Abstract: An improved bit mapping method and apparatus for a communication system is provided. A bit mapping method of the present invention includes arranging coded bits in a codeword in an order of recovery capability. A shift region including a number of coded bits is set. The coded bits are rearranged in the shift region by shifting the shift region by a number of bits equal to a number of bits that is indicated by a shift factor. The rearranged coded bits are mapped into a modulation symbol in an order of reliability from a lowest reliability bit position to a highest reliability bit position of the modulation symbol.

Abstract: A method and apparatus for transmitting control information in a wireless communication system using a Low Density Parity Check (LDPC) code is provided. The number of LDPC blocks, through which L1 post-signaling information is to be transmitted, is determined according to the total number of bits of the L1 post-signaling information. The number of input information bits of each LDPC block is calculated when the determined number of LDPC blocks is plural. The number of puncturing bits among parity bits of each LDPC block is determined considering a modulation order. A frame including one or multiple LDPC blocks generated through the preceding steps is transmitted.

Abstract: An apparatus and a method for channel encoding/decoding in a communication system are provided. The apparatus and the method generate LDPC-encoded blocks with various lengths from an LDPC code with fixed length in a communication system using a Low-Density Parity-Check (LDPC) code. The apparatus and the method perform shortening using a predetermined number of shortened bits and perform LDPC encoding. The apparatus and the method apply predetermined rules according to the predetermined number of shortened bits and determine the number of bits to be punctured, and perform puncturing based on the determined number of punctured bits.

Abstract: A method for reducing a Peak to Average Power Ratio (PAPR) using reserved tones in a transmission apparatus of an Orthogonal Frequency Division Multiplexing (OFDM) communication system is provided. The method includes detecting a subcarrier spacing interval and the number of spaced symbols based on a predetermined pilot pattern upon signal reception, and determining positions of shifted reserved tones obtained by shifting positions of reserved tones allocated to a predetermined symbol during the number of the spaced symbols at intervals of the spacing interval; determining an impulse waveform obtained by rotating a phase of a complex value of an impulse stored in a memory, using the determined positions of frequency-domain reserved tones of each symbol; calculating a subtrahend for a PAPR of an output signal using the phase-rotated impulse waveform; and reducing a PAPR of an input signal by performing a gradient algorithm using the phase-rotated impulse waveform.

Abstract: An apparatus for generating a linear code according to the present invention includes a coding unit for coding input bits with a second coding scheme which is different from a first coding scheme for generating the linear code; and a rearrangement unit for generating the linear code by rearranging the bits coded with the second coding scheme. The present invention can provide a coding apparatus and method capable of reducing complexity by adaptively applying it to various coding scheme.

Abstract: An apparatus and method for generating a parity-check matrix of a Low-Density Parity-Check (LDPC) code are provided. Parameters for designing the LDPC code are determined, and a first parity-check matrix of a quasi-cyclic LDPC code is formed according to the determined parameters. A second parity-check matrix is created through the elimination of a predetermined portion of a parity part in the first parity-check matrix, and a third parity-check matrix is created by rearranging the second parity-check matrix.

Abstract: An apparatus and method for encoding a channel in a communication system using a Low-Density Parity-Check (LDPC) code. The method includes determining a number of parity bits to be subjected to puncturing; dividing the parity bits at predetermined intervals, and determining a number of puncturing bits, which are subjected to puncturing within the predetermined intervals; determining positions of puncturing parity bits corresponding to the determined number of puncturing bits; and repeatedly performing puncturing on the puncturing parity bits corresponding to the determined positions at the predetermined intervals. The predetermined intervals are determined by dividing a length of parity bits by a length of one column group in a parity-check matrix.

Abstract: An apparatus and method for supporting both a receiver using a single antenna and a receiver using multiple antennas in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. The apparatus and method in a MIMO wireless communication system include a first synthesizer for generating a first Transmit (Tx) signal by adding a first signal and a second signal, a second synthesizer for generating a second Tx signal by subtracting the second signal from the first signal and a plurality of transmitting units for transmitting the first Tx signal and the second Tx signal through corresponding antennas. Accordingly, receivers having either a single antenna or multiple antennas may be employed in the same communication system.

Abstract: A method for encoding a channel in a communication system using a Low-Density Parity-Check (LDPC) code is provided. The method includes determining a number of parity bits for puncturing; dividing the parity bits at predetermined intervals, and determining a number of puncturing parity bits, which are subjected to puncturing within the predetermined intervals; determining a modulation scheme; determining positions of puncturing parity bits corresponding to the determined number of the puncturing parity bits within the predetermined intervals according to the modulation scheme; repeatedly performing puncturing on puncturing parity bits corresponding to the determined positions at the predetermined intervals; and transmitting remaining bits except for the punctured bits according to the modulation scheme.

Abstract: A method and apparatus for generating Low-Density Parity Check (LDPC) codes of various block lengths from a structured LDPC code in a communication system is provided. To support various block lengths, predefined rules are applied to a parity check matrix of an LDPC code, and then shortening is selectively applied to the parity check matrix. Subsequently, if information data bits are input, the input data information bits are encoded into an LDPC codeword by using the parity check matrix according to a preset encoding scheme, and then the encoded LDPC codeword is transmitted after puncturing is selectively applied.

