Method and System for Controlling a Communications Carrier's Power Spectral Density (PSD) Using Spread Spectrum for Matched Spectral Allocation

• US 20120156986A1
• Filed: 02/28/2012
• Published: 06/21/2012
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: Comtech Satellite Network Technologies, Inc. (Comtech Telecommunications Corporation)
• Original Assignee: Comtech EF Data (Comtech Telecommunications Corporation)
• Inventors: Mamaril, Cris M., Beeler, Michael, Davis, Wallace
• Granted Patent: US 9,178,605 B2
• Time in Patent Office: Days
• US Class Current: 455/9
• CPC Class Codes: H04B 7/0678 using different spreading codes between antennas code allocation H04J13/16
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 76/20 Manipulation of established connections

Abstract

A method of reducing adjacent satellite interference, the method comprising monitoring, by a processor, a power spectral density (PSD) of a signal transmitted by a remote transmitter, determining, by the processor, that the PSD of the signal transmitted by the remote transmitter is above a predetermined level, and reducing the PSD of the signal transmitted by the remote transmitter by adjusting at least one of a spread spectrum spreading factor, a power level, a modulation factor, and a forward error correction (FEC) rate using a modulator while maintaining a constant spectral allocation and center frequency of the signal.

Claims

1. A method of reducing adjacent satellite interference, the method comprising:

monitoring, by a processor, a power spectral density (PSD) of a signal transmitted by a remote transmitter;

determining, by the processor, that the PSD of the signal transmitted by the remote transmitter is above a predetermined level; and

reducing the PSD of the signal transmitted by the remote transmitter by adjusting at least one of a spread spectrum spreading factor, a power level, a modulation factor, and a forward error correction (FEC) rate using a modulator while maintaining a constant spectral allocation and center frequency of the signal.

2. The method of claim 1, further comprising maintaining a communications link between the remote transmitter and a remote receiver while reducing the PSD of the signal.

3. The method of claim 2, further comprising applying one or more predetermined timing parameters by the modulator when more than one of the spread spectrum spreading factor, the power level, the modulation factor, and the forward error correction (FEC) rate are adjusted.

4. The method of claim 1, further comprising interrupting a communications link between the remote transmitter and a remote receiver while reducing the PSD of the signal.

5. The method of claim 1, wherein the PSD of the signal is reduced by adjusting only the modulation factor while maintaining a constant spectral allocation and center frequency of the signal.

6. The method of claim 1, wherein the PSD of the signal is reduced by adjusting only the FEC rate while maintaining a constant spectral allocation and center frequency of the signal.

7. The method of claim 1, wherein the PSD of the signal is reduced by adjusting only the power level while maintaining a constant spectral allocation and center frequency of the signal.

8. The method of claim 1, wherein the signal transmitted by the remote transmitter is a non-spread waveform.

9. The method of claim 8, further comprising transitioning the non-spread waveform to a spread waveform wherein the non-spread waveform and the spread waveform have a same spectral allocation.

10. The method of claim 9, wherein the PSD of the signal is reduced by adjusting only the modulation factor while maintaining a constant spectral allocation and center frequency of the signal.

11. The method of claim 9, wherein the PSD of the signal is reduced by adjusting only the FEC rate while maintaining a constant spectral allocation and center frequency of the signal.

12. The method of claim 9, wherein the PSD of the signal is reduced by adjusting only the power level while maintaining a constant spectral allocation and center frequency of the signal.

13. The method of claim 9, further comprising applying a spread factor of a type 2̂

N while transitioning the non-spread waveform to a spread waveform.

14. The method of claim 9, further comprising applying an integer spreading spread factor while transitioning the non-spread waveform to a spread waveform.

15. The method of claim 9, further comprising applying a fractional spreading spread factor while transitioning the non-spread waveform to a spread waveform.

16. A system for reducing adjacent satellite interference, the system comprising:

a remote transmitter configured to transmit a signal to a remote receiver;

a processor configured to;

monitor a power spectral density (PSD) of the signal transmitted by the remote transmitter; and

determine that the PSD of the signal transmitted by the remote transmitter is above a predetermined level; and

a modulator configured to reduce the PSD of the signal transmitted by the remote transmitter by adjusting at least one of a spread spectrum spreading factor, a power level, a modulation factor, and a forward error correction (FEC) rate while maintaining a constant spectral allocation and center frequency of the signal.

17. The system of claim 16, wherein the modulator is further configured to maintain a communications link between the remote transmitter and the remote receiver while reducing the PSD of the signal.

18. The system of claim 17, wherein the modulator is further configured to apply one or more predetermined timing parameters by the modulator when more than one of the spread spectrum spreading factor, the power level, the modulation factor, and the forward error correction (FEC) rate are adjusted.

19. The system of claim 16, wherein the modulator is further configured to interrupt a communications link between the remote transmitter and a remote receiver while reducing the PSD of the signal.

20. The system of claim 16, wherein the modulator is further configured to reduce the PSD of the signal is by adjusting only the modulation factor while maintaining a constant spectral allocation and center frequency of the signal.

21. The system of claim 16, wherein the modulator is further configured to reduce the PSD of the signal by adjusting only the FEC rate while maintaining a constant spectral allocation and center frequency of the signal.

22. The system of claim 16, wherein the modulator is further configured to reduce the PSD of the signal by adjusting only the power level while maintaining a constant spectral allocation and center frequency of the signal.

23. The system of claim 16, wherein the signal transmitted by the remote transmitter is a non-spread waveform.

24. The system of claim 23, wherein the modulator is further configured to transition the non-spread waveform to a spread waveform wherein the non-spread waveform and the spread waveform have a same spectral allocation.

25. The system of claim 24, wherein the modulator is further configured to reduce the PSD of the signal by adjusting only the modulation factor while maintaining a constant spectral allocation and center frequency of the signal.

26. The system of claim 24, wherein the modulator is further configured to reduce the PSD of the signal by adjusting only the FEC rate while maintaining a constant spectral allocation and center frequency of the signal.

27. The system of claim 24, wherein the modulator is further configured to reduce the PSD of the signal by adjusting only the power level while maintaining a constant spectral allocation and center frequency of the signal.

28. The system of claim 24, wherein the modulator is further configured to apply a spread factor of a type 2̂

N while transitioning the non-spread waveform to a spread waveform.

29. The system of claim 24, wherein the modulator is further configured to apply an integer spreading spread factor while transitioning the non-spread waveform to a spread waveform.

30. The system of claim 24, wherein the modulator is further configured to apply a fractional spreading spread factor while transitioning the non-spread waveform to a spread waveform.