An Assisted High-Sensitivity Acquisition Technique for GPS Indoor Positioning

TitoloAn Assisted High-Sensitivity Acquisition Technique for GPS Indoor Positioning
Publication TypeConference Proceedings
Year of Publication2008
AuthorsDovis, F., R. Lesca, D. Margaria, G. Boiero, and G. Ghinamo
Conference NameIEEE/ION Position Location and Navigation Symposium (PLANS)
Date Published05/2008
Conference LocationMonterey, California, USA
AbstractThe extremely low signal-to-noise ratio experienced indoors impairs the acquisition stage of common GPS receivers, since reliable correlation peaks are hardly detected. The optimal strategy to increase the acquisition sensitivity is the extension of the coherent integration time, but the presence of data bits limits the maximum achievable performance. Noncoherent processing is typically used to improve the detection performance, but it requires a large amount of accumulations when applied to indoor signals, resulting in relevant "squaring loss". Additionally, the two strategies require high computational efforts, possibly not affordable by mass-market terminals (e.g. mobile phones). The "assisted GPS" paradigm, included for instance in 3GPP specifications for GSM/EDGE and UMTS networks, allows for both reducing the overall acquisition complexity and for increasing the acuqisition sensitivity, eventually enabling indoor GPS positioning of low-cost/low-power receivers. In this paper we describe an assisted High-Sensitivity acquisition engine for GPS signals suitable for the indoor location of mobile terminals. A low-complexity data wipe-off technique enables coherent integration times up to 2s. We finally show the results of some tests carried out with indoor signals and the results obtained with both high- and lowaccuracy local oscillators
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