response (IIR) filtering in a wireless communication system. The apparatus includes a storage unit for storing coefficient sets for a plurality of channel estimation types. A controller selects one of the plurality of channel estimation types according to at least one of a type of a pilot signal and a reliability value of a channel parameter. An N-tap filter, including N multipliers and (N−1) adders, determines channel estimation values of data tones by using the coefficient sets for the selected channel estimation type. | 07-07-2011 |
20110182339 | METHOD AND APPARATUS FOR REDUCING PEAK TO AVERAGE POWER RATIO USING PEAK WINDOWING - A method and apparatus for reducing a Peak to Average Power Ratio (PAPR) using peak windowing is provided. In the apparatus, an absolute value calculator calculates an absolute value of an input signal, a subtractor subtracts a predetermined clipping threshold level from the absolute value, a smoothing unit performs smoothing on the subtracted signal according to a predetermined smoothing scheme and outputs a first smoothed signal, an adder adds the first smoothed signal to the clipping threshold level, an inverse calculator outputs a second smoothed signal by multiplying the clipping threshold level by an inverse of the added signal, and a multiplier outputs a final PAPR-reduced signal by multiplying the input signal by the second smoothed signal. The method and apparatus address an overcompensation problem while processing signals having a large bandwidth and a high data rate without delay, thereby minimizing the clipping influences on Bit Error Rate (BER) and Adjacent Channel Leakage Ratio (ACLR) performances. | 07-28-2011 |
20120320729 | APPARATUS AND METHOD FOR RECEIVING SIGNAL IN WIRELESS COMMUNICATION SYSTEM - A technique for avoiding reception performance deterioration caused by a tone interference that occurs at a position carrying a pilot signal in a wireless communication system is provided. A receiving end includes an operator for converting a time-axis signal into a frequency-axis signal, an extractor for generating channel values in positions carrying pilot signals among the frequency-axis signals, a compensator for compensating for a channel value of a position at which tone interference occurs by using at least one channel value of a position at which no tone interference occurs among the channel values. | 12-20-2012 |
20130072139 | APPARATUS AND METHOD FOR PROCESSING REDUCED BANDWIDTH ENVELOPE TRACKING AND DIGITAL PRE-DISTORTION - An apparatus and a method for processing reduced bandwidth Envelope Tracking (ET) and Digital Pre-Distortion (DPD) are provided. The apparatus includes a Crest Factor Reduction (CFR) unit, a resealing Digital Pre-Distortion (DPD) unit, an envelope converter, a Supply Modulator (SM), and a Power Amplifier (PA). The CFR unit suppresses an increase of a side lobe occurring when a Peak to Average Power Ratio (PAPR) decreases with respect to a signal generated in a baseband according to a standard and passes through a transmit (Tx) filter. The resealing DPD unit receives an original envelope amplitude and a reduced bandwidth envelope amplitude of an In-phase/Quadrature-phase (I/Q) signal output from the CFR unit to perform a pre-distortion process. The envelope converter converts an envelope signal to a reduced bandwidth envelope signal based on the I/Q signal output from the CFR unit. | 03-21-2013 |
20130159369 | APPARATUS AND METHOD FOR PERFORMING DISCRETE FOURIER TRANSFORM - A Discrete Fourier Transform (DFT) apparatus is provided. The DFT apparatus includes a first delay, a second delay, an operator, and a multiplier. The first delay delays one sampling data by N-sample in a time axis when the one sampling data is input. The second delay delays an output value of a frequency component for a previous sampling data by 1-sample. The operator performs an operation based on the input one sampling data, the one sampling data delayed by the N-sample in the time axis, and the 1-sample delayed output value of the frequency component for the previous sampling data. The multiplier multiplies an output value from the operator by a twiddle factor | 06-20-2013 |
20130324117 | METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING CONTROL INFORMATION IN WIRELESS COMMUNICATION SYSTEM - Methods, a Base Station (BS), and a User Equipment (UE) in a wireless communication system for transmitting and receiving control information are provided. The method for transmitting control information by a BS in a wireless communication system includes receiving information related to a signal transmitted by a second BS that the second BS which is a neighboring BS of the first BS, determining whether a second UE using an identical resource to that used by a first UE included in a cell of the first BS exists within a cell of the second BS based on the received information, when the second UE exists, generating control information for controlling a signal transmitted to the second UE by the second BS based on the received information, and transmitting the generated control information to the first UE through a control channel. | 12-05-2013 |
