DBMC-aNOMAly: Asynchronous NOMA with Pilot-Symbol Optimization Protocol for Diffusion-Based Molecular Communication Networks

2025-12-08

AI Summary

In diffusion-based molecular communication (DBMC) networks, non-orthogonal multiple access (NOMA) suffers from high bit error probability (BEP) under asynchronous transmission conditions. Method: This paper proposes DBMC-aNOMAly—a pilot-symbol-assisted asynchronous NOMA protocol for DBMC. It explicitly models and mitigates worst-case timing offsets via joint parameter optimization, leverages asynchrony for performance gain, and employs a lightweight, adaptive operational mechanism implementable by chemical reaction networks to support dynamic deployment. Contribution/Results: A closed-form analytical expression for BEP is derived and validated via Monte Carlo simulations. Experiments demonstrate that DBMC-aNOMAly significantly reduces BEP across varying network scales, noise intensities, sampling jitter, and runtime variations, outperforming existing DBMC-NOMA schemes in robustness and adaptability.

Technology Category

• Multiagent Systems: Agent Communication
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

Multiple access (MA) schemes can enable cooperation between multiple nodes in future diffusion-based molecular communication (DBMC) networks. Non-orthogonal MA for DBMC networks (DBMC-NOMA) is a promising option for efficient simultaneous MA using a single molecule type. Expanding significantly upon previous work on the topic, this paper addresses the question of parameter optimization and bit error probability (BEP) reduction in an asynchronous network using DBMC-NOMA. First, we analytically derive the associated BEP and use the result for a thorough comparison with other MA schemes like time-division and molecule-division MA. We show that the asynchronous nature of the system can be exploited for performance gain, and the upper-bound performance can be achieved in all circumstances by avoiding a few worst-case offset configurations. Subsequently, we propose DBMC-aNOMAly, a pilot-symbol-based optimization protocol for asynchronous DBMC-NOMA, and extensively evaluate it using Monte-Carlo simulations. DBMC-aNOMAly is shown to provide robust BEP reduction for different network sizes, noise levels, subjected to sampling jitter, as well as for changing conditions during runtime, particularly, compared to protocols in previous work. DBMC-aNOMAly consists of a set of simple operations such as comparisons and additions, deliberately designed to be implementable with chemical reaction networks, setting up future work on the realistic modeling of the protocol.

Problem

• Optimizes parameters for asynchronous NOMA in molecular communication
• Reduces bit error probability in diffusion-based molecular networks
• Proposes a pilot-symbol protocol robust to noise and jitter

Innovation

• Asynchronous NOMA exploiting timing offsets for performance gain
• Pilot-symbol optimization protocol reducing bit error probability
• Simple operations implementable with chemical reaction networks