SYSTEMS AND METHODS FOR COMPENSATING FOR TRANSMISSION PHASING ERRORS IN A COMMUNICATIONS SYSTEM USING A RECEIVE SIGNAL

• US 20100124895A1
• Filed: 11/19/2008
• Published: 05/20/2010
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Minear, Kathleen, Martin, G. Patrick
• Granted Patent: US 7,970,365 B2
• Time in Patent Office: Days
• US Class Current: 455/276.100
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 17/23 Indication means, e.g. displays, alarms, audible means
• CPC Class Codes: H04B 17/3912 Simulation models, e.g. distribution of spectral power density or received signal strength indicator [RSSI] for a given geographic region
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays
• CPC Class Codes: H04B 7/0848 Joint weighting

Abstract

A method for correcting transmission phasing errors in an plurality of antenna elements is provided. The method includes receiving at least a first signal having a first frequency at the plurality of antenna elements at an angle of arrival (AOA). The method also includes identifying an actual fractional wavelength value (f_true) for the first signal received with respect to a reference location for at least one of the plurality of antenna elements, obtaining a estimated phase propagation of the first signal at the one of the plurality of antenna elements relative to the reference location based at least on configuration data for plurality of antenna elements, and updating the configuration data associated with the AOA for the one of the plurality of antenna elements based on the estimated phase propagation and f_true

Claims

1. A method for correcting transmission phasing errors in an plurality of antenna elements, the method comprising:

receiving at least a first signal having a first frequency at said plurality of antenna elements at an angle of arrival (AOA);

for at least one of said plurality of antenna elements, identifying an actual fractional wavelength value (f_true) for the first signal received with respect to a reference location;

obtaining a estimated phase propagation of the first signal at said one of said plurality of antenna elements relative to the reference location based at least on configuration data for plurality of antenna elements; and

updating said configuration data associated with said AOA for said one of said plurality of antenna elements based on the estimated phase propagation and f_true

2. The method of claim 1, wherein the obtaining comprises:

calculating the estimated phase propagation by modeling said first signal traversing an estimated differential distance for said one of said plurality of antenna elements relative to said reference location based on the configuration data and the AOA; and

calculating an estimated fractional wavelength value (f_model) and an estimated whole wavelength value (n_model) for the first signal from the estimated phase propagation.

3. The method of claim 2, wherein said updating further comprises:

estimating an actual whole wavelength value (n_true) for the first signal based on the estimated phase propagation and f_true; and

determining an actual differential distance (z_true) for the one of said plurality of antenna elements relative to the reference location based on a sum of f_true and n_true.

4. The method of claim 3, further comprising:

transmitting a second signal having a second frequency (c/λ

_Tx) from the one of said plurality of antenna elements at said AOA using a complex weight having a phase correction, wherein said phase correction is

5. The method of claim 4, further comprising:

receiving a third signal having a third frequency at the plurality of antenna elements at said AOA; and

repeating the identifying, the obtaining, the updating, and the transmitting steps based on the third signal.

6. The method of claim 3, wherein said estimating n_true further comprises computing an adjusted value of n_model (n_model—

_adjusted) for n_true.

7. The method of claim 6, wherein said computing of n_model—

_adjusted is performed according to the equation

8. The method of claim 1, wherein said reference location comprises a location of another of said plurality of antenna elements.

9. The method of claim 1, wherein said identifying further comprises analyzing the first signal at said one of said plurality of antenna elements using an adaptive blind separation signal (BSS).

10. A communications system comprising:

a plurality of antenna elements; and

an array control system communicatively coupled to said plurality of antenna elements, said array control system comprising;

a storage element for storing signal data for at least a first signal having a first frequency received at said plurality of antenna elements at an angle of arrival (AOA) and for storing configuration data for said plurality of antenna elements;

a processing element communicatively coupled to said storage element, said processing element configured for;

identifying an actual fractional wavelength value (f_true) for at least one of said plurality of antenna element for the first signal with respect to a reference location, obtaining a estimated phase propagation of the first signal at said one of said plurality of antenna elements relative to the reference location based at least on configuration data for plurality of antenna elements, and updating said configuration data associated with said AOA for said one of said plurality of antenna elements based on the estimated phase propagation and f_true.

