{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:32:25Z","timestamp":1760146345343,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2024,10,20]],"date-time":"2024-10-20T00:00:00Z","timestamp":1729382400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["62271386","62471385","61801371"],"award-info":[{"award-number":["62271386","62471385","61801371"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>This paper proposes a three-step joint rate optimization method for intelligent reflecting surface (IRS)-assisted coal mine wireless communication systems. Different from terrestrial IRS-assisted communication scenarios, in coal mines, IRSs can be installed flexibly on the tops of rectangular tunnels to address the issues of signals being blocked and interfered with by mining equipment. Therefore, it is necessary to optimize the IRS deployment position, the transmit power and IRS phase shifts to achieve the maximum effective achievable rate at user stations equipped with the proposed system. However, due to the complex channel models of coal mines, the optimization problem of IRS deployment position is non-convex. To solve this problem, two auxiliary variables along with logarithmic operations and Taylor approximation are introduced. On this basis, a three-step joint rate optimization involving the transmit power, IRS phase shifts and IRS deployment position is proposed to maximize the effective achievable rates at the user station. The simulation results show that compared with other rate optimization schemes, the effective achievable rates at the user station using the proposed joint rate optimization scheme can be improved by approximately 12.32% to 54.17% for different parameter configurations. It is also pointed out that the deployment position of the IRS can converge to the same optimal position independent of the initial deployment position. Moreover, we investigate the effects of the roughness of the tunnel walls in a coal mine on the effective achievable rates at the user station, and the simulation results indicate that the proposed three-step joint rate optimization scheme performs better in the coal mine scenario regardless of the roughness.<\/jats:p>","DOI":"10.3390\/e26100880","type":"journal-article","created":{"date-parts":[[2024,10,21]],"date-time":"2024-10-21T10:49:22Z","timestamp":1729507762000},"page":"880","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Rate Optimization of Intelligent Reflecting Surface-Assisted Coal Mine Wireless Communication Systems"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1859-6300","authenticated-orcid":false,"given":"Yang","family":"Liu","sequence":"first","affiliation":[{"name":"School of Communication and Information Engineering, Xi\u2019an University of Science and Technology, Xi\u2019an 710054, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-0990-365X","authenticated-orcid":false,"given":"Zhao","family":"Yang","sequence":"additional","affiliation":[{"name":"School of Communication and Information Engineering, Xi\u2019an University of Science and Technology, Xi\u2019an 710054, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2940-3001","authenticated-orcid":false,"given":"Bin","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Communication and Information Engineering, Xi\u2019an University of Science and Technology, Xi\u2019an 710054, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3480-2736","authenticated-orcid":false,"given":"Yanhong","family":"Xu","sequence":"additional","affiliation":[{"name":"School of Communication and Information Engineering, Xi\u2019an University of Science and Technology, Xi\u2019an 710054, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,10,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Ranjany, A., Misraz, P., Dwivediz, B., and Sahuy, H.B. (2016, January 5\u201310). Channel modeling of wireless communication in underground coal mines. Proceedings of the 8th International Conference on Communication Systems and Networks (COMSNETS), Bangalore, India.","DOI":"10.1109\/COMSNETS.2016.7440023"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4866","DOI":"10.1109\/TAP.2012.2207361","article-title":"MIMO-UWB Channel Characterization Within an Underground Mine Gallery","volume":"60","author":"Talbi","year":"2012","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"de Oliveira Gomes, P.H., Guieiro, G., de Almeida, E.P.L., and Garcia, L.G.U. (2018, January 9\u201312). Evaluation of Shadowing Caused by Mining Machinery in V2I Communications. Proceedings of the IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Bologna, Italy.","DOI":"10.1109\/PIMRC.2018.8580829"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"185445","DOI":"10.1109\/ACCESS.2020.3030615","article-title":"A VLC Channel Model for Underground Mining Environments With Scattering and Shadowing","volume":"8","author":"Seguel","year":"2020","journal-title":"IEEE Access"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"990","DOI":"10.1109\/TCCN.2020.2992604","article-title":"Reconfigurable Intelligent Surfaces for Wireless Communications: Principles, Challenges, and Opportunities","volume":"6","author":"ElMossallamy","year":"2020","journal-title":"IEEE Trans. Cogn. Commun. Netw."