Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and apparatus for transmitting a signal whereby it is determined 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, an input signal to be transmitted Q times in a time domain when the Q is an integer is expanded, a Single Carrier Frequency Division Multiplexing Access (SC-FDMA) signal is generated, and the SC-FDMA signal is transmitted.

Abstract: 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.

Abstract: A decoding apparatus and method in a BWA communication system are provided, in which an ID-based decoder controller detects an ID from a data block by partially decoding the data block, and if the ID indicates that the data block is not for the receiver, outputs a control signal commanding non-decoding for the data block, a bitmap table controller indicates the data block as a non-decoding data block in a bitmap table according to the control signal, and a decoder distinguishes data blocks to be decoded from non-decoding data blocks based on the bitmap table, decodes the data blocks to be decoded and outputs the decoded data blocks, and simply outputs the non-decoding data blocks without decoding.

Abstract: 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.

Abstract: 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 ? 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 ?, 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.

Abstract: An apparatus and a method for receiving a multiple frequency band are provided. In the method for receiving a multiple frequency band of a terminal is a mobile communication system, respective received signal strengths or respective gains are measured with respect to a signal received via at least one Radio Frequency (RF) chain. Whether multiple frequency band reception that uses a single RF chain is possible is determined using the respective received signal strengths or the respective gains. When the multiple frequency band reception that uses the single RF chain is possible, the multiple frequency band is received using the single RF chain.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is a method and apparatus for efficiently controlling buffers which support a Hybrid Automatic Repeat Request (HARQ) in a wireless communication system. Buffer regions for the HARQ scheme are not fixedly allocated according to channel identification information, but are allocated from the viewpoint of one overall memory through aggregation support. That is, an HARQ buffer is dynamically controlled. Therefore, there are the effects reducing the size of the entire chip, as well as reducing power consumption of the entire system according to the reduction of the chip size.

Abstract: 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.

Abstract: 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.

Abstract: 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.