An enhanced iterative receiver based on vector approximate message passing for deep-sea vertical underwater acoustic...

Area of Science:

• Underwater Acoustic Communications
• Signal Processing
• Deep-Sea Technology

Background:

• Vertical underwater acoustic (UWA) channels present challenges including multipath, time-varying Doppler shifts, and impulsive noise.
• Robust single-carrier UWA communication is essential for various deep-sea applications.

Purpose of the Study:

• To propose an enhanced iterative receiver for robust vertical single-carrier UWA communication.
• To address time-varying Doppler effects, residual timing errors, multipath interference, and impulsive noise.

Main Methods:

• A spline interpolation-based timing estimation approach for Doppler compensation.
• A fractionally spaced self-iterative soft equalizer (SISE) utilizing the vector approximate message passing (VAMP) algorithm.
• VAMP-SISE incorporates soft slicer, soft equalizer, denoiser, and minimum mean-squared error estimator for iterative information exchange.
• Transmitter employs channel-fitting irregular convolutional code and unity-rate code.

Main Results:

• The proposed receiver demonstrates superior performance in deep-sea experiments.
• Effective compensation for time-varying Doppler effects.
• Successful mitigation of multipath interference and impulsive noise.

Conclusions:

• The enhanced iterative receiver significantly improves the robustness of vertical UWA communications.
• The VAMP-SISE algorithm combined with advanced coding schemes achieves reliable communication under challenging channel conditions.
• The proposed methods offer a promising solution for deep-sea acoustic communication systems.