Resource Allocation in Twin-Field QKD Coexisting With Classical Communication Over Multicore Fiber

With the development of quantum key distribution (QKD), integration with classical communications has become one of the future development trends. In this paper, in order to solve the problems of fiber resource waste and noise interference in twin-field QKD (TF-QKD) where servo signals exist, we design a high-security and fiber-saving classical-quantum coexistence architecture that ensures both high security and efficient utilization of fiber resources, which is designed to be seamlessly compatible with quantum signals, servo signals of TF-QKD, and bidirectional classical signals over multicore fiber (MCF). Subsequently, an in-depth analysis of noise on the quantum channels is conducted. Furthermore, a quantum-priority core and wavelength allocation (QPCWA) scheme is proposed, which effectively reduces the noise interference from servo signals and classical signals to QKD, improving the performance of QKD. Simulation results show that the QPCWA scheme can extend the secure transmission distance up to nearly 300 km compared with the benchmark scheme. Experimental results show that the QPCWA scheme can effectively reduce noise photons by 50.8%. This research establishes a technical foundation for the integrated deployment of QKD and classical communications.