Communication system using geographic position data

• US 6,512,481 B1
• Filed: 10/10/1996
• Issued: 01/28/2003
• Est. Priority Date: 10/10/1996
• Status: Expired due to Fees

• Current Assignee: Teratech Corporation
• Original Assignee: Teratech Corporation
• Inventors: Velazquez, Scott R., Broadstone, Steven R.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US08/729,289
• Time in Patent Office: 2,301 Days
• Field of Search: 342/357, 342/367, 342/372, 342/359, 342/457, 342/357.1, 342/357.06, 342/357.08, 455/456, 455/562
• US Class Current: 342/367
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/51 Relative positioning
• CPC Class Codes: G01S 19/53 Determining attitude
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

A wireless communication system employs directive antenna arrays and knowledge of position of users to form narrow antenna beams to and from desired users and away from undesired users to reduce co-channel interference. By reducing co-channel interference coming from different directions, spatial filtering with antenna arrays improves the call capacity of the system. A space division multiple access (SDMA) system allocates a narrow antenna beam pattern to each user in the system so that each user has its own communication channel free from co-channel interference. The position of the users is determined using geo-location techniques. Geo-location can be derived via triangulation between cellular base stations or via a global positioning system (GPS) receiver.

Claims

1. A communication system comprising:

a first mobile transceiver having a first processor and a first directional antenna;

a second transceiver having a second processor and a second antenna;

a locator coupled to the first transceiver for determining the physical location of the first antenna relative to the second antenna;

a communication link formed between the first and second transceivers, the link including a first wireless beam from the first antenna to the second antenna and a second wireless beam from the second antenna to the first antenna;

a first beamformer in the first transceiver for shaping the first wireless beam to be directed toward the second antenna so as to reduce interference, the first beamformer having a first deterministic direction finder to compute an angle of arrival of the second wireless beam;

the angle of arrival being used by a first steering circuit in the first beamformer to determine a first beam steering direction of a first antenna pattern directed toward the second antenna, and the first beamformer having a first nulling circuit that rejects beams outside the first beam steering direction to the second antenna; and

a second beamformer in the second transceiver for shaping the second wireless beam to be directed toward the first antenna so as to reduce interference, the second beamformer having a deterministic direction finder to compute an angle of arrival of the first wireless beam, the angle of arrival being used by a second steering circuit in the second beamformer to determine a second beam steering direction of a second antenna pattern directed toward the first antenna, and the second beamformer having a second nulling circuit that rejects beams outside the second beam steering direction to the first antenna.

2. The system of claim 1 wherein the first and second antennas are movable relative to one another and the beamformer updates the direction of the wireless beam in response to the relative motion of the antennas.

3. The system of claim 1 wherein the wireless beam is a radio frequency beam.

4. The system of claim 1 wherein the second antenna is in a mobile unit.

5. The system of claim 1 wherein the locator includes input from a satellite positioning system.

6. The system of claim 1 wherein the locator includes input from a ground-based positioning system.

7. The system of claim 1 where the communication link is spatially multiplexed.

8. A cellular communication system comprising:

a base transceiver having a first directional antenna, the base transceiver having a fixed geographical location,

a mobile transceiver having a second antenna, the second antenna being movable relative to the base transceiver;

a spatially multiplexed communication link between the base and the mobile transceivers formed by a wireless signal between the antennas;

a positioning system for detecting the geographical position of the second antenna, the position of the second antenna being communicated to the base transceiver over the communication link;

a first beamformer in the base transceiver for modifying the signal in response to the relative motion of the antennas, the first beamformer having a first deterministic direction finder to compute a first angle of arrival of the wireless signal, the first angle of arrival being used by a first steering circuit in the first beamformer to determine a first antenna pattern directed toward the second antenna, the first beamformer having a first nulling circuit for rejecting signals outside a first beam direction of the second antenna; and

a second beamformer in the mobile transceiver for modifying the signal in response to the relative motion of the antennas, the second beamformer having a second deterministic direction finder to compute a second angle of arrival of the wireless signal, the second angle of arrival being used by a second steering circuit in the second beamformer to determine a second beam steering direction of a second antenna pattern directed toward the first antenna, the second beamformer having a second nulling circuit for rejecting signals outside a second beam direction of the first antenna.

