Distance Estimation Based on Impulse Response Distortion in Diffusive Molecular Communication

The study of communication systems based on the exchange of molecules is currently a fertile research direction in communications, encouraged by novel practical tools to engineer such systems from living substrates. Distance estimation in these systems is one of the critical functionalities. In this paper, we propose two distance estimation methods based on peak attenuation and widening of an emitted molecular pulse, which differently from previous solutions, do not rely on synchronization between the communicating devices. Their performance is evaluated through simulations in a 3-D space in terms of normalized Root Mean-Squared Error (RMSE) by varying several parameters, such as the diffusion coefficient, the transmitter-receiver distance, and the number of released molecules. The use of a variable-length smoothing filter is also proposed to further improve the performance of the two considered methods, demonstrating the existence of an optimal filter length, paving the road for the design of further improved distance estimation methods.