Spread spectrum applications of universal frequency translation

• US 7,599,421 B2
• Filed: 04/17/2006
• Issued: 10/06/2009
• Est. Priority Date: 03/15/1999
• Status: Expired due to Fees

• Current Assignee: ParkerVision, Inc.
• Original Assignee: ParkerVision, Inc.
• Inventors: Hamilla, Joseph M., Clements, Charles D., Silver, Gregory S., Cook, Robert W., Rawlins, Gregory S., Bultman, Michael J., Sorrells, David F., Moses, Charley D. Jr., Looke, Richard C., Rawlins, Michael W.
• Primary Examiner(s): Odom; Curtis B
• Application Number:
  US11/404,957
• Publication Number:
  US 20060280231A1
• Time in Patent Office: 1,268 Days
• Field of Search: 375/130, 375/136, 375/137, 375/142, 375/145, 375/147, 375/149
• US Class Current: 375/147
• CPC Class Codes: H03D 7/00 Transference of modulation from one carrier to another, e.g. frequency-changing H03D9/00, H03D11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as a frequency-changers H03F
• CPC Class Codes: H04B 1/707 using direct sequence modulation

Abstract

Frequency translation and spread spectrum applications of same are described herein. Such applications include, but are not limited to, unified down-conversion and de-spreading, unified up-conversion and spreading, RAKE receivers utilizing unified down-conversion and de-spreading, and Early/Late receivers utilizing unified down-conversion and de-spreading, and combinations and applications of same. Additionally, applications are included for limiting spectral growth during unified up-conversion and spreading of a baseband signal.

Claims

1. A system for down-converting and de-spreading a spread spectrum signal, comprising:

a first module configured to generate a spreading code corresponding to the spread spectrum signal;

a second module configured to generate a control signal that comprises said spreading code; and

a third module configured to sample said spread spectrum signal and store said samples, said third module controlled at least in part by said control signal, so as to down-convert and de-spread said spread spectrum signal to obtain a de-spread baseband signal;

wherein said third module comprises a storage device coupled to a switch to store said samples, wherein successive samples form said de-spread baseband signal; and

wherein said storage device integrates energy over multiple half-cycles of said spread spectrum signal as a function of said control signal.

2. The system of claim 1, further comprising a fourth module configured to generate an oscillating signal.

3. The system of claim 2, further comprising a fifth module configured to modulate the oscillating signal with the spreading code to generate a spread oscillating signal.

4. The system of claim 3, further comprising a sixth module configured to convert said spread oscillating signal into said control signal that comprises a plurality of pulses.

5. The system of claim 4, wherein a pulse width of a pulse of said control signal is non-negligible.

6. The system of claim 4, wherein a pulse width of a pulse of said control signal is negligible.

7. The system of claim 4, wherein a pulse width of a pulse of said control signal is any fraction of a center frequency of a baseband of said spread spectrum signal.

8. The system of claim 4, wherein a frequency of said control signal is based at least in part on a frequency of said spread oscillating signal.

9. The system of claim 1, wherein said control signal is a harmonic or sub-harmonic of said spread spectrum signal.

10. The system of claim 1, wherein said third module comprises a switch controlled by said control signal to under-sample the spread spectrum signal, resulting in under-samples.

11. The system of claim 10, wherein said switch is a transistor.

12. The system of claim 1, wherein said storage device is a capacitor.

13. The system of claim 1, wherein a center frequency of said control signal is approximately equal to a center frequency of said spread spectrum signal.

14. The system of claim 1, wherein a center frequency of said control signal is above a baseband frequency of said spread spectrum signal.

15. The system of claim 1, wherein sampling comprises transferring charge from said spread spectrum signal.

16. The system of claim 1, wherein the spread spectrum signal is directly down-converted and de-spread to obtain a de-spread baseband signal.

17. The system of claim 16, wherein directly down-converting said spread spectrum signal to a de-spread baseband signal eliminates use of front-end mixers, front-end radio frequency amplification circuitry and intermediate frequency conversion circuitry.

18. A system to down-convert and de-spread a spread spectrum signal, comprising:

a first circuit configured to modulate an oscillating signal based on a spreading code, and to generate a control signal that comprises a plurality of pulses; and

a second circuit configured to transfer charge from said spread spectrum signal and integrate said charge over multiple cycles of said spread spectrum signal as a function of said control signal;

wherein the second circuit comprises a switch controlled by said control signal to under-sample the spread spectrum signal, resulting in under-samples.

19. The system of claim 18, wherein a frequency of said control signal is a harmonic or sub-harmonic of said spread spectrum signal.

20. The system of claim 18, further comprising a third circuit for generating an oscillating signal.

21. The system of claim 18, wherein a frequency of said control signal is based at least in part on a frequency of said oscillating signal.

22. The system of claim 18, wherein said control signal is a harmonic or sub-harmonic of said spread spectrum signal.

23. The system of claim 18, wherein said switch is a transistor.

24. The system of claim 18, wherein a center frequency of said control signal is approximately equal to a center frequency of said spread spectrum signal.

25. The system of claim 18, wherein a center frequency of said control signal is above a baseband frequency of said spread spectrum signal.

26. The system of claim 18, wherein the spread spectrum signal is directly down-converted and de-spread to obtain a de-spread baseband signal.

27. The system of claim 26, wherein directly down-converting said spread spectrum signal to a de-spread baseband signal eliminates use of front-end mixers, front-end radio frequency amplification circuitry and intermediate frequency conversion circuitry.

28. A system to down-convert and de-spread a spread spectrum signal, comprising:

a first circuit configured to modulate an oscillating signal based on a spreading code, and to generate a control signal that comprises a plurality of pulses; and

a second circuit configured to transfer charge from said spread spectrum signal and integrate said charge over multiple cycles of said spread spectrum signal as a function of said control signal;

wherein the second circuit further comprises a storage device coupled to a switch to store said charge, wherein successive samples of said charge form said de-spread baseband signal.

29. The system of claim 28, wherein said storage device is a capacitor.