Indoor Navigation Using Asynchronous Pseudolites

Indoor navigation using Global Navigation Satellite System (GNSS) signals is a challenging task which involves the solution of several problems such as signal attenuation, fading and measurements biases due to multipath propagation. A possible solution is represented by pseudolites or pseudo-satellites which have been considered for their ability to provide GNSS-like signals which could be used with minimal receiver hardware changes. In this paper, the potentialities of asynchronous pseudolites are investigated and the basic technology developed by the Japanese Aerospace Exploration Agency (JAXA) for their Indoor MEssaging System (IMES) is extended using a Received Signal Strength (RSS) approach. The final goal is to reduce the number of transmitters and increase the accuracy of the system with respect to proximity-based techniques. Asynchronous pseudolites have been implemented on Universal Software Radio Platforms (USRPs) and tested in a deep indoor environment. C/N0 measurements were obtained from the pseudolite signals and processed using a Least Squares (LS) approach. An improved algorithm was also design to take into account the quality of the different measurements. From the experiments, it emerged that three pseudolites are sufficient to enable indoor navigation in an office area of about 350 square meters with meter level accuracy. These results are particularly encouraging since they were obtained without exploiting map constraints and prior knowledge of the user position.

BORIO Daniele;  GIOIA Ciro; 

2014-08-11

Institute of Space Technology and Space Application. Universität der Bundeswehr München

JRC84685

https://publications.jrc.ec.europa.eu/repository/handle/JRC84685,