A novel wideband DOA estimation technique based on harmonic source model for a uniform linear array

Wideband direction of arrival (DOA) estimation problem has attracted a lot of attention in recent years due to its practical importance in many important areas. In this paper, a wideband DOA technique is proposed. This technique is based on two main ideas: (i) the correlation between the sensor measurements of a uniform linear array (ULA) and a sine or cosine waveform with known frequency forms a sequence that may be regarded as a sinusoidal signal with multiple frequencies associated with the time delays of all the sources; (ii) the DOA estimation can then be cast into a frequency estimation problem that may be solved by utilizing the AR model of a sinusoidal signal. The DOAs are identified by a grid search based on the estimated AR model. The new technique may be applied to both incoherent as well as coherent real-valued sources of harmonic or nonharmonic nature. Furthermore, the method does not require the use of the computationally intensive singular value decomposition (SVD) operation and the a priori knowledge of the number sources. It has been demonstrated through extensive simulations that the proposed technique is advantageous compared to the other commonly used techniques, such as the incoherent wideband MUSIC (IWM) and the coherent steered covariance matrix (STCM) based methods.