Summary: | 碩士 === 華梵大學 === 資訊管理學系碩士班 === 99 === ABSTRACT
To provide favorable mobile positioning service, quality of signal
reception for cellphone is considered to be critical. During process of
research and development by cellphone manufacturer, if they can clearly
know the location of base station and cellphone and their distance, it can be
most helpful to the improvement of cellphone function. Actually, it is
oftentimes reckoned as the key reason why cellphone product can stand out
from several brands. Nonetheless, the location of base station is hard to
collect due to the fact of commercial and confidential information of each
telecom operator. Therefore, the positioning system of base station is the
area most worthy of devotion for research.
This study has made use of robust method to conduct positioning
accuracy investigation and analysis regarding geometical positioning for
time of arrival (TOA). When permutaiton and combiantion of information
points among three cellphones are approximate to a straight line, it would
be impossible to conduct positioning. If the location of the three
information poins and r1 , r2 , r3 can be learned specifically (the distance
value from base station to cellpbone), the coordiatnes of base station can be
then accurately positioned. As indicated from experiment, when the value
of condition number is smaller it will be helpful to lower the marginal error
of MSE value for positioning base station, and the results obtained will also
run towards stability. Besides, the placement distribution of coordinates in
estimation of base station can better cluster together. This study has put
-Vforth
the fact that consideration of three factors when condition number
turns smaller, size larger, and geometric intensity strong in combination of
correponding distance domain to TA value is used to eliminate outlier
ceated during road test. As such, estimated coordinates of base station can
be converged within scope of cluster.
Within road test information of Huafan University, final convergence
of cluster scope for base station can be narrowed down to circle of diameter
in 11m,while each“convergence coordinates of base station” within circle
and the distance of average marginal error for actual base station is 200.3m
inside the circle. Within road test information of Wenshan District, final
convergence of cluster scope for base station can be narrowed down to
diameter of 13m, while each“convergence coordinates of base station”
within circle and the distance of average marginal error for actual base
station is 87.9m inside the circle. In the experiment, “percentage of
effective filtering outlier,”“clustering effect of base station coordinates at
final convergence,” and “distance of average marginal error each estimated
coordinates of each base station and actual base station within cluster
scope” have obtained favorable effect, while percentage of effective
filtering for outlier has obtained more than 98%.
Keywords:robust, TOA, outlier, arithmetic average
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