On the Performance Evaluation of Quasi-Cyclic LDPC Codes with Arbitrary Puncturing

A novel algorithm, named Improved Protograph-based Extrinsic Information Transfer (IP-EXIT), is proposed in this paper. With the proposed algorithm, quite accurate performance evaluations of Quasi-Cyclic LDPC (QC-LDPC) codes with arbitrary puncturing can be provided. LDPC codes combined with IR-HARQ technique have been a hot topic at present and puncturing is definitely one of the most efficient ways to achieve LDPC combined with HARQ. Unlike Turbo codes, different puncturing patterns for the same LDPC code may result in huge performance gap, so researchers are trying to design the puncturing pattern with better performance for LDPC codes. Inevitably, a large number of puncturing pattern with different performance should be compared in order to choose the best one from them, and usually this work is done by simulations with computer. In this paper, a novel algorithm is proposed to replace the work of simulation. It has been proved that the proposed algorithm can accurately evaluate the performance of arbitrary puncturing pattern, with very low complexity and very little time.