Affinity-Division Multiplexing for Molecular Communications with Promiscuous Ligand Receptors

TL;DR

This paper introduces a multiplexing scheme for molecular communications using ligand-receptor affinity diversity, enabling multiple channels with a single receptor type, and analyzes its error performance based on various system parameters.

Contribution

It proposes a practical multiplexing method leveraging ligand affinity diversity with promiscuous receptors and derives analytical BEP expressions.

Findings

BEP depends on ligand affinity similarity and receptor count.

Increasing receptor number improves multiplexing performance.

Design parameters significantly influence system error rates.

Abstract

A key challenge in Molecular Communications (MC) is low data transmission rates, which can be addressed by channel multiplexing techniques. One way to achieve channel multiplexing in MC is to leverage the diversity of different molecule types with respect to their receptor binding characteristics, such as affinity and kinetic binding/unbinding rates. In this study, we propose a practical multiplexing scheme for MC, which is based on the diversity of ligand-receptor binding affinities. This method requires only a single type of promiscuous receptor on the receiver side, capable of interacting with multiple ligand types. We analytically derive the mean Bit Error Probability (BEP) over all multiplexed MC channels as a function of similarity among ligands in terms of their receptor affinities, the number of receptors, the number of multiplexed channels, and the ratio of concentrations encoding bit-1 and bit-0. We investigate the impact of each design parameter on the performance of multiplexed MC system.