Modulation, ISI, and Detection for Langmuir Adsorption-Based Microfluidic Molecular Communication

TL;DR

This paper analyzes microfluidic molecular communication receivers using Langmuir adsorption, deriving response models, approximations, and detection methods to understand and mitigate inter-symbol interference in the channel.

Contribution

It introduces a closed-form response kernel, approximations, and a low-complexity detection scheme for Langmuir adsorption-based microfluidic molecular communication.

Findings

Channel memory and ISI are explicitly characterized.

Long-pulse regime shows interference asymmetry due to saturation.

Proposed detector performs well with reduced complexity.

Abstract

This paper studies microfluidic molecular communication receivers with finite-capacity Langmuir adsorption driven by an effective surface concentration. In the reaction-limited regime, we derive a closed-form single-pulse response kernel and a symbol-rate recursion for on-off keying that explicitly exposes channel memory and inter-symbol interference. We further develop short-pulse and long-pulse approximations, revealing an interference asymmetry in the long-pulse regime due to saturation. To account for stochasticity, we adopt a finite-receptor binomial counting model, employ pulse-end sampling, and propose a low-complexity midpoint-threshold detector that reduces to a fixed threshold when interference is negligible. Numerical results corroborate the proposed characterization and quantify detection performance versus pulse and symbol durations.