The Cycle-Concentrating PEG Algorithm for Protograph Generalized LDPC Codes

In this paper, we propose the cycle-concentrating progressive edge growth (CC-PEG) algorithm for lifting protograph generalized low-density parity-check (GLDPC) codes. GLDPC codes, undoped variable nodes (VNs) that are not connected to constraint (GC) nodes more vulnerable channel errors than xmlns:xlink="http://www.w3.org/1999/xlink">doped VNs protected by GC nodes. We observe among codes sharing same structure, with fewer local cycles at undoped VNs have better decoding performances. Inspired observation, CC-PEG is proposed concentrate doped and avoid during process. Specifically, first collects edges result in maximum girth , defined as length of shortest cycle containing VNs. Following this, selects lowest xmlns:xlink="http://www.w3.org/1999/xlink">concentrated metric . Consequently, lifted exhibit asymmetric distributions concentrated around robust Simulation results various protographs show achieves a performance gain up 20 times lower frame error rate compared conventional algorithms.