Multipath parameters estimation of near-field spatial-wideband systems

This letter proposes a low-complexity, one-snapshot angle, range and channel gain estimation algorithm for a sparse multipath near-field spatial-wideband system. With upcoming mm-wave & sub-THz systems expected to operate massive antenna arrays, the transmitted wideband signal is not only sensitive to the propagation delay across the array aperture but the resulting wavefront is no longer planar. A modified wideband discrete linear chirp transform (DLCT) is used to estimate the multipath parameters of such a system. Furthermore, an iterative neighbourhood search is proposed to acquire super-resolution estimates of the scatterer locations, path gain and the multipath’s arrival angle. We also show that they are asymptotically optimal approaching their respective Cramér-Rao bounds.