{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:03:14Z","timestamp":1760148194191,"version":"build-2065373602"},"reference-count":27,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,4,9]],"date-time":"2023-04-09T00:00:00Z","timestamp":1680998400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["92271202"],"award-info":[{"award-number":["92271202"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>In this paper, we propose a promising signal-sensing method based on both single- and multiple-antenna covariance matrices of the received signal. In comparison with microwave diagnostics or energy detection, the proposed method does not need prior information of signal and noise. Therefore, it can be widely used in noise power uncertainty scenarios, such as signal transmission in hypersonic plasma sheath, with symmetry to the signal-sensing method in cognitive radio. Designing an efficient signal-sensing method that supports both the application for the field of hypersonic plasma sheath communication or cognitive radio is still an attractive subject deserving of study in symmetry journals. Theoretical analysis and the implementation algorithm of a single-antenna covariance matrix are carried out for the proposed method, with a possible extension to multiple-antenna situations. Simulations show the proposed method has excellent performance, even for very low signal-noise-ratio (SNR) signals, and is competitive with state-of-the-art algorithms.<\/jats:p>","DOI":"10.3390\/sym15040888","type":"journal-article","created":{"date-parts":[[2023,4,10]],"date-time":"2023-04-10T03:49:29Z","timestamp":1681098569000},"page":"888","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Low SNR Signal-Sensing Method Based on a Multiple-Antenna Covariance Matrix"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-0460-5429","authenticated-orcid":false,"given":"Yumin","family":"Zhong","sequence":"first","affiliation":[{"name":"Beijing Research Institute of Telemetry, Beijing 100076, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yanhua","family":"Li","sequence":"additional","affiliation":[{"name":"Beijing Research Institute of Telemetry, Beijing 100076, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,4,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"879","DOI":"10.1109\/TAES.1971.310328","article-title":"Progress in Reentry Communications","volume":"7","author":"Rybak","year":"1971","journal-title":"IEEE Trans. Aerosp. Electron. Syst. AES"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1063\/1.4998302","article-title":"Plasma sheath: An equivalent nonlinear mirror between electron density and transmitted electromagnetic signal","volume":"24","author":"Yao","year":"2017","journal-title":"Phys. Plasmas"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"451","DOI":"10.1109\/JSEN.2010.2060322","article-title":"Broadband reflectometry for diagnostics and monitoring applications","volume":"11","author":"Cataldo","year":"2010","journal-title":"IEEE Sens. J."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"102105","DOI":"10.1063\/5.0053242","article-title":"Broadband microwave reflectometry plasma diagnostic based on invariant point of reflection data","volume":"28","author":"Yang","year":"2021","journal-title":"Phys. Plasmas"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Minashin, P.V., and Kukushkin, A.B. (2023). Spectral Intensity of Electron Cyclotron Radiation Emerging from the Plasma to the First Wall in ITER. Symmetry, 15.","DOI":"10.3390\/sym15010118"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"573","DOI":"10.1109\/TAP.1968.1139245","article-title":"Antenna impedance in a reentry environment","volume":"16","author":"Mayhan","year":"1968","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_7","unstructured":"Swenson, C.M., Baker, K.D., Pound, E., and Jensen, M.D. (1993). Lunar and Planetary Inst., Workshop on Advanced Technologies for Planetary Instruments, Part 1, Lunar and Planetary Institute."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Sharma, M., Vashist, P.C., Alsukayti, I., Goyal, N., Anand, D., and Mosavi, A.H. (2022). A Wider Impedance Bandwidth Dual Filter Symmetrical MIMO Antenna for High-Speed Wideband Wireless Applications. Symmetry, 14.","DOI":"10.3390\/sym14010029"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"075018","DOI":"10.1063\/1.5038763","article-title":"Transmission coefficient estimation based on antenna voltage standing wave ratio under plasma sheath","volume":"8","author":"Yang","year":"2018","journal-title":"AIP Adv."