{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T15:53:59Z","timestamp":1776182039370,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2023,8,15]],"date-time":"2023-08-15T00:00:00Z","timestamp":1692057600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Jiangsu Provincial Special Fund for Science and Technology","award":["BE2022820"],"award-info":[{"award-number":["BE2022820"]}]},{"name":"Jiangsu Provincial Special Fund for Science and Technology","award":["2020YFD1100202"],"award-info":[{"award-number":["2020YFD1100202"]}]},{"name":"Jiangsu Provincial Special Fund for Science and Technology","award":["KYCX18_0076"],"award-info":[{"award-number":["KYCX18_0076"]}]},{"name":"National Key Research and Development Plan of China","award":["BE2022820"],"award-info":[{"award-number":["BE2022820"]}]},{"name":"National Key Research and Development Plan of China","award":["2020YFD1100202"],"award-info":[{"award-number":["2020YFD1100202"]}]},{"name":"National Key Research and Development Plan of China","award":["KYCX18_0076"],"award-info":[{"award-number":["KYCX18_0076"]}]},{"name":"Postgraduate Research &amp; Practice Innovation Program of Jiangsu Province","award":["BE2022820"],"award-info":[{"award-number":["BE2022820"]}]},{"name":"Postgraduate Research &amp; Practice Innovation Program of Jiangsu Province","award":["2020YFD1100202"],"award-info":[{"award-number":["2020YFD1100202"]}]},{"name":"Postgraduate Research &amp; Practice Innovation Program of Jiangsu Province","award":["KYCX18_0076"],"award-info":[{"award-number":["KYCX18_0076"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Among many indoor positioning technologies, pseudolite positioning technology has become an important supplement to GNSS. In indoor open environments, pseudolite positioning technology can usually perform high-precision positioning. However, in a complex environment, the pseudolite receiver is seriously interfered by multipath and other interference signals, which will lead to a serious decline in the observation accuracy, signal lock loss or even no positioning results. Therefore, this work proposes a pseudolite indoor anti-multipath receiver based on reference multipath estimating delay lock loop (Ref-MEDLL). It adds the Ref-MEDLL multipath estimator module and the multipath mitigation module to the traditional receiver signal processing architecture. In the multipath mitigation module, the multipath estimation adaptive mitigation of vector tracking (MEAM-VT) method and the multipath estimation direct mitigation (MEDM) method for multipath mitigation is proposed. Experimental results show that the Ref-MEDLL multipath estimation method has good adaptability to multipath signals that have different time delays and different amplitudes; both the MEDM receiver and the MEAM-VT receiver have good multipath mitigation performance. The MEAM-VT method performs better than the MEDM method in multipath mitigation and tracking, but the stability of the pseudorange observations of the MEAM-VT method is not as good as that of the MEDM method. The positioning accuracy of the MEDM receiver and the MEAM-VT receiver has been improved to different degrees in static positioning experiments and dynamic positioning experiments.<\/jats:p>","DOI":"10.3390\/rs15164041","type":"journal-article","created":{"date-parts":[[2023,8,16]],"date-time":"2023-08-16T10:08:09Z","timestamp":1692180489000},"page":"4041","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Pseudolite Multipath Estimation Adaptive Mitigation of Vector Tracking Based on Ref-MEDLL"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3608-0842","authenticated-orcid":false,"given":"Bo","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Instrument Science and Engineering, Southeast University, No. 2 Sipailou Road, Nanjing 210096, China"}]},{"given":"Qing","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Instrument Science and Engineering, Southeast University, No. 2 Sipailou Road, Nanjing 210096, China"}]},{"given":"Wenqing","family":"Xia","sequence":"additional","affiliation":[{"name":"School of Instrument Science and Engineering, Southeast University, No. 2 Sipailou Road, Nanjing 210096, China"}]},{"given":"Yu","family":"Sun","sequence":"additional","affiliation":[{"name":"School of Civil and Environment Engineering, The University of New South Wales, Sydney 2052, Australia"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6485-780X","authenticated-orcid":false,"given":"Jinling","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Civil and Environment Engineering, The University of New South Wales, Sydney 2052, Australia"}]}],"member":"1968","published-online":{"date-parts":[[2023,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1007\/s10291-022-01230-6","article-title":"Mitigation of multipath and NLOS with stochastic modeling for ground-based indoor positioning","volume":"26","author":"Sun","year":"2022","journal-title":"GPS Solut."