Wireless communications rely, among other things, on the understanding of the properties of the radio propagation channel, the antennas and their interplay. Adequate measurements are required to verify theoretical models and to gain knowledge of the channel behavior and antenna performance.
As a result of this master thesis we built a 3D field scanner measurement system to predict multipath propagation and to measure antenna characteristics. The 3Dscanner allows measuring a signal at the point of interest along a line, on a surface or within a volume in space.
In order to evaluate the system, we have performed narrow band channel sounding measurements of the spatial distribution of waves impinging at an imaginary spherical sector. Data was used to estimate the Angle-of-Arrivals (AoA) and amplitude of the waves. An estimation method is presented to solve the resulting inverse problem by means of regularization with truncated singular value decomposition.
The regularized solution was then further improved with the help of a successive interference cancellation algorithm. Before applying the method to measurement data, it was tested on synthetic data to evaluate its performance as a function of the noise level and the number of impinging waves.
In order to minimize estimation errors it was also required to find the phase center of the horn antenna used in the channel measurements. The task was accomplished by direct measurements and by the regularization method, both results being in good agreement.
Authors: Aagaard Fransson, Erik Johannes | Wall-Horgen, Tobias