Polarization diversity phased array cellular base station and associated methods

• US 5,724,666 A
• Filed: 05/11/1995
• Issued: 03/03/1998
• Est. Priority Date: 03/24/1994
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul W.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Nguyen, Lee
• Application Number:
  US08/439,116
• Time in Patent Office: 1,027 Days
• Field of Search: 455/33.3, 455/33.4, 455/33.1, 455/56.1, 455/272, 455/273, 455/275, 455/277.1, 455/277.2, 455/279.1, 455/101-103, 455/132-135, 343/700 MS, 343/890, 343/893, 342/361, 342/371, 370/915, 370/337, 370/347, 370/344, 379/59, 379/60
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/0428 radiating a circular polarised wave
• CPC Class Codes: H01Q 9/0435 using two feed points
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A base station includes first and second antenna arrays for receiving first and second rotational polarizations, and a polarization diversity receiver connected to the first and second antenna arrays for processing respective first and second receive signals from a mobile station to generate an enhanced quality output receive signal based upon polarization diversity reception. Polarization isolation between the transmit and receive antenna elements may also provided by having a first plurality of transmit antenna elements for the second polarization mounted on a substrate carrying the first receive antenna elements. The second antenna array includes a second plurality of antenna elements of second polarization on a substrate carrying the second receive antenna elements. To achieve polarization diversity gain at the mobile station, the base station preferably further includes an alternating polarization transmitter for alternately transmitting signals at respective alternating first and second rotational polarizations. Method aspects of the invention are also disclosed.

Claims

1. A base station for communicating with at least one mobile station in a cellular communications system, said base station comprising:

a first antenna array comprising a first plurality of receive antenna elements for receiving signals having a first polarization and being oriented to define a first receive coverage area;

a second antenna array comprising a second plurality of receive antenna elements for receiving signals having a second polarization different from said first polarization and being oriented to define a second receive coverage area;

antenna mounting means for mounting said first and second antenna arrays so that said first and second receive coverage areas are overlapping; and

polarization diversity receiver means connected to said first and second pluralities of receive antenna elements for processing respective first and second receive signals having said first and second polarizations from a mobile station in said overlapping area to generate an enhanced quality output receive signal based upon polarization diversity reception;

wherein said first antenna array further comprises a first plurality of transmit antenna elements arranged in a predetermined pattern for transmitting signals having said second polarization to thereby provide polarization isolation from said first plurality of receive antenna elements; and

wherein said second antenna array comprises a second plurality of transmit antenna elements arranged in a predetermined pattern for transmitting signals having said first polarization to thereby provide polarization isolation from said second plurality of receive antenna elements.

2. An apparatus according to claim 1 wherein said polarization diversity receiver means comprises signal quality determining means for determining signal-to-noise ratios of said first and second receive signals, and weighting means for weighting said first and second receive signals based upon said respective signal-to-noise ratios thereof to generate the enhanced quality output receive signal.

3. A base station according to claim 1 wherein said polarization diversity receiver means further comprises means for separating said first and second receive signals into a plurality of respective individual channels based upon frequency and for processing each of said individual channels to generate a respective enhanced quality output receive signal.

4. A base station according to claim 1 wherein said polarization diversity receiver means further comprises means for separating said first and second receive signals into a plurality of respective individual channels based upon time slot and for processing each of said individual channels to generate a respective enhanced quality output receive signal.

5. A base station according to claim 1 wherein a respective one of said receive antenna elements of said first antenna array and a respective one of said transmit antenna elements of said first antenna array are provided on a common patch antenna for receiving signals having said first polarization and transmitting signals having said second polarization.

6. A base station according to claim 1 further comprising alternating polarization transmitter means connected to said first and second pluralities of transmitter antenna elements for alternately transmitting signals at respective alternating first and second rotational polarizations to provide enhanced received signal quality at a mobile station.

7. A base station according to claim 6 further comprising transmitter coding means connected to said alternating polarization transmitter means for generating coded and interleaved time division multiple access signals transmitted from said first and second antenna arrays to a mobile station.

