Hybrid SADOA/TDOA mobile positioning for cellular networks

Abstract

A signal attenuation difference of arrival (SADOA) scheme is proposed to combine with the time difference of arrival (TDOA) method for mobile location estimation. On the basis of ratio of distances between the mobile and base stations derived from differences of signal attenuations, each SADOA measurement yields a circle on which the mobile may lie. Meanwhile, each TDOA measurement defines a hyperbola on which the mobile may reside. The proposed hybrid SADOA/TDOA scheme uses Taylor-series expansion to linearise the circles and hyperbolas and iteratively computes the mobile position based on least-squares estimation. Without perfect path loss modelling and hardware modification, the proposed scheme reduces location errors compared with either technique separately. Simulations demonstrate encouraging performance with 50% improvement over the conventional TDOA method in shadowing and non-line-of-sight propagation environments.

GNSS/Cellular Hybrid Positioning System for Mobile Users in Urban Scenarios

“…13(a) and (b) shows the histogram of the positioning error when 20% and 30% outlier removal thresholds, respectively, are used. Table II reports a comparison among our results and those presented in [7], [18], [21], [33], [34], and [35]. The results found in the cited works are expressed in terms of either RMS error or 90% cumulative distribution function (cdf) error.…”

Wireless sensor network using hybrid TDOA/RSS tracking of uncooperative targets

“…[15] uses only two anchor nodes for TDOA measurements to constrain the RSS solution from the other nodes to a single hyperbola. [16] is a hybrid of the signal attenuation difference of arrival (SADOA) algorithm and TDOA method, in which the equations are linearized and a least squares estimate of the location is iteratively found. This demonstrated improvement in positioning, but does not allow for measurement noise that is not Normally distributed, nor does it use temporal correlations (tracking) to improve performance.…”

Multidimensional Scaling Algorithm for Mobile Location Based on Hybrid SADOA/TOA Measurement

“…Clearly, adding more extra information is expected to yield smaller errors. Therefore, the hybrid techniques, such as hybrid SADOA/TDOA [16,17], hybrid TOA/AOA [18] and hybrid TDOA/AOA [19], have been suggested. The hybrid techniques promote location accuracy even though without increasing the number of BSs.…”