Angle localization and orientation system with 4 receivers and based on audible sound signals

This paper presents a 2D indoor localization and orientation system based on a TDOA (Time Difference of Arrival) technique. It uses an array of receivers to implement low computational effort DOA (Direction of Arrival) algorithms. The system is implemented in the audible bandwidth (reference signal frequency is 11 kHz) with low cost microphones and speakers and its performance is compared to the same system but implemented with ultrasonic devices.