SYSTEMS AND METHODS FOR COMBINING SIGNALS FROM MULTIPLE ACTIVE WIRELESS RECEIVERS

• US 20120082072A1
• Filed: 09/28/2011
• Published: 04/05/2012
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Aviat U.S., Inc. (Aviat Networks Incorporated)
• Original Assignee: Aviat U.S., Inc. (Aviat Networks Incorporated)
• Inventors: SHEN, Ying
• Granted Patent: US 8,570,920 B2
• Time in Patent Office: Days
• US Class Current: 370/297
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04L 27/0002 analog front ends; means for connecting modulators, demodulators or transceivers to a transmission line duplex arrangements H04L5/143
• CPC Class Codes: H04L 27/22 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/2334 using filters

Abstract

Systems and methods for combining signals from multiple active wireless receivers are discussed herein. An exemplary system comprises a first downconverter, a phase comparator, a phase adjuster, and a second downconverter. The first downconverter may be configured to downconvert a received signal from a first antenna to an intermediate frequency to create an intermediate frequency signal. The phase comparator may be configured to mix the received signal and a downconverted signal to create a mixed signal, compare a phase of the mixed signal to a predetermined phase, and generate a phase control signal based on the comparison, the downconverted signal being associated with the received signal from the first antenna. The phase adjuster may be configured to alter the phase of the intermediate frequency signal based on the phase control signal. The second downconverter may be configured to downconvert the phase-shifted intermediate frequency signal to create an output signal.

Claims

1. A system, comprising:

a first receiving radio frequency unit comprising;

a first downconverter configured to downconvert a received signal from a first antenna to an intermediate frequency to create an intermediate frequency signal;

a phase comparator configured to mix the received signal and a oscillating signal from the first downconverter to create a mixed signal, compare a phase of the mixed signal to a predetermined phase, and generate a phase control signal based on the comparison;

a phase adjuster configured to alter the phase of the intermediate frequency signal based on the phase control signal from the phase comparator; and

a second downconverter configured to downconvert the phase-shifted intermediate frequency signal to create an output signal.

2. The system of claim 1, wherein the downconverted signal comprises the intermediate frequency signal.

3. The system of claim 1, wherein the received signal is received from a diplexer which is coupled to the first antenna.

4. The system of claim 3, wherein the received signal is filtered with a low noise amplifier after being provided from the diplexer.

5. The system of claim 1, wherein the first downconverter is configured to mix a filtered oscillator signal with the received signal to create the intermediate frequency signal.

6. The system of claim 1, further comprising comparing a gain to a predetermined gain value and adjusting the gain of the downconverted phase-shifted intermediate frequency signal based on the comparison.

7. The system of claim 1, further comprising a second radio frequency unit configured to receive the received signal from a second antenna, the second radio frequency unit configured to alter a phase of the received signal from the second antenna to a phase that is substantially similar to the altered phase of the intermediate frequency signal of the first radio frequency unit.

8. The system of claim 7, wherein the second radio frequency unit is configured to adjust a gain of an output signal, the gain of the output signal of the second radio frequency unit being substantially similar to the gain of the output signal of the first radio frequency unit.

9. The system of claim 7, further comprising a signal combiner configured to combine the output signal from the first radio frequency unit and the output signal from the second radio frequency unit.

10. The system of claim 7, further comprising:

a postdistortion module configured to add distortion to the output signal; and

a demodulator configured to receive the output signal from the postdistortion module and provide in-phase (I) and quadrature (Q) signals.

11. The system of claim 1, further comprising a waveguide configured to receive the received signal from the first antenna and provide the received signal to the first downconverter.

12. The system of claim 11, wherein the first antenna is part of a point-to-point microwave communication system.

13. A system comprising:

a first receiving radio frequency unit configured to compare a phase of a received signal from a first antenna to a predetermined phase value, and to adjust the phase of the received signal from the first antenna to generate a first phase-adjusted signal;

a second receiving radio frequency unit configured to compare a phase of a received signal from a second antenna to the predetermined phase value, and to adjust the phase of the received signal from the second antenna to generate a second phase-adjusted signal; and

a signal combiner configured to combine the first and second phase-adjusted signals, the phase of the first and second phase-adjusted signals being substantially similar.

14. The system of claim 13, wherein the first receiving radio frequency unit is configured to downconvert the received signal from the first antenna to generate a first downconverted signal and the second radio frequency unit is configured to downconvert the received signal from the second antenna to generate a second downconverted signal.

