Time Domain Impulsive Noise Mitigation in UWA Systems using Compressive Sensing Approach

Orthogonal frequency-division multiplexing (OFDM) is a popular choice for implementation in underwater acoustic (UWA) communication due to its resiliency in fading channels. However, the presence of impulsive noise is a major issue in UWA channels as it severely deteriorates the transmitted data. Impulsive noise has high power and spreads out to the entire frequency domain when the OFDM modulation is performed, hence affecting the transmitted data symbols. Compressive sensing (CS) technique is able to estimate and reconstruct the impulsive noise by exploiting the sparse nature of the impulsive noise in UWA channels. In this paper, we propose to use the smoothed $\ell_{0}$-norm (SL0) minimization algorithm to estimate the symmetric $\alpha$-stable (S$\alpha$S) impulsive noise in UWA channels. The objective function is formulated to minimize the sparsest solution of the impulsive noise. Simulation results show that the SL0 CS approach is able to reduce the BER. It is also shown that the proposed CS approach has a comparable performance to the conventional $\ell_{1}$-norm algorithm where the SL0 has faster processing time.