“…Additionally, the L-shaped array allows for simple implementation, because it consists of two ULAs connected orthogonally at one end of each ULA. For these reasons, the L-shaped array is widely applied to the 2D DOA estimation method [17,18,19,20,21,22,23,24,25,26], and its practical applications can be found in the past researches [27,28]. Although the narrowband subspace method may be unable to directly estimate wideband DOAs, one possible way to solve this problem is to employ the narrowband subspace method in each temporal frequency intensively, and then the wideband DOA results can be estimated by interpolating the narrowband DOA results all frequency bins [29,30].…”