Molecular Communication in Fluid Media: The Additive Inverse Gaussian Noise Channel

TLDR

Molecular communication conveys information through the timing of molecule release. The paper develops a theoretical foundation for molecular communication and outlines open problems arising from the additive inverse Gaussian model. The authors introduce an additive inverse Gaussian noise channel, derive capacity bounds, and propose a maximum‑likelihood receiver. The model fits fluid‑media propagation with Brownian motion and drift, shows no single SNR‑like metric, and demonstrates that using multiple molecules reduces error rates similarly to diversity in wireless systems.

Abstract

We consider molecular communication, with information conveyed in the time of release of molecules. The main contribution of this paper is the development of a theoretical foundation for such a communication system. Specifically, we develop the additive inverse Gaussian (IG) noise channel model: a channel in which the information is corrupted by noise with an inverse Gaussian distribution. We show that such a channel model is appropriate for molecular communication in fluid media - when propagation between transmitter and receiver is governed by Brownian motion and when there is positive drift from transmitter to receiver. Taking advantage of the available literature on the IG distribution, upper and lower bounds on channel capacity are developed, and a maximum likelihood receiver is derived. Theory and simulation results are presented which show that such a channel does not have a single quality measure analogous to signal-to-noise ratio in the AWGN channel. It is also shown that the use of multiple molecules leads to reduced error rate in a manner akin to diversity order in wireless communications. Finally, we discuss some open problems in molecular communications that arise from the IG system model.