System for generating constant envelope simultaneous data and ranging waveform with anti-jam properties

1. A system for combining a plurality of signals to form a constant-envelope composite signal, comprising:

a complex binary offset carrier (BOC) modulator configured to perform BOC modulation on a first signal to generate first and second complex BOC signals;

a real BOC modulator configured to perform BOC modulation on a second signal to generate a real BOC signal; and

an interplex modulator configured to combine the first and second complex BOC signals and the real BOC signal via interplex modulation to form a constant-envelope composite signal, wherein the first and second signals are components of the constant-envelope composite signal.

2. The system of claim 1 , wherein power levels of the first and second signals are independently controllable via the interplex modulator.

3. The system of claim 1 , wherein data rates of the first and second signals are independently controllable via the complex and real BOC modulators.

4. The system of claim 1 , wherein bandwidths of the first and second signals are independently controllable via the complex and real BOC modulators.

5. The system claim 1 , wherein the system generates the constant-envelope composite signal as a multi-carrier constant-envelope signal.

6. The system of claim 1 , wherein the first signal is a data signal and the second signal is a ranging signal.

7. The system of claim 1 , wherein a transmission band of the constant-envelope composite signal includes a center portion and edge portions, wherein a carrier frequency in the center portion is modulated with the first signal and carrier frequencies in the edge portions are modulated with the second signal.

8. The system of claim 1 , wherein the complex BOC modulator is configured to modify a sub-carrier frequency such that the first signal is a frequency-agile signal within the constant-envelope composite signal.

9. The system of claim 1 , wherein the system comprises satellites and the constant envelope composite signal is a satellite crosslink signal for point-to-point transmission between the satellites.

10. The system of claim 9 , wherein the satellites communicate in a full duplex mode with constant-envelope composite signals that simultaneously carry data and ranging signals.

11. A modem, comprising:

a transmitter including: a complex binary offset carrier (BOC) modulator configured to modulate a first BOC sub-carrier with a first transmit signal to generate first and second complex BOC signals; a real BOC modulator configured to modulate a second BOC sub-carrier with a second transmit signal to generate a real BOC signal; and an interplex modulator configured to combine the first and second complex BOC signals and the real BOC signal to form a constant-envelope composite transmit signal including the first and second transmit signals at different frequencies; and

a receiver configured to receive a constant-envelope composite receive signal including first and second receive signals at different frequencies within a transmission band of the constant-envelope composite receive signal.

12. The modem of claim 11 , wherein the first BOC sub-carrier of the complex BOC modulator results in the first transmit signal modulating a carrier signal in a center portion of a transmission band of the constant-envelope composite transmit signal and the second BOC sub-carrier of the real second BOC modulator results in the second transmit signal modulating a carrier signal in an edge portion of the transmission band of the constant-envelope composite transmit signal.

13. The modem of claim 11 , wherein the power levels, data rates, and bandwidths of the first and second transmit signals are independently controllable by the modem.

14. The modem of claim 11 , wherein the complex BOC modulator is configured to modify the first BOC sub-carrier such that the first transmit signal is a frequency-agile signal within the constant-envelope composite transmit signal.

15. A system, comprising:

a first modem according to the modem of claim 11 ; and

a second modem according to the modem of claim 11 , wherein the first and second modems communicate in a full duplex mode in which first and second signals are simultaneously transmitted and received via constant-envelope composite signals.

16. The system of claim 15 , wherein the first signal is a data signal and the second signal is a ranging signal.

17. A method of combining a plurality of signals to form a constant-envelope composite signal, the method comprising:

performing complex binary offset carrier (BOC) modulation on a first signal, using a complex BOC modulator, to produce first and second complex BOC signals;

performing real BOC modulation on a second signal, using a real BOC modulator, to produce a real BOC signal; and

combining the first and second complex BOC signals and the real BOC signal via interplex modulation, using an interplex modulator, to form a constant-envelope composite signal containing the first and second signals.

18. The method of claim 17 , further comprising:

independently controlling power levels of the first and second signals.

19. The method of claim 17 , further comprising:

independently controlling data rates of the first and second signals.

20. The method of claim 17 , further comprising:

independently controlling bandwidths of the first and second signals.

21. The method of claim 17 , wherein the first signal is a data signal and the second signal is a ranging signal.

22. The method of claim 17 , wherein the constant-envelope composite signal is generated such that a carrier frequency in a center portion of a transmission band of the constant-envelope composite signal is modulated with the first signal and carrier frequencies in edge portions of the transmission band of the constant-envelope composite signal are modulated with the second signal.

23. The method of claim 17 , wherein the constant-envelope composite signal is generated such that the first signal is a frequency-agile signal within the constant-envelope composite signal.