{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T04:22:51Z","timestamp":1775708571816,"version":"3.50.1"},"reference-count":65,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,5,10]],"date-time":"2021-05-10T00:00:00Z","timestamp":1620604800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Leistungszentrum Nachhaltigkeit","award":["MERLIN"],"award-info":[{"award-number":["MERLIN"]}]},{"name":"Bundesministerium f\u00fcr Bildung und Forschung","award":["01IS16010A"],"award-info":[{"award-number":["01IS16010A"]}]},{"name":"Bundesministerium f\u00fcr Bildung und Forschung","award":["01IS18011C"],"award-info":[{"award-number":["01IS18011C"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We propose an asynchronous acoustic chirp slope keying to map short bit sequences on single or multiple bands without preamble or error correction coding on the physical layer. We introduce a symbol detection scheme in the demodulator that uses the superposed matched filter results of up and down chirp references to estimate the symbol timing, which removes the requirement of a preamble for symbol synchronization. Details of the implementation are disclosed and discussed, and the performance is verified in a pool measurement on laboratory scale, as well as the simulation for a channel containing Rayleigh fading and Additive White Gaussian Noise. For time-bandwidth products (TB) of 50 in single band mode, a raw data rate of 100 bit\/s is simulated to achieve bit error rates (BER) below 0.001 for signal-to-noise ratios above \u22126 dB. In dual-band mode, for TB of 25 and a data rate of 200 bit\/s, the same bit error level was achieved for signal-to-noise ratios above 0 dB. The simulated packet error rates (PER) follow the general behavior of the BER, but with a higher error probability, which increases with the length of bits in each packet.<\/jats:p>","DOI":"10.3390\/s21093282","type":"journal-article","created":{"date-parts":[[2021,5,10]],"date-time":"2021-05-10T10:49:51Z","timestamp":1620643791000},"page":"3282","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Asynchronous Chirp Slope Keying for Underwater Acoustic Communication"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0869-4604","authenticated-orcid":false,"given":"Dominik Jan","family":"Schott","sequence":"first","affiliation":[{"name":"Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3167-760X","authenticated-orcid":false,"given":"Andrea","family":"Gabbrielli","sequence":"additional","affiliation":[{"name":"Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8530-1053","authenticated-orcid":false,"given":"Wenxin","family":"Xiong","sequence":"additional","affiliation":[{"name":"Department of Computer Science (IIF), University of Freiburg, 79110 Freiburg, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1460-1061","authenticated-orcid":false,"given":"Georg","family":"Fischer","sequence":"additional","affiliation":[{"name":"Fraunhofer EMI, 79588 Efringen-Kirchen, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5877-1439","authenticated-orcid":false,"given":"Fabian","family":"H\u00f6flinger","sequence":"additional","affiliation":[{"name":"Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg, Germany"},{"name":"Fraunhofer EMI, 79588 Efringen-Kirchen, Germany"}]},{"given":"Johannes","family":"Wendeberg","sequence":"additional","affiliation":[{"name":"Department of Computer Science (IIF), University of Freiburg, 79110 Freiburg, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8320-8581","authenticated-orcid":false,"given":"Christian","family":"Schindelhauer","sequence":"additional","affiliation":[{"name":"Department of Computer Science (IIF), University of Freiburg, 79110 Freiburg, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4806-9838","authenticated-orcid":false,"given":"Stefan Johann","family":"Rupitsch","sequence":"additional","affiliation":[{"name":"Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,10]]},"reference":[{"key":"ref_1","unstructured":"Batchelder, J.M. 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