DOA Estimation for Wideband Signal: Multiple Frequency Bins Versus Multiple Sensors

In conventional direction of arrival (DOA) estimation techniques, the inter-sensor spacing of an array is designed according to the minimal wavelength of an applied signal to avoid spatial ambiguity. This constraint greatly restricts the resolution of array or the performance of DOA estimation for a wideband signal. In this work, a new concept of wideband DOA estimation is described. Compared with multiple signal classification (MUSIC) method, the proposed method in this work uses multiple frequency bins instead of multiple sensors to form the steering vector, which reduces the sensor number for DOA estimation into 2. Besides, in this wideband DOA estimation method, the inter-sensor spacing is determined by the frequency resolution rather than the highest frequency (or minimal wavelength), so this method greatly decreases the restriction on sensor interval. Simulation results show that the proposed method with only two sensors can achieve comparative performance with conventional DOA estimation method using more than 20 sensors.