Optimized IR-HARQ Schemes Based on Punctured LDPC Codes over the BEC

TL;DR

This paper investigates optimized IR-HARQ schemes using punctured LDPC codes over erasure channels, demonstrating near-optimal performance and rateless operation in mobile wireless scenarios.

Contribution

It introduces a novel IR-HARQ protocol based on punctured LDPC codes, optimized for erasure channels, with bounds and extensions for rateless operation.

Findings

Achieves near-theoretical maximum throughput

Operates effectively over a wide range of erasure rates

Can be extended to a rateless scheme

Abstract

We study incremental redundancy hybrid ARQ (IR-HARQ) schemes based on punctured, finite-length, LDPC codes. The transmission is assumed to take place over time varying binary erasure channels, such as mobile wireless channels at the applications layer. We analyze and optimize the throughput and delay performance of these IR-HARQ protocols under iterative, message-passing decoding. We derive bounds on the performance that are achievable by such schemes, and show that, with a simple extension, the iteratively decoded, punctured LDPC code based IR-HARQ protocol can be made rateless, and operating close to the general theoretical optimum for a wide range of channel erasure rates.