DOA estimation of wideband sources without estimating the number of sources

In this paper, we propose a new technique to estimate wideband source directions from the sensor snapshots without requiring to know the number of sources present in the scenario. This work is motivated by the fact that the existing model order estimation (number of sources) techniques for wideband source scenario are either inaccurate or computationally expensive. Direction-of-arrival (DOA) estimation is realized using a beamformer framework which imposes nulls in the spatial spectrum along the source directions. The null width along the frequency axis is widened by introducing a new data dependent term into the optimization problem, thus achieving wideband capability. Furthermore, the temporal processing of the data snapshots drastically reduces the number of snapshots required for wideband DOA estimation. The effectiveness of the proposed formulation is studied with simulated experiments.

► We estimate DOA of wideband sources.
► DOA estimation is achieved with a beamformer framework which enables to include derivative constraints.
► The proposed technique does not require estimating the number of sources present in the scenario.
► Compared to frequency-domain DOA estimation techniques, the number of snapshots required is considerably low.
► The method can estimate directions of varying bandwidth sources.