Broad-band high-resolution direction-of-arrival estimation of a conditional wavenumber-spectral-density based approach

A broad-band high-resolution Direction-of-Arrival(DOA) estimation algorithm named the Conditional Wavenumber Spectral Density based(CWSD-based) is proposed in this paper aimed at the problem of large error and high complexity of wide-band.The super-resolution DOA estimation,minimal main-lobe width,ultra-low side-lobe and high precision target resolution performance can be obtained after transforming the array signals to f-k space and using the characteristic of wideband signal power distributed as a line on the Conditional Wavenumber Spectral Density.Moreover,there are no DOA pre-estimates of the incident signals and the number of sources to be required in this algorithm.Computer simulations indicate that the theoretical resolution of the algorithm is inversely proportional to the highest processing frequency,the estimated mean square error is about 0.1 degree,and also is robust to array elements distortion.Meanwhile,it achieves lower time complexity.The proposed algorithm,whose performance is superior to CBF and MVDR in the aspects of resolution,weak target detection,non-target direction noise suppression and robustness etc.,can achieve ultra-low sidelobe high-resolution DOA in real marine environment.