Weighting factor adjustment in adaptive antenna arrays

• US 8,577,296 B2
• Filed: 08/29/2008
• Issued: 11/05/2013
• Est. Priority Date: 08/29/2008
• Status: Expired due to Fees

• Current Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Original Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Inventors: Eldering, Charles A.
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US12/201,415
• Publication Number:
  US 20100056191A1
• Time in Patent Office: 1,894 Days
• Field of Search: 455/67.11, 455/562.1, 455/575.7, 455/272, 455275-2761, 455/69, 455/522, 455/101, 455 631- 632, 455/63.4, 455/67.16, 455132-135, 4552261-2264, 4552761-2772, 455/456.1, 455/456.5
• US Class Current: 455/63.1
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04Q 2213/13003 Constructional details of switching devices
• CPC Class Codes: H04Q 2213/13098 Mobile subscriber
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

A method of forming an adaptive antenna array includes calculating intra-unit phase relationships between antenna elements of a plurality of access units and measuring inter-unit phase relationships between the access units. An indication of a desired coverage area collectively produced by the plurality of access units is received. A set of weighting factors is determined. Each weighting factor is associated with an individual antenna element in the plurality of access units and the set of weighting factors provide the desired coverage pattern. Phase lock between the plurality of access units is maintained to control the desired coverage pattern.

Claims

1. A method of adjusting a plurality of weighting factors associated with a first access unit located at a first geographic location to collectively produce a collective radiation pattern over a defined geographic coverage area with a plurality of second access units, wherein each second access unit is located at a second geographic location distinct from the first geographic location, the method comprising:

receiving, by the first access unit, user input of location coordinates defining the geographic coverage area;

identifying, by the first access unit, the plurality of second access units based on the defined geographic coverage area;

tracking, by the first access unit, a signal received from each of the second access units using a plurality of phase lock loops, wherein each phase lock loop is associated with an antenna element within the first access unit;

determining, by the first access unit, a phase relationship between the first access unit and each second access unit based on the tracked signals;

generating, by the first access unit, a plurality of weighting factors that produce a first portion of the collective radiation pattern based on the determined phase relationships, wherein each first weighting factor is associated with one of the plurality of antenna elements;

detecting, by the first access unit, that the first portion of the collective radiation pattern conflicts with a second portion of the collective radiation pattern produced by one of the second access units; and

adjusting, by the first access unit, the plurality of weighting factors based on the phase relationship, wherein the adjusted weighting factors produce a modified first portion of the collective radiation pattern that does not conflict with the second portion of the collective radiation pattern.

2. The method of claim 1, further comprising:

periodically monitoring the phase relationship between the access unit and the at least one other access unit;

determining that the phase relationship has changed; and

adjusting the plurality of weighting factors based on the changed phase relationship.

3. The method of claim 1, wherein the access unit is mobile and the at least one other access unit is stationary.

4. The method of claim 1, wherein the plurality of weighting factors are adjusted using an iterative method selected from a group comprising:

Conjugate Gradient Method, Constant Modulus Algorithm, Least Mean Squares Algorithm, Recursive Least Squares Algorithm, and Sample Matrix Inversion Algorithm.

5. The method of claim 1, further comprising:

detecting, by the first access unit, a source of signal degradation in the defined geographic coverage area; and

modifying, by the first access unit, the defined geographic coverage area based on the detected source of signal degradation to create a modified geographic coverage area.

6. The method of claim 5, further comprising:

generating, by the first access unit, a plurality of new weighting factors that produce a portion of a new collective radiation pattern over the modified geographic coverage area.

7. The method of claim 1, wherein the modified geographic coverage area excludes a region of the defined coverage area associated with the source of signal degradation.

8. The method of claim 1, wherein each of the plurality of weighing factors is associated with a respective one of the plurality of antenna elements and wherein the plurality of weighting factors are arranged in the same configuration as the plurality of antenna elements.