Abstract: A method of encoding input data using a low density parity check (LDPC) code or decoding the encoded data is disclosed. Each index of a model matrix is expanded to an index matrix which includes two or more indexes. Each index included in the index matrix means a specific sub-matrix, and can be replaced with a corresponding sub-matrix to generate a parity check matrix.

Abstract: A data transmitting and receiving method is disclosed. In transmitting a response signal for a transmission signal from at least one transmitter, the present invention includes receiving at least one data block from the at least one transmitter, the at least one data block grouped into at least one group and then transmitted by the at least one transmitter, checking whether each data block is successfully received for the at least one data block belonging to the corresponding group per the group, selecting a transmission scheme of transmitting a response signal instructing a presence or non-presence of successful reception of the each data block to the at least one transmitter, and transmitting a response signal for the each data block to the at least one transmitter by the selected response signal transmission scheme. Hence, the present invention reduces overhead of control information necessary for data transmission.

Abstract: A method of encoding data using a parity check matrix, a method of decoding encoded data, and a data retransmission method using the same are disclosed. A data retransmission method in a communication system includes transmitting a codeword encoded by a first parity check matrix corresponding to a first coding rate, among at least two parity check matrixes corresponding to different coding rates, receiving NACK from the receiver in response to the codeword, and transmitting parity bits encoded by some of the second parity check matrix corresponding to a second coding rate, among the at least two parity check matrixes, to the receiver.

Abstract: A method for retransmitting signals in a MIMO system that uses an HARQ scheme is provided. In the method, an additional codeword-to-layer mapping scheme for retransmission in a MIMO system that uses an HARQ scheme is defined and used to efficiently retransmit signals. In addition, required information is obtained using existing control information to more efficiently retransmit signals in terms of control signal overhead.

Abstract: A method for efficiently transmitting downlink control information is described. A method for transmitting control information in a multiple antenna system which can simultaneously transmit a maximum of two codewords includes transmitting modulation and coding scheme (MCS) information, a new data indicator (NDI) and a redundancy version (RV) for information blocks transmitted through the two codewords, and transmitting additional control information including at least one of a swapping indicator and enable/disable information. The swapping indicator indicates whether or not swapping occurs between the information blocks transmitted through the two codewords, and the enable/disable information indicates whether or not any one of transmissions through the two codewords is disabled. The swapping indicator is reserved when any one of transmissions through the two codewords is disabled, thereby reducing signaling overhead and efficiently transmitting necessary information.

Abstract: A low density parity check (LDPC) coding method, and more particularly, a method of executing LDPC coding using a parity check matrix is disclosed. The present invention comprises providing an information bit stream for channel encoding, and encoding the information bit stream by using a first parity check matrix including at least one row generated by combining at least two rows of a second parity check matrix.