J. Fuhl et al., HIGH-RESOLUTION 3-D DIRECTION-OF-ARRIVAL DETERMINATION FOR URBAN MOBILE RADIO, IEEE transactions on antennas and propagation, 45(4), 1997, pp. 672-682
The in-depth knowledge of the mobile radio channel is particularly imp
ortant for radio communication modeling and advanced technology system
design, We propose an accurate method to determine jointly azimult an
d elevation angle and the delay of waves incoming at the receiver. The
method is applied to measurements of the complex impulse response of
the mobile radio channel, performed on a planar array placed on a mobi
le in an urban cellular environment, The directians-of-arrival (DOA) w
ere obtained by the means of a recently presented direction finding al
gorithm-Two-Dimensional (2-D) Unitary ESPRIT. Two-dimensional spatial
smoothing as an extension of ordinary spatial smoothing is utilized to
decorrelate coherent waves, The application of 2-D Unitary ESPRIT inc
reases the angular resolution over conventional Fourier analysis or th
e scattering function by an order of magnitude and overcomes difficult
ies due to secondary lobes, The time delay is determined from wideband
channel sounder measurements. The results confirm some assumptions on
propagation mechanisms: 1) The wave-guiding property of streets (cany
on effect), which Is especially pronounced for long-delayed paths; 2)
the variation of the number of incoming waves with their excess delay-
the larger the excess delay, the lower the number of paths comprising
an echo in the power delay profile; 3) if a single path remains, the p
rivileged DOA is the direction of the street; 4) the exponential part
of the power delay profile due to scatterers all around the receiver;
and 5) the elevation dependence of the impinging power, In the tested
receiver locations, paths with elevations between 0 degrees and 40 deg
rees dominate, containing about 90% of the received power.