An Improved DOA Algorithm for Wideband Coherent Signals

When estimating wideband direction of arrival, coherent signal subspace method (CSM) require a pre-estimation of angles. Such shortcoming has motivated many scholars to improve the algorithm. However, these algorithms often require processing of all subbands, and there is subspace leakage in the post-focus covariance matrix. Therefore, an improved algorithm is proposed in this paper to overcome these limitations. A new focusing matrix is constructed to avoid providing initial angles. The optimal subbands are selected based on signal energy to reduce calculation. In comparison with focusing signal subspace (FSS) and Autofocus algorithms, simulations indicate that the proposed method achieves higher estimation resolution and requires less computation.