11. The communications system of claim 10, wherein said processing element is further configured during said obtaining for:

calculating the estimated phase propagation by modeling said first signal traversing an estimated differential distance for said one of said plurality of antenna elements relative to said reference location based on the configuration data and the AOA; and

calculating an estimated fractional wavelength value (f_model) and an estimated whole wavelength value (n_model) for the first signal from the estimated phase propagation.

12. The communications system of claim 11, wherein said processing element is further configured during said updating for:

estimating an actual whole wavelength value (n_true) for the first signal based on the estimated phase propagation and f_true; and

determining an actual differential distance (z_true) for the one of said plurality of antenna elements relative to the reference location based on a sum of f_true and n_true.

13. The communications system of claim 12, wherein said processing element is further configured for comprising:

generating control signals for transmitting a second signal having a second frequency (c/λ

_Tx) from the one of said plurality of antenna elements at said AOA, said control signals comprising a complex weight having a phase correction for said one of said plurality of antenna elements, wherein said phase correction is

14. The communications system of claim 13, wherein said storage element further configured for receive signal data for a third signal having a third frequency at the plurality of antenna elements at said AOA, and wherein said processing element is further configured for repeating the identifying, the obtaining, the updating, and the transmitting steps based on the third signal.

15. The communications system of claim 12, wherein said processing element is further configured during said estimating n_true for computing an adjusted value of n_model (n_model—

_adjusted ) for n_true.

16. The communications system of claim 15, wherein said processing element performs said computing of n_model—

_adjusted according to the equation

17. The communications system of claim 10, wherein said reference location comprises a location of another of said plurality of antenna elements.

18. The communications system of claim 10, wherein said processing element is further configured during said identifying for analyzing the first signal at said one of said plurality of antenna elements using an adaptive blind source separation (BSS) algorithm.

19. A computer-readable storage, having stored thereon a computer program for correcting transmission phasing errors in plurality of antenna, the computer program comprising a plurality of code sections for performing the steps of:

receiving signal data for at least a first signal having a first frequency at said plurality of antenna elements at an angle of arrival (AOA);

for at least one of said plurality of antenna elements, identifying an actual fractional wavelength value (f_true) for the first signal received with respect to a reference location using a blind source separation algorithm;

obtaining a estimated phase propagation of the first signal at said one of said plurality of antenna elements relative to the reference location based at least on configuration data for plurality of antenna elements; and

updating said configuration data associated with said AOA for said one of said plurality of antenna elements based on the estimated phase propagation and f_true

20. The computer-readable storage claim 19, wherein said obtaining further comprises code sections for:

calculating the estimated phase propagation by modeling said first signal traversing an estimated differential distance for said one of said plurality of antenna elements relative to said reference location based on the configuration data and the AOA; and

calculating an estimated fractional wavelength value (f_model) and an estimated whole wavelength value (n_model) for the first signal from the estimated phase propagation.

21. The computer-readable storage claim 20, wherein said updating further comprises code sections for:

estimating an actual whole wavelength value (n_true) for the first signal based on the estimated phase propagation and f_true; and

determining an actual differential distance (z_true) for the one of said plurality of antenna elements relative to the reference location based on a sum of f_true and n_true.

22. The computer-readable storage claim 21, further comprising:

transmitting a second signal having a second frequency (c/λ

_Tx) from the one of said plurality of antenna elements at said AOA using a complex weight having a phase correction, wherein said phase correction is

23. The computer-readable storage claim 22, further comprising:

receiving a third signal having a third frequency at the plurality of antenna elements at said AOA; and

repeating the identifying, the obtaining, the updating, and the transmitting steps based on the third signal.

24. The computer-readable storage claim 20, wherein said estimating n_true further comprises computing an adjusted value of n_model (n_model—

_adjusted) for n_true.

25. The computer-readable storage claim 24, wherein said computing of n_model—

_adjusted is performed according to the equation