Non-Line-of-Sight localization of a controlled sound source

This paper presents a non-line-of-sight (NLoS) localization technique, which locates a controlled sound source in a known and small environment based on the time-of-arrivals (ToAs) of received signals. The proposed technique first estimates and corrects the bias error in the ToAs using a map. The technique then estimates the location of the sound source recursively by using the corrected ToAs. The strength of the proposed technique is that the positioning accuracy is not affected by any small or known obstacle. The performance of the technique is investigated by comparison with three other techniques in an experiment. The experimental results show successful localization of two different sound sources with an accuracy of 0.14-0.50 m in various background noise levels up to 75.8 dB. This demonstrates the effectiveness of the technique as a possible solution to the NLoS localization problem.