Abstract: An apparatus and method for transmitting/receiving a signal in a communication system are provided. The method includes inputting an information word during initial transmission and transmitting a first code word created by encoding the inputted information word based on a first coding ratio, and transmitting a portion of a second code word created by encoding the first code word based on a second coding ratio at a retransmission request. Accordingly, the apparatus and method provide for transmitting/receiving signals in a communication system in such a manner that the complexity of the communication system is reduced.

Abstract: In a transmission device and method for a CDMA communication system, when a shorter frame message is generated during transmission of a longer frame message, the transmission of the longer frame message is interrupted, whereupon the shorter frame message is immediately transmitted in place of a portion of the longer frame message. In one embodiment, after the longer frame message is interrupted and the shorter frame message is transmitted, only the tail portion of the longer frame message is transmitted thereafter. That is, the replaced portion of the longer frame message is not transmitted following the shorter frame message transmission. In an alternative embodiment, following the shorter frame message transmission, the remainder of the longer frame message, from the point of interruption, is transmitted in its entirety. In the latter case, the longer frame message is delayed by the length of the shorter frame message.

Abstract: A method for transmitting data in a communication system using a Low Density Parity Check (LDPC) matrix includes generating an LDPC codeword by encoding information data bits, interleaving the LDPC codeword, mapping the interleaved LDPC codeword to a modulation signal, and generating a mapped signal by mapping the LDPC codeword bits separately to a bit corresponding to a real part and a bit corresponding to an imaginary part of said modulation signal, among bits constituting the modulation signal, generating a modulation signal by high-order-modulating the mapped signal and Radio Frequency (RF)-processing the modulation signal, and transmitting the RF-processed signal via a transmission antenna.

Abstract: An apparatus for transmitting data in a communication system using a Low Density Parity Check (LDPC) matrix is provided. The apparatus includes an interleaver for interleaving a descending bit-ordered codeword having a predetermined size and in accordance with a predetermined modulation scheme; and a bit mapper for mapping codeword bits constituting the interleaved codeword in accordance with a predetermined mapping scheme that takes into account degrees of the codeword bits and reliability characteristics of modulation symbol-constituting bits based on the predetermined modulation scheme.

Abstract: A method and apparatus for encoding and decoding a channel in a communication system using a Low-Density Parity-Check (LDPC) code. The encoding method includes determining a modulation scheme for transmitting a symbol; determining a shortening pattern in consideration of the determined modulation scheme; grouping columns corresponding to an information word in a parity-check matrix of the LDPC code into a plurality of column groups; ordering the column groups; determining a range of a resulting information word desired to be obtained by shortening the information word; based on the range of the resulting information word, performing column group-by-column group shortening on the ordered column groups of the information word, according to the determined shortening pattern; and LDPC-encoding the shortened information word.

Abstract: A method for encoding a channel in a communication system using a Low-Density Parity-Check (LDPC) code. The method includes generating a plurality of column groups by grouping (categorizing) columns corresponding to an information word in a parity-check matrix of the LDPC code, and ordering the column groups; determining a range of an information word desired to be obtained by performing shortening; based on the determined range of the information word, performing column group-by-column group shortening on the column groups in order according to a predetermined shortening pattern; and LDPC encoding the shortened information word.

Abstract: An apparatus and method to encode a block Low Density Parity Check (LDPC) code in a signal transmission apparatus is disclosed. The method includes generating a first block LDPC codeword by encoding an information vector using a first parity check matrix when a code rate to be used in the signal transmission apparatus is a first code rate as a code rate of the first parity check matrix, and generating a second block LDPC codeword by encoding the information vector using a second parity check matrix when the code rate to be used in the signal transmission apparatus is a second code rate as a code rate of the second parity check matrix.

Abstract: A signal detection apparatus and method in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. The apparatus includes a receiver for receiving training symbol vectors and a data signal vector from a transmitting end through a plurality of receive (Rx) antennas and a detector for expanding the training symbol vectors into second- or higher-order polynomials, for generating a weighting parameter vector for multivariate polynomial expansion of the data signal vector by using the polynomials expanded from the training symbol vectors and thereafter for expanding the data signal vector into a second- or higher-order multivariate polynomial using the weighting parameter vector, and for detecting Transmit (Tx) values of the data signal vector from the multivariate polynomial. Therefore, signal detection performance in a Multiple Input Multiple Output (MIMO) wireless communication system resembles that of a non-linear scheme while complexity resembles that of a linear scheme.

Abstract: A channel decoding apparatus and method in a communication system using Low-Density Parity-Check (LDPC) codes are provided in which an encoded signal is received from a transmitter and decoded using a parity-check matrix. At least one of input orders and output orders of the parity-check matrix are determined so that same values are not overlapped in a column direction between the at least one of the input orders and the output orders.

Abstract: An apparatus and method for allocating a data rate in a multi-antenna system are provided, wherein a noise threshold corresponding to a modulation scheme, a coding rate, or a combination of both applied to a base layer from among a plurality of layers is set as a reference noise threshold, and a data rate is allocated to an enhanced layer among the plurality of layers, based on the reference noise threshold and a use or non-use of hierarchical transmission.