Experimental results from an ultra-tightly coupled GPS/Galileo/WiFi/ZigBee/MEMS-IMU indoor navigation test system featuring coherent integration times of several seconds

This paper contains selected test results of an indoor positioning prototype system making use of GPS/Galileo signals on L1/E1 and L5/E5a in addition to WiFi data, ZigBee data and a MEMS-based dead reckoning algorithm called pedestrian navigation system (PNS). The system uses a partially coherent ultra-tightly coupled integration scheme. The GNSS signal processing (acquisition and tracking) supports coherent integration times up to several seconds, which reduces the squaring loss and mitigates multipath by the high Doppler selectivity of a few hertz. The system works in post processing and is intended to be an indoor analysis system allowing to get a better understanding of the indoor positioning problem and to act as a reference system. GNSS signal acquisition is demonstrated at ∼ 3 dBHz and tracking well below 0 dBHz.