Extended Aperture DOA Estimation Using Coprime Arrays via Coarray Interpolation

In this paper, we propose an extended aperture direction-of-arrival (DOA) estimation algorithm using a coprime acoustic vector sensor array. Each acoustic vector sensor consists of one pressure sensor and one uniaxial velocity sensor, collocated in a single point in space. By full utilization of both pressure and particle-velocity information in the acoustic wavefield, the whole coarray output is shown to be treated as four pressure–velocity (p–v) components. In this way, array interpolation and Toeplitz matrix reconstruction are performed on each of the four p–v components to exploit the entire coarray aperture. After interpolation, DOA estimates are derived in closed form using the interpolated coarray data. The proposed algorithm allows the inter-sensor spacing of the interpolated coarray to be significantly greater than half a wavelength, thereby achieving aperture extension without needing extra sensors. Moreover, it enables provide the unambiguous DOA estimates with high accuracy, despite the phase aliasing caused by aperture extension. All these advantages are not offered by the existing coprime array DOA estimation algorithms. Finally, computer simulations are carried out to verify the superiority of the proposed algorithm.