A general non-Gaussian semiparametric model is adopted to characterize the measurement vectors, i.e.\ the \textit{ snapshots}, collected by a linear array. Moreover, the recently derived \textit{ robust semiparametric efficient} $R$-estimator of the data covariance matrix is exploited to implement an original version of the MUSIC estimator. The efficiency of the resulting $R$-MUSIC algorithm is investigated by comparing its Mean Squared Error (MSE) in the estimation of the source spatial frequencies with the relevant Semiparametric Stochastic Cram\'{ e}r-Rao Bound (SSCRB).
Categories: eess.SP