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

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.

Accepted and to be presented at the Optica Advanced Photonics Congress: Signal Processing in Photonic Communications (SPPCom), pp. p. SpTh1F.3, Long Beach, CA, USA, Jul. 2026