Spatially Coupled Codes with Sub-Block Locality: Joint Finite Length-Asymptotic Design Approach

TL;DR

This paper introduces a joint finite-length and asymptotic design framework for spatially coupled LDPC codes with sub-block locality, enabling efficient local decoding and reliable global decoding.

Contribution

It proposes a novel mixed analysis and design approach for SC-LDPC codes with sub-block locality, optimizing both local and global performance.

Findings

Optimized local code design for threshold and cycle counts

Coupling strategies that minimize global cycle counts

Enhanced decoding performance at both local and global levels

Abstract

SC-LDPC codes with sub-block locality can be decoded locally at the level of sub-blocks that are much smaller than the full code block, thus providing fast access to the coded information. The same code can also be decoded globally using the entire code block, for increased data reliability. In this paper, we pursue the analysis and design of such codes from both finite-length and asymptotic lenses. This mixed approach has rarely been applied in designing SC codes, but it is beneficial for optimizing code graphs for local and global performance simultaneously. Our proposed framework consists of two steps: 1) designing the local code for both threshold and cycle counts, and 2) designing the coupling of local codes for best cycle count in the global design.