15. The system of claim 14, wherein the first receiving radio frequency unit configured to compare a phase of the received signal from the first antenna of the first receiving radio frequency unit comprises the first receiving radio frequency unit configured to mix the received signal with an oscillator signal from the first downconverter and to compare the phase of the mixed signal to the predetermined phase value.

16. The system of claim 15, wherein the first receiving radio frequency unit configured to adjust the phase of the received signal from the first antenna comprises the first receiving radio frequency unit configured to adjust the phase of the downconverted signal based on the comparison.

17. The system of claim 15, wherein the first downconverted signal comprises an intermediate frequency signal.

18. The system of claim 15, wherein the first radio frequency unit is further configured to downconvert the first phase-adjusted downconverted signal to generate a first output signal.

19. The system of claim 18, wherein the second receiving radio frequency unit configured to compare a phase of the received signal from the second antenna of the second receiving radio frequency unit comprises the second receiving radio frequency unit configured to mix the received signal with the second downconverted signal and to compare the phase of the mixed signal to the predetermined phase value.

20. The system of claim 19, wherein the second receiving radio frequency unit configured to adjust the phase of the received signal from the second antenna comprises the second receiving radio frequency unit configured to adjust the phase of the downconverted signal based on the comparison.

21. The system of claim 20, wherein the second radio frequency unit is further configured to downconvert the second phase-adjusted downconverted signal to generate a second output signal.

22. The system of claim 21, wherein the signal combiner configured to combine the first and second phase-adjusted signals comprises the signal combiner configured to combine the first and second output signals.

23. The system of claim 13, wherein the first and second receiving radio frequency units further comprise a first and second waveguide, respectively, the first and second waveguides configured to receive the received signal from the first and second antenna, respectively, prior to comparison of the received signals to the predetermined phase value.

24. The system of claim 23, wherein the first and second antenna are part of a point-to-point microwave communication system.

25. A method comprising:

comparing, by a first receiving radio frequency unit, a phase of a received signal from a first antenna to a predetermined phase value;

adjusting, by the first receiving radio frequency unit, the phase of the received signal from the first antenna to generate a first phase-adjusted signal;

comparing, by a second receiving radio frequency unit, a phase of a received signal from a second antenna to the predetermined phase value

adjusting, by the second receiving radio frequency unit the phase of the received signal from the second antenna to generate a second phase-adjusted signal; and

combining the first and second phase-adjusted signals, the phase of the first and second phase-adjusted signals being substantially similar.

26. The method of claim 25, further comprising downconverting, by the first receiving radio frequency unit, the received signal from the first antenna to generate a first downconverted signal and downconverting, by the second receiving radio frequency unit, the received signal from the second antenna to generate a second downconverted signal.

27. The method of claim 26, wherein comparing, by the first receiving radio frequency unit, the phase of the received signal from the first antenna, comprises mixing, by the first receiving radio frequency unit, the received signal with an oscillator signal, the oscillator signal also being mixed with the received signal to provide the first downconverted signal, and comparing, by the first receiving radio frequency unit, the phase of the mixed signal to the predetermined phase value.

28. The method of claim 27, wherein adjusting, the first receiving radio frequency, the phase of the received signal from the first antenna comprises adjusting, by the first receiving radio frequency unit, the phase of the downconverted signal based on the comparison.

29. The method of claim 27, further comprising downconverting, by the first radio frequency unit, the first phase-adjusted downconverted signal to generate a first output signal.

30. The method of claim 29, wherein comparing, by the second receiving radio frequency unit, the phase of the received signal from the second antenna of the second receiving radio frequency unit comprises mixing, by the second receiving radio frequency unit, the received signal with an oscillator signal and comparing the phase of the mixed signal to the predetermined phase value.

31. The method of claim 29, wherein adjusting, by the second receiving radio frequency unit, the phase of the received signal from the second antenna comprises adjusting the phase of the downconverted signal based on the comparison.

32. The method of claim 30, further comprising downconverting, by the second receiving radio frequency unit, the second phase-adjusted downconverted signal to generate a second output signal.

33. The method of claim 31, wherein combining the first and second phase-adjusted signals comprises combining the first and second output signals.

34. The method of claim 25, further comprising:

propagating the received signal from the first antenna through a first waveguide;

filtering the received signal with a first waveguide filter prior to comparing the phase of the received signal from the first antenna to the predetermined phase value;

propagating the received signal from the second antenna through a second waveguide; and

filtering the received signal with a second waveguide filter prior to comparing the phase of the received signal from the second antenna to the predetermined phase value.