  Quantum key distribution is one of the first quantum technologies ready for
the market. Current quantum telecommunication systems usually utilize a service
channel for synchronizing the transmitter (Alice) and the receiver (Bob).
However, the possibility of removing this service channel and exploiting a
clock recovery method is intriguing for future implementation, both in fiber
and free-space links. In this paper, we investigate criteria to recover the
clock in a quantum communication scenario, and experimentally demonstrated the
possibility of using a quantum-based clock recovery system in a time-bin
quantum key distribution protocol. The performance of the clock recovery
technique, in terms of quantum bit error rate and secret key rate, is
equivalent to using the service channel for clock sharing.
