Abstract: Provided are a method and an apparatus for transmitting resource allocation information. In the case when a wireless resource for a new terminal is fixedly allocated to a fixed allocation zone, the apparatus for transmitting resource allocation information determines a resource allocation method of allocating the wireless resource and determines an allocation form of a resource that is allocated by a resource allocation method to select any one information displaying method of a plurality of information displaying methods of displaying allocation information on the allocated resource on the basis of the determined resource allocation method and resource allocation form. Next, the resource allocation information is generated and transmitted on the basis of the selected displaying method.

Abstract: A data processing method, an equalizer, and a receiver in a wireless communication system including a relay station are provided. The data processing method includes: receiving a base station signal from a base station; receiving a relay station signal from a relay station; determining a propagation delay between the base station signal and the relay station signal; generating an equalizing signal in which interference generated between the base station signal and the relay station signal is alleviated in consideration of the propagation delay; and recovering information bits transmitted by the base station from the equalizing signal. According to an exemplary embodiment of the present invention, it is possible to alleviate performance deterioration due to an interference problem generated in a relay system.

Abstract: Provided are a transmitting apparatus and voice data transmitting and receiving methods for providing VoIP services. When a call is started and an analog signal including a voice signal is input, the transmitting apparatus divides the analog signal into a plurality of voice data packets for transmission. Here, the plurality of voice data packets are generated by sampling with different phases in the same frequency. In addition, the transmitting apparatus inserts a time indication bit that is changed every transmission period into each of the voice data packets and transmits the voice data packets, and distinguishes voice data corresponding to a current transmission period based on the time indication bit.

Abstract: A data processing method, an equalizer, and a receiver in a wireless communication system including a relay station are provided. The data processing method includes: receiving a base station signal from a base station; receiving a relay station signal from a relay station; determining a propagation delay between the base station signal and the relay station signal; generating an equalizing signal in which interference generated between the base station signal and the relay station signal is alleviated in consideration of the propagation delay; and recovering information bits transmitted by the base station from the equalizing signal. According to an exemplary embodiment of the present invention, it is possible to alleviate performance deterioration due to an interference problem generated in a relay system.

Abstract: The present invention relates to a low density parity check (LDPC) encoding method and an apparatus thereof. In the LDPC encoding method, a matrix multiplication corresponding to ET?1 and T?1 is eliminated according to a structural characteristic in an encoding process. Accordingly, shift weights that are not ?1 among shift weights corresponding to partial blocks A, B, and C of a parity check matrix are used to perform an encoding operation, and a cyclic shift operation of an information unit block is performed in parallel so that a first parity block and a second parity block may be simultaneously generated.

Abstract: An apparatus and method for canceling a DC offset efficiently removes the DC offset by calculating the DC offset after acquiring synchronization in a terminal receiver used for an orthogonal frequency division multiplexing system. The apparatus for canceling the DC offset includes an adding/averaging unit (130), an accumulator (140), a synchronization determiner (150), and a pulse density modulation signal generator (160). The adding and averaging the added input data signals over one frame. The accumulator (140) outputs a DC offset control value by successively accumulating the DX offsets calculated from the adding and averaging unit. The synchronization determiner (150) determines whether to output the DC offset control value provided by the accumulator (140) based on synchronization information. The pulse density modulation signal generator (160) generates a digital pulse density modulation signal based on a representative value provided by the synchronization determiner (150).

Abstract: Disclosed herein are a method and an apparatus for transmitting a downlink control signal in a wireless communication system. The apparatus for transmitting a downlink control signal includes: a preamble symbol generator generating preamble orthogonal frequency division multiplexing (OFDM) symbols based on a first pilot pattern among pilot patterns for each of the plurality of transmit antennas; a midamble symbol generator generating midamble OFDM symbols based a second pilot pattern excluding the first pilot pattern from the pilot patterns for each of the plurality of transmit antennas; an IFFT unit performing inverse fast Fourier transform (IFFT) for each transmit antenna on the preamble OFDM symbol and the midamble OFDM symbol; and a plurality of transmit antennas transmitting the preamble OFDM symbols and the midamble OFDM symbols.

Abstract: A subcarrier allocating apparatus allocating data to be transmitted to a plurality of orthogonal subcarriers in an orthogonal frequency division multiplexing (OFDM) system is provided. The apparatus includes a logical index generator generating a logical index for allocating a data subcarrier to a physical index, the logical index being included with only data subcarriers and the physical index indicating a location of a substantial subcarrier within a symbol, an intermediate index converter converting the logical index into an intermediate index by performing a given operation on the generated logical index and a pilot location constant, and a physical index converter converting the intermediate index into a physical index based on the number of data subcarriers on the left and right sides of a null subcarrier for insertion of a guard interval formed by the null subcarrier.

Abstract: The present invention relates an apparatus and method of estimating a signal-to-noise ratio (SNR) of a received signal when the received signal has a timing offset. An apparatus for estimating a signal-to-noise ratio (SNR) according to an exemplary embodiment of the present invention includes a fast Fourier transform (FFT) unit that performs a fast Fourier transform on a received signal to convert the received signal into a frequency domain signal; a preamble selector that extracts a preamble from the frequency domain signal; a correlator that correlates the preamble to a preamble reference signal generated by a receiver to calculate a correlation value; an entire power estimator that calculates entire power; a noise power estimator that applies a differential demodulation method to the correlation value to remove a timing offset and calculate noise power; and an estimating unit that uses the entire power and the noise power to estimate the signal-to-noise ratio (SNR).

