Abstract: A method is provided for puncturing a low density parity check (LDPC) code decoded by a parity check matrix that is expressed by a factor graph including a check node and a bit node, being connected to each other at an edge, and includes a parity part having a dual diagonal matrix with a single 3-weight column and the remaining columns being 2-weight columns. The method includes generating a puncturing pattern such that bits of the LDPC code are punctured in an order of a bit mapped to a column with a higher weight from among the columns constituting the parity part; and puncturing the LDPC code according to the generated puncturing pattern.

Abstract: A method for puncturing a low density parity check (LDPC) code that is decoded through a parity check matrix expressed by a factor graph including check nodes and bit nodes connected to the check nodes through edges. The method includes classifying the bit nodes mapped to a parity part of a codeword into hierarchical groups according to their decoding facilities when the bit nodes are punctured, determining puncturing order of the groups, and sequentially performing puncturing on the bit nodes from a bit node belonging to a corresponding group according to the puncturing order of the groups to acquire a codeword with a desired coding rate.

Abstract: An improved receiver for a multicarrier-based MIMO (Multiple-Input Multiple-Output) system is provided. A MIMO receiving apparatus includes a detection priority decision unit, which receives via N receiving antennas signals transmitted from M transmitting antennas and determines the detection priorities of the signals, and a signal detector, which successively detects the signals in a decreasing order from a signal having a higher priority according to the detection priorities determined by the detection priority decision unit. System complexity can be reduced by minimizing the number of the inverse matrix calculations required for an SIC mechanism using one MIMO DFE and MISO DFEs corresponding to the number of transmitting antennas.

Abstract: Disclosed are an apparatus and a method for reducing the coding complexity in an LDPC code used in a digital communication system. In the method, parameters required for coding are determined according to a coding rate and a code length, a seed matrix is generated according to values of the parameters, a plurality of cell matrices are generated according to the values of the parameters, a parity check matrix is generated using the seed matrix and the cell matrix, and information bits are coded from the parity check matrix. The method can be realized by a small memory and a simple shift register and can perform coding even without obtaining a generation matrix, thereby remarkably reducing the complexity of a system.

Abstract: A system, an apparatus and a method for transmitting/receiving data coded by a low density parity check matrix code are provided. The apparatus for transmitting data coded by a low density parity check code includes: a low density parity check encoder for encoding input data based on the low density parity check code; and a bit puncturer for puncturing columns in an order of columns which least degrade a performance caused by puncturing in the low density check code according to a code rate of an output data. Accordingly, the low density parity check code having superior performance can be implemented to the next generation mobile communication system supporting various code rates.

Abstract: A channel encoding apparatus and method are provided in which part of the parity bits are set to erroneous bits, and full parity bits are created by correcting the erroneous bits using a channel decoding apparatus of a receiver in a communication system. In the channel encoding apparatus, in order to generate a coded bit stream by adding a parity bit stream to a message bit stream, a partial parity generator generates a partial parity bit stream as a part of the parity bit stream using the message bit stream, an erasure generator generates a bit stream having an erroneous value as the remaining part of the parity bit stream, and a decoder calculates the value of the parity bit stream by correcting the bit stream having the erroneous value using a parity-check matrix that determines the parity bit stream, the message bit stream, and the partial parity bit stream.

Abstract: An LDPC encoding method in a digital communication system is provided, in which a parity-check matrix H having a plurality of circulant matrices as elements is first generated. A generation matrix G is generated using the parity-check matrix. Information bits are then encoded using the generation matrix G.

Abstract: Disclosed is a space-time trellis code (STTC) encoding method for performing space-time coding of a serially-concatenated space-time code (SC-STC) in an encoder having an outer encoder for performing channel coding and an inner encoder for performing the space-time coding, in a mobile communication system including one or more transmission antennas, by transmitting via a first transmission antenna a symbol generated by encoding a first input signal output from the outer encoder by a first recursive convolutional encoder and a symbol generated by encoding a second input signal output from the outer encoder by a second recursive convolutional encoder; and transmitting via a second transmission antenna the first and second input signals.

Abstract: An apparatus and method for improving decoding performance of a Normalized-BP algorithm in an LDPC-code decoder. The present invention to provides an LDPC-code decoding apparatus, which can be implemented in the form of a simpler configuration than the LLR-BP algorithm, and a method for controlling the same. Further, the present invention provides an LDPC-code decoding apparatus, which improves decoding performance of the Normalized-BP algorithm and at the same time provides similar performance to that of the LLR-BP algorithm, and a method for controlling the same.