  In this work, a simple and effective robust adaptive beamforming technique is
proposed for uniform linear arrays, which is based on the power spectral
estimation and uncertainty region (PSEUR) of the interference plus noise (IPN)
components. In particular, two algorithms are presented to find the angular
sector of interference in every snapshot based on the adopted spatial
uncertainty region of the interference direction. Moreover, a power spectrum is
introduced based on the estimation of the power of interference and noise
components, which allows the development of a robust approach to IPN covariance
matrix reconstruction. The proposed method has two main advantages. First, an
angular region that contains the interference direction is updated based on the
statistics of the array data. Secondly, the proposed IPN-PSEUR method avoids
estimating the power spectrum of the whole range of possible directions of the
interference sector. Simulation results show that the performance of the
proposed IPN-PSEUR beamformer is almost always close to the optimal value
across a wide range of signal-to-noise ratios.
