Relative Localization for Silent Absorbing Target in Diffusive Molecular Communication System

Recently, anomaly detection or localization in molecular communication (MC) system has become a research hot topic which can be used to distinguish the abnormal cells in the human body. Due to no or very few molecules the target released, it is difficult to detect the silent target in the MC system. In this paper, we construct a three-node molecular communication (TNMC) system including a point source transmitter, a passive receiver and a silent absorbing target (SAT), the SAT cannot release but has the ability to absorb the molecules. Based on the above system, we propose a probability equivalent modeling (PEM) method to model the channel of TNMC system, and derive the channel impulse response (CIR) of the receiver. Besides, we propose a localization algorithm based on maximum likelihood estimation (MLE) and Newton-Raphson method to spot the relative location of the SAT. Simulation results verify the correctness of PEM method and effectiveness for localizing the target.