文摘
This paper presents an acoustic local positioning system (ALPS) suitable for indoor positioning of portable devices such as smartphones or tablets, based on the transmission of high frequency CDMA-coded signals from a fixed network of beacons. The main novelty of the proposed ALPS is its capability to mitigate the effects of multipath propagation by performing an accurate estimation of the Line-of-Sight Time-of-Flights (LOS-TOF) through the Matching Pursuit algorithm. Signal detection, multipath cancellation and positioning estimation all take place within the portable device, which provides a graphical representation of the updated position in less than a second. The performance of the Matching Pursuit algorithm is analyzed in a real scenario and the results show that the proposed method is capable to retrieve the multipath-free System Availability under strong multipath conditions with SNR levels as low as 0 dB.