Enhanced Adaptive Equalization for MIMO Underwater Acoustic Communications
An enhanced normalized least mean squares (NLMS) adaptive equalization scheme is proposed for single-carrier underwater acoustic (UWA) communications. The enhancement is achieved via two techniques: the sparse adaptation (SA) technique and the data reuse (DR) technique. The SA technique speeds up the convergence and improves the performance of the adaptive equalization, by taking advantage of the inherent sparsity of the equalizer. It is implemented as the selective zero-attracting NLMS (SZA-NLMS) algorithm, developed by introducing a range of attraction for the existing zero-attracting NLMS (ZA-NLMS) algorithm. Compared with the ZA-NLMS, the SZA-NLMS incurs a lower complexity and achieves a better performance. The DR technique effectively prolongs the training length and significantly reduces the training overhead. Attributed to the DR technique, a high transmission efficiency is achieved even for a block transmission. The proposed adaptive equalization is verified by the real data collected in an at-sea multiple-input multiple-output (MIMO) underwater acoustic communication trial. The experimental results show it considerably outperforms the standard NLMS adaptive equalization, especially with a low DR number.
J. Tao et al., "Enhanced Adaptive Equalization for MIMO Underwater Acoustic Communications," Proceedings of OCEANS 2017 MTS/IEEE Anchorage (2017, Anchorage, AK), Institute of Electrical and Electronics Engineers (IEEE), Sep 2017.
OCEANS '17 MTS/IEEE Anchorage (2017, Sep. 18-21, Anchorage, AK)
Electrical and Computer Engineering
Key Laboratory of Underwater Acoustic Signal Processing, Southeast University, China
Key Laboratory of System Control and Information Processing, China
Fundamental Research Funds for the Central Universities
Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions
Keywords and Phrases
Anchorages (foundations); Carrier communication; Equalizers; MIMO systems; Adaptive equalization; Block transmissions; High transmission; Lower complexity; Normalized least mean square; Training overhead; Underwater acoustic communications; Zero-attracting; Underwater acoustics
International Standard Book Number (ISBN)
Article - Conference proceedings
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