Frequency-Domain Turbo Equalization with Iterative Channel Estimation for MIMO Underwater Acoustic Communications


This paper proposes a new iterative receiver for single-carrier multiple-input-multiple-output (SC-MIMO) underwater acoustic (UWA) communications, which utilizes frequency-domain turbo equalization (FDTE) and iterative channel estimation. Soft-decision symbols are not only fed back to the equalizer to cancel the intersymbol interference (ISI) and cochannel interference (CCI), but also used as training signals in the channel estimator to update the estimated channel state information (CSI) after each turbo iteration. This iterative channel estimation scheme helps to combat the problem commonly suffered by block-processing receivers in fast time-varying channels. Compared with time-domain turbo equalization, FDTE achieves comparable performance with significantly reduced computational complexity. Using soft-decision symbols to reestimate the time-varying channels, iterative channel estimation further improves the accuracy of the estimated CSI. The proposed iterative receiver has been verified through undersea experimental data collected in the Surface Processes and Acoustic Communications Experiment 2008 (SPACE08).


Electrical and Computer Engineering


Beijing Higher Education Young Elite Teacher Project
National Science Foundation of China
National Science Foundation (U.S.)


This work was supported in part by the Beijing Higher Education Young Elite Teacher Project under Grant YETP0101), the National Science Foundation of China under Grant 61471221, and the U.S. National Science Foundation under Grant ECCS-1408316).

Keywords and Phrases

Channel state information; Codes (symbols); Communication channels (information theory); Equalizers; Feedback control; Frequency domain analysis; Frequency estimation; MIMO systems; Signal receivers; Telecommunication repeaters; Time varying networks; Underwater acoustics; Acoustic communications; Cochannel interference (CCI); Fast time-varying channels; Frequency domain equalization; Frequency-domain turbo equalizations; Iterative channel estimation; Turbo equalizations; Underwater acoustic communications; Channel estimation; Frequency-domain equalization; Multiple-input-multiple-output (MIMO); Underwater acoustic (UWA) communications

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Article - Journal

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© 2017 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jul 2017