{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T11:57:44Z","timestamp":1784548664840,"version":"3.55.0"},"reference-count":42,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2024,9,29]],"date-time":"2024-09-29T00:00:00Z","timestamp":1727568000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"Joint Funds of the National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["U22A2009"],"award-info":[{"award-number":["U22A2009"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"Joint Funds of the National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2021YFC2803000"],"award-info":[{"award-number":["2021YFC2803000"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program","doi-asserted-by":"publisher","award":["U22A2009"],"award-info":[{"award-number":["U22A2009"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program","doi-asserted-by":"publisher","award":["2021YFC2803000"],"award-info":[{"award-number":["2021YFC2803000"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Underwater wireless sensor networks play an important role in exploring the oceans as part of an integrated space\u2013air\u2013ground\u2013ocean network. Because underwater energy is limited, the equipment\u2019s efficiency is significantly impacted by the battery duration. Underwater backscatter technology does not require batteries and has significant potential in positioning, navigation, communication, and sensing due to its passive characteristics. However, underwater backscatter signals are susceptible to being swamped by the excitation signal. Additionally, the signals from different reflection signals share the same frequency and overlap, and contain fewer useful features, leading to significant challenges in detection. In order to solve the above problems, this paper proposes a recurrent neural network that introduces time-frequency and reference signal features for underwater backscatter signal separation (TF-REF-RNN). In the feature extraction part, we design an encoder that introduces time-frequency domain features to learn more about the frequency details. Additionally, to improve performance, we designed a separator that incorporates the reference signal\u2019s pure global information features. The proposed TF-REF-RNN network model achieves metrics of 28.55 dB SI-SNRi and 19.51 dB SDRi in the dataset that includes shipsEar noise data and underwater simulated backscatter signals, outperforming similar classical methods.<\/jats:p>","DOI":"10.3390\/rs16193635","type":"journal-article","created":{"date-parts":[[2024,9,30]],"date-time":"2024-09-30T05:45:27Z","timestamp":1727675127000},"page":"3635","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["TF-REF-RNN: Time-Frequency and Reference Signal Feature Fusion Recurrent Neural Network for Underwater Backscatter Signal Separation"],"prefix":"10.3390","volume":"16","author":[{"given":"Jun","family":"Liu","sequence":"first","affiliation":[{"name":"School of Electronic Information Engineering, Beihang University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shenghua","family":"Gong","sequence":"additional","affiliation":[{"name":"School of Electronic Information Engineering, Beihang University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tong","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Electronic Information Engineering, Beihang University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhenxiang","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Electronic Information Engineering, Beihang University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hao","family":"Dong","sequence":"additional","affiliation":[{"name":"School of Electronic Information Engineering, Beihang University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jie","family":"Tan","sequence":"additional","affiliation":[{"name":"School of Electronic Information Engineering, Beihang University, Beijing 100083, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1379","DOI":"10.1007\/s11831-019-09354-8","article-title":"Recent Advances and Future Directions on Underwater Wireless Communications","volume":"27","author":"Ali","year":"2020","journal-title":"Arch. Comput. Methods Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"13126","DOI":"10.1109\/JIOT.2021.3081918","article-title":"Localization Algorithm for Underwater Sensor Network: A Review","volume":"8","author":"Luo","year":"2021","journal-title":"IEEE Internet Things J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"6403161","DOI":"10.1155\/2020\/6403161","article-title":"A Review of Underwater Localization Techniques, Algorithms, and Challenges","volume":"2020","author":"Su","year":"2020","journal-title":"J. Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2021","DOI":"10.1109\/COMST.2023.3278239","article-title":"Backscatter Communication Meets Practical Battery-Free Internet of Things: A Survey and Outlook","volume":"25","author":"Jiang","year":"2023","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"109","DOI":"10.23919\/JCC.2022.02.009","article-title":"Sensitivity and Distance Based Performance Analysis for Batteryless Tags with Transmit Beamforming and Ambient Backscattering","volume":"19","author":"Jia","year":"2022","journal-title":"China Commun."