Robust GPS Receiver for Indoor Navigation System by Utilizing Long Integration Time and Data-less Pseudolite

Taikjin Lee

Abstract:	In the future, indoor navigation techniques will be very important for seamless navigation. But it is not easy to use GPS in indoors because of indoor environments. In this situation, Pseudolite can be a solution to overcome this weaknesses of GPS or GNSS. To use GPS or pseudolite receiver in indoors, however, tracking status must be stable and receiver can track weak signal. If the integration time of I and Q for a GPS receiver was longer, as you know, then the receiver could track a weak signal and the tracking status of the GPS receiver would be more stable because the noise level of the signal would be lower in the case of white noise. Unfortunately, it is not easy to increase the I and Q integration time for general GPS signals because of the bit transition. Therefore, the integration time of general GPS receivers is 1ms. In this research, we extended the integration time of a GPS receiver for a navigation data-less pseudolite with a pure C/A code. We show that a pseudolite can work without navigation data with GPS and the integration time of a GPS receiver can be extended without any modification to the hardware and its effects. Simulations and experimental results are given as proof of the possibility of a receiver with a longer integration time for pseudolite without navigation data. This receiver could track weaker signals and make it possible for a pseudolite to transmit a weaker signal. Therefore, the tracking status would be more stable and the interference decreased.
Published in:	Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007) September 25 - 28, 2007 Fort Worth Convention Center Fort Worth, TX
Pages:	1359 - 1369
Cite this article:	Lee, Taikjin, "Robust GPS Receiver for Indoor Navigation System by Utilizing Long Integration Time and Data-less Pseudolite," Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007), Fort Worth, TX, September 2007, pp. 1359-1369.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In