Commack, NY — Anticipating that by 2011 30 percent of cellphones will have GPS capability and 70 percent will have Bluetooth, Texas Instruments is using this week's CTIA wireless conference as the launchpad for the NaviLink 6.0, the first chip to integrate assisted GPS, Bluetooth 2.1 and ultra low-power technologies (ex-Wibree), as well as FM receive and transmit capability.
The 65-nm chip, designated the NL5500, is the latest instantiation of TI's Digital RF Processing (DRP), a technology intended to enable the low-cost, low-power integration of multiple radios in a single chip when the attach rates for those radios gets to a certain level. With IMS Research now putting that number at 30 percent, TI has clearly decided now's the time for the inclusion of A-GPS.
“GPS is breaking out of the E911 market with the arrival of Google maps [and other location-based applications],” said Amir Faintuch, director of business marketing and product management for TI's Mobile Connectivity Solutions division. (See: Cellphones get the call for personal navigation.)
To meet the increasing demand and the integration requirements therein, TI is taking the same Bluetooth 2.1/ULP/FM technology from its WiLink6.0 1271/3 and BlueLink7.0 BL6450 chips and integrating that with the A-GPS function of its NaviLink 5.0 (NL5350) chip to create the single-chip implementation.
GPS integration issues
According to Faintuch, the time to first fix (TTFF) at -155dBm is approximately 10 seconds which he compares favorably with other typical GPS solutions. In open sky conditions the NL5500 can obtain a fix in under 1 second. Given such low sensitivity levels, interference among the co-located radios are real issues. For more on this problem, see “Design considerations when integrating GPS into a cell phone”. However, Faintuch said that those issues were addressed using time- and spectrum-deviation techniques. To further improve A-GPS performance, Faintuch said the designers also added more acquisition and tracking channels.
All told, Faintuch said the chip reduces board space by 40 percent, power by 50 percent and is suited to handsets priced in the $70 to $100 range. Handsets with the chip are expected by the second half of 2009. So armed, consumers can simultaneously perform navigation, have a conversation using a Bluetooth headset and transmit an MP3 file to the car radio using the FM transmit capability.
Cellphones get the call for personal navigation
Design considerations when integrating GPS into a cell phone
Reduce interference in GPS-enabled applications
Designing for a dual Galileo-based GPS system