COMMUNICATION SYSTEM USING GEOGRAPHIC POSITION DATA

• US 20010003443A1
• Filed: 11/09/1998
• Published: 06/14/2001
• Est. Priority Date: 10/10/1996
• Status: Active Grant

• Current Assignee: Teratech Corporation
• Original Assignee: Teratech Corporation
• Inventors: CHIANG, ALICE M., VELAZQUEZ, SCOTT R., BROADSTONE, STEVEN R.
• Granted Patent: US 6,593,880 B2
• Time in Patent Office: Days
• 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. The system can be optimized by applying partially adaptive processing algorithms, which are seeded by geo-location data.

Claims

1. 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 the physical location of the second antenna relative to the first antenna;

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

a first beamformer in the first transceiver for shaping the wireless beam to be directed between the first antenna and the second antenna.

2. The system of

claim 1

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

3. The system of

claim 1

wherein the wireless beam is a radio frequency beam.

4. The system of

claim 1

wherein the first transceiver is in a base station and the second transceiver is in a mobile unit.

5. The system of

claim 1

wherein the first transceiver is in a mobile unit and the second transceiver is in a base station.

6. The system of

claim 1

wherein the locator is responsive to location data from a satellite positioning system.

7. The system of

claim 1

wherein the locator is responsive to location data from a ground-based positioning system.

8. The system of

claim 1

wherein the beamformer includes a nulling circuit for suppressing signals outside of the direction of the second antenna.

9. The system of

claim 1

wherein the beamformer includes an adaptive processing module to alter the shape of the wireless beam over time.

10. A cellular communication system comprising:

a base transceiver having a directional base antenna, the base antenna having a fixed geographical position within the cell;

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

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

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

a beamformer in the base transceiver for modifying the signal in response to the relative motion of the antennas; and

a nulling module coupled to the beamformer for suppressing interference to the signal.

11. The system of

claim 10

wherein the beamformer updates the shape of the signal over time.

12. The system of

claim 10

wherein the signal is a radio frequency beam.

13. The system of

claim 10

wherein the positioning system is responsive to position data from a satellite positioning system.

14. The system of

claim 10

wherein the positioning system is responsive to position data from a ground-based positioning system.

15. The system of

claim 10

wherein the beamformer includes a plurality of programmable filter arrays.

16. The system of

claim 10

further comprising a table of stored antenna weights stored in memory, the table accessed by the nulling module to modify the signal.

17. The system of

claim 10

further comprising an adaptive processing module to alter the shape of the beam over time.

18. The system of

claim 10

wherein the mobile antenna is a directional antenna.

19. The system of

claim 10

wherein the communication link is spatially multiplexed.

20. A method for operating a communication system comprising:

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

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

in a first beamformer in the first transceiver, responding to the physical location of the second antenna and shaping the wireless beam to be directed between the first antenna and the second antenna.

21. The method of

claim 20

further comprising the steps of:

moving the first and second antennas relative to one another; and

in the beamformer, updating the direction of the signal over time in response to the relative movement.

22. The method of

claim 20

wherein the first wireless beam is a radio frequency beam.

23. The method of

claim 20

wherein the first transceiver is in a base station and the second transceiver is in a mobile unit.

24. The method of

claim 20

wherein the first transceiver is in a mobile unit and the second transceiver is in a base station.

25. The method of

claim 20

wherein the locator is responsive to position data from a satellite positioning system.

26. The method of

claim 20

wherein the locator is responsive to position data from a ground-based positioning system.

27. The method of

claim 20

wherein the beamformer includes a nulling circuit to suppress signals outside the direction of the second antenna.

28. The method of

claim 20

wherein the beamformer includes an adaptive processing module for altering the shape of the wireless beam over time.

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

operating a base transceiver having a directional base antenna, the base antenna having a fixed geographical position within a cell;

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

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

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

in a beamformer in the base transceiver, modifying the signal in response to the relative motion of the antennas; and

in a nulling module coupled to the beamformer, suppressing interference with the signal.

