POSITIONING SYSTEM AND METHOD WITH STEGANOGRAPHIC ENCODED DATA STREAMS IN AUDIBLE-FREQUENCY AUDIO

摘要

System and method for location positioning with steganographic encoded data streams in audible-frequency range audio, wherein said method comprises encoding, modulating and audio-hiding two or more data streams each into a corresponding audible-frequency range steganographic audio signal; transmitting each said audio signal by a corresponding loudspeaker, wherein each said data stream includes the geographic location of the corresponding loudspeaker and a time stamp of transmission of periodic frames of the data stream or other information of interest for safety purposes. A mobile device is used for: acquiring an audio signal from the acoustic environment that includes the transmitted audio signals; separating, demodulating and decoding the data streams from the acquired audio signal; calculating the distance between the mobile device and each of the loudspeakers based on the time of flight between transmission and acquisition of each of the audio signals, the time of flight being obtained from difference between the time of acquisition and the time of transmission of each of the audio signals; estimating the geographic location of the mobile device based on the distance between the mobile device and each of the loudspeakers and on the geographic location of each of the loudspeakers.