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Multiple-Input-Multiple-Output Filtered Multitone Time Reversal Acoustic Communications Using Direct Adaptation-Based
1School of Cyber Science and Engineering, Qufu Normal University, Qufu, 273165, China.
Sensors (Basel, Switzerland)
|July 14, 2023
Summary
This study introduces direct adaptation-based turbo equalization for multiple-input-multiple-output filtered multitone time reversal acoustic communications. The method effectively suppresses noise and interference, improving communication performance.
Area of Science:
- Electrical Engineering
- Signal Processing
- Acoustic Communications
Background:
- Underwater acoustic communication systems face challenges from noise and interference.
- Time reversal (TR) is a technique used to focus acoustic energy, but residual interference remains.
- Filtered multitone (FMT) modulation is employed in multiple-input-multiple-output (MIMO) systems.
Purpose of the Study:
- To propose a novel direct adaptation (DA)-based turbo equalization method for MIMO-FMT TR acoustic communications.
- To jointly suppress noise, co-channel interference (CCI), and intersymbol interference (ISI) after TR.
- To enhance the performance of underwater acoustic communication systems.
Main Methods:
- Utilizing soft information-based adaptive decision feedback equalization (ADFE) with the recursive expected least squares (RELS) algorithm.
- Implementing iterative exchange of soft information between symbols and decoding decisions.
- Employing interference cancellation and decoding within the turbo equalization framework.
Main Results:
- The proposed DA-based turbo equalization method demonstrates improved performance compared to systems without error control coding (ECC).
- It outperforms methods using hard decision equalization and decoding by effectively exploiting soft information.
- Performance was validated using real experimental acoustic channel responses.
Conclusions:
- Direct adaptation-based turbo equalization is a viable and effective technique for MIMO-FMT TR acoustic communications.
- The iterative soft information exchange significantly enhances interference suppression and overall system performance.
- This approach offers a robust solution for challenging underwater acoustic communication environments.
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