Signal acquisition systems with applications of general clocks

1. A signal acquisition system comprising:

a clock module for providing a plurality of counter values at a plurality of time points; and

a system module coupled to said clock module, and said system module being capable of

obtaining a plurality of time values for said time points according to a plurality of signals from a signal source,

establishing each equation of a plurality of equations using a respective time value of said time values and a respective counter value of said counter values,

calculating a plurality of parameters based on said equations, and

determining an estimated time value using said parameters and a present counter value from said clock module.

2. The signal acquisition system as claimed in claim 1 , wherein said signal source comprises at least one satellite.

3. The signal acquisition system as claimed in claim 1 , wherein said plurality of signals comprise a global positioning system (GPS) signal.

4. The signal acquisition system as claimed in claim 1 , wherein said system module comprises a control unit for calculating a time value of said time values according to a navigation message.

5. The signal acquisition system as claimed in claim 4 , wherein said system module further comprises a signal process engine for demodulating a global positioning system (GPS) signal into said navigation message.

6. The signal acquisition system as claimed in claim 1 , wherein said parameters determine a relation function between a time value of said time values and a corresponding counter value of said counter values.

7. The signal acquisition system as claimed in claim 6 , wherein said relation function is a polynomial equation

T

⁡

(

C

)

=

∑

k

=

0

n

⁢

A

k

×

C

k

,

wherein C represents a counter value provided by said clock module at a selected time point, T(C) represents a time value for said selected time point, A K represents a parameter of said parameters, and n represents a finite positive integer.

8. The signal acquisition system as claimed in claim 1 , wherein said system module comprises a control unit or determining a boundary of a data bit in a present signal based on said estimated time value.

9. A method for acquiring a present signal comprising:

providing a plurality of counter values by a counter at a plurality of time points;

obtaining a plurality of time values for said time points according to a plurality of acquired signals;

establishing each equation of a plurality of equations using a respective time value of said time values and a respective counter value of said counter values;

calculating a plurality of parameters by a system module based on said equations; and

determining an estimated time value using said parameters and a present counter value from said counter.

10. The method as claimed in claim 9 , further comprising:

demodulating a global positioning system (GPS) signal into a navigation message; and

calculating a time value of said time values according to said navigation message.

11. The method as claimed in claim 9 , further comprising:

determining a relation function between a time value of said time values and a corresponding counter value of said counter values by said parameters.

12. The method as claimed in claim 9 , wherein said present signal is a global positioning system (GPS) signal.

13. The method as claimed in claim 9 , further comprising:

determining a boundary of a data bit in said present signal based on said estimated time value.

14. A signal acquisition system comprising:

a signal receiver for receiving a plurality of signals;

a system module coupled to said signal receiver, said system module being capable of

obtaining a plurality of time values based on said plurality of signals,

establishing each equation of a plurality of equations using a respective time value of said time values and a respective counter value of a plurality of counter values associated with said time values,

calculating a plurality of parameters based on said equations, and

acquiring a present signal received by said signal receiver based on said parameters and a present counter value; and

a counter coupled to said system module and for providing said plurality of counter values and said present counter value.

15. The signal acquisition system as claimed in claim 14 , wherein said system module comprises a control unit for calculating a time value of said time values according to a navigation message.

16. The signal acquisition system as claimed in claim 15 , wherein said system module further comprises a signal process engine for demodulating a global positioning system (GPS) signal into said navigation message.

17. The signal acquisition system as claimed in claim 14 , wherein said parameters determine a relation function between a counter value of said counter values and a corresponding time value of said time values.

18. The signal acquisition system as claimed in claim 17 , wherein said relation function is a polynomial equation

T

⁡

(

C

)

=

∑

k

=

0

n

⁢

A

k

×

C

k

,

wherein C represents a counter value provided by said clock module at a selected time point, T(C) represents a time value for said selected time point, A K represents a parameter of said parameters, and n represents a finite positive integer.

19. The signal acquisition system as claimed in claim 14 , wherein said present signal is a global positioning system (GPS) signal.

20. The signal acquisition system as claimed in claim 14 , wherein said system module comprises a control unit for calculating an estimated time value according to said parameters and said present counter value.

21. The signal acquisition system as claimed in claim 20 , wherein said system module determines a boundary of a data bit in said present signal based on said estimated time value.

22. The signal acquisition system as claimed in claim 7 , wherein said system module is capable of reducing error in said estimated time value by increasing said finite positive integer in said polynomial equation.