Abstract:

In order to improve the puncturing performance of low density parity check (LDPC) codes, a method to optimize the extension of the parity checking matrix for rate compatible LDPC codes is proposed. Considering the rate compatible constraint, an algorithm is presented to optimize the degree distribution of the LDPC codes. Based on the recovery rules of punctured nodes, a new structure of the paritycheck matrix is devised to facilitate puncturing. A greedy search algorithm is adopted to stepwisely maximize the number of diffe rent types of punctured variable nodes, which results in good puncturing performance. The experiment results show that the proposed method is superior to the efficientlyencodable ratecompatible LDPC (E2RC-LDPC) codes over wide range of rates. When the rate is greater than 0.8, the proposed method can obtain about 0.7~0.8 dB gain over the E2RC-LDPC codes.