Rate-Compatible Short-Length Protograph LDPC Codes

TL;DR

This paper presents a novel rate-compatible protograph LDPC code at 1k blocklength that achieves excellent performance across different rates, overcoming design challenges associated with small block lengths and structured constraints.

Contribution

The paper introduces a new design method for rate-compatible protograph LDPC codes at short block lengths with superior error performance and no error floor down to very low FER levels.

Findings

Achieves no error floor down to FER of 10^-6

Supports rates from 1/3 to 4/5

Outperforms existing codes in waterfall and error floor regions

Abstract

This paper produces a rate-compatible protograph LDPC code at 1k information blocklength with superior performance in both waterfall and error floor regions. The design of such codes has proved difficult in the past because the constraints imposed by structured design (protographs), rate-compatibility, as well as small block length, are not easily satisfied together. For example, as the block length decreases, the predominance of decoding threshold as the main parameter in coding design is reduced, thus complicating the search for good codes. Our rate-compatible protograph codes have rates ranging from 1/3 to 4/5 and show no error floor down to $10^{-6}$ FER.