EXIT-Chart Aided Near-Capacity Quantum Turbo Code Design

TL;DR

This paper introduces an adaptation of EXIT charts for quantum turbo codes, enabling efficient near-capacity code design without extensive simulations or distance spectrum analysis, and demonstrates improved performance close to the hashing bound.

Contribution

It presents a novel method using EXIT charts for quantum turbo code design, replacing traditional analysis techniques and achieving near-capacity performance.

Findings

EXIT chart predictions align with Monte-Carlo simulations

Optimized entanglement-assisted QTC outperforms previous codes

Performance is within 0.3 dB of the hashing bound

Abstract

The design of Quantum Turbo Codes (QTCs) typically relies on the analysis of their distance spectra, followed by Monte-Carlo simulations. By contrast, in this paper we appropriately adapt the conventional non-binary EXtrinsic Information Transfer (EXIT) charts for quantum turbo codes by exploiting the intrinsic quantum-to-classical isomorphism. The EXIT chart analysis not only allows us to dispense with the time-consuming Monte-Carlo simulations, but also facilitates the design of near-capacity codes without resorting to the analysis of their distance spectra. We have demonstrated that our EXIT chart predictions are in line with the Monte-Carlo simulations results. We have also optimized the entanglement-assisted QTC using EXIT charts, which outperforms the existing distance spectra based QTCs. More explicitly, the performance of our optimized QTC is as close as 0.3 dB to the corresponding hashing bound.