Ultra-Low-Rate Information Reconciliation: Repetition Coding or Dedicated Codes?

2026-06-19

AI Summary

This study addresses the trade-off between performance and complexity in information reconciliation for continuous-variable quantum key distribution (CV-QKD) at extremely low code rates. The authors systematically compare repetition coding with specialized low-rate error-correcting codes and demonstrate that repetition coding reduces decoding complexity by approximately 50% while incurring only a moderate penalty in residual bit error rate. This approach achieves high reconciliation efficiency with significantly simplified implementation, offering a practical and feasible reconciliation strategy for resource-constrained quantum communication systems.

Abstract

We compare repetition-based ultra-low-rate information reconciliation with dedicated ultra-low-rate codes for CV-QKD. Repetition coding offers a favorable performance-complexity trade-off, incurring only a moderate error-rate penalty while reducing decoding complexity by $2\times$, making it attractive for implementation-constrained systems.

Problem

• information reconciliation
• ultra-low-rate codes
• CV-QKD
• repetition coding
• decoding complexity

Innovation

• ultra-low-rate coding
• information reconciliation
• repetition coding
• CV-QKD
• decoding complexity