Efficient Puncturing Scheme for Irregular LDPC Codes Based on Serial Schedules

Abstract

In practice, low-density parity-check (LDPC) codes are usually decoded by serial schedules. However, the existing schemes for rate-compatible puncturing LDPC codes are proposed on the assumption that the flooding schedules are employed in decoding algorithm. In this letter, an efficient puncturing scheme is proposed for irregular LDPC codes based on serial schedule. The scheme selects variable nodes to be punctured one at a time. At each time, a check node is selected firstly based on the idea that the punctured variable nodes are allocated evenly to all the check nodes. Then the puncturing variable node is selected among its neighbors. Furthermore, the order of the check nodes in the selection serves as the updating order in the serial schedule, which ensures that all the punctured codes can be recovered at the first iteration. Simulation results demonstrate that the scheme performs better for a wide range of code rates compared with the existing puncturing scheme, especially for high-rate punctured codes.Index Terms-Rate-compatible punctured LDPC codes, highrate punctured codes, serial schedules, approximate cycle extrinsic message degree (ACE).