1. Field of the Invention
The present invention relates generally to a non-binary structured Low Density Parity Check (LDPC) code, and in particular, to a method for generating a non-binary structured LDPC code.
2. Description of the Related Art
The key issue in communication is to transmit data efficiently and reliably over a channel. The next generation multimedia mobile communication system, now being developed, requires a high-speed communication system that can process and transmit a variety of information such as image and radio data beyond the early voice-oriented service. Therefore, it is necessary to increase the system efficiency with the use of a channel coding technique suitable for the system.
During data transmission, inevitable error due to noise, interference and fading occurs according to channel condition, causing a loss of information. Generally, in order to reduce the loss of information, the system uses various error control techniques according to the characteristics of the channel, thereby increasing the system reliability. The most typical the error control technique uses error correction codes. The LDPC code is one of the error correction codes.
The LDPC code, a code proposed by Gallager, is defined by a sparse binary parity check matrix in which the major elements have a value of ‘0’ and the minor elements except for the elements having a value of ‘0’ have a value of ‘1’. That is, the elements constituting the binary parity check matrix have only one of ‘0’ and ‘1’.
Unlike this, a parity check matrix of a non-binary LDPC code is made up of elements in a Galois Field (GF) (q=2p) (where q is an integer greater than 2). Herein, p has an integer value greater than 1, and if p=1, the corresponding code is a binary LDPC code.
It has been experimentally proven that the non-binary LDPC code is superior in performance to the binary LDPC code. In addition, the structured parity check matrix is superior to the unstructured parity check matrix in terms of high decoding speed and low required storage capacity. Therefore, a scheme for generating (designing) the non-binary structured LDPC code is now the subject of extensive research.