Abstract: Provided are a transmitter and a method for transmitting a data block in a wireless communication system. The method comprises the following steps: deciding the number of bits (s) and encoders (NES) to allocate to one axis of a signal constellation; encoding an information bit based on the s and the NES and generating a coded block; parsing the coded block based on the s and the NES and generating a plurality of frequency sub-blocks; and transmitting the plurality of frequency sub-blocks to a receiver.

Abstract: Provided are a transmitter and a method for transmitting a data block in a wireless communication system. The method comprises the following steps: encoding an information bit and generating a block coded with an NCBPSS bit; generating two sub-blocks by parsing the coded block; and transmitting the two sub-blocks to the transmitter. By preventing the bits that are contiguous to the encoding block from having continuous identical reliabilities on a signal constellation, the deterioration of the decoding performance of the transmitter can be prevented.

Abstract: Provided is a reception apparatus and method of a Multiple Input Multiple Output (MIMO) system that receives a plurality of different data streams in a multiple cell environment. The reception apparatus for receiving a plurality of different data streams in a multiple input multiple output (MIMO) antenna system includes a data stream detector for detecting each data stream by removing interference between the different data streams while maintaining channel information; and a cochannel interference (CCI) remover for removing cochannel interference from each data stream detected in the data stream detector. The present invention can remove cochannel interference and increase channel capacity to thereby acquire both diversity gain and multiplexing gain.

Abstract: A method and apparatus of selecting N metrics among M metrics is provided. The apparatus determines M metrics P(i), where i=1, . . . , M. Each P(i) is represented by B bits. The apparatus determines N metrics among M metrics. The complexity for configuring the circuit is decreased, and the length of the critical path is reduced.

Abstract: Disclosed are an apparatus and a method for transmitting/receiving data by acquiring channel information of a terminal receiving data in a communication system providing services to users through beamforming according to a multi-input multi-output (MIMO) scheme, wherein so as to acquire channel information of the terminal for transmitting/receiving data through the beamforming according to the MIMO scheme, a null data packet announcement (NDPA) frame and a null data packet (NDP) frame are transmitted to the terminal, the beamforming frame is received from the terminal as a response of the null data packet announcement frame and the null data packet frame, and the channel information of the terminal included in the beamforming frame and the indication information on which the null data packet frame included in a control information field of the beamforming frame is normally received are checked.

Abstract: The present invention relates to a method and apparatus for transmitting and receiving data. A data transmission method from a sender terminal to a receiver terminal in a MIMO system using a variable frequency band according to one embodiment of the present invention comprises: repeatedly generating a signal field depending on a frequency band that is applied to the transmission of a data frame; generating a data field including the data; generating a data frame including the signal field and the data field; and transmitting the data frame to the receiver terminal. The present invention is advantageous in that a signal field which is transmitted together with the data being transmitted from the sender terminal to the receiver terminal in the MIMO system can be sent more efficiently.

Abstract: The present invention particularly relates to a method and an apparatus for improving the efficiency of data transmission in a multi-user wireless transmission system.

Abstract: Disclosed is an apparatus for receiving data in a communication system, including: a receiving unit configured to receive data transmitted from an access point (AP) by a multi-input multi-output (MIMO) scheme; a detecting unit configured to detect a data stream of the received data using an LQ decomposition scheme; a generating unit configured to generate channel information regarding the data stream; and a transmitting unit configured to feedback the channel information to the AP.

Abstract: The present invention relates to a method and apparatus for transceiving data. A method in which a transmitting terminal transmits data to a receiving terminal in a MIMO system according to one embodiment of the present invention comprises the following steps: generating a data field containing the data; generating a signal field containing information on the data field; generating a data frame containing the data field and the signal field; and transmitting the data frame to the receiving terminal. According to the present invention, an end of the frame being transmitted is accurately notified to the receiving terminal in a communication system in which the frame is transmitted using MIMO, thereby decoding the frame in a more efficient manner at the receiving terminal.

Abstract: Provided are an apparatus for receiving signals in an OFDM communication system using multiple transmission/reception antennas and a method thereof. The method includes modulating a predetermined part of a data stream based on a multi-dimensional reception procedure to generate a first modulated data stream; regenerating a symbol corresponding to the modulated data stream; eliminating the regenerated symbol from a remained data stream; modulating the eliminated data stream to generate a second modulated data stream; and outputting an output signal obtained by serializing the first modulated data stream and the second modulated data stream.

Abstract: Provided is an apparatus and method for decoding a Low Density Parity Check (LDPC) code based on prototype parity check matrixes. The apparatus, includes: a parity check matrix selecting means for determining multiple prototype parity check matrixes according to a sub-matrix size and a parallelization figure for processing the parity check matrix; a bit input means for receiving a log likelihood probability value for input bit according to the sub-matrix size and the parallelization figure; a check matrix process means for sequentially performing a partial parallel process on the parity check matrix based on the received log likelihood probability value and the determined multiple prototype parity check matrixes; and a bit process means for determining a bit level based on the partial-parallel processed parity check matrix value and recovering the input bit according to the sub-matrix size and the parallelization figure.

