From Coherent Communications to Quantum Security: Modern Techniques in CV-QKD
Valéria Loureiro da Silva, Micael Andrade Dias, Nelson Alves Ferreira Neto, Alexandre B. Tacla · 2024
Quantum key distribution (QKD) leverages quantum information theory to enable two remote parties to establish a random key with unconditional secrecy. Performing QKD with coherent light states integrates with modern optical communication techniques but presents new challenges. This survey reviews advancements in applying digital signal processing (DSP) techniques, transformative in coherent optical communications, to continuous-variable QKD (CV-QKD). We discuss how DSP methods enhance CV-QKD performance, security, and feasibility. The areas examined include phase estimation, channel equalization, error correction, and noise reduction, highlighting associated challenges and future research directions.