Time Synchronization for Molecular Communication With Drift

Abstract

Molecular communication is a promising communication paradigm which enables information exchange by emitting and sensing molecules at a micro- or nano-scale. Time synchronization is a basic but important issue for molecular communication. This letter proposes a maximum likelihood estimator for the clock offset between two nanomachines in a molecular communication system with drift. In a directional fluid medium, the transmitter nanomachine records the message sending time instant and passes it to the receiver. The receiver uses this information to estimate the clock offset. Newton–Raphson method is used to approximate the maximum likelihood estimator. The conditions of the channel parameters, such as the flow velocity, the distance between the transmitter and the receiver, and the diffusion coefficient, are discussed. The simulation results validate the effectiveness of the proposed estimator.