Continuous Fine Time Aiding to a GPS Receiver in Tracking Mode in a GSM Terminal

摘要

The requirements of personal navigation applications in mass-market cellular terminals pose formidable problems. Any solution must be robust, must supply smooth and predictable performance as the terminal moves from one environment to another, must live within the reasonable assignment of terminal resources, and must not have an unacceptable impact on the terminal's battery performance. This can be achieved only with a hybrid solution combining more than one positioning technology. In this paper, we show how EGPS - that is a combination of GPS and the Matrix network-based positioning method - can provide quasi-continuous time tracking using just the network signals to within an accuracy of about 0.125 μs over 10 s, enabling occasional GPS ranging measurements to be combined with network timing measurements to provide a solution suitable for personal navigation.