A New Positioning Scheme Exploiting RSS Difference of Arrival in Indoor Environments

Three basic properties of radio signal, such as received signal strength (RSS), time of flight, and angle of arrival, are commonly used in estimation of distance for positioning of a target. Among them, the positioning technique based on RSS attracts much more interests of researchers due to its high feasibility in realization. However, the performance of the conventional positioning scheme based on RSS is significantly degraded than that of TOA or fingerprinting scheme because of error components from multipath and shadowing effects. In this paper, the RSS-based positioning scheme, which defines RSS difference of arrival (RDOA) likewise time difference of arrival (TDOA) to mitigate error components, is proposed and its performance of position estimation is experimentally analyzed in indoor environments. The performance of the proposed RDOA scheme is compared with that of conventional scheme likewise TOA scheme with respect to the fixed AP selection case, the base AP changing case, and the adaptive AP selection case, respectively. According to the experiment results, it is shown that a high accuracy in position estimation also can be achieved with the RDOA scheme compared to the conventional scheme likewise TOA, while the RDOA scheme can provide less standard deviation than the conventional scheme.