Extended Barrel-Shifter for Versatile QC-LDPC Decoders

Abstract

In this letter, we present a Barrel-Shifter of size n extended by an additional layer that can handle any circular permutation on a vector of size m, m ≤ n, thanks to a specific initial positioning of the data. The construction of the so-called Extended Barrel-Shifter is motivated by the hardware decoder constraint related to the Low-Density Parity-Check (LDPC) code recently adopted for the 5G mobile standard. The proposed algorithm requires 42% less multiplexers than the best state-of-the-art solution for n = 384 of the 5G LDPC standard. This proposal is also able to process several inputs in parallel without extra hardware cost.