8. A base station according to claim 1 wherein said first antenna array comprises an elongate substrate carrying said first plurality of receive antenna elements and said first plurality of transmit antenna elements extending in a vertical direction;

and wherein said second antenna array comprises a second elongate substrate adjacent said first elongate substrate and carrying said second plurality of receive antenna elements and said second plurality of transmit antenna elements extending in a vertical direction.

9. A base station according to claim 8 wherein each of said first and second antenna arrays further comprises a plurality of transmit amplifiers on said elongate substrate and connected to respective transmit antenna elements to thereby define an active phased array antenna.

10. A base station according to claim 8 wherein each receive antenna element comprises an electrically conductive portion on a respective elongate substrate, and wherein each transmit antenna element comprises an electrically conductive portion on a respective elongate substrate.

11. A base station according to claim 8 wherein each of said first and second array antennas further comprises receive in-phase coupling means on said elongate substrate and operatively connected to respective receive antenna elements for combining signals therefrom in-phase with one another;

and wherein each of said first and second array antennas further comprises transmit in-phase coupling means on said elongate substrate and operatively connected to respective transmit antenna elements for distributing signals delivered thereto in-phase with one another.

12. A base station according to claim 8 wherein each of said first and second antenna arrays further comprises a radio-transparent housing surrounding said elongate substrate.

13. A base station according to claim 1 wherein said first plurality of receive antenna elements comprises means for receiving right-hand-circular polarization, and wherein said second plurality of receive antenna elements comprises means for receiving left-hand-circular polarization.

14. A base station for communicating with at least one mobile station in a cellular communications system, said base station comprising:

a first antenna array comprising a first elongate substrate and a first plurality of receive antenna elements for receiving signals having a first polarization and being arranged on said first elongate substrate in a predetermined pattern to define a first receive coverage area;

a second antenna array comprising a second elongate substrate and a second plurality of receive antenna elements for receiving signals having a second polarization different from said first polarization and being arranged on said second elongate substrate in a predetermined pattern to define a second receive coverage area overlapping with said first receive coverage area; and

polarization diversity receiver means connected to said first and second pluralities of receive antenna elements for processing respective first and second receive signals received from a mobile station to generate an enhanced quality output receive signal based upon polarization diversity reception;

wherein said first antenna array further comprises a first plurality of transmit antenna elements arranged in a predetermined pattern on said first elongate substrate for transmitting signals having said second polarization to thereby provide polarization isolation from said first plurality of receive antenna elements; and

wherein said second antenna array comprises a second plurality of transmit antenna elements arranged in a predetermined pattern on said second elongate substrate for transmitting signals having said first polarization to thereby provide polarization isolation from said second plurality of receive antenna elements.

15. An apparatus according to claim 14 wherein said polarization diversity receiver means comprises signal quality determining means for determining signal-to-noise ratios of said first and second receive signals, and weighting means for weighting said first and second receive signals based upon the respective signal-to-noise ratios thereof to generate the enhanced quality output receive signal.

16. A base station according to claim 14 wherein said polarization diversity receiver means further comprises means for separating said first and second receive signals into a plurality of respective individual channels based upon frequency and for processing each of said individual channels to generate a respective enhanced quality output receive signal.

17. A base station according to claim 14 wherein said polarization diversity receiver means further comprises means for separating said first and second receive signals into a plurality of respective individual channels based upon time slot and for processing each of said individual channels to generate a respective enhanced quality output receive signal.

18. A base station according to claim 14 wherein a respective one of said receive antenna elements of said first antenna array and a respective one of said transmit antenna elements of said first antenna array are provided on a common patch antenna for receiving signals having said first polarization and transmitting signals having said second polarization.

19. A base station according to claim 14 further comprising alternating polarization transmitter means connected to said first and second pluralities of transmitter antenna elements for alternately transmitting signals at respective alternating first and second polarizations to provide enhanced received signal quality at a mobile station.

20. A base station according to claim 19 further comprising transmitter coding means connected to said alternating polarization transmitter means for generating coded and interleaved time division multiple access signals transmitted from said first and second antenna arrays to a mobile station.