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Galisteo, A., Varshney, A., and Giustiniano, D. (2020, January 15\u201319). Two to Tango: Hybrid Light and Backscatter Networks for next Billion Devices. Proceedings of the 18th International Conference on Mobile Systems, Applications, and Services, Toronto, ON, Canada.","DOI":"10.1145\/3386901.3388918"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"170","DOI":"10.23919\/ICN.2020.0013","article-title":"Backscatter Technologies and the Future of Internet of Things: Challenges and Opportunities","volume":"1","author":"Yao","year":"2020","journal-title":"Intell. Converg. Netw."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1145\/2534169.2486015","article-title":"Ambient backscatter: Wireless communication out of thin air","volume":"43","author":"Liu","year":"2013","journal-title":"ACM SIGCOMM Comput. Commun. Rev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2906","DOI":"10.1109\/TVT.2021.3061661","article-title":"Energy-Efficient Covert Communications for Bistatic Backscatter Systems","volume":"70","author":"Wang","year":"2021","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1020","DOI":"10.1109\/COMST.2023.3259224","article-title":"Coding Techniques for Backscatter Communications\u2014A Contemporary Survey","volume":"25","author":"Rezaei","year":"2023","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_11","unstructured":"Guo, X., Shangguan, L., He, Y., Jing, N., Zhang, J., Jiang, H., and Liu, Y. (2022, January 4\u20136). Saiyan: Design and Implementation of a Low-Power Demodulator for {LoRa} Backscatter Systems. Proceedings of the 19th USENIX Symposium on Networked Systems Design and Implementation, Renton, WA, USA."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"19676","DOI":"10.1109\/TITS.2021.3126766","article-title":"Learning-Based Resource Allocation for Backscatter-Aided Vehicular Networks","volume":"23","author":"Khan","year":"2022","journal-title":"IEEE Trans. Intell. Transp. Syst."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1007\/s43154-023-00100-4","article-title":"Communication for Underwater Robots: Recent Trends","volume":"4","author":"Carver","year":"2023","journal-title":"Curr. Robot. Rep."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Jang, J., and Adib, F. (2019, January 19\u201323). Underwater Backscatter Networking. Proceedings of the ACM Special Interest Group on Data Communication, Beijing, China.","DOI":"10.1145\/3341302.3342091"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1577","DOI":"10.1007\/s12083-022-01312-9","article-title":"Interference-free source deployment for coverage in underwater acoustic backscatter networks","volume":"15","author":"Bereketli","year":"2022","journal-title":"Peer-to-Peer Netw. Appl."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Zhao, Y., Afzal, S.S., Akbar, W., Rodriguez, O., Mo, F., Boyle, D., Adib, F., and Haddadi, H. (2022, January 9\u201310). Towards Battery-Free Machine Learning and Inference in Underwater Environments. Proceedings of the 23rd Annual International Workshop on Mobile Computing Systems and Applications, Tempe, AZ, USA.","DOI":"10.1145\/3508396.3512877"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"5546","DOI":"10.1038\/s41467-022-33223-x","article-title":"Battery-Free Wireless Imaging of Underwater Environments","volume":"13","author":"Afzal","year":"2022","journal-title":"Nat. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Hu, G., Lin, J., Wang, G., He, R., and Wei, X. (2021, January 25\u201328). Sparse Reconstruction Based Channel Estimation for Underwater Piezo-Acoustic Backscatter Systems. Proceedings of the 2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), Helsinki, Finland.","DOI":"10.1109\/VTC2021-Spring51267.2021.9449012"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Akbar, W., Allam, A., and Adib, F. (2023, January 2\u20136). The Underwater Backscatter Channel: Theory, Link Budget, and Experimental Validation. Proceedings of the 29th Annual International Conference on Mobile Computing and Networking, Madrid, Spain.","DOI":"10.1145\/3570361.3613265"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Ghaffarivardavagh, R., Afzal, S.S., Rodriguez, O., and Adib, F. (2020, January 4\u20136). Underwater Backscatter Localization: Toward a Battery-Free Underwater GPS. Proceedings of the 19th ACM Workshop on Hot Topics in Networks, Virtual.","DOI":"10.1145\/3422604.3425950"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"10181","DOI":"10.1109\/TVT.2024.3367935","article-title":"Anti-Jamming Colonel Blotto Game for Underwater Acoustic Backscatter Communication","volume":"73","author":"Zhang","year":"2024","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Yin, F., Li, C., Wang, H., Nie, L., Zhang, Y., Liu, C., and Yang, F. (2023). Weak Underwater Acoustic Target Detection and Enhancement with BM-SEED Algorithm. J. Mar. Sci. Eng., 11.","DOI":"10.3390\/jmse11020357"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1016\/j.apacoust.2016.06.008","article-title":"ShipsEar: An underwater vessel noise database","volume":"113","year":"2016","journal-title":"Appl. Acoust."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Hershey, J.R., Chen, Z., Le Roux, J., and Watanabe, S. (2016, January 20\u201325). Deep clustering: Discriminative embeddings for segmentation and separation. Proceedings of the 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Shanghai, China.","DOI":"10.1109\/ICASSP.2016.7471631"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1256","DOI":"10.1109\/TASLP.2019.2915167","article-title":"Conv-TasNet: Surpassing Ideal Time\u2013Frequency Magnitude Masking for Speech Separation","volume":"27","author":"Luo","year":"2019","journal-title":"IEEE\/ACM Trans. Audio Speech Lang. Process."