A GSM / GPS Receiver With a Bandpass Sigma-Delta Analog to Digital Converter

In traffic telematic systems (route guidance, fleet management etc.) vehicle-side terminals are required for the quasi-simultaneous reception of cellular phone (GSM) and satellite navigation (GPS). A conventional approach uses two complete receivers for these two tasks. We describe a cost-saving solution for a combined receiver which relies on the TDM structure of the GSM signal. Our solution is based on an bandpass-sigma-delta ADC for IF digitizing