Abstract

In this paper, we present a novel method to expand a graph over a finite field into a larger one over one of the original field's subfields. This allows a number of different graph expansions for any given graph. These expansions can be used in various applications, and we focus specifically on the case of decoding NB-LDPC codes. Using the novel expanded graphs, it is possible to reduce decoding complexity of NB- LDPC codes significantly with minimal performance losses.