Метод комбинированного декодирования кодов с малой плотностью проверок на четность

Abstract

UA: Предложен комбинированный подход к декодированию кодов с малой плотностью проверок на четность с использованием популяционных процедур. Приведены особенности реализации основных этапов декодирования. Представлены результаты исследования эффективности метода комбинированного декодирования для кодов с разными параметрами.

EN: The error-correcting codes have been widely used in telecommunication systems. Currently low-density parity check codes became widespread. These codes have some advantages over turbo-codes and other code constructions. The iterative hard and soft decoding methods of low-density parity check codes are used. The soft belief propagation decoding allows increasing correcting capabilities such codes. Belief propagation decoding is suboptimal decoding and has reasonable error probability only for long low-density parity check codes. The maximum likelihood decoding can not be achieved even for medium-length codes in practice. The features of several decoding methods of block codes and low-density parity check codes are presented. The parity-check matrix and graphical representation of binary and bipolar low-density parity check codes are described. The joint approach for decoding low-density parity check codes with using population-based procedures is proposed. On the first stage of joint decoding hard decoding is performed on the basis on syndrome. Further soft belief propagation decoding is applied. After that decoding with using reliability information about received symbols and population-based procedures are performed. The implementation features of main decoding stages are given. The research results of performance joint decoding method for codes with different parameters are presented. Analysis of the obtained results showed that joint decoding method can be used for relatively long low-density parity check codes. The performance joint decoding method decreases with growth of the code length.