SDN-Enabled Continuous-Variable QKD in Coexistence with 8×200 Gb/s 16-QAM Classical Channels

We analyze the coexistence of continuous variable quantum key distribution (CV-QKD) and 8×200Gb/s 16-QAM classical channels, evaluating parameters such as quantum channel spectral position, classical channel power, guard-band, and the number of exchanged quantum symbols. Additionally, we assess the performance of classical signals in terms of bit error rate (BER) to jointly analyze the impact of coexistence on both classical and quantum channels. These parameters can be exposed to a Software Defined Network (SDN) controller to dynamically optimize the performance of the CV-QKD system. Our results demonstrate that CV-QKD achieves successful key generation with a 100 GHz guard-band with classical channels at −10 dBm and 200 GHz at 0 dBm. The channel position within the spectrum has minimal impact, and lower key rates for short distances do not necessitate asymptotic convergence in quantum symbols. [−20, −10] dBm per channel with 100 GHz guard-band provides error-free classical signals and positive key generation.