An efficient distance measurement approach in diffusion-based molecular communication based on arrival time difference

This paper studies the distance measurement problem in diffusion-based molecular communication (DBMC). In order to design efficient and robust distance measurement method, we firstly model three types of noises may exist at different phases of DBMC. The proposed models include input noise, convection noise, and reception noise. Then, two existing distance measurement methods, based on round trip time (RTT) and signal attenuation (SA), are briefly reviewed. By using two types of message molecules with different diffusion coefficients, a novel method based on signal arrival time difference (ATD) is proposed. The proposed method overcomes synchronization problem and improves efficiency by using only one-way signal. The performances are evaluated and compared through simulation experiments. Results show that to most simulated parameters, SA-based method outperforms over the other two, however, is easily influenced by fluctuation in the input signal. We find out that this problem can be solved by increasing the input signal width. Furthermore, it is also shown that between the two arrival time-based methods, the proposed ATD method, using distinguishable information molecules, can not only increase the distance measurement efficiency but also improve the accuracy performance.