Performance of Indoor Positioning in Multipath Environments based on TDOA over OFDM-like Signals

Alessandro Neri, Roberto Capua, Massimo Massaro and Pietro Salvatori

Peer Reviewed

Abstract:	This paper deals with the performance analysis of indoor positioning systems over Orthogonal Frequency-Division Multiplexing (OFDM) like signals. The interest in Indoor positioning systems has exploded in the last few years thanks to the diffusion of smartphones and all those applications related to smart environments. The study of solutions in that field is linked to the fact that inside the buildings the classic navigation systems, that rely on GNSS, cannot be used because of the absence or the weakness of the signals themselves. However, in those environments many services that rely on Radio Frequency (RF) signals are already present for communication purposes like Wi-Fi IEEE 802.11 and UMTS Long Term Evolution (LTE), both based on OFDMlike signals. Incidentally, we noticed that the bandwidth available is about 100 MHz, making this signals appealing also for positioning purposes. Moreover, both Wi-Fi and LTE in their standards have foreseen protocols for localization scopes. The main difference between these approaches is that LTE foresees the simultaneous Time Of Arrival (TOA) estimation on the signals received, while Wi-Fi foresees a sequential procedure performing a separate TOA estimation for each signal received. We refer to the interval between the TOA estimation among two consecutives beacons as Fine Timing Measurement (FTM) delay. In this contribution, we briefly review the market perspective and the technology at the state of the art to perform positioning services in indoor contest. A simulation tool that aims to represent a reference platform for the performance assessment and algorithms verification has been developed. In this work, the simulator tool is described in details and a comparison analysis among the positioning protocols is performed by means of Monte Carlo simulations. The main parameters under study are the FTM delay and the observation noise that is assumed to be white and Gaussian distributed. The estimation error is expressed directly in the user position domain while the target is moving in the space.
Published in:	Proceedings of the ION 2017 Pacific PNT Meeting May 1 - 4, 2017 Marriott Waikiki Beach Resort & Spa Honolulu, Hawaii
Pages:	362 - 375
Cite this article:	Neri, Alessandro, Capua, Roberto, Massaro, Massimo, Salvatori, Pietro, "Performance of Indoor Positioning in Multipath Environments based on TDOA over OFDM-like Signals," Proceedings of the ION 2017 Pacific PNT Meeting, Honolulu, Hawaii, May 2017, pp. 362-375. https://doi.org/10.33012/2017.15035
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