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1109\/PROC.1967.5573","article-title":"Energy detection of unkown deterministic signals","volume":"55","author":"Urkowitz","year":"1967","journal-title":"Proc. IEEE"},{"key":"ref_11","unstructured":"Kay, S.M. (1998). Fundamentals of Statistical Signal Processing: Detection Theory, Prentice Hall."},{"key":"ref_12","unstructured":"Kostylev, V.I. (May, January 28). Energy detection of a signal with random amplitude. Proceedings of the Energy Detection of a Signal with Random Amplitude, New York, NY, USA."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1109\/TCOMM.2006.887483","article-title":"On the energy detection of unknown signals over fading channels","volume":"55","author":"Digham","year":"2007","journal-title":"IEEE Trans. Commun."},{"key":"ref_14","unstructured":"Sahai, A., and Cabric, D. (2005, January 8\u201311). Spectrum sensing: Fundamental limits and practical challenges. Proceedings of the IEEE International Symposium on New Frontiers DySPAN (Tutorial), Baltimore, MD, USA."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Chen, H.S., Gao, W., and Daut, D.G. (2007, January 24\u201328). Signature based spectrum sensing algorithms for IEEE 802.22 WRAN. Proceedings of the 2007 IEEE International Conference on Communications, Glasgow, UK.","DOI":"10.1109\/ICC.2007.1073"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1109\/79.81007","article-title":"Exploitation of spectral redundancy in cyclostationary signals","volume":"8","author":"Gardner","year":"1991","journal-title":"IEEE Signal Process. Mag."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1109\/JSAC.2008.080103","article-title":"Cyclostationary signatures in practical cognitive radio applications","volume":"26","author":"Sutton","year":"2008","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_18","unstructured":"Cabric, D., Mishra, S.M., and Brodersen, R.W. (2004, January 7\u201311). Implementation issues in spectrum sensing for cognitive radios. Proceedings of the Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, Pacific Grove, CA, USA."},{"key":"ref_19","unstructured":"Tandra, R., and Sahai, A. (2005, January 13\u201316). Fundamental limits on detection in low SNR under noise uncertainty. Proceedings of the 2005 International Conference on Wireless Networks, Communications and Mobile Computing, Maui, HI, USA."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Zeng, Y., and Liang, Y.C. (2007, January 3\u20137). Maximum-minimum eigenvalue detection for cognitive radio. Proceedings of the 2007 IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC\u201907, Athens, Greece.","DOI":"10.1109\/PIMRC.2007.4394211"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1784","DOI":"10.1109\/TCOMM.2009.06.070402","article-title":"Eigenvalue-based spectrum sensing algorithms for cognitive radio","volume":"57","author":"Zeng","year":"2009","journal-title":"IEEE Trans. Commun."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Zeng, Y., and Liang, Y.-C. (2010, January 26\u201329). Robust spectrum sensing in cognitive radio. Proceedings of the 2010 IEEE 21st International Symposium on Personal, Indoor and Mobile Radio Communications Workshops, Istanbul, Turkey.","DOI":"10.1109\/PIMRCW.2010.5670361"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Tian, Z., and Giannakis, G.B. (2007, January 8\u201310). A wavelet approach to wideband spectrum sensing for cognitive radios. Proceedings of the 1st International Conference on Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM \u201907), Mykonos, Greece.","DOI":"10.1109\/CROWNCOM.2006.363459"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Zhang, S., Wang, Y., Yuan, H., Wan, P., and Zhang, Y. (2019). Multiple-Antenna Cooperative Spectrum Sensing Based on the Wavelet Transform and Gaussian Mixture Model. Sensors, 19.","DOI":"10.3390\/s19183863"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Zeng, Y.H., and Liang, Y.-C. (2007, January 17\u201320). Covariance based signal detections for cognitive radio. Proceedings of the 2nd IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks (DySPAN \u201907), Dublin, Ireland.","DOI":"10.1109\/DYSPAN.2007.33"},{"key":"ref_26","unstructured":"Maida, M., Najim, J., Bianchi, P., and Debbah, M. (September, January 31). Performance analysis of some eigen-based hypothesis tests for collaborative sensing. Proceedings of the IEEE Workshop on Statistical Signal Processing, Cardiff, UK."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1804","DOI":"10.1109\/TVT.2008.2005267","article-title":"Spectrum-sensing algorithms for cognitive radio based on statistical covariances","volume":"58","author":"Zeng","year":"2009","journal-title":"IEEE Trans. Veh. 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