Frequency-difference beamforming and sparse processing

Frequency-difference processing enables the estimation of the direction of arrival (DOA) for sources beyond the spatial aliasing frequency. The beamforming method takes advantage of the frequency difference between multiple frequencies, enabling processing at a lower frequency than the aliasing frequency. During this process, the number of DOAs we need to estimate becomes squared, and we require a high-resolution DOA estimator. Sparse processing has demonstrated high-resolution capabilities in DOA estimation, resulting in beamforming spectra with sharp peaks and enhancing resolution for accuracy. This presentation proposes the utilization of both frequency-difference processing and sparse processing. The suggested method is an aliasing-free beamformer for high-frequency sources using frequency-difference processing and achieves high-resolution capability using sparse processing.