Non-Line-of-Sight Time-Difference-of-Arrival Localization with Explicit Inclusion of Geometry Information in a Simple Diffraction Scenario

Time-difference-of-arrival (TDOA) localization is a technique for finding the position of a wave emitting object, e.g., a car horn. Many algorithms have been proposed for TDOA localization under line-of-sight (LOS) conditions. In the non-line-of-sight (NLOS) case the performance of these algorithms usually deteriorates. There are techniques to reduce the error introduced by the NLOS condition, which, however, do not directly take into account information on the geometry of the surroundings. In this paper a NLOS TDOA localization approach for a simple diffraction scenario is described, which includes information on the surroundings into the equation system. An experiment with three different loudspeaker positions was conducted to validate the proposed method. The localization error was less than 6.2 % of the distance from the source to the closest microphone position. Simulations show that the proposed method attains the Cramer-Rao-Lower-Bound for low enough TDOA noise levels.