| 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 |
