Huang, XinyuHuang, YuWen, MiaowenYang, NanSchober, Robert2025-05-232025-05-230090-6778http://www.scopus.com/inward/record.url?scp=85203429036&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733752529This paper establishes a molecule harvesting transmitter (TX) model in molecular communication (MC). In particular, we consider that molecules are encapsulated in vesicles generated within the TX and released from the TX through membrane fusion process. We also consider that the TX membrane is covered by heterogeneous receptors of varying sizes and at arbitrary locations, where the receptors can absorb the released molecules once the molecules hitting any of the receptor. Assuming that the vesicle generation follows a jump process, with each vesicle generated at distinct time instants, and assuming a transparent receiver (RX), we calculate the molecule release rate, the expected fraction of absorbed molecules at the TX, and the received signal at the RX. All obtained analytical expressions are functions of all receptors' locations and sizes, and are validated by particle-based simulations. Our numerical results indicate that evenly distributed receptors on the TX membrane absorb more molecules than randomly distributed receptors or a single receptor. Furthermore, inspired by the biological phenomenon that cells can regulate their release of new molecules by interacting with the molecules that are already present in the environment, we incorporate a negative feedback mechanism (NFM) at the TX. This mechanism utilizes the number of molecules absorbed by the TX as a criterion to determine if the TX should stop releasing additional molecules. We then derive the closed-form expression for the expected fraction of recyclable molecules for a single emission. Here, the pool of recyclable molecules comprises both the molecules that remain unreleased by the TX due to NFM and those that are absorbed back by the TX. Our numerical results demonstrate that incorporating NFM can reduce inter-symbol interference (ISI) while maintaining the same peak received signal as without NFM. Additionally, our results show that TXs incorporating both molecule harvesting and NFM can achieve a higher energy efficiency and lower error probability than TXs employing only molecule harvesting or neither functionality.Manuscript received July 18, 2023; revised February 7, 2024 and July 20 2024; accepted August 25, 2024. Yu Huang\u2019s work was supported in part by the National Natural Science Foundation of China under Grant 62201161, Miaowen Wen\u2019s work was supported by the National Natural Science Foundation of China under Grant 62471183, Robert Schober\u2019s work was supported in part by the DFG Project SCHO 831/6-2 (Project number 290825040). An earlier version of this paper was presented in part at 2023 IEEE Global Communications Conference (GLOBECOM) [1] [DOI: 10.1109/GCWkshps58843.2023.10464756]. Part of this paper was published in X. Huang\u2019s PhD dissertation [2]. The associate editor coordinating the review of this article and approving it for publication was L. Mucchi. (Corresponding author: Yu Huang.) X. Huang is with the School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm, Sweden and School of Engineering, Australian National University, Canberra, ACT 2600, Australia (e-mail: xinyh@kth.se) Y. Huang is with the Research Center of Intelligent Communication Engineering, School of Electronics and Communication Engineering, Guangzhou University, Guangzhou 510006, China (e-mail: yuhuang@gzhu.edu.cn) M. Wen is with School of Electronic and Information Engineering, South China University of Technology, Guangzhou 510641, China (e-mail: eemwwen@scut.edu.cn) N. Yang is with the School of Engineering, Australian National University, Canberra, ACT 2600, Australia (e-mail: nan.yang@anu.edu.au) R. Schober is with the Institute for Digital Communications, Friedrich-Alexander-University Erlangen-N\u00FCrnberg (FAU), 91054 Erlangen, Germany (e-mail: robert.schober@fau.de) Yu Huang's work was supported in part by the National Natural Science Foundation of China under Grants 62201161 and 62411560161, Miaowen Wen's work was supported by the National Natural Science Foundation of China under Grant 62471183, Robert Schober's work was supported in part by the DFG Project SCHO 831/6-2 (Project number 290825040).enPublisher Copyright: © 1972-2012 IEEE.channel impulse responseenergy efficiencyheterogeneous receptorsinter-symbol interference mitigationMolecular communicationmolecule harvesting202410.1109/TCOMM.2024.345523285203429036