Performance monitor for antenna arrays

• US 6,266,528 B1
• Filed: 12/23/1998
• Issued: 07/24/2001
• Est. Priority Date: 12/23/1998
• Status: Expired due to Term

• Current Assignee: Tumbleweed Holdings LLC (Equitable IP Corporation)
• Original Assignee: ArrayComm LLC (Ygomi LLC)
• Inventors: Farzaneh, Farhad
• Primary Examiner(s): LEGREE, TRACY MICHELLE
• Application Number:
  US09/219,040
• Time in Patent Office: 944 Days
• Field of Search: 455/423, 455/424, 455/272, 455/226.1, 455/226.2, 455/226.3, 455/226.4, 455/132, 455/133, 455/67.1, 455/67.3, 455/562, 455/8-10, 455/504-506, 455/67.6, 342/173, 342/174, 342/372, 342/373, 342/368, 342/360, 343/702, 343/703, 343/824, 343/835
• US Class Current: 455/423
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

An antenna monitor collects statistics about the received signal strengths of each antenna in a cooperating antenna array over long periods of time. In cellular telephone base station applications for a base station using an array of antenna elements to obtain spatial diversity, samples of the received signal strength are taken during particular times whenever an active mobile subscriber is operating in the area. Periodically, such samples are averaged and added to a running total that is maintained in a long-term accumulator for each antenna. The accumulated totals are then compared after a statistically sufficient number of samples have been collected and averaged. Faulty antennas, including broken ones and ones with bad connections, will be revealed by those corresponding signal paths having relatively low accumulated totals. Given long enough collection periods, the spatial diversity of the antennas in the array will have only a minimal impact on favoring one antenna over another.

Claims

1. A method for monitoring an antenna array, comprising:

periodically sampling a quality of a signal received at each of the plurality of antennas;

maintaining a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples;

generating an indication for a given antenna in the array of antennas that the given antenna is faulty or poorly situated if the maintained value indicating the quality of the signal received for the given antenna indicates the quality is poor relative to the values indicating the quality of the signal received by other of the plurality of antennas.

2. The method of claim 1, wherein sampling the quality of the signal received comprises sampling the strength of the signal received.

3. The method of claim 2, wherein sampling the strength of the signal received comprises sampling a measure of the strength of the signal received.

4. The method of claim 3, wherein sampling a measure of the strength of the signal received comprises sampling a received signal strength indication of the strength of the signal received.

5. The method of claim 3, wherein sampling a measure of the strength of the signal received comprises sampling a measure of the strength of the signal received when the measure of the strength of the signal received exceeds a minimum threshold.

6. The method of claim 1, wherein sampling the quality of the signal received comprises sampling the quality of the signal received only when a subscriber unit is transmitting within receiving range of the antenna array.

7. The method of claim 1, wherein maintaining a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples comprising maintaining an value indicating the average received signal strength of the signal received at each of the plurality of antennas over a period of multiple samples.

8. The method of claim 1, wherein maintaining a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples comprises:

collecting a number of samples of the quality of the signal received at each of the plurality of antennas over the period; and

calculating for each of the plurality of antennas a value indicating an average of the number of samples collected.

9. The method of claim 1, wherein maintaining a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples comprises:

collecting a number of samples of the quality of the signal received at each of the plurality of antennas over the period;

calculating for each of the plurality of antennas a value indicating an short term average of the number of samples collected; and

accumulating the value indicating a short term average over repeated periods of multiple samples to form a long term average associated with each antenna.

10. A apparatus that monitors an antenna array, comprising:

a plurality of antennas;

a plurality of receivers each coupled to a respective one of the plurality of antennas to receive a signal therefrom;

a sampling circuit coupled to the receivers to periodically sample a quality of a signal received at each of the receivers from the respective ones of the plurality of antennas;

a memory coupled to the sampling circuit, the memory providing for storage of a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples;

a comparator coupled to the memory to compare the quality of the signal received for each of the plurality of antennas;

an output coupled to the comparator to provide an indication for a given antenna in the array of antennas that the given antenna is faulty or poorly situated if the comparator determines the value stored in memory indicates that the quality of the signal received for the given antenna is poor relative to the values indicating the quality of the signal received by other of the plurality of antennas.

11. An apparatus that monitors an antenna array, comprising:

means for periodically sampling a quality of a signal received at each of the plurality of antennas;

means for maintaining a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples;

means for generating an indication for a given antenna in the array of antennas that the given antenna is faulty or poorly situated if the maintained value indicating the quality of the signal received for the given antenna indicates the quality is poor relative to the values indicating the quality of the signal received by other of the plurality of antennas.

12. An article of manufacture, comprising:

a machine accessible medium, the machine accessible medium providing instructions, that when executed by a machine, cause the machine to;

periodically sample a quality of a signal received at each of the plurality of antennas;

maintain a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples;

generate an indication for a given antenna in the array of antennas that the given antenna is faulty or poorly situated if the maintained value indicating the quality of the signal received for the given antenna indicates the quality is poor relative to the values indicating the quality of the signal received by other of the plurality of antennas.

13. The article of manufacture of claim 12, wherein the machine readable medium providing instructions that when executed by the machine cause the machine to sample the quality of the signal received cause the machine to sample the strength of the signal received.

14. The article of manufacture of claim 13, wherein the machine readable medium providing instructions that when executed by the machine cause the machine to sample the strength of the signal received cause the machine to sample a measure of the strength of the signal received.

15. The article of manufacture of claim 14, wherein the machine readable medium providing instructions that when executed by the machine cause the machine to sample a measure of the strength of the signal received cause the machine to sample a received signal strength indication of the strength of the signal received.

16. The article of manufacture of claim 14, wherein the machine readable medium providing instructions that when executed by the machine cause the machine to sample a measure of the strength of the signal received cause the machine to sample a measure of the strength of the signal received when the measure of the strength of the signal received exceeds a minimum threshold.

17. The article of manufacture of claim 12, wherein the machine readable medium providing instructions that when executed by the machine cause the machine to sample the quality of the signal received cause the machine to sample the quality of the signal received only when a subscriber unit is tansmitting within receiving range of the antenna array.

18. The article of manufacture of claim 12, wherein the machine readable medium providing instructions that when executed by the machine cause the machine to maintain a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples cause the machine to maintain an value indicating the average received signal strength of the signal received at each of the plurality of antennas over a period of multiple samples.

19. The article of manufacture of claim 12, wherein the machine readable medium providing instructions that when executed by the machine cause the machine to maintain a value indicating the quality of the signal received at each of the plurality of antennas over a period of multiple samples cause the machine to:

collect a number of samples of the quality of the signal received at each of the plurality of antennas over the period; and

calculate for each of the plurality of antennas a value indicating an average of the number of samples collected.