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Luo, Y., Chen, Z., and Yoshioka, T. (2020, January 4\u20138). Dual-Path RNN: Efficient Long Sequence Modeling for Time-Domain Single-Channel Speech Separation. Proceedings of the ICASSP 2020-2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Barcelona, Spain.","DOI":"10.1109\/ICASSP40776.2020.9054266"},{"key":"ref_27","unstructured":"Stoller, D., Ewert, S., and Dixon, S. (2018). Wave-U-Net: A Multi-Scale Neural Network for End-to-End Audio Source Separation. arXiv."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2840","DOI":"10.1109\/TASLP.2021.3099291","article-title":"Wavesplit: End-to-End Speech Separation by Speaker Clustering","volume":"29","author":"Zeghidour","year":"2021","journal-title":"IEEE\/ACM Trans. Audio Speech Lang. Proc."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Subakan, C., Ravanelli, M., Cornell, S., Bronzi, M., and Zhong, J. (2021, January 6\u201311). Attention Is All You Need in Speech Separation. Proceedings of the ICASSP 2021-2021 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Toronto, ON, Canada.","DOI":"10.1109\/ICASSP39728.2021.9413901"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Zhang, W., Li, X., Zhou, A., Ren, K., and Song, J. (2021, January 24). Underwater Acoustic Source Separation with Deep Bi-LSTM Networks. Proceedings of the 2021 4th International Conference on Information Communication and Signal Processing (ICICSP), Shanghai, China.","DOI":"10.1109\/ICICSP54369.2021.9611911"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Shi, Z., and Wang, K. (2022, January 20\u201322). Separation of Underwater Acoustic Signals Based on C-RNN Network. Proceedings of the International Conference on Electronic Information Engineering, Big Data, and Computer Technology (EIBDCT 2022), Sanya, China.","DOI":"10.1117\/12.2635805"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Li, D., Wu, M., Yu, L., Han, J., and Zhang, H. (2023). Single-Channel Blind Source Separation of Underwater Acoustic Signals Using Improved NMF and FastICA. Front. Mar. Sci., 9.","DOI":"10.3389\/fmars.2022.1097003"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"109513","DOI":"10.1016\/j.apacoust.2023.109513","article-title":"A Deep-Learning Based High-Gain Method for Underwater Acoustic Signal Detection in Intensity Fluctuation Environments","volume":"211","author":"Chu","year":"2023","journal-title":"Appl. Acoust."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Song, R., Feng, X., Wang, J., Sun, H., Zhou, M., and Esmaiel, H. (2024). Underwater Acoustic Nonlinear Blind Ship Noise Separation Using Recurrent Attention Neural Networks. Remote Sens., 16.","DOI":"10.3390\/rs16040653"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1177\/14613484241226524","article-title":"Study on Weak Sound Signal Separation and Pattern Recognition under Strong Background Noise in Marine Engineering","volume":"43","author":"Liu","year":"2024","journal-title":"J. Low Freq. Noise Vib. Act. Control."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Chen, Z., Luo, Y., and Mesgarani, N. (2017, January 5\u20139). Deep Attractor Network for Single-Microphone Speaker Separation. Proceedings of the 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), New Orleans, LA, USA.","DOI":"10.1109\/ICASSP.2017.7952155"},{"key":"ref_37","first-page":"545","article-title":"Single-Channel Multi-Speaker Separation Using Deep Clustering","volume":"2016","author":"Isik","year":"2016","journal-title":"Interspeech"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1708","DOI":"10.1109\/TSP.2009.2038424","article-title":"Sparse Channel Estimation for Multicarrier Underwater Acoustic Communication: From Subspace Methods to Compressed Sensing","volume":"58","author":"Berger","year":"2010","journal-title":"IEEE Trans. Signal Process."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1016\/j.neunet.2005.06.042","article-title":"Framewise Phoneme Classification with Bidirectional LSTM and Other Neural Network Architectures","volume":"18","author":"Graves","year":"2005","journal-title":"Neural Netw."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1901","DOI":"10.1109\/TASLP.2017.2726762","article-title":"Multitalker Speech Separation with Utterance-Level Permutation Invariant Training of Deep Recurrent Neural Networks","volume":"25","author":"Kolbaek","year":"2017","journal-title":"IEEE\/ACM Trans. Audio Speech Lang. Process."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Roux, J.L., Wisdom, S., Erdogan, H., and Hershey, J.R. (2019, January 12\u201317). SDR\u2014Half-Baked or Well Done?. Proceedings of the ICASSP 2019-2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Brighton, UK.","DOI":"10.1109\/ICASSP.2019.8683855"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Luo, Y., and Mesgarani, N. (2018, January 15\u201320). TaSNet: Time-Domain Audio Separation Network for Real-Time, Single-Channel Speech Separation. Proceedings of the 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Calgary, AB, Canada.","DOI":"10.1109\/ICASSP.2018.8462116"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/19\/3635\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:06:44Z","timestamp":1760112404000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/16\/19\/3635"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,29]]},"references-count":42,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2024,10]]}},"alternative-id":["rs16193635"],"URL":"https:\/\/doi.org\/10.3390\/rs16193635","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,29]]}}}