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3962014","DOI":"10.1155\/2022\/3962014","article-title":"An Approach to Improve the Indoor Positioning Performance of Pseudolite\/UWB System with Ambiguity Resolution","volume":"2022","author":"Gan","year":"2022","journal-title":"J. Sens."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1007\/s10291-019-0869-4","article-title":"Indoor non-line-of-sight and multipath detection using deep learning approach","volume":"23","author":"Liu","year":"2019","journal-title":"GPS Solut."},{"key":"ref_4","first-page":"2050","article-title":"Multipath estimation algorithms based on data processing in software receiver","volume":"35","author":"Cheng","year":"2013","journal-title":"Syst. Eng. Electron."},{"key":"ref_5","first-page":"709","article-title":"An Improved Multipath Estimation Algorithm Using Particle Filter and Sliding Average Extended Kalman Filter","volume":"39","author":"Lan","year":"2016","journal-title":"J. Electron. Inf. Technol."},{"key":"ref_6","unstructured":"Fishler, E., and Bobrovsky, B.Z. (November, January 31). Anti multipath cellular radio location for DS\/CDMA systems using a novel EKF subchip RAKE tracking loop. Proceedings of the MILCOM 1999. IEEE Military Communications. Conference Proceedings (Cat. No.99CH36341), Atlantic City, NJ, USA."},{"key":"ref_7","unstructured":"Jin Young, K. (2004, January 2\u20136). PN code tracking loop with extended Kalman filter for a direct-sequence spread-spectrum system. Proceedings of the 30th Annual Conference of IEEE Industrial Electronics Society, 2004. IECON 2004, Busan, Republic of Korea."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1109\/TWC.2004.840231","article-title":"Highly efficient techniques for mitigating the effects of multipath propagation in DS-CDMA delay estimation","volume":"4","author":"Lohan","year":"2005","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_9","first-page":"1139","article-title":"GPS multipath estimation based particle filtering","volume":"25","author":"Wang","year":"2010","journal-title":"Control Decis."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1051\/proc\/201444001","article-title":"Particle methods: An introduction with applications","volume":"44","author":"Moral","year":"2014","journal-title":"ESAIM Proc."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Zhang, H.Y., Xu, L.P., Yan, B., Zhang, H., and Luo, L.Y. (2017). A Carrier Estimation Method Based on MLE and KF for Weak GNSS Signals. Sensors, 17.","DOI":"10.3390\/s17071468"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Yan, S., and Yan, Z. (2017, January 6\u20139). The research on multipath mitigation of GNSS in intelligent crane. Proceedings of the 2017 IEEE International Conference on Mechatronics and Automation (ICMA), Takamatsu, Japan.","DOI":"10.1109\/ICMA.2017.8015930"},{"key":"ref_13","unstructured":"Nee, R.D.J.v. (December, January 29). The Multipath Estimating Delay Lock Loop. Proceedings of the IEEE Second International Symposium on Spread Spectrum Techniques and Applications, Manaus, Brazil."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"502","DOI":"10.1002\/j.2161-4296.1995.tb01903.x","article-title":"Performance Evaluation of the Multipath Estimating Delay Lock Loop","volume":"42","author":"Townsend","year":"1995","journal-title":"Navigation"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1002\/(SICI)1099-1247(199701)15:1<25::AID-SAT565>3.0.CO;2-F","article-title":"GNSS code and carrier tracking in the presence of multipath","volume":"15","author":"Brodin","year":"1997","journal-title":"Int. J. Satell. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1302","DOI":"10.1109\/TCE.2007.4429216","article-title":"Performance analysis and parameter optimization of DLL and MEDLL in fading multipath environments for next generation navigation receivers","volume":"53","year":"2007","journal-title":"IEEE T Consum. Electr."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"794","DOI":"10.1017\/S0373463315001022","article-title":"A New High-Resolution GPS Multipath Mitigation Technique Using Fast Orthogonal Search","volume":"69","author":"Tamazin","year":"2016","journal-title":"J. Navig."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1588","DOI":"10.1049\/iet-rsn.2018.5587","article-title":"GNSS multipath estimation and mitigation based on particle filter","volume":"13","author":"Qin","year":"2019","journal-title":"Iet Radar Sonar Nav."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5518","DOI":"10.1109\/TWC.2020.2994037","article-title":"Multipath Estimating Delay Lock Loop for LTE Signal TOA Estimation in Indoor and Urban Environments","volume":"19","author":"Wang","year":"2020","journal-title":"IEEE T Wirel. Commun."