Method for finding signal direction using modal antenna

Patent metadata

Field	Value
Publication number	US-9983290-B2
Application number	US-201514660086-A
Country	US
Kind code	B2
Filing date	Mar 17, 2015
Priority date	Mar 17, 2014
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

A method for obtaining the direction of a signal incoming to a communication device is provided using a modal antenna that has multiple modes corresponding to multiple radiation patterns with a single feed.

First claim

What is claimed is:

1. A method for obtaining a direction of a signal incoming to a communication device, which is provided with a modal antenna having a plurality of modes corresponding to a plurality of radiation patterns, respectively, the method comprising:
obtaining a gain of the modal antenna at each of predetermined angles for each of the plurality of radiation patterns;
first computing a first difference in gain at each of the predetermined angles between each selected pair of the plurality of radiation patterns to obtain a gain variation;
measuring a signal strength in a configuration with each of the plurality of radiation patterns;
second computing a second difference in signal strength between configurations with each selected pair of the plurality of radiation patterns to obtain a signal strength variation;
third computing a third difference between the first difference and the second difference for each of the predetermined angles and for each selected pair of the plurality of radiation patterns;
summing a plurality of third differences over all selected pairs of the plurality of radiation patterns to have a value for each of the predetermined angles; and
determining an angle of arrival (AOA) of the signal, the AOA giving a minimum among a plurality of values obtained for the predetermined angles, respectively, in the summing
wherein:
the measuring the signal strength comprises measuring a main signal strength and one or more multipath component signal strengths;
the second computing the second difference comprises second computing a main signal strength difference and each of one or more multipath component signal strength differences between configurations with each selected pair of the plurality of radiation patterns;
the third computing the third difference comprises third computing a third difference associated with the main signal between the first difference and the main signal strength difference, and one or more third differences associated with the one or more multipath component signals, respectively, between the first difference and the one or more multipath component signal strength differences, respectively, for each of the predetermined angles and for each selected pair of the plurality of radiation patterns;
the summing the plurality of third differences over all selected pairs of the plurality of radiation patterns comprises summing a plurality of third differences associated with the main signal over all selected pairs of the plurality of radiation patterns to have a value associated with the main signal for each of the predetermined angles, and summing a plurality of third differences associated with each of the one or more multipath component signals over all selected pairs of the plurality of radiation patterns to have a value associated with each of the one or more multipath component signals for each of the predetermined angles; and
the determining the AOA comprises:
finding a temporary AOA associated with the main signal, which gives a minimum among a plurality of values associated with the main signal obtained for the predetermined angles, respectively, in the summing, and a temporary AOA associated with each of the one or more multipath component signals, which gives a minimum among a plurality of values associated with each of the one or more multipath component signals obtained for the predetermined angles, respectively, in the summing;
judging if the temporary AOA associated with the main signal and the temporary AOA associated with each of the one or more multipath component signals are within a predetermined tolerance;
if yes in the judging, determining the temporary AOA associated with the main signal to be the AOA; and
if no in the judging, repeating the obtaining through the determining.

2. The method of claim 1 , wherein
the gain of the modal antenna at each of the predetermined angles for each of the plurality of radiation patterns is premeasured under various conditions or environments, and stored in a memory according to the various conditions or environments.

3. The method of claim 2 , wherein
the obtaining the gain comprises:
sensing the condition or environment using one or more sensors during a time interval; and
selecting the gain in the memory according to the sensed condition or environment.

4. The method of claim 1 , further comprising:
updating the first difference in gain at each of the predetermined angles between each selected pair of the plurality of radiation patterns to update the gain variation for use when the obtaining through the determining are repeated.

5. The method of claim 4 , wherein
the updating comprises:
second measuring an updating signal strength in a configuration with each of the plurality of radiation patterns;
fourth computing a difference in updating signal strength between configurations with each selected pair of the plurality of radiation patterns to obtain an updating signal strength variation;
first storing the updating signal strength variation as the gain variation between each selected pair of the plurality of radiation patterns at the AOA; and
second storing a difference in gain at each of the predetermined angles other than the AOA between each selected pair of the plurality of radiation patterns based on premeasured gains to update the gain variation at each of the predetermined angles other than the AOA.

6. The method of claim 1 , further comprising:
decision making as to whether the obtaining through the determining be repeated.

7. The method of claim 6 , wherein
the decision making comprises:
second obtaining a difference between the gain variation at the AOA between a selected pair of the plurality of radiation patterns and the signal strength variation between configurations with the selected pair of the plurality of radiation patterns;
judging if the difference is larger than or smaller than a predetermined threshold;
making decision to repeat the obtaining through the determining if the difference is larger than the predetermined threshold.

8. The method of claim 7 , wherein
the gain variation at the AOA between the selected pair of the plurality of radiation patterns is the first difference in gain at the AOA between the selected pair of the plurality of radiation patterns.

9. The method of claim 7 , wherein
the gain variation at the AOA between the selected pair of the plurality of radiation patterns is an average of a plurality of the first differences in gain at the AOA between the selected pair of the plurality of radiation patterns, wherein one or more of the plurality of the first differences are obtained based on an updating procedure prior to the averaging.

10. The method of claim 1 , wherein
the main signal strength and the one or more multipath component signals are measured by using a rake receiver coupled to the modal antenna.

11. The method of claim 1 , wherein
the obtaining the gain of the modal antenna comprises obtaining the gain including a phase of the gain at each of predetermined angles for each of the plurality of radiation patterns; and
the measuring the signal strength comprises obtaining the signal strength including a phase of the signal strength in a configuration with each of the plurality of radiation patterns, based on a phase shift measurement.

12. A method for obtaining a direction of a signal incoming to a communication device, which is provided with a modal antenna having a plurality of modes corresponding to a plurality of radiation patterns, respectively, the method comprising:
obtaining a gain of the modal antenna at each of predetermined angles for each of the plurality of radiation

Assignees

• Ethertronics Inc

Inventors

• Pajona Olivier
• Roe Michael
• Mohd Zaini Mohd Faizal
• Rowson Sebastian
• Desclos Laurent

Classifications

• G01S3/06

  Means for increasing effective directivity, e.g. by combining signals having differently oriented directivity characteristics or by sharpening the envelope waveform of the signal derived from a rotating or oscillating beam antenna (comparing amplitude of signals having differently oriented directivity characteristics to determine direction G01S3/16, G01S3/28) · CPC title

• G01S3/16

  using amplitude comparison of signals derived sequentially from receiving antennas or antenna systems having differently-oriented directivity characteristics or from an antenna system having periodically-varied orientation of directivity characteristic · CPC title

• H01Q1/243

  with built-in antennas · CPC title

• H01Q25/04 Primary

  Multimode antennas {(corrugated horns H01Q13/0208)} · CPC title

• G01S3/28 Primary

  using amplitude comparison of signals derived simultaneously from receiving antennas or antenna systems having differently-oriented directivity characteristics · CPC title