On the use of beamforming for estimation of spatially distributed signals

In wireless communications, spatially distributed signals originate from local scattering around the transmitter. Spatially distributed signals cause conventional high-resolution methods to show degradation in performance, since the underlying data model is of full rank theoretically. In this paper, a relationship between the distribution of the spatial spread and the power azimuth spectrum is derived. Using this relationship, two simple and robust estimators based on the conventional beamformer and Capon's beamformer for estimation of the nominal direction and spatial spread are found. The proposed estimators show very good performance in numerical examples.

[1]  Mats Bengtsson.  Antenna array signal processing for high rank data models , 2000 .

[2]  Björn E. Ottersten,et al.  Estimation of nominal direction of arrival and angular spread using an array of sensors , 1996, Signal Process..

[3]  Björn E. Ottersten,et al.  A generalization of weighted subspace fitting to full-rank models , 2001, IEEE Trans. Signal Process..

[4]  K. M. Wong,et al.  Estimation of the directions of arrival of spatially dispersed signals in array processing , 1996 .

[5]  M. Fattouche,et al.  Angle of arrival analysis of the indoor radio propagation channel , 1993, Proceedings of 2nd IEEE International Conference on Universal Personal Communications.

[6]  J. Capon.  High-resolution frequency-wavenumber spectrum analysis , 1969 .

[7]  Shahrokh Valaee,et al.  Parametric localization of distributed sources , 1995, IEEE Trans. Signal Process..

[8]  Qiang Wu,et al.  A parametric method for determining the number of signals in narrow-band direction finding , 1991, IEEE Trans. Signal Process..

[9]  Björn E. Ottersten,et al.  Low-complexity estimators for distributed sources , 2000, IEEE Trans. Signal Process..

[10]  Mikael Coldrey,et al.  Direction and Spread Estimation of Spatially Distributed Signals via the Power Azimuth Spectrum , 2002 .

[11]  Raviv Raich,et al.  Bearing estimation for a distributed source via the conventional beamformer , 1998, Ninth IEEE Signal Processing Workshop on Statistical Signal and Array Processing (Cat. No.98TH8381).