Abstract
In this article, we propose a molecular communication system to localize an abnormality in a diffusion-based medium. We consider a general setup to perform joint sensing, communication, and localization. This setup consists of three types of devices, each for a different task: mobile sensors for navigation and molecule releasing (for communication), fusion centers (FCs) for sampling, amplifying, and forwarding the signal, and a gateway (GW) for making decision or exchanging the information with an external device. The sensors move randomly in the environment to reach the abnormality. We consider both collaborative and noncollaborative sensors that simultaneously release their molecules to the FCs when the number of activated sensors or the moving time reaches a certain threshold, respectively. The FCs amplify the received signal and forward it to the GW for making a decision using either an ideal or a noisy communication channel. A practical application of the proposed model is drug delivery in a tissue of the human body, to guide the nanomachine-bound drug to the exact location and so to eliminate the adverse effects of the drug on normal cells. Further applications are health-care, treatments of localized disease (e.g., tumors and inflammations), immune system triggering, and nanosurgery. The decision rules and probabilities of error are obtained for two considered sensor types in both ideal and noisy communication channels.