Abstract: The present invention relate to a wireless communication system; and, more particularly, to a communicating apparatus and method in a high rate wireless communication system. A transmitting method of data in accordance with an embodiment of the present invention, as a transmitting method of data in a high rate wireless communication system, includes: allocating one or more bands among two or more multi-bands to each of users; and simultaneously transmitting data through the allocated bands to two or more users by using the multiple antennas for the allocated respective bands.

Abstract: Provided are a method for producing a parity check matrix for low complexity and high speed decoding, and an apparatus and method for coding a Low Density Parity Check (LDPC) code using the same. The method includes: calculating a cyclic shift value of a subblock to a matrix; and when the calculated cyclic shift values of the subblock are arrayed in the matrix, producing a parity check matrix by arraying the cyclic shift values of the subblock except ‘0 matrix’ without duplication to any one column.

Abstract: Disclosed is an apparatus and method for transmitting/receiving data using a low-density parity check (LDPC) coding scheme in a communication system. The method includes generating a multi-user data packet containing data to be transmitted to a plurality of users, encoding the multi-user data packet as a BCC and an LDPC code, and transmitting the encoded multi-user data packet to the plurality of users. In the method, the encoding of the multi-user data packet encodes MPDU subframes corresponding to each of the plurality of users in the multi-user data packet as the LDPC code, and calculates information on a length in LDPC encoding, corresponding to the encoding of the multi-user data packet as the LDPC code.

Abstract: A space-time code has a codeword matrix. The codeword matrix is a square matrix with dimension equal to the number of the transmit antennas, wherein a row of the codeword matrix represents combined signals transmitted by each transmit antenna and a column of the codeword matrix represents timeslots of the number of the transmit antennas. Signals are transmitted through the rows of the number of spatial multiplexing rate, in each column of the matrix. Further, the symbols of the number of the transmit antennas are combined by way of utilizing complex weights, in each row of the matrix. With this space-time code, a delay is minimized, so that change of channels can be managed efficiently. Also, the space-time code has minimum number of data symbols, and thus its complexity is minimized.

Abstract: The present invention relates to a multi-input multi-output (MIMO) system for enhancing transmission performance. The MIMO system uses space-time encoding and transmit antenna selection methods, and includes a transmitter (100) and a receiver (200). The transmitter (100) includes N transmit antennas (130-1, 130-4) that are more than M transmit antennas (130-1, 130-3) used for transmitting a signal to space channel, selects the M transmit antennas (130-1, 130-3) among the N transmit antennas (130-3 130-4), and transmits symbol by space-time encoding the symbol. The receiver (200) includes M receive antenna (120-1, 210-2) for receiving a signal from the space channel, detects an information symbol by using the signal received through the receive antenna (210-1, 210-2), generates transmit antenna selection information for selecting M transmit antennas (130-1, 130-3) among transmit antennas (i30-1, . . . 7130-4) with reference to a channel estimate, and returns the information to the transmitter.

Abstract: Provided are a multi-dimensional detector for a receiver of an MIMO system and a method thereof. The multi-dimensional detector includes a first symbol detecting unit for calculating symbol distance values using an upper triangular matrix (R) obtained from QR decomposition to detect an mth symbol; a symbol deciding unit for deciding a symbol having a minimum distance value among the calculated symbol distance values from the first symbol detecting unit; and a second symbol detecting unit for calculating symbol distance values using an updated received signal y and the upper triangular matrix R to detect a (m?1)th symbol.

Abstract: Respective codewords of quantization codebooks corresponding to a number of data streams are selected based on channel information estimated by a received training symbol. A stream mode is selected among stream modes to determine a modulation method applied to each data stream. The data stream is detected by using the codeword corresponding to the quantization codebook of the data stream corresponding to the selected stream mode as a precode matrix, and the detected data stream is modulated. In this case, a receiving apparatus performs a feedback operation so that indexes of the selected stream mode and the codeword used as the precode matrix may be transmitted to the transmitting apparatus. The transmitting apparatus selects the number of transmitted data streams and the modulation method based on the transmitted index of feedback streams by the feedback operation.

Abstract: A data transmission apparatus in a wireless communication system includes: a data field generation unit configured to generate a data field for transmitting data; a signal field generation unit configured to generate a signal field for transmitting information on the data field; and a transmission unit configured to transmit a data packet containing the data field and the signal field. The signal field includes a rate bit, a reservation bit, a length bit, a parity check bit, and a tail bit, and the data transmission apparatus transmits a check bit for checking whether the signal field is normal or not through two or more bits of the bits of the signal field.

Abstract: A method for reducing power consumption in a wireless communication system includes: generating a descramble initial value by using at least some bits of identification information of an STA, which is known to an AP or base station and the STA; generating a first descramble sequence by using the generated descramble initial value and comparing at least some bits of the generated first descramble sequence with at least some bits of a service field of a currently-received signal; as the comparison result, when it is determined that the destination of the currently-received signal is not set to the STA, stopping the signal reception; and as the comparison result, when it is determined that the destination of the currently-received signal is set to the STA, generating a second descramble sequence by using the descramble initial value and descrambling the currently-received signal.