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1546","DOI":"10.1109\/COMST.2021.3077737","article-title":"Reconfigurable Intelligent Surfaces: Principles and Opportunities","volume":"23","author":"Liu","year":"2021","journal-title":"IEEE Commun. Surveys Tut."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1707","DOI":"10.1109\/TCOMM.2022.3231893","article-title":"Active RIS vs. Passive RIS: Which Will Prevail in 6G?","volume":"71","author":"Zhang","year":"2023","journal-title":"IEEE Trans. Commun."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Wang, B., Yuan, Z., Lu, J., and Zhang, X. (2024). Multitask Collaborative Learning Neural Network for Radio Signal Classification. IEEE Trans. Commun., 1.","DOI":"10.1109\/TCOMM.2024.3477322"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1109\/MWC.001.2000256","article-title":"Reconfigurable-Intelligent-Surface Empowered Wireless Communications: Challenges and Opportunities","volume":"28","author":"Yuan","year":"2021","journal-title":"IEEE Wirel. Commun."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"150214","DOI":"10.1109\/ACCESS.2021.3125461","article-title":"Reconfigurable Intelligent Surfaces in Challenging Environments: Underwater, Underground, Industrial and Disaster","volume":"9","author":"Kisseleff","year":"2021","journal-title":"IEEE Access"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1410","DOI":"10.1109\/LWC.2019.2919685","article-title":"Secure Wireless Communication via Intelligent Reflecting Surface","volume":"8","author":"Cui","year":"2019","journal-title":"IEEE Wireless Commun. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Song, Y., Khandaker, M.R.A., Tariq, F., Wong, K.-K., and Toding, A. (2021, January 25\u201328). Truly Intelligent Reflecting Surface-Aided Secure Communication Using Deep Learning. Proceedings of the IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), Helsinki, Finland.","DOI":"10.1109\/VTC2021-Spring51267.2021.9448826"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Kumar, V., Flanagan, M.F., Kwan Ng, D.W., and Tran, L.-N. (2021, January 7\u201311). On the Secrecy Rate under Statistical QoS Provisioning for RIS-assisted MISO Wiretap Channel. Proceedings of the IEEE Global Communications Conference (GLOBECOM), Madrid, Spain.","DOI":"10.1109\/GLOBECOM46510.2021.9685957"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3313","DOI":"10.1109\/TCOMM.2021.3051897","article-title":"Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial","volume":"69","author":"Wu","year":"2021","journal-title":"IEEE Trans. Commun."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1756","DOI":"10.1109\/LWC.2023.3292125","article-title":"On Deployment Position of RIS in Wireless Communication Systems: Analysis and Experimental Results","volume":"12","author":"Ren","year":"2023","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2045","DOI":"10.1109\/LWC.2024.3397839","article-title":"How to Extend 3-D GBSM to Integrated Sensing and Communication Channel With Sharing Feature?","volume":"13","author":"Liu","year":"2024","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Ji, X., Wang, C.-X., and Chang, H. (2023, January 10\u201312). A Novel MIMO Channel Model for Underground Mine Communications. Proceedings of the IEEE\/CIC International Conference on Communications in China (ICCC), Dalian, China.","DOI":"10.1109\/ICCC57788.2023.10233601"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1109\/LWC.2023.3336361","article-title":"How to Extend 3-D GBSM to RIS Cascade Channel With Non-Ideal Phase Modulation?","volume":"13","author":"Gong","year":"2024","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2624","DOI":"10.1109\/TAP.2017.2677398","article-title":"Ray Tracing and Modal Methods for Modeling Radio Propagation in Tunnels With Rough Walls","volume":"65","author":"Zhou","year":"2017","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"150162","DOI":"10.1109\/ACCESS.2021.3125445","article-title":"Antenna System for Communication in Underground Mining Environment to Ensure Miners Safety","volume":"9","author":"Gangwar","year":"2021","journal-title":"IEEE Access"}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/26\/10\/880\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:17:05Z","timestamp":1760113025000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/26\/10\/880"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10,20]]},"references-count":20,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2024,10]]}},"alternative-id":["e26100880"],"URL":"https:\/\/doi.org\/10.3390\/e26100880","relation":{},"ISSN":["1099-4300"],"issn-type":[{"type":"electronic","value":"1099-4300"}],"subject":[],"published":{"date-parts":[[2024,10,20]]}}}