9. The system of claim 8 wherein the beamformer updates the direction of the wireless beam in response to the relative motion of the antennas.

10. The system of claim 8 wherein the signal is a radio frequency beam.

11. The system of claim 8 wherein the positioning system includes input from a satellite positioning system.

12. The system of claim 8 wherein the positioning system includes input from a ground-based positioning system.

13. The system of claim 8 wherein the beamformer includes a plurality of programmable filter arrays.

14. The system of claim 8 wherein the beamformer includes a table stored in memory for providing antenna weights to modify the signal.

15. The system of claim 8 wherein the second antenna is a directional antenna.

16. A method for operating a communication system comprising the steps of:

providing a first mobile transceiver having a first processor and a first directional antenna;

providing a second transceiver having a second processor and a second antenna;

determining the physical location of the second antenna relative to the first antenna;

forming a communication link between the first and second transceivers, the link including a first wireless beam from the first antenna to the second antenna and a second wireless beam from the second antenna to the first antenna;

in a first beamformer in the first transceiver, responding to the relative physical location of the second antenna and shaping the first wireless beam to be directed toward the second antenna, the first beamformer having a first deterministic direction finder for computing a first angle of arrival of the second wireless beam, the first angle of arrival being used by a first steering circuit in the first beamformer for determining a first beam steering direction of a first antenna pattern directed toward the second antenna, and nulling a first plurality of wireless beams outside a beam direction of the second antenna; and

in a second beamformer in the second transceiver, responding to the relative physical location of the first antenna and shaping the second wireless beam to be directed toward the first antenna, the second beamformer having a second deterministic direction finder for computing a second angle of arrival of the first wireless beam, the second angle of arrival being used by a second steering circuit in the second beamformer for determining a second beamsteering direction of a second antenna pattern directed toward the first antenna, and nulling a second plurality of wireless beams outside a beam direction of the first antenna.

17. The method of claim 16 wherein the first and second antennas are movable relative to one another and the beamformer updates the direction of the signal in response to the relative motion of the antennas.

18. The method of claim 16 wherein the wireless beam is a radio frequency beam.

19. The method of claim 16 wherein the second transceiver is in a mobile unit.

20. The method of claim 16 wherein the locator includes input from a satellite positioning system.

21. The method of claim 16 wherein the locator includes input from a ground-based positioning system.

22. The method of claim 16 where the communication link is spatially multiplexed.

23. A method of operating a cellular communication system comprising the steps of:

providing a base transceiver having a first directional antenna, the base transceiver having a fixed geographical position;

providing a mobile transceiver having a second antenna, the mobile being movable relative to the base transceiver;

a spatially multiplexed communication link between the base and mobile transceivers forming a wireless signal between the antennas;

in a positioning system, detecting the geographical position of the second antenna, the position of the second antenna being communicated to the base transceiver over the communication link;

in a first beamformer in the base transceiver, modifying the signal in response to the relative motion of the antennas, the first beamformer having a deterministic direction finder for computing a first angle of arrival of the wireless signal, the first angle of arrival being used by a first steering circuit in the first beamformer for determining a first beam steering direction of a first antenna pattern directed toward the second antenna, and nulling a first plurality of signals outside a beam direction of the antennas; and

in a second beamformer in the mobile transceiver, modifying the signal in response to the relative motion of the antennas, the second beamformer having a deterministic direction finder computing a second angle of arrival of the wireless signal, the second angle of arrival being used by a second steering circuit in the second beamformer for determining a second beam steering direction of a first antenna pattern directed toward the second antenna, and nulling a second plurality of signals outside a beam direction of the antennas.

