Method and apparatus for a mapping receiver

• US 6,400,927 B1
• Filed: 08/30/1999
• Issued: 06/04/2002
• Est. Priority Date: 08/30/1999
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Waddoups, Ray O., Cornils, Curtis L., Daniel, Brian M., Olds, Keith A.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Milord, Marceau
• Application Number:
  US09/385,555
• Time in Patent Office: 1,009 Days
• Field of Search: 455/13.1, 455/13.3, 455/427, 455/429, 455/428, 455/430, 455/434, 455/436, 455/12.1, 455/13.2, 455/63, 342/350, 342/352, 342/355, 370/315, 370/316, 370/252, 370/333, 370/334, 370/317, 370/332, 370/323
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system

Abstract

A satellite ground station (500) mitigates potential interference from a fixed service installation (130, 150) by scanning a field of view and logging potentially interfering transmitters in a data structure (400). The data structure includes fields for azimuth, elevation, and frequency channel, and when complete, forms a map of potentially interfering transmitters within the field of view of the ground station. When a satellite traverses the field of view such that the ground station may interfere with, or be interfered with by, a known potentially interfering transmitter as identified in the map, the ground station takes mitigation measures such as changing frequency channels or handing-off to a different satellite.

Claims

1. A method of operating a ground station to detect potential interfering transmitters, the method comprising:

pointing an antenna in a plurality of discrete directions in a field of view of the ground station;

for each of the plurality of discrete directions in the field of view, scanning a frequency band of interest; and

when energy is detected in the frequency band of interest, logging a discrete direction in which the energy was detected, thereby creating a map of potentially interfering transmitters in the field of view of the ground station.

2. The method of claim 1 wherein:

the frequency band of interest is segmented into a plurality of frequency channels; and

a frequency channel in which energy was detected is also logged.

3. The method of claim 2 wherein the plurality of discrete directions are at substantially the same elevation such that the map is a function of at least azimuth and frequency channel.

4. The method of claim 2 wherein the plurality of discrete directions combine to encompass substantially an entire field of view of the ground station such that the map is a function of at least azimuth, elevation, and frequency channel.

5. The method of claim 1 wherein the method is repeated periodically such that a plurality of maps is created, each of the plurality of maps corresponding to one repetition of the method.

6. The method of claim 5 wherein the plurality of maps is maintained at a substantially constant number such that one map is added and one map is discarded for each repetition of the method.

7. The method of claim 1 wherein the pointing of the antenna is performed while tracking a signal from a satellite, and if in one of the plurality of discrete directions, the signal from the satellite drops below a power threshold, the method further includes updating the map to reflect a signal blockage in the one of the plurality of discrete directions.

8. The method of claim 7 wherein updating the map comprises:

for every frequency channel in the frequency band of interest, logging a potentially interfering transmitter in the map in the one of the plurality of discrete directions.

9. The method of claim 1 further comprising:

communicating with a first satellite while tracking the first satellite through at least one of the plurality of discrete directions within the field of view; and

if the map indicates a potentially interfering transmitter exists in the at least one of the plurality of discrete directions, taking action to mitigate potential interference.

10. The method of claim 9 wherein the action to mitigate potential interference is a communications hand-off from the first satellite to a second satellite.

11. The method of claim 9 wherein the action to mitigate potential interference is a request to the first satellite to change frequency channels.

12. A ground station comprising:

a first antenna pointing device that controls a pointing direction of an antenna in a first dimension;

a second antenna pointing device that controls a pointing direction of the antenna in a second dimension;

a data storage device;

a transceiver; and

wherein the first and second antenna pointing devices are configured to point the antenna at discrete directions within a field of view, the transceiver is configured to measure signals from potentially interfering transmitters, and the data storage device is configured to receive the pointing directions of the first and second antenna pointing devices when potentially interfering transmitters are found.

13. The ground station of claim 12 wherein:

the transceiver comprises a frequency scanning receiver;

the frequency scanning receiver is configured to scan a plurality of frequency channels within a frequency band of interest; and

the data storage device is configured to receive a frequency channel within which a potentially interfering transmitter is found.

14. The ground station of claim 13 wherein the transceiver is further configured to change from a first frequency channel to a second frequency channel when a satellite approaches a direction within the field of view such that the pointing directions of the first and second antenna pointing devices are substantially equal to the pointing directions received by the data storage device, and the first frequency channel has been received by the data storage device.