Hydrodynamic Whispering: Enabling Near-Field Silent Communication via Artificial Lateral Line Arrays

TL;DR

This work introduces Hydrodynamic Whispering to achieve near-field, covert underwater communication by leveraging an Artificial Lateral Line (ALL) as an active transceiver. A dipole-based physical channel model is derived under potential flow, showing a distinctive $1/r^{2}$ near-field decay and a dipole-like radiation pattern, enabling a localized communication bubble with intrinsic LPI. A two-stage receiver—Spatial Matched-Field Beamforming followed by Temporal Coherent Demodulation—coupled with mechanical BPSK modulation demonstrates robust signal recovery, achieving an array gain of about $\approx 13.8$ dB and BER approaching zero within the effective range. The results underline the feasibility of using localized hydrodynamic pressure fluctuations for secure, short-range underwater networking, while revealing fundamental mechanical bandwidth limits and stealth advantages that shape design choices for swarm coordination.

Abstract

To address the imperative for covert underwater swarm coordination, this paper introduces "Hydrodynamic Whispering," a near-field silent communication paradigm utilizing Artificial Lateral Line (ALL) arrays. Grounded in potential flow theory, we model the transmitter as an oscillating dipole source. The resulting pressure field exhibits steep nearfield attenuation (scaling with 1/r^2, naturally delimiting a secure "communication bubble" with intrinsic Low Probability of Interception (LPI) properties. We propose a transceiver architecture featuring a Binary Phase Shift Keying (BPSK) modulation scheme adapted for mechanical actuator inertia, coupled with a bio-inspired 24-sensor conformal array. To mitigate low Signal-to-Noise Ratio (SNR) in turbulent environments,a Spatio-Temporal Joint Processing framework incorporating Spatial Matched-Field Beamforming is developed. Simulation results demonstrate that the system achieves an array gain of approximately 13.8 dB and maintains a near-zero Bit Error Rate (BER) within the effective range. This study validates the feasibility of utilizing localized hydrodynamic pressure fluctuations for reliable and secure short-range underwater networking.

Figures (6)

• Figure 1: Schematic of the submerged hydrodynamic communication scenario and coordinate system.
• Figure 2: The "Spatial Fingerprint": Dipole Field
• Figure 3: Beamforming Effect
• Figure 4: BPSK Eye Diagram
• Figure 5: 3D Array Sensitivity "Bubble"