24. The method of claim 23 wherein the step of modifying the signal comprises updating the direction of the signal in response to the relative motion of the antennas.

25. The method of claim 23 wherein the signal is a radio frequency beam.

26. The method of claim 23 wherein the step of detecting comprises receiving input from a satellite positioning system.

27. The method of claim 23 wherein the step of detecting comprises receiving input from a ground-based positioning system.

28. The method of claim 23 wherein the beamformer includes a plurality of programmable filter arrays.

29. The method of claim 23 wherein the step of modifying the signal comprises providing antenna weights from a table stored in memory.

30. The method of claim 23 wherein the second antenna is a directional antenna.

31. A cellular communication system comprising:

a base transceiver having a first directional antenna, the base transceiver having a fixed geographic position;

a mobile transceiver having a second directional antenna, the second directional antenna being movable relative to the base transceiver;

a wireless communication link between the base and mobile transceivers formed by a signal between the antennas;

a positioning system for detecting the geographical position of the second directional antenna, the position of the second directional antenna being communicated to the base transceiver over the communication link;

a first beamformer in the base transceiver and a second beamformer in the mobile transceiver for modifying the signal in response to the relative motion of the antennas, the first beamformer having a first deterministic direction finder to compute a first angle of arrival of the signal, the first angle of arrival being used by a first steering circuit in the first beamformer to determine a first beam steering direction of a first antenna pattern directed toward the second antenna, the first beamformer having a nulling circuit for rejecting signals outside a beam direction of the second antenna, the second beamformer having a second deterministic direction finder to compute a second angle of arrival of the signal, the second angle of arrival being used by a second steering circuit in the second beamformer to determine a second beam steering direction of a second antenna pattern directed toward the first antenna, the second beamformer having a nulling circuit for rejecting signals outside a beam direction of the first antenna.

32. The system of claim 31 wherein the beamformers update the direction of the wireless beam in response to the relative motion of the antennas.

33. The system of claim 31 wherein the beamformers modify the signal to be omnidirectional when the antennas are separated by less than a specific range.

34. The system of claim 31 wherein the signal is a radio frequency beam.

35. The system of claim 31 wherein the positioning system includes input from a satellite positioning system.

36. The system of claim 31 wherein the positioning system includes input from a ground-based positioning system.

37. The system of claim 31 wherein the beamformers include a plurality of programmable filter arrays.

38. The system of claim 31 wherein the beamformers include a table stored in memory for providing antenna weights to modify the signal.

39. A method of operating a cellular communication system comprising:

providing a base transceiver having a first directional antenna, the base transceiver having a fixed geographical position;

providing a mobile transceiver having a second directional antenna, the second directional antenna being movable relative to the base transceiver;

a wireless communication link between the base and mobile transceivers forming a signal between the antennas;

in a positioning system, detecting the geographical position of the mobile transceiver, the position of the second directional antenna being communicated to the base transceiver over the communication link;

in a first beamformer in the base transceiver and a second beamformer in the mobile transceiver, modifying the signal in response to the relative motion of the antennas, the first beamformer having a first deterministic direction finder for computing a first angle of arrival of the signal, the first signal of arrival being used by a first steering circuit in the first beamformer for determining a first antenna pattern to be directed toward the second antenna and nulling a first plurality of signals outside a beam direction of the antennas and the second beamformer having a second deterministic direction finder for computing a second angle of arrival of the signal, the second angle of arrival being used by a second steering circuit in the second beamformer for determining a second antenna pattern to be directed toward the first antenna.

40. The method of claim 39 wherein the step of modifying the signal comprises updating the direction of the signal in response to the relative motion of the antennas.

41. The method of claim 40 wherein the step of modifying comprises determining the range between the antennas and, when the range is less than a specific range, modifying the signal to be omnidirectional.

42. The method of claim 39 wherein the signal is a radio frequency beam.

43. The method of claim 39 wherein the step of detecting comprises receiving input from a satellite positioning system.

44. The method of claim 39 wherein the step of detecting comprises receiving input from a ground-based positioning system.

