Self-interference cancellation in underwater acoustic communications systems using orthogonal pilots in IBFD


  • Hala A. Naman Al-Nahrain University, College of Information Engineering, Department of computer Networks Engineering, Baghdad , Iraq; University of Wasit, College of Engineering, Department of Architecture, Wasit, Iraq
  • Ammar E. Abdelkareem Al-Nahrain University, College of Information Engineering, Department of computer Networks Engineering, Baghdad, Iraq



full duplex, self-interference cancellation, Far channel model, channel estimation, multipath propagation, underwater acoustic communication


This paper proposes a Self-interference (SI) cancellation system model of Underwater acoustic (UWA) communication for in-band full-duplex (IBFD) technology. The SI channel is separated from the Far channel by exploiting a concurrently orthogonal pilot channel estimation technique using two orthogonal frequency-division multiplexing (OFDM) blocks to establish orthogonality between them based on a unitary matrix. Compared to the half-duplex channel estimator, the mean squared error (MSE) and the bit error rate (BER) provided strong evidence for the efficiency of the proposed SI cancellation. Since full-duplex systems are more efficient than half-duplex ones, the proposed approach might be seen as a viable option for them. The proposed method proved effective when used with a fixed full-duplex (FD) position and FD shifting of up to 4°. Different channel lengths and distances are adopted to evaluate the proposed method. Initial findings indicate that MSE for the SI channel minimum mean-square error (MMSE) estimator at 20 dB is 0.118 · 10−3, for fixed FD. In addition, this paper presents a geometry channel model for the Far channel in the IBFD underwater communication system that describes the propagation delay of the multipath reflection. The simulation results for the multipath propagation delay spread are similar to the traditional results, with the delay spread of the suggested model reaching (79 ms), which is close to the Bellhop simulator result (78 ms).


Download data is not yet available.


M. Stojanovic, J. Preisig. Underwater acoustic communication channels: Propagation models and statistical characterization. IEEE Communications Magazine 47(1):84–89, 2009.

A. E. Abdelkareem, B. S. Sharif, C. C. Tsimenidis, J. A. Neasham. Compensation of linear multiscale Doppler for OFDM-based underwater acoustic communication systems. Compensation of Linear Multiscale Doppler for OFDMBased Underwater Acoustic Communication Systems 2012:139416, 2012.

M. C. Domingo. Overview of channel models for underwater wireless communication networks. Physical Communication 1(3):163–182, 2008.

Z. Zhang, K. Long, A. V. Vasilakos, L. Hanzo. Full-duplex wireless communications: Challenges, solutions, and future research directions. Proceedings of the IEEE 104(7):1369–1409, 2016.

K. E. Kolodziej, B. T. Perry, J. S. Herd. In-band full-duplex technology: Techniques and systems survey. IEEE Transactions on Microwave Theory and Techniques 67(7):3025–3041, 2019.

G. Qiao, S. Liu, Z. Sun, F. Zhou. Full-duplex, multi-user and parameter reconfigurable underwater acoustic communication modem. In 2013 OCEANS – San Diego, pp. 1–8. 2013.

J. Zhang, G. Qiao, C. Wang. Acoustic communication networks. In 2013 OCEANS – San Diego, pp. 1–6. 2013.

L. Shen, B. Henson, Y. Zakharov, P. Mitchell. Digital self-interference cancellation for full-duplex underwater acoustic systems. IEEE Transactions on Circuits and Systems II: Express Briefs 67(1):192–196, 2020.

L. Li, A. Song, L. J. Cimini, et al. Interference cancellation in in-band full-duplex underwater acoustic systems. In OCEANS 2015 - MTS/IEEE Washington, pp. 1–6. 2015.

Y. Widiarti, Suwadi, Wirawan, T. Suryani. A geometry-based underwater acoustic channel model for time reversal acoustic communication. In 2018 International Seminar on Intelligent Technology and Its Applications (ISITIA), pp. 345–350. 2018.

J. Zhou, H. Jiang, P. Wu, Q. Chen. Study of propagation channel characteristics for underwater acoustic communication environments. IEEE Access 7:79438–79445, 2019.

X. Zhu, C.-X. Wang, R. Ma. A 2D non-stationary channel model for underwater acoustic communication systems. In 2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), pp. 1–6. 2021.

S. Panchal, S. Patel, S. Panchal, J. Pabari. Design of novel channel propagation model for underwater acoustic wireless communication inside a tank. Research Square 2022.

G. Qiao, S. Gan, S. Liu, Q. Song. Self-interference channel estimation algorithm based on maximum-likelihood estimator in in-band full-duplex underwater acoustic communication system. IEEE Access 6:62324–62334, 2018.

M. Shammaa, H. Vogt, A. El-Mahdy, A. Sezgin. Adaptive self-interference cancellation for full duplex systems with auxiliary receiver. In 2019 International Conference on Advanced Communication Technologies and Networking (CommNet), pp. 1–8. 2019.

Z. S. Liu, Q. J. Zhou, W. S. Gan, et al. Adaptive joint channel estimation of digital self-interference cancelation in cotime co-frequency full-duplex underwater acoustic communication. In 2019 IEEE International Conference on Signal, Information and Data Processing (ICSIDP), pp. 1–5. 2019.

A. M. M. Chandran, L. Wang, M. Zawodniok. Channel estimators for full-duplex communication using orthogonal pilot sequences. IEEE Access 8:117706–117713, 2020.

R. F. W. Coates. Underwater acoustic systems. Macmillan, 1990.

N. Morozs. Channel modeling for underwater acoustic network simulation, 2020. P. 1–25.

H. A. Naman, A. E. Abdelkareem. Variable direction-based self-interference full-duplex channel model for underwater acoustic communication systems. International Journal of Communication Systems 35(7):e5096, 2022.




How to Cite

Naman, H. A., & Abdelkareem, A. E. (2023). Self-interference cancellation in underwater acoustic communications systems using orthogonal pilots in IBFD. Acta Polytechnica, 63(1), 23–35.