Improving GPS/AGPS receivers

Fujitsu has introduced a new chipset to help designers develop high-sensitivity GPS/AGPS receivers. The chipset support telematics and navigation applications for mobile location, tracking and monitoring.

Fujitsu Microelectronics America (FMA) has introduced a new chipset to help designers develop high-sensitivity GPS/AGPS receivers. The chipset support telematics and navigation applications for mobile location, tracking and monitoring.

The chipset is said to achieve the industry’s highest levels of sensitivity, accuracy and Time-to-First-Fix (TTFF) with low power and a small PCB footprint. The chipset consists of a baseband chip, the MB87Q2040, which interfaces to a host CPU/MCU via an UART serial interface; and an RF front-end chip, the MB15H156, which supports GPS L-band C/A code.

Capable of operating in both “autonomous GPS/standalone” mode and “assisted GPS” mode, the chipset supports leading air interfaces, including UMTS/WCDMA, GSM/GPRS, PDC and CDMA. The chipset is also versatile: a receiver can be initially developed as an autonomous GPS receiver and subsequently upgraded through software to AGPS when assistance becomes available.

The MB87Q2040 baseband chip is said to incorporate highly optimised GPS/AGPS baseband IP that has been licensed from eRide Inc, based in San Francisco. eRide’s patented GPS/AGPS IP is based on the company’s extensive experience in the GPS market. Using power-saving techniques with the 0.11um technology results in a peak baseband power dissipation of 67mW during low signal strength acquisition, while power dissipation is less than 40mW while continuous tracking is at a 1Hz update rate.

The acquisition/tracking engine on the chip has 44,000 effective correlators, resulting in high indoor sensitivity calibrated to -157.5dBm, with indoor accuracy of less than 20m. The chipset meets FCC-E911 requirements for October 2005, and achieves fast TTFF of less than 1 second when hot and around 32 seconds when cold for outdoor fixes.

The MB87Q2040 and MB15H156 samples are now available in 7x7mm 48-pin and 5x5mm 32-pin BCC plastic packages, respectively, with pin pitch at 0.5mm, delivering a total footprint of below 100mm2. The chipset operates over the industrial temperature range of -40 to +85 degrees C.