Hybrid spread spectrum radio system

• US 20080019422A1
• Filed: 12/29/2006
• Published: 01/24/2008
• Est. Priority Date: 12/31/2003
• Status: Active Grant

• Current Assignee: Stephen Smith, William Dress
• Original Assignee: Stephen Smith, William Dress
• Inventors: Smith, Stephen, Dress, William
• Granted Patent: US 7,660,338 B2
• Time in Patent Office: Days
• US Class Current: 375/136
• CPC Class Codes: H04B 1/692 Hybrid techniques using combinations of two or more spread spectrum techniques
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/713 using frequency hopping

Abstract

Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies

Claims

1. A method, comprising receiving a hybrid spread spectrum signal including:

fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal,

wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

2. The method of claim 1, wherein fast frequency hopping demodulating includes frequency sweeping.

3. The method of claim 1, further comprising time hopping demodulating the direct sequence spread spectrum signal.

4. The method of claim 1, wherein demodulating the direct sequence spread spectrum signal includes increasing multipath immunity including demodulating a signal, the signal having an amplitude that has been dithered, using one or more pseudorandom control codes which are programmably related by one or more relationships selected from the groups consisting of direct subsets, rolling code segments, scrambling of code vectors and table-based reassignments of the bit-pattern relationships.

5. The method of claim 1, further comprising demodulating at least one of two identical orthogonally polarized components including detecting an amplitude.

6. An apparatus, comprising a receiver capable of receiving a hybrid spread-spectrum signal including:

a pseudo-random code generator;

a fast hopping frequency synthesizer coupled to the pseudo-random code generator;

a balanced modulator coupled to the pseudo-random code generator and the fast hopping frequency synthesizer, wherein the balanced modulator generates a direct sequence spread spectrum signal;

a balanced mixer coupled to the balanced modulator; and

a demodulator coupled to the balanced mixer,

wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

7. The apparatus of claim 6, further comprising a logic interface coupled to the fast hopping frequency synthesizer.

8. The apparatus of claim 7, wherein the logic interface includes a field-programmable gate array.

9. The apparatus of claim 6, further comprising a multipath amplitude detector coupled to the balanced mixer.

10. A method, comprising receiving a hybrid spread-spectrum signal including:

combining a first identical orthogonally polarized hybrid spread spectrum signal and a second identical orthogonally polarized hybrid spread spectrum signal to define a combined hybrid spread spectrum signal; and

frequency hopping demodulating and direct sequence demodulating the combined hybrid spread spectrum signal; and

demodulating at least one of two identical orthogonally polarized components including detecting an amplitude,

wherein the first identical orthogonally polarized hybrid spread spectrum signal and the second identical orthogonally polarized hybrid spread spectrum signal define an orthogonal polarization.

11. The method of claim 10, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

12. The method of claim 10, wherein frequency hopping demodulating includes frequency sweeping.

13. The method of claim 10, further comprising time hopping demodulating the combined hybrid spread spectrum signal.

14. The method of claim 10, wherein demodulating includes increasing multipath immunity using one or more pseudorandom control codes which are programmably related by one or more relationships selected from the groups consisting of direct subsets, rolling code segments, scrambling of code vectors and table-based reassignments of the bit-pattern relationships.

29. The method of claim 10, wherein combining includes majority-logic directed feedback.

15. An apparatus, comprising a receiver capable of receiving a hybrid spread-spectrum signal including:

a pseudo-random code generator;

a hopping frequency synthesizer coupled to the pseudo-random code generator;

a balanced modulator coupled to the pseudo-random code generator and the hopping frequency synthesizer, wherein the balanced modulator generates a direct sequence spread spectrum signal;

a first balanced mixer coupled to the balanced modulator;

a second balanced mixer coupled to the balanced modulator; and

a combiner coupled to the first balanced mixer and the second balanced mixer,

wherein the combiner detects an amplitude of at least one of two identical orthogonally polarized components that are combined via gating, weighted summing, unweighted summing or maximal-ratio combining.

16. The apparatus of claim 15, further comprising a logic interface coupled to the hopping frequency synthesizer.

17. The apparatus of claim 16, wherein the logic interface includes a field-programmable gate array.

18. The apparatus of claim 15, wherein the hopping frequency synthesizer includes a fast hopping frequency synthesizer wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

19. The apparatus of claim 15, further comprising a multipath amplitude detector coupled to the first balanced mixer and the second balanced mixer.

20. A method, comprising receiving a hybrid spread-spectrum signal including:

fast frequency hopping demodulating and time hopping demodulating a hybrid spread spectrum signal,

wherein i) frequency hopping demodulating includes utilizing a subset of bits from a pseudo-random code generator to control a fast hopping frequency synthesizer and ii) multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

21. The method of claim 20, wherein the hybrid spread spectrum signal includes a direct sequence spread spectrum signal.

22. The method of claim 20, wherein fast frequency hopping demodulating includes frequency sweeping.

23. The method of claim 20, wherein demodulating the signal includes increasing multipath immunity Including controlling a signal, the signal having an amplitude that has been dithered, using one or more pseudorandom control codes which are programmably related by one or more relationships selected from the groups consisting of direct subsets, rolling code segments, scrambling of code vectors and table-based reassignments of the bit-pattern relationships.

24. The method of claim 20, further comprising demodulating at least one of two identical orthogonally polarized components including detecting an amplitude.

25. An apparatus, comprising a receiver capable of receiving a hybrid spread-spectrum signal including:

a pseudo-random code generator;

a fast hopping frequency synthesizer coupled to the pseudo-random code generator, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies;

a master clock coupled to the pseudo-random code generator and the fast hopping frequency synthesizer;

a coincidence gate coupled to the pseudo-random code generator; and

a balanced modulator coupled to the coincidence gate, the pseudo-random code generator and the fast hopping frequency synthesizer.

26. The apparatus of claim 25, further comprising a logic interface coupled to the hopping frequency synthesizer.

27. The apparatus of claim 26, wherein the logic interface includes a field-programmable gate array.

28. The apparatus of claim 25, further comprising a multipath amplitude controller coupled to the balanced mixer.