30. The method of

claim 29

wherein the step of modifying the signal comprises updating the direction of the signal over time in response to relative motion between the antennas.

31. The method of

claim 29

wherein the signal is a radio frequency beam.

32. The method of

claim 29

wherein the step of detecting comprises receiving position data from a satellite positioning system.

33. The method of

claim 29

wherein the step of detecting comprises receiving position data from a ground-based positioning system.

34. The method of

claim 29

wherein the beamformer includes a plurality of programmable filter arrays.

35. The method of

claim 29

wherein the step of modifying the signal comprises providing antenna weights from a table stored in memory.

36. The method of

claim 29

wherein the step of modifying includes adaptively altering the shape of the signal over time.

37. The method of

claim 29

wherein the mobile antenna is a directional antenna.

38. The method of

claim 29

wherein the step of forming a communication link comprises spatially multiplexing the signal within the cell.

39. A cellular communication system comprising:

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

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

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

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

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.

40. The system of

claim 39

wherein the beamformers update the direction of the signal over time in response to the relative movement between the antennas.

41. The system of

claim 39

wherein the beamformers modify the signal to be omnidirectional when the antennas are separated by less than a specific range.

42. The system of

claim 39

wherein the signal is a radio frequency beam.

43. The system of

claim 39

wherein the positioning system is responsive to position data from a satellite positioning system.

44. The system of

claim 39

wherein the positioning system is responsive to position data from a ground-based positioning system.

45. The system of

claim 39

wherein the beamformers include a plurality of programmable filter arrays.

46. The system of

claim 39

further comprising a table stored in memory for providing antenna weights to the beamformer to modify the signal.

47. The system of

claim 39

further comprising an adaptive processing module coupled to the beamformer to alter the shape of the signal over time.

48. The system of

claim 39

further comprising a nulling module coupled to the beamformer to suppress interference with the signal.

49. The system of

claim 39

wherein the communication link includes a spatially multiplexed signal.

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

operating a base transceiver having a directional base antenna, the base antenna having a fixed geographical position within a cell;

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

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

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

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.

51. The method of

claim 50

wherein the step of modifying the signal comprises updating the direction of the signal over time in response to the relative movement of the antennas.

52. The method of

claim 50

wherein the step of modifying comprises determining the range between the base antenna and the mobile antenna and, when the range is less than a specific range, modifying the signal to be omnidirectional.

53. The method of

claim 50

wherein the signal is a radio frequency beam.

54. The method of

claim 50

wherein the step of detecting comprises receiving position data from a satellite positioning system.

55. The method of

claim 50

wherein the step of detecting comprises receiving position data from a ground-based positioning system.

56. The method of

claim 50

wherein the beamformers include a plurality of programmable filter arrays.

57. The method of

claim 50

wherein the step of modifying the signal comprises providing antenna weights from a table stored in memory.

58. The method of

claim 50

wherein the step of modifying the signal comprises performing adaptive processing to alter the shape of the signal over time.

59. The method of

claim 50

wherein the step of modifying the signal comprises suppressing interference with the signal in a nulling module.

60. The method of

claim 50

wherein the step of forming the communication link comprises a spatially multiplex signal.

61. A beamforming circuit for a communication system comprising:

a plurality of sampling circuits for receiving communication signals;

a plurality of programmable finite impulse response (FIR) filters, each FIR filter being connected to a sampling circuit;

a summing circuit that sums filtered signals from the plurality of FIR filters; and

a directional wireless signal formed from the summed signals.

62. The circuit of

claim 61

wherein the sampling circuits, the plurality of programmable FIR filters and the summing circuit are formed on a single integrated circuit.

63. The circuit of

claim 61

further comprising a multiplier connected to each sampling circuit to generate an in-phase channel and a quadrature channel, each channel being connected to a filter, a converter and one of the FIR filters.

64. The circuit of

claim 61

wherein the communication system comprises a cellular network including a plurality of transceivers that communicate by wireless link with mobile transceiver units, and further including a base station having an adaptive array processor providing weighting signals to the FIR filters.