Spatial signature estimation in cumulant domain and application to smart antenna system

In this paper, we propose a subspace-based spatial signature estimation algorithm of cochannel multiuser signals by exploiting cumulant, and apply it to multiuser signal copy in uplink SDMA (space-division multiple-access) for smart antenna system. Our method constructs a new matrix called spatial signature matrix (SS Matrix), and estimates multiuser spatial signature through the eigen-decomposition of the SS matrix. Based on estimated spatial signature, a spatial filter bank is designed for cochannel multiuser waveform estimation. Computer simulations show that the spatial response of the filter bank can be used to find direction-of-arrival (DOA) of the correlated multiuser signals.