The thesis addresses the implementation of an angle of arrival estimation system
using Bluetooth Low Energy, which added an angle of arrival (AoA) estimation
feature to more accurately determine the location of devices. The angle of arrival
is estimated based on the phase differences caused by the different signal prop-
agation times to multiple antennas. We designed a circular antenna array with
12 vertical monopole antennas and RF switches to select the active antenna. We
used the combination of the designed antenna array and the MUSIC algorithm to
estimate the angle of arrival of the signal. This combination was compared with
the combination of the BOOSTXL-AOA antenna array and the trivial algorithm.
We have described the methods for (1) calculating the phase correction due to
mismatches in the carrier frequency of the receiver and transmitter (2) calculating
the phase difference using a trivial algorithm. We analyzed the influences that
add phase errors to the system. We evaluated the system with measurements in
a partially controlled environment and in a confined space. Using the algorithm
MUSIC and the designed antenna array, we were able to achieve an estimate of
the angle of arrival within 1° in a partially controlled environment. In the con-
fined space, we obtained an incorrect angle estimate for some channels due to the
effect of multipath signal propagation, which can be detected and filtered out in
simple environments. The trivial algorithm combined with the BOOSTXL-AOA
antenna array provides a rough estimate of the signal angle in a controlled envi-
ronment. Due to the large scatter of angle estimates, it is necessary to calculate
the average of several angle estimates.
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