Angle of arrival estimation by using stereo ultrasonic technique for local positioning system

Abstract

Human knows the source of the sound when receiving the sound though ears, because the difference of time is received by left and right ears. The proposed system demonstrates how human's ears respond to well-known-position audio source to estimate direction and angle of arrival by measuring the Time Difference of Arrival (TDOA) by using left and right ultrasonic sensors, in the same way of stereophonic technique. The key of work is a precise TDOA detection by using a very high sampling rate, this will provide a time-delay (TimeLag) in a fraction of millisecond. All these factors, mathematical theories finally encourage a 2-dimension Cartesian coordinates result. Furthermore, the suitable adjustments such as sampling rate, bit rate, distance between sensors, ultrasonic waveform, and others increase system efficiency as well as reduce the complexity. The proposed system can be applied in a variety of applications especially the LPS that fulfill the limitation of Global Positioning System (GPS) as well.