Alleviation of uniform ambient noise in underwater acoustic communication receivers using spectral subtraction

Suraj Kamal , Supriya Menonkattil Hariharan , Saseendran Pillai

The acoustic medium of the ocean is exceedingly turbid with a multitude of simultaneously active noise sources like water currents, shipping noise, drilling, construction, off-shore oil rigs, marine life, shore waves and other hydrodynamic activities. These inherent mechanisms produces spectrally overlapping acoustic waves that radiate into the depths of the ocean, and the superposition of these signals from across large area of the sea surface cumulatively constitutes a spatially homogeneous uniform ambient noise field. It is often difficult to utilize such a cluttered and exacerbated acoustic channel for communication or other observational purposes. In this paper a method based on spectral subtraction, for alleviating the uniform acoustic ambient noise is presented. Spectral subtraction is a technique used to retrieve the power spectrum of a non-stationary signal of interest in a uniform noise field by subtracting an estimated average of noise spectrum from the originally observed signal spectrum. The noise spectrum is estimated while the signal of interest is absent or silent and will cyclically updated in a periodic manner at intentionally put blanking periods in communication signals. The method can be used with acoustic receiver front ends as a preconditioning stage for improving the overall signal quality.

Mots clés: Spectral Subtarction; Ambient Noise

Domaines: Acoustique [physics.class-ph]

Suraj Kamal, Supriya Menonkattil Hariharan, Saseendran Pillai. Alleviation of uniform ambient noise in underwater acoustic communication receivers using spectral subtraction. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811358⟩