45. The method of claim 39 wherein the beamformers include a plurality of programmable filter arrays.

46. The method of claim 39 wherein the step of modifying the signal comprises providing antenna weights from a table stored in memory.

47. A communication system comprising:

a first transceiver having a first processor and a first directional antenna;

a second transceiver having a second processor and a second antenna;

a locator coupled to the first transceiver for determining a physical

location of the first transceiver relative to the second antenna;

a spatially multiplexed communication link formed between the first and second transceivers, the link including a first wireless beam from the first antenna to the second antenna; and

a second wireless beam from the second antenna to the first antenna;

a first beamformer in the first transceiver for shaping the first wireless beam to be directed toward the second antenna, the first beamformer having a first deterministic direction finder to compute an angle of arrival of the second wireless beam;

the angle of arrival being used by a first steering circuit in the first beamformer to determine a first beam steering direction of a first antenna pattern directed toward the second antenna, and the first beamformer having a first nulling circuit that rejects beams outside the first beam steering direction to the second antenna; and

a second beamformer in the second transceiver for shaping the second wireless beam to be directed toward the first antenna, the second beamformer having a second deterministic direction finder to compute a second angle of arrival of the first wireless beam, the second angle of arrival being used by a second steering circuit in the second beamformer to determine a second beam steering direction of a second antenna pattern directed toward the first antenna, and the second beamformer having a second nulling circuit that rejects beams outside the second beam steering direction to the first antenna.

48. The system of claim 47 wherein the first and second antennas are movable relative to one another and the beamformer updates the direction of the wireless beam in response to the relative motion of the movable antenna.

49. The system of claim 47 wherein the wireless beam is a radio frequency beam.

50. The system of claim 47 wherein the first transceiver is a stationary base station and the second antenna is in a mobile unit.

51. The system of claim 47 wherein the locator includes input from a satellite positioning system.

52. The system of claim 47 wherein the locator includes input from a ground-based positioning system.

53. The system of claim 47 wherein the first transceiver is a mobile transceiver and the second transceiver is a stationary transceiver.

54. A method for operating a communication system comprising the steps of:

providing a first transceiver having a first processor and a first directional antenna;

providing a second transceiver having a second processor and a second antenna;

determining a physical location of the second antenna relative to the first antenna;

forming a spatially multiplexed communication link between the first and second transceivers, the link including a first wireless beam from the first antenna to the second antenna, and a second wireless beam from the second antenna to the first antenna;

in a first beamformer in the first transceiver, responding to the physical location of the second antenna and shaping the first wireless beam to be directed toward the second antenna, the first beamformer having a first deterministic direction finder for computing a first angle of arrival of the second wireless beam, the first angle of arrival being used by a first steering circuit in the first beamformer for determining a first antenna pattern to be directed toward the second antenna, and nulling beams outside a beam direction of the second antenna; and

in a second beamformer in the second transceiver, responding to the physical location of the first antenna and shaping the second wireless beam to be directed toward the first antenna, the second beamformer having a second deterministic direction finder for computing a second angle of arrival of the first wireless beam, the second angle of arrival being used by a second steering circuit in the second beamformer for determining a second antenna pattern to be directed toward the first antenna and nulling beams outside a second beam direction of the first antenna.

55. The method of claim 54 wherein the first and second directional antennas are movable relative to one another and the beamformer updates the direction of the signal over time in response to the relative movement of the antennas.

56. The method of claim 54 wherein the wireless beam is a radio frequency beam.

57. The method of claim 54 wherein the first transceiver is in a cellular mobile unit and the second transceiver is in a cellular base station.

58. The method of claim 54 wherein the locator includes input from a satellite positioning system.

59. The method of claim 54 wherein the locator includes input from a ground-based positioning system.

60. The method of claim 54 wherein the first transceiver is in a cellular base station and the second transceiver is in a cellular mobile unit.