Claims
- 1. A method for re-modulating a signal comprising:
modulating a RF carrier modulated signal having a center frequency of a first frequency and time sampled at a second frequency with a repeating sample sequence of {1, −1, 1, −1, . . . } at the sample rate of the second frequency to produce a remodulated RF carrier modulated signal whose center frequency is a third frequency.
- 2. The method of claim 1 wherein said second frequency is equal to four times the first frequency resulting in the third frequency being equal to the first frequency.
- 3. The method of claim 1 further comprising:
resampling the digitized RF carrier modulated signal prior to said modulating step.
- 4. The method of claim 1 further comprising:
inverting a spectrum of the remodulated RF carrier modulated signal.
- 5. A method for re-modulating a RF carrier modulated signal comprising:
sampling an analog RF carrier modulated signal to form a digitized RF carrier modulated signal having a carrier frequency of a first frequency; modulating the digitized RF carrier modulated signal with a repeating sequence of {1, −1, 1, −1, . . . } having a sample rate of a second frequency to produce a remodulated RF carrier modulated signal; and inverting a spectrum of the remodulated RF carrier modulated signal.
- 6. The method of claim 5 wherein said remodulated RF carrier modulated signal has a carrier frequency equal to the first frequency minus one-half of the second frequency.
- 7. The method of claim 5 wherein said sampling is performed by an analog-to-digital converter.
- 8. A method for re-modulating a RF carrier modulated signal comprising:
resampling a digital RF carrier modulated signal to form a digitized RF carrier modulated signal having a carrier frequency of a first frequency; modulating the digitized RF carrier modulated signal with a repeating sequence of {1, −1, 1, −1, . . . } having a sample rate of a second frequency to produce a remodulated RF carrier modulated signal; and inverting a spectrum of the remodulated RF carrier modulated signal.
- 9. The method of claim 5 wherein said remodulated RF carrier modulated signal has a carrier frequency equal to the first frequency minus one-half of the second frequency.
- 10. Apparatus for re-modulating a signal comprising:
a modulating signal source providing a repeating digital sequence of {1, −1, 1, −1, . . . } having a sample rate of a second frequency; a digital modulator for sampling a digitized RF carrier modulated signal having a center frequency of a first frequency using the digital sequence to produce a remodulated RF carrier modulated signal whose carrier is a third frequency.
- 11. The apparatus of claim 10 wherein said second frequency is equal to four times the first frequency resulting in the third frequency being equal to the first frequency.
- 12. The apparatus of claim 10 further comprising:
a resampler for resampling the digitized RF carrier modulated signal prior to said digital modulator.
- 13. The apparatus of claim 10 further comprising:
a spectrum inverter for inverting a spectrum of the remodulated RF carrier modulated signal.
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/323,174, filed Sep. 18, 2001, which is incorporated herein by reference in its entirety.
Provisional Applications (1)
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Number |
Date |
Country |
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60323174 |
Sep 2001 |
US |