20130343302 | METHOD AND APPARATUS FOR TRANSMITTING/RECEIVING SIGNAL IN WIRELESS COMMUNICATION SYSTEM - In a wireless communication system, a first Base Station (BS) receives control information including information related to transmission of a Reference Signal (RS) of at least one second BS from the at least one second BS which corresponds to an adjacent BS of the first BS, and transmits the RS by using a preset scheme of controlling interference based on the received control information. | 12-26-2013 |
20140086160 | METHOD AND APPARATUS FOR SIGNALING POWER INFORMATION IN WIRELESS COMMUNICATION SYSTEM - A method and apparatus for signaling power information in a wireless communication system are provided. A base station apparatus co-schedules a plurality of User Equipments (UEs) to at least one resource element, and transmits power information indicating transmit power values, which are allocated for the co-scheduled UEs, to the co-scheduled UEs. The power information includes first power information including information about a pilot signal power value and a transmit power value for a first UE among the co-scheduled UEs, and second power information indicating a transmit power value for each of at least one second UE except for the first UE among the co-scheduled UEs. | 03-27-2014 |
20140184440 | CIRCUIT, APPARATUS AND METHOD FOR ANTENNA MODE STEERING - An Antenna Mode Steering (AMS) method in a signal receiving apparatus using at least one antenna is provided. The method includes measuring a received signal quality of a signal received through the at least one antenna for each of antenna modes available in the signal receiving apparatus, and selecting a specific antenna mode from among the antenna modes as an antenna mode to be used in the signal receiving apparatus based on the measured received signal quality. | 07-03-2014 |
20140254444 | APPARATUS AND METHOD FOR SAVING POWER BY TRANSMISSION INTERVAL IN WIRELESS COMMUNICATION SYSTEM - An apparatus and a method for controlling power consumption of a terminal in a wireless communication system are provided. The method includes deactivating one or more of hardware components for signal reception in a transmission interval if there is no data to be received in the transmission interval, and receiving a control signal by activating all the components in a next transmission interval. | 09-11-2014 |
20140254553 | APPARATUS AND METHOD FOR RECEIVING PAGING IN MOBILE COMMUNICATION SYSTEM - A method operating a user equipment for avoiding paging missing in a mobile communication system is provided. The method of operating a user equipment includes performing an area update process caused by a registration area change, performing a reselection of a previous registration area after performing the area update process, and attempting to receive a paging in the previous registration area. | 09-11-2014 |
20140321521 | LINK PERFORMANCE ABSTRACTION METHOD AND APPARATUS IN A WIRELESS COMMUNICATION SYSTEM - A method and an apparatus for link performance abstraction for a receiver employing Interference-Aware Communications (IAC) technology in a wireless communication system are provided. A method for operating a receiving apparatus for the link performance abstraction in the wireless communication system, includes receiving an Orthogonal Frequency Division Multiplexing (OFDM) over a plurality of spatial layers, splitting and post-processing the received signal based on the spatial layers, deriving a post-processing Signal-to-Interference-plus-Noise Ratio (SINR) of each spatial layer, converting the post-processing SINR of the spatial layers to a Mutual Information per coded Bit (MIB) adaptively tuned based on an instantaneous Interference-to-Signal Ratio (ISR), and estimating a Block Error Rate (BLER) from a mean of the MIB metrics of the spatial layers. | 10-30-2014 |
20140341122 | METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING DATA IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting data in a wireless communication, by a first Base Station (BS) is provided. The method includes receiving control information including information related to transmission of a Reference Signal (RS) of at least one second BS from the at least one second BS adjacent to the first BS and transmitting data by using a preset method based on the control information when an RS transmission mode of the at least one second BS is different from an RS transmission mode of the first BS. | 11-20-2014 |
20150050929 | APPARATUS AND METHOD FOR CONTROLLING TRANSMISSION FOR DEVICE TO DEVICE (D2D) COMMUNICATION IN WIRELESS COMMUNICATION SYSTEM - A method for operating a User Equipment (UE) is provided to minimize performance degradation due to a difference between a transmit power for D2B communication and a transmit power for Device to Device (D2D) communication. The method includes transmitting a signal for D2B communication to a Base Station (BS) and a signal for D2D communication to another UE in a first time period, and configuration for the D2D communication, when it is determined there is a difference between a transmit power for the D2B communication and a transmit power for the D2D communication. | 02-19-2015 |