A.O. Chilingarov1, A.L. Gelgor2

1,2 Peter the Great St. Petersburg Polytechnic University (St. Petersburg, Russia)

1 Concern Oceanpribor, JSC (St. Petersburg, Russia)

1 chilingarov.ao@gmail.com; 2 agelgor@spbstu.ru

The problem formulation. The wideband OFDM underwater acoustic communication system adaptation for mobile vehicles is a highly topical issue. OFDM signals are widely used for underwater acoustic communication due to their low computational complexity for severe multipath propagation channel. However, wideband OFDM signals require precise frequency synchronization to avoid intercarrier interference between subcarriers. Preamble synchronization errors and slow user velocity fluctuations cause the residual frequency shift. To improve frequency synchronization quality, we propose residual frequency shift compensation algorithm based on pilot subcarrier analysis.

Objective. The main objective is to estimate improvement of wideband underwater acoustic communication system performance for mobile vehicles using residual frequency shift compensation algorithm.

Results. The residual frequency shift compensation algorithm is proposed. Simulation results confirm that residual frequency shift compensation algorithm provides significant performance improvement for mobile vehicles. Experimental demonstration of the underwater acoustic communication system with proposed frequency synchronization algorithm results in insignificant performance improvement for stationary users.

Practical significance. Residual frequency shift compensation algorithm reduces the performance losses caused by preamble-based frequency shift estimation. Wideband communication system with OFDM using residual frequency shift compensation allows data transmission in multipath propagation acoustic channel for mobile vehicles. The research results can be used in further spectral efficiency improvement of underwater acoustic communication systems with OFDM.

Chilingarov A.O., Gelgor A.L. Frequency synchronization algorithm for underwater acoustic communication signals with OFDM. Radiotekhnika. 2025. V. 89. № 3. P. 109−120. DOI: https://doi.org/10.18127/j00338486-202503-10 (In Russian)

1. Jaafar A.N., Ja’afar H., Pasya I., Abdullah R., Yamada Y. Overview of underwater communication technology. Proceedings of the 12th National Technical Seminar on Unmanned System Technology. 2020. V. 770. P. 93-104.
2. Jimenez E., Quintana G. Investigation on radio wave propagation in shallow seawater: Simulations and measurements. IEEE third underwater communications and networking conference (UComms). 2016. P. 1–5.
3. Jensen F.B., Kuperman W.A., Porter M.B., Schmidt H. Fundamentals of ocean acoustics. Computational Ocean Acoustics. Modern Acoustics and Signal Processing. 2011. P. 1-64.
4. Chitre M., Shahabudeen S., Freitag L., Stojanovic M. Recent advances in underwater acoustic communications & networking. Proceedings of the IEEE OCEANS. 2008. P. 1-10.
5. Zhou S., Wang Z. OFDM for underwater acoustic communications. New York: Wiley. 2014. 410 c.
6. El-Mahallawy M., TagEldien A.S., Elagooz S.S. Performance Enhancement of Underwater Acoustic OFDM Communication Systems. Wireless Pers. Commun. 2019. V. 108. P. 2047-2057.
7. Aziz B., Elbahhar F. Impact of frequency synchronization errors on BER performance of MB-OFDM UWB in Nakagami channels. 2015 IEEE International Conference on Communications (ICC). 2015. P. 2698-2703.
8. Abdelkareem A.E., Sharif B.S., Tsimenidis C.C., Neasham J.A., Hinton O.R. Low-complexity Doppler compensation for OFDM-based underwater acoustic communication systems. OCEANS 2011 IEEE Spain. Santander. Spain. 2011. Р. 1-6.
9. Lee H.-G., Kim J., Joung J., Choi J. Frequency-varying Doppler shift effect on wideband orthogonal time-frequency space systems. International Conference on Electronics, Information, and Communication (ICEIC). 2023. P. 1-4.
10. Wang Y., Tao J., Ma L., Jiang M., Chen W. Joint timing and frequency synchronization for OFDM underwater acoustic communications. IEEE/CIC International Conference on Communications in China. 2021. P. 272-277.
11. Gel'gor A.L., Puz'ko D.A., Skorodumov Ju.M., Lukojanov E.V., Panarin A.E., Pashkevich I.V. Primenenie OFDM-signalov dlja gidroakusticheskoj podvodnoj svjazi v uslovijah priema signala nizhe urovnja shumov. Radiotehnika. 2024. T. 88. № 3. S. 48-62. DOI: https://doi.org/10.18127/j00338486-202403-06 (in Russian).
12. Ali Mohamad Bassam, Mae L. Seto. Doppler tracking and compensation for underwater acoustic channels using shift-orthogonal pilot sequences. Proc. Mtgs. Acoust. 11 December 2020. V. 42. № 1.
13. Chilingarov A.O., Gel'gor A.L. Vlijanie oshibki ocenki kojefficienta doplerovskogo smeshhenija chastoty na pomehoustojchivost' shirokopolosnoj sistemy gidroakusticheskoj svjazi pri ispol'zovanii signalov s OFDM. Materialy vseross. konf. «Nedelja nauki IJeiT». SPb: POLITEH-PRESS. 2024. S. 18-21 (in Russian).
14. Khorov E., Kiryanov A., Lyakhov A., Bianchi G. A Tutorial on IEEE 802.11ax High Efficiency WLANs. IEEE Communications Surveys & Tutorials. Firstquarter. 2019. V. 21. № 1. Р. 197-216.
15. Zakharov Y., Morozov A., Preisig J. Doppler effect compensation for cyclic-prefix-free OFDM signals in fast-varying underwater acoustic channel. Proc. Mtgs. Acoust. 2 July 2012. V. 17. № 1.
16. Chilingarov A., Gelgor A. Doppler Effect Compensation with chirp-z transform for underwater acoustic communications with OFDM signaling. 2022 International Conference on Electrical Engineering and Photonics (EExPolytech). St. Petersburg. Russian Federation. 2022. Р. 87-90.
17. Kranc V.Z. Gidroakusticheskie kommunikacionnye sistemy (osnovy razrabotki). SPb: SPbGJeTU «LJeTI». 2024 (in Russian).
18. Yerramalli S., Mitra U. Optimal resampling of OFDM signals for multiscale–multilag underwater acoustic channels. IEEE Journal of Oceanic Engineering. Jan. 2011. V. 36. № 1. Р. 126-138.
19. Qarabaqi P., Stojanovic M. Statistical characterization and computationally efficient modeling of a class of underwater acoustic communication channels. IEEE Journal of Oceanic Engineering. Oct. 2013. V. 38. № 4. Р. 701-717.
20. Volkov A.N., Ryzhkov A.E., Sivers M.A. UMTS. Standart sotovoj svjazi tret'ego pokolenija. SPb: Izd-vo «Link». 2008. 224 s. (in Russian).
21. Khuc B., Vylegzhanin E., Chilingarov A., Puzko D., Batov Y. Preamble signals for detection timing and Doppler synchronization in underwater acoustic communications. Velichko E., Vinnichenko M., Kapralova V., Koucheryavy Y. (Eds). International Youth Conference on Electronics, Telecommunications and Information Technologies. Springer Proceedings in Physics. 2021. V. 255.
22. Murad Mohsin, Tasadduq Imran, Otero Pablo. Pilot-assisted OFDM for underwater acoustic communication. Journal of Marine Science and Engineering. 2021. № 9. 1382 p.
23. Holthuijsen L.H. Waves in oceanic and coastal waters. Cambridge University Press. 2007. 404 p.