In the emerging field of molecular communication (MC), testbeds are needed to validate theoretical concepts, motivate applications, and guide further modeling efforts. To this end, this paper presents a flexible and extendable in-vessel MC testbed based on superparamagnetic iron oxide nanoparticles (SPIONs) dispersed in an aqueous suspension as they are also used for drug targeting in biotechnology. The transmitter is realized by an electronic pump for injection of the SPIONs stored in a syringe via a Y-tubing-connector. A second pump generates a background flow for signal propagation in the main tube, e.g., modeling a part of a chemical reactor or a blood vessel. For signal reception, we employ a commercial susceptometer, an electronic device including a coil, through which the magnetic particles move and non-intrusively generate an electrical signal. We identify the physical mechanisms governing transmission, propagation, and reception of SPIONs as signal carriers and propose a simple two-parameter mathematical model for the system's channel impulse response (CIR). Reliable communication is demonstrated for model-agnostic and model-based detection methods for experiments with 400 random symbols transmitted via on-off keying modulation with a 1 s symbol interval. Moreover, the proposed CIR model is shown to consistently capture the experimentally observed distance-dependent impulse response peak heights and peak decays for transmission distances from 5 to 40 cm.

中文翻译：

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磁性纳米粒子在管道流动中分子传递的实验系统

在新兴的分子通讯（MC）领域中，需要测试平台来验证理论概念，激发应用程序并指导进一步的建模工作。为此，本文提出了一种基于可分散在水性悬浮液中的超顺磁性氧化铁纳米粒子（SPIONs）的灵活且可扩展的车载MC试验床，因为它们也用于生物技术中的药物靶向。发射器由电子泵实现，该电子泵用于通过Y型管接头注入存储在注射器中的SPION。第二个泵产生背景流，以使信号在主管中传播，例如对化学反应器或血管的一部分建模。为了接收信号，我们使用了商用的电度表，一种包括线圈的电子设备，磁性粒子通过它运动并以非侵入方式生成电信号。我们确定了控制SPION作为信号载体的传输，传播和接收的物理机制，并为系统的信道冲激响应（CIR）提出了一个简单的两参数数学模型。证明了与模型不可知和基于模型的检测方法的可靠通信，该方法可用于通过具有1 s符号间隔的开-关键控调制来传输400个随机符号的实验。此外，所提出的CIR模型显示出能够持续捕获实验观察到的距离相关的脉冲响应峰高和5到40 cm传输距离的峰衰减。并接收SPION作为信号载体，并为系统的信道冲激响应（CIR）提出了一个简单的两参数数学模型。证明了与模型不可知和基于模型的检测方法的可靠通信，该方法可用于通过具有1 s符号间隔的开-关键控调制来传输400个随机符号的实验。此外，所提出的CIR模型显示出能够持续捕获实验观察到的距离相关的脉冲响应峰高和5到40 cm传输距离的峰衰减。并接收SPION作为信号载体，并为系统的信道冲激响应（CIR）提出了一个简单的两参数数学模型。证明了与模型不可知和基于模型的检测方法的可靠通信，该方法可用于通过具有1 s符号间隔的开-关键控调制来传输400个随机符号的实验。此外，所提出的CIR模型显示出能够持续捕获实验观察到的距离相关的脉冲响应峰高和5到40 cm传输距离的峰衰减。