Emission Time Estimation with Rectangular Input Concentration in Molecular Communication Systems

The nanomachine has a finite processing capability due to size, power, and complexity constraints. To overcome these issues, nanomachine must cooperate to optimize its information exchange operations. Clock synchronization is required for nanomachine cooperation. In Molecular Communication (MC), synchronization is a challenging task due to the random move-ment of molecules that causes inter-symbol interference (ISI) and non-stationary noise. In this paper, we propose a method for clock synchronization between the transmitter nanomachine (TN) and the receiver nanomachine (RN) based on the molecule's emission time estimation. In the presence of both signal-dependent noise and ISI, clock synchronization is performed using maximum likelihood estimation (MLE). The proposed method takes into account a non-zero emission duration of molecules by the TN. The clock synchronization with rectangular input concentration is realistic for practical applications because the emission duration of molecules can not be zero. The effectiveness of the proposed method is shown by numerical results.