Method for efficiently computing the beamforming weights for a large antenna array

• US 7,414,578 B1
• Filed: 09/27/2006
• Issued: 08/19/2008
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: Jensen, Dana J., Courtade, Thomas A.
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Mull; Fred H.
• Application Number:
  US11/528,058
• Time in Patent Office: 692 Days
• Field of Search: 342/372, 342/377, 342/378, 342/423
• US Class Current: 342/377
• CPC Class Codes: G01S 3/023 Monitoring or calibrating
• CPC Class Codes: G01S 3/48 the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured
• CPC Class Codes: G01S 3/74 Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14
• 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

Abstract

A method of determining the size of a sub-array for an antenna array is described. The method includes choosing a number of elements of a sub-array of antenna elements. Further, the method includes determining a direction of arrival of the signal using data from the sub-array. The method also includes computing weights for the antenna array. Further still, the method includes determining whether the size of the sub-array meets a predetermined criteria.

Claims

1. A method of beamforming for an antenna array, comprising:

choosing a number of sub-array antenna elements from an array of antenna elements using an iterative algorithm;

correlating an incoming signal with a training sequence at each element of the sub-array to produce correlation data of the received signal at each sub-array element;

estimating a direction of arrival of the signal using the correlation data; and

computing weights for the antenna array.

2. The method of claim 1, wherein the correlation data comprises correlation peak data at the sync position.

3. The method of claim 1, wherein the weights of the antenna array comprise adaptive weights.

4. The method of claim 3, wherein the adaptive weights comprise gains.

5. The method of claim 1, wherein the antenna array is a part of an airborne platform.

6. The method of claim 1, wherein the algorithm comprises computing weights for the antenna array.

7. A communication platform, comprising:

an antenna array comprising a plurality of antenna elements;

a sub-array comprising a subset of the plurality of antenna elements of the antenna array, a number of elements of the sub-array are chosen by an iterative algorithm;

a correlation algorithm to correlate an incoming signal with a training sequence to produce correlation data for the sub-array;

a direction of arrival estimation algorithm to compute an estimate of the direction of arrival based on the correlation data; and

a weight computation algorithm to compute weights for the antenna array.

8. The platform of claim 7, wherein the correlation data comprises correlation peak data at the sync position.

9. The platform of claim 7, wherein the weights of the antenna array comprise adaptive weights.

10. The platform of claim 9, wherein the adaptive weights comprise gains.

11. The platform of claim 7, wherein the antenna array is a part of an airborne platform.

12. The platform of claim 7, wherein the weight computation algorithm includes an iterative algorithm.

13. A method of determining the size of a sub-array of an antenna array, comprising:

choosing a number of elements of the sub-array;

determining a direction of arrival estimate using data from the sub-array;

computing weights for the antenna array; and

determining whether the size of the sub-array meets a predetermined criteria.

14. The method of claim 13, further comprising:

repeating the process steps if the predetermined criteria is not met.

15. The method of claim 13, wherein the predetermined criteria is an error function.

16. The method of claim 13, wherein the method is an iterative method in which the number of elements of the sub-array are increased with each iteration.

17. The method of claim 13, wherein the weights comprise gains.

18. The method of claim 13, wherein the weights comprise complex weights.