A subspace approach for DOA estimation of uniform linear arrays with increased element spacing applicable to wideband transmission

In this paper, the problem of joint direction of arrival (DOA) and signal estimation is addressed with a uniform linear array (ULA) when the array has an increased element spacing (i.e., an array with crossed manifold) under wideband scenario. Similar to the temporal aliasing, spatial aliasing can occur when the array´s interelement spacing exceeds lambda/2, (where lambda is the wavelength of the transmission at a certain frequency.) A subspace-based algorithm is proposed which uses the inherent spectral diversity in the wideband transmission to resolve the aliasing ambiguity in joint DOA and data signal estimation. The auxiliary constraints to ensure identifiability have been investigated and it is shown that by an appropriate choice of frequency bins, the aperture size of the antenna can be arbitrarily increased. The performance of the proposed algorithm is studied through confirmatory simulation and Monte Carlo analysis