Molecule Mixture Detection and Alphabet Design for Non-linear, Cross-reactive Receiver Arrays in MC

TL;DR

This paper presents a novel detection method and alphabet design algorithm for air-based molecular communication systems using non-linear, cross-reactive sensor arrays, enabling more reliable communication with fewer training samples.

Contribution

It introduces a detector for non-linear, cross-reactive sensor arrays and an alphabet design algorithm tailored to sensor characteristics, advancing air-based molecular communication.

Findings

Detector achieves similar error rates as data-driven methods with fewer training samples.

Alphabet design algorithm outperforms non-adaptive methods.

Proposed methods are applicable to various chemical sensors.

Abstract

Air-based molecular communication (MC) has the potential to be one of the first MC systems to be deployed in real-world applications, enabled by existing sensor technologies such as metal-oxide semi-conductor (MOS) sensors. However, commercially available sensors usually exhibit non-linear and cross-reactive behavior, contrary to the idealizing assumptions about linear and perfectly molecule type-specific sensing often made in the MC literature. To address this gap, we propose a detector for molecule mixture communication with a general non-linear, cross-reactive receiver (RX) array that performs approximate maximum likelihood detection on the sensor outputs. Additionally, we introduce an algorithm for the design of mixture alphabets that accounts for the RX characteristics. We evaluate our detector and alphabet design algorithm through simulations that are based on measurements reported for two commercial MOS sensors. Our simulations demonstrate that the proposed detector achieves similar symbol error rates as data-driven methods without requiring large numbers of training samples and that the alphabet design algorithm outperforms methods that do not account for the RX characteristics. Since the proposed detector and alphabet design algorithm are also applicable to other chemical sensors, they pave the way for reliable air-based MC.