Ricerc@Sapienza

The generation and propagation of a second harmonic water wave have been investigated in the
frequency range between 7 Hz and 60 Hz where the velocity vs. frequency curve attains its minimum
value. A model is proposed by assuming that the second harmonic is locally generated by point
sources on the wavefront of the fundamental wave, and that at any point along the propagation
direction the second harmonic be given by the cumulative contribution from all the sources up to

Nonlinear acoustic echo cancellation (NAEC) can be mainly addressed by solving two different sub-problems: the estimation of the acoustic impulse response and the modeling of the nonlinearities rebounding in it, mostly caused by the electroacoustic chain. Both the modeling processes share an important characteristic: the majority of the parameters to be estimated are very close to zero, with only a small fraction of them having non-negligible magnitude. In this paper, a novel NAEC model is proposed taking into account both the above sub-problems under a joint optimization problem.