Abstract: Provided are a method and an apparatus for transmitting resource allocation information. In the case when a wireless resource for a new terminal is fixedly allocated to a fixed allocation zone, the apparatus for transmitting resource allocation information determines a resource allocation method of allocating the wireless resource and determines an allocation form of a resource that is allocated by a resource allocation method to select any one information displaying method of a plurality of information displaying methods of displaying allocation information on the allocated resource on the basis of the determined resource allocation method and resource allocation form. Next, the resource allocation information is generated and transmitted on the basis of the selected displaying method.

Abstract: The present invention relates to a method of calculating a log-likelihood ratio and a method of detecting a transmission signal. According to the present invention, when a transmission symbol candidate vector is detected on the basis of a received signal, a threshold value and an ML metric of each transmission symbol candidate vector are calculated and the ML metric that is larger than the threshold value is updated by the threshold value. Further, a log-likelihood ratio of the transmission signal bit is calculated using the updated ML metric and the threshold value, and a transmission signal is detected using the log-likelihood ratio.

Abstract: Disclosed is an apparatus for acquiring initial frame timing in a communication system having a normalizer that calculates a normalized window power from powers of samples of received signal during a monitoring period, a cross power calculator that calculates a window cross power from cross powers of the samples during the monitoring period, and each cross power corresponds to multiplication of two of the samples, a divider that divides the window cross power by the normalized window power and outputs a metric for a sample corresponding to the monitoring period, and a peak-value detector that searches a sample having the maximum value among metrics for the samples of the received signals during a predetermined period, and the metrics are calculated by shifting the monitoring period, with a sample next to the sample searched by the peak-value detector being determined as a starting point of a frame.

Abstract: Provided are a transmitting apparatus and voice data transmitting and receiving methods for providing VoIP services. When a call is started and an analog signal including a voice signal is input, the transmitting apparatus divides the analog signal into a plurality of voice data packets for transmission. Here, the plurality of voice data packets are generated by sampling with different phases in the same frequency. In addition, the transmitting apparatus inserts a time indication bit that is changed every transmission period into each of the voice data packets and transmits the voice data packets, and distinguishes voice data corresponding to a current transmission period based on the time indication bit.

Abstract: An apparatus and method for canceling a DC offset efficiently removes the DC offset by calculating the DC offset after acquiring synchronization in a terminal receiver used for an orthogonal frequency division multiplexing system. The apparatus for canceling the DC offset includes an adding/averaging unit (130), an accumulator (140), a synchronization determiner (150), and a pulse density modulation signal generator (160). The adding and averaging the added input data signals over one frame. The accumulator (140) outputs a DC offset control value by successively accumulating the DX offsets calculated from the adding and averaging unit. The synchronization determiner (150) determines whether to output the DC offset control value provided by the accumulator (140) based on synchronization information. The pulse density modulation signal generator (160) generates a digital pulse density modulation signal based on a representative value provided by the synchronization determiner (150).

Abstract: A subcarrier allocating apparatus allocating data to be transmitted to a plurality of orthogonal subcarriers in an orthogonal frequency division multiplexing (OFDM) system, the apparatus including: a logical index generator (142) generating a logical index for allocating a data subcarrier to a physical index, the logical index being included with only data subcarriers and the physical index indicating a location of a substantial subcarrier within a symbol; an intermediate index converter (144) converting the logical index into an intermediate index by performing a given operation on the generated logical index and a pilot location constant; and a physical index converter (146) converting the intermediate index into a physical index based on the number of data subcarriers on the left and right sides of a null subcarrier for insertion of a guard interval formed by the null subcarrier.

Abstract: The present invention relates an apparatus and method of estimating a signal-to-noise ratio (SNR) of a received signal when the received signal has a timing offset. An apparatus for estimating a signal-to-noise ratio (SNR) according to an exemplary embodiment of the present invention includes a fast Fourier transform (FFT) unit that performs a fast Fourier transform on a received signal to convert the received signal into a frequency domain signal; a preamble selector that extracts a preamble from the frequency domain signal; a correlator that correlates the preamble to a preamble reference signal generated by a receiver to calculate a correlation value; an entire power estimator that calculates entire power; a noise power estimator that applies a differential demodulation method to the correlation value to remove a timing offset and calculate noise power; and an estimating unit that uses the entire power and the noise power to estimate the signal-to-noise ratio (SNR).

Abstract: The present invention relates to a method of calculating a log-likelihood ratio and a method of detecting a transmission signal. According to the present invention, when a transmission symbol candidate vector is detected on the basis of a received signal, a threshold value and an ML metric of each transmission symbol candidate vector are calculated and the ML metric that is larger than the threshold value is updated by the threshold value. Further, a log-likelihood ratio of the transmission signal bit is calculated using the updated ML metric and the threshold value, and a transmission signal is detected using the log-likelihood ratio.

Abstract: The present invention relates to a low density parity check (LDPC) encoding method and an apparatus thereof. In the LDPC encoding method, a matrix multiplication corresponding to ET?1 and T?1 is eliminated according to a structural characteristic in an encoding process. Accordingly, shift weights that are not ?1 among shift weights corresponding to partial blocks A, B, and C of a parity check matrix are used to perform an encoding operation, and a cyclic shift operation of an information unit block is performed in parallel so that a first parity block and a second parity block may be simultaneously generated.

Abstract: Disclosed is an apparatus for acquiring initial frame timing in a communication system having a normalizer that calculates a normalized window power from powers of samples of received signal during a monitoring period, a cross power calculator that calculates a window cross power from cross powers of the samples during the monitoring period, and each cross power corresponds to multiplication of two of the samples, a divider that divides the window cross power by the normalized window power and outputs a metric for a sample corresponding to the monitoring period, and a peak-value detector that searches a sample having the maximum value among metrics for the samples of the received signals during a predetermined period, and the metrics are calculated by shifting the monitoring period, with a sample next to the sample searched by the peak-value detector being determined as a starting point of a frame.