},{"key":"ref_20","unstructured":"Im, S.H., and Jee, G.I. (2010, January 25\u201327). Indoor Navigation and Multipath Mitigation Using Code-Offset Based Pseudolite Transmitter Array. Proceedings of the 2010 International Technical Meeting of the Institute of Navigation, San Diego, CA, USA."},{"key":"ref_21","first-page":"1202","article-title":"An Efficient Method for GPS Multipath Mitigation Using the Teager-Kaiser-Operator-Based MEDLL","volume":"22","author":"Hui","year":"2013","journal-title":"Radioengineering"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"108702","DOI":"10.1016\/j.sigpro.2022.108702","article-title":"On the positivity of Teager-Kaiser\u2019s energy operator","volume":"201","author":"Boudraa","year":"2022","journal-title":"Signal Process."},{"key":"ref_23","first-page":"117","article-title":"Multipath analysis of GNSS measured data based on TK-MEDLL","volume":"5","author":"Yang","year":"2017","journal-title":"J. Navig. Position."},{"key":"ref_24","first-page":"1466","article-title":"GPS Multipath Estimation Based on Maximum Likelihood Estimation","volume":"30","author":"Yu","year":"2009","journal-title":"J. Chin. Soc. Astronaut."},{"key":"ref_25","first-page":"1197","article-title":"GPS Multipath Estimation Based on Colored Noise Kalman Filtering","volume":"30","author":"Tang","year":"2010","journal-title":"Trans. Beijing Inst. Technol."},{"key":"ref_26","first-page":"2506","article-title":"Indoor pseudolite multipath estimation algorithm based on adaptive MEDLL","volume":"45","author":"Xia","year":"2022","journal-title":"J. Syst. Eng. Electron."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"6324","DOI":"10.3390\/s100706324","article-title":"Implementation of a Vector-based Tracking Loop Receiver in a Pseudolite Navigation System","volume":"10","author":"So","year":"2010","journal-title":"Sensors"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1007\/s10291-019-0839-x","article-title":"Open-source MATLAB code for GPS vector tracking on a software-defined receiver","volume":"23","author":"Xu","year":"2019","journal-title":"GPS Solut."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Yang, H.T., Zhou, B., Wang, L.X., Wei, Q., Ji, F., and Zhang, R. (2021). Performance and Evaluation of GNSS Receiver Vector Tracking Loop Based on Adaptive Cascade Filter. Remote Sens., 13.","DOI":"10.3390\/rs13081477"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4604","DOI":"10.1109\/TIM.2019.2950578","article-title":"Vector Tracking Loop-Based GNSS NLOS Detection and Correction: Algorithm Design and Performance Analysis","volume":"69","author":"Xu","year":"2020","journal-title":"Ieee T Instrum. Meas."},{"key":"ref_31","first-page":"96","article-title":"Application of improved MEDLL technique in multipath error estimation","volume":"7","author":"Zhang","year":"2019","journal-title":"J. Navig. Position"},{"key":"ref_32","unstructured":"Fernandez-Prades, C., Arribas, J., Closas, P., Aviles, C., and Esteve, L. (2011, January 20\u201323). GNSS-SDR: An Open Source Tool For Researchers and Developers. Proceedings of the 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (Ion Gnss 2011), Portland, OR, USA."},{"key":"ref_33","unstructured":"Townsend, B., Fenton, P., Van Dierendonck, K., and van Nee, R. (1995, January 12\u201315). L1 carrier phase multipath error reduction using MEDLL technology. Proceedings of the Ion Gps-95\u2014The 8th International Technical Meeting of the Satellite Division of the Institute of Navigation, Pts 1 and 2, Palm Springs, CA, USA."},{"key":"ref_34","unstructured":"Qin, H.L., Jin, X.Q., Cong, L., and Yao, J.T. (2019, January 1\u20133). MEDLL-based method of ground-wave and cycle identification for Loran-C signal. Proceedings of 2019 14th Ieee International Conference on Electronic Measurement & Instruments (Icemi), Changsha, China."},{"key":"ref_35","unstructured":"Gao, Y., Liu, F., and Long, T. (2013). China Satellite Navigation Conference (Csnc) 2013 Proceedings: Beidou\/Gnss Navigation Applications, Test & Assessment Technology, User Terminal Technology, Springer."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"8210","DOI":"10.1007\/s10291-020-00994-z","article-title":"Site-specific real-time GPS multipath mitigation based on coordinate time series window matching","volume":"24","author":"Shen","year":"2020","journal-title":"GPS Solut."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/16\/4041\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:34:28Z","timestamp":1760128468000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/16\/4041"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,15]]},"references-count":36,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2023,8]]}},"alternative-id":["rs15164041"],"URL":"https:\/\/doi.org\/10.3390\/rs15164041","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,8,15]]}}}