Dual LO receiver

1. A selectable frequency source for use in a Global Positioning System (GPS) receiver, comprising

at least one reference frequency source;

a circuit, coupled to the at least one reference frequency source; and

a mixer, coupled to an output of the circuit, for mixing a GPS signal with the output of the circuit,

wherein a frequency output of the mixer is changed based on an input to the circuit and wherein the input depends upon expected interference conditions.

2. The selectable frequency source of claim 1 , wherein the circuit is coupled to a single reference frequency source.

3. The selectable frequency source of claim 2 , wherein the frequency output of the circuit is changed when the GPS receiver determines that the GPS receiver is in a predetermined geographic region.

4. The selectable frequency source of claim 3 , wherein the predetermined geographic region is determined by a presence of an interfering signal.

5. The selectable frequency source of claim 4 , wherein the interfering signal is a PDC signal.

6. The selectable frequency source of claim 3 , wherein the frequency output of the circuit is manually changed.

7. A selectable frequency source for use in a Global Positioning System (GPS) receiver, comprising:

a reference frequency source generating a reference frequency;

a circuit, coupled to the reference frequency source, the circuit having an output frequency based on the reference frequency; and

a mixer, coupled to the circuit, for mixing a GPS signal with the output frequency of the circuit,

wherein the output frequency of the circuit is changed based upon expected interference conditions to change a frequency output of the mixer.

8. The selectable frequency source of claim 7 , wherein the output frequency is changed by changing an input signal to the circuit.

9. The selectable frequency source of claim 7 , wherein the output frequency is changed when the GPS receiver determines that the GPS receiver is in a predetermined geographic region.

10. The selectable frequency source of claim 7 , wherein the predetermined geographic region is determined by a presence of an interfering signal.

11. The selectable frequency source of claim 10 , wherein the interfering signal is a PDC signal.

12. A method for changing a local oscillator frequency in a Global Positioning System (GPS) receiver, comprising:

determining the presence of a signal outside of a GPS spectra; and

setting the local oscillator frequency to a predetermined frequency based on the presence of the signal outside of the GPS spectra.

13. The method of claim 12 , wherein the signal outside of the GPS spectra is a PDC signal.

14. The method of claim 12 , wherein the signal outside of the GPS spectra is a GSM signal.