Patent ID: 8805376

Claim:
An electronic circuit for use with time of arrival signals from a network, the electronic circuit comprising: a position determination unit operable to generate a global time value and to convey a first global time from said position determination unit as an output; a first clock greater than 1 MHz, said first clock operable to be powered on and off; a second clock less than 1 MHz having cycles; and processing circuitry coupled to said first clock and to said second clock and to said position determination unit, said processing circuitry operable to: measure a time interval between the time of arrival signals relative to first clock counts and measure a time interval between cycles of said second clock relative to first clock counts; generate a number n 2 of clock counts of said first clock when said first clock is powered on and generate a number of clock counts n 3 of said second clock while said first clock is powered off; and project a relatively-accurate subsequent global time based on said first global time and using said measure and generate operations; and then return said relatively-accurate subsequent global time to said position determination unit to facilitate a subsequent position determination by said position determination unit; and wherein said processing circuitry is operable to project the relatively-accurate subsequent global time as a sum of products and ratios of time intervals and counter values representing numbers n of clock beats according to a relation t CT =t 0 +[n 1 +( n 2 /RCP 0)+ n 3 ( X RTC /RCP 0)] T cellular where t 0 is the first global time value, t CT is the relatively-accurate subsequent global time from time projection, T cellular is the time interval between the time of arrival signals, RCPO is number of first clock counts in the time interval T cellular , X RTC is number of first clock counts between cycles of said second clock, n 1 is a number of received instances of the time interval T cellular , n 2 is the number of first clock counts distinct from periods counted with n 1 , and n 3 is the number of second clock periods distinct from periods counted with n 1 and n 2 .