INDOOR GPS : THE NO-CHIP CHALLENGE

Abstract

This article is a continuation of the series of articles on the one- chip challenge, to make GPS receivers small enough to be integrated into wider range of devices, especially portable ones such as cell phones. With 426.5 million handsets sold in 2000 and an estimated 715 million sold each year by 2005, the U.S. government requirement for cell phones to be trackable for 911 calls could significantly increase the market for GPS receivers. A single-chip GPS, though, may not be the best solution. The author reports on a proposed architecture that uses massively parallel hardware correlators and is less reliant on a CPU to let the GPS receiver pick up weak signals while indoors and get a first fix very rapidly while outdoors. Recommendations for further reading, illustrations and sidebar on the 911 mandate are also included.