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Mobile GPS chip detects faint signal levels at -162dBm

Posted: 08 Oct 2007 ?? ?Print Version ?Bookmark and Share

Keywords:low power GPS chip? AGPS? personal navigation devices? detects faint signals?

Broadcom Corp. has rolled its first single-chip GPS solution that sets new standards in performance and power consumption with state-of-the-art sensitivity and navigation performance, and less than half the power consumption of competitive solutions, said Broadcom.

GPS technologies have become increasingly important with growing consumer interest in personal navigation devices (PNDs) and the strong desire by cellular service operators to add location-based services to their offerings. According to In-Stat, about 47 million PNDs and over 436 million mobile phones with GPS technology will ship in 2010. As GPS chip solutions become more integrated and costs decline, the technology will expand into new applications.

"As consumer use of location-based services grows, we are seeing an incredible amount of interest from our customers in the cellular and PND markets for GPS and assisted GPS technologies," said Scott Pomerantz, vice president and general manager of Broadcom's GPS line of business. "Broadcom has now established itself as a technology leader in the GPS chip market with a solution that provides the industry's best tracking sensitivity, lowest average power and most complete portfolio of software, complemented by the company's unique ability to integrate its GPS technology into other leading mobile chips and processors."

Smart solution
The BCM4750 is produced in a low cost 90nm CMOS process and features superior receiver technology and tracking sensitivity. The receiver makes full use of the Global Locate architecture, and can measure the faintest GPS signals deep indoors and in "urban canyon" environments at signal levels as low as -162dBm. It also consumes less than 15mW while navigating with 1s map updates, less than half the power of competitive solutions based on published datasheets.

The BCM4750 is well suited for PNDs where rapid time-to-first-fix (TTFF) and superior navigation performance are required. In addition, products that include network connectivity, such as wireless PNDs and cellphones, are able to exploit the full feature set of the BCM4750 software solution. These features include Assisted GPS (AGPS) and long-term orbit (LTO) extended ephemeris assistance, reducing TTFF to less than one second in many conditions. In all cases, Broadcom provides both the chip and the software including AGPS stacks and client software.

Broadcom said it also maintains a reference network with land-based GPS receivers, and carrier hardened servers to collect and provide AGPS and LTO data directly to GPS-equipped cellphones and wireless PNDs. Working with the BCM4750 and Broadcom's client software, customer products can benefit from AGPS and LTO.

Product details
The BCM4750 is a single-die CMOS GPS receiver used for tracking and navigation, primarily in mobile devices. Its massive parallel hardware correlators provide faster signal searches, accurate real-time navigation, improved tracking sensitivity and very low average power consumption. With tracking sensitivity of -162dBm, the BCM4750 sets a new benchmark for the industry.

Enhanced tracking sensitivity allows GPS-enabled mobile devices to detect very weak signals including those partially blocked or reflected by buildings or other structures. In these environments, GPS units sometimes fail to achieve a location "fix" or take a long time to do so. With the high sensitivity of the new BCM4750 GPS receiver chip, these initial location fixes occur much faster and in many cases, the BCM4750 can get a fix where competitors' products do not get a fix at all. The BCM4750 also integrates a number of external components, resulting in a very small footprint to design GPS into mobile devices. A complete GPS solution featuring the BCM4750 will use less than 35mm? of board space, including all of the necessary components for a typical cellphone implementation.

The BCM4750 includes software that is optimized for cellular integration and the demands of international standards bodiessuch as 3GPP and SUPLthat promote high speed data in cellular systems. The software includes message handling protocols for user and control plane-assisted GPS standards, and native support for LTO extended ephemeris service. The software has also been optimized for personal navigation performance and includes sophisticated algorithms to mitigate multipath errors.

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