초록 ▼

A GPS receiver and a method for improving time to first fix (TTFF). The GPS receiver includes an internal clock for maintaining an approximate clock time during a standby mode and a microprocessor system including a data bit timer code, a temperature compensation code, and a learned time adjustment

A GPS receiver and a method for improving time to first fix (TTFF). The GPS receiver includes an internal clock for maintaining an approximate clock time during a standby mode and a microprocessor system including a data bit timer code, a temperature compensation code, and a learned time adjustment code. When the GPS receiver enters an operational mode, the data bit timer code instructs the microprocessor system for determining a GPS-based clock time by aligning the approximate clock time according to a time-of-arrival of a GPS data bit when the approximate clock time and the GPS-based clock time are estimated to be within a correction range of ten milliseconds. The temperature compensation code and a learned time adjustment code include instructions for using a stored frequency/temperature characteristic and a learned time correction, respectively, for estimating and compensating for time drift that has occurred during the standby mode. A temperature sensor provides a temperature measurement of a reference oscillator used as a time base for the internal clock.

대표청구항 ▼

[ What is claimed is:] [10.] A method in a global positioning system (GPS) receiver for receiving a GPS satellite signal having a GPS data bit having a time-of-arrival synchronized to a GPS-based clock time, comprising steps of:providing an internal clock time in a time clock signal from a local clo

[ What is claimed is:] [10.] A method in a global positioning system (GPS) receiver for receiving a GPS satellite signal having a GPS data bit having a time-of-arrival synchronized to a GPS-based clock time, comprising steps of:providing an internal clock time in a time clock signal from a local clock;correlating to a GPS signal representative of said GPS satellite signal for providing a correlation signal having information for said time-of-arrival of said GPS data bit; andaligning said internal clock time to GPS-based clock time by synchronizing to said time-of-arrival of said GPS data bit.