擴散型分子通訊下之距離估計與訊號源追蹤

Distance Estimation and Source Tracking in Diffusion-Based Molecular Communications

黃駿挺(Jiun-Ting Huang)

指導教授 ： 葉丙成

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.10772

摘要

利用分子作為訊息載體進行奈米機器間的溝通，為近年來被視為最
具有發展性的奈米通訊技術。由於分子通訊具有高度的生物相容性，
未來有望被大量應用於生物醫學領域。在分子通訊的各種型態中，擴
散型分子通訊因憑藉分子在流體中的自然運動來傳輸分子，具有節省
能量的優點。然而，分子在流體中的移動的隨機性會導致訊息的錯誤
傳遞。再者，訊息分子從傳送端出發於固定時刻抵達接收端的機率受
傳送端與接收端之間的距離影響甚鉅。因此，距離估計在擴散型分子
通訊中有相當的重要性。除此之外，在某些應用中（如：藥物遞送），
接收端不僅需知道傳送端的距離還需知道傳送端的所在方向。雖然距
離估測與訊號源追蹤在傳統無線電磁通訊中已存在解決方案，但由於
分子通訊的通道具有與傳統電磁通訊截然不同的物理本質，無法使用
現存的方法。在本研究中，我們探討擴散型分子通訊下的距離估計與
訊號源追蹤問題。主要的貢獻，除了將上述問題做系統化的陳述，對
於反應式與被動式這兩種不同的分子接收模式，我們皆建構其相對應
的數學模型，並基於此些模型提出多樣的估計方法來解決問題。數值
結果顯示，本論文所提出的估計方法能有效使接收端量測傳送端的距
離與所在方位。另一方面，透過電腦模擬實務案例，證實論文中提出
之訊號源追蹤法能提升使用有向性接收之擴散型分子通訊系統的效
能，而距離與訊號源方向的共同估計則能應用於藥物的遞送。

關鍵字

分子通訊 ； 通道估計 ； 奈米機器 ； 布朗運動 ； 距離估計 ； 訊號源追蹤 ； 方向估計 ； 擴散

並列摘要

Using molecules as information carriers is one of the most promising solution to nanoscale communications. Due to its biocompatibility, molecular communication is expected to have various biomedical applications. In
diffusion-based molecular communications, the transport of molecules between nanomachines is performed via molecular diffusion, which requires low energy consumption. Nevertheless, the movement of diffusing molecule is by nature stochastic. Different distance between nanomachines causes different arrival probability of information molecules, significantly impacting
the communication performance. In order to enhance the system reliability, it is of great importance to develop mechanisms for the receiver to estimate its distance to the transmitter. In addition, in some applications (e.g. drug delivery), not only the distance information but also the source direction is needed by the receiver. Therefore in this thesis, distance estimation and source tracking methods are designed for diffusion-based molecular communication systems with different molecular reception models. The performance of the proposed
methods are tested through numerical simulations. Besides, this thesis involves two case studies in which the applications of the proposed methods are demonstrated. Simulation results show that by applying the proposed source tracking methods, the error rate of the communication system can be reduced. Also, targeted drug delivery can be achieved.

並列關鍵字

molecular communication ； channel estimation ； nanomachine ； Brownian motion ； distance estimation ； direction estimation ； source tracking ； diffusion

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