21. A base station according to claim 14 wherein each of said first and second antenna arrays further comprises a plurality of transmit amplifiers on said elongate substrate and connected to respective transmit antenna elements to thereby define an active phased array antenna.

22. A base station according to claim 14 wherein each of said first and second array antennas further comprises receive in-phase coupling means on said elongate substrate and operatively connected to respective receive antenna elements for combining signals therefrom in-phase with one another;

and wherein each of said first and second array antennas further comprises transmit in-phase coupling means on said elongate substrate and operatively connected to respective transmit antenna elements for distributing signals delivered thereto in-phase with one another.

23. A base station according to claim 14 wherein each of said first and second antenna arrays further comprises a radio-transparent housing surrounding said elongate substrate.

24. A base station according to claim 14 wherein said first plurality of receive antenna elements comprises means for receiving right-hand-circular polarization, and wherein said second plurality of receive antenna elements comprises means for receiving left-hand-circular polarization.

25. A cellular base station for communicating with at least one mobile station in a cellular communications system over one of a plurality of cellular communications channels, said base station comprising:

a first antenna array comprising a first plurality of transmit antenna elements for transmitting signals having a first polarization to the mobile station over the cellular communications channel and being arranged in a predetermined pattern to define a first transmit coverage area;

a second antenna array comprising a second plurality of transmit antenna elements for transmitting signals having a second polarization different from said first polarization to the mobile station over the cellular communications channel and being arranged in a predetermined pattern to have a second transmit coverage area overlapping with said first transmit coverage area; and

alternating polarization transmitter means operatively connected to said first and second antenna arrays for alternately transmitting signal segments from said first and second antenna arrays to the mobile station to provide enhanced received signal quality at the mobile station;

wherein said first antenna array further comprises a first plurality of receive antenna elements arranged in a predetermined pattern for receiving signals having said second polarization from the mobile station over the cellular communications channel to thereby provide polarization isolation from said first plurality of transmit antenna elements; and

wherein said second antenna array further comprises a second plurality of receive antenna elements arranged in a predetermined pattern for receiving signals having said first polarization from the mobile station over the cellular communications channel to thereby provide polarization isolation from said second plurality of transmit antenna elements.

26. A base station according to claim 25 further comprising transmitter coding means connected to said alternating polarization transmitter means for generating coded and interleaved time division multiple access signals transmitted from said first and second antenna arrays to a mobile station.

27. A base station according to claim 25 wherein said first antenna array comprises an elongate substrate carrying said first plurality of transmit antenna elements extending in a vertical direction;

and wherein said second antenna array comprises a second elongate substrate adjacent said first elongate substrate and carrying said second plurality of transmit antenna elements extending in a vertical direction.

28. A base station according to claim 27 wherein each of said first and second antenna arrays further comprises a plurality of transmit amplifiers on said elongate substrate and connected to respective transmit antenna elements to thereby define an active phased array antenna.

29. A base station according to claim 27 wherein each of said first and second array antennas further comprises transmit in-phase coupling means on said elongate substrate and operatively connected to respective transmit antenna elements for combining signals delivered thereto in-phase with one another.

30. A base station according to claim 27 wherein each of said first and second antenna arrays further comprises a radio-transparent housing surrounding said elongate substrate.

31. A base station according to claim 25 wherein said first plurality of transmit antenna elements comprises means for transmitting left-hand-circular polarization, and wherein said second plurality of transmit antenna elements comprises means for transmitting right-hand-circular polarization.

32. A base station for communicating with at least one mobile station in a cellular communications system, said base station comprising:

a first antenna array comprising

a first plurality of receive antenna elements for receiving signals having a first polarization and being arranged in a predetermined pattern to define a first receive coverage area,

a first plurality of transmit antenna elements arranged in a predetermined pattern for transmitting signals having a second polarization different from said first polarization to define a first transmit coverage area and to thereby provide polarization isolation from said first plurality of receive antenna elements;

a second antenna array comprising

a second plurality of receive antenna elements for receiving signals having said second polarization and being arranged in a predetermined pattern to define a second receive coverage area overlapping said first receive coverage area, and

a second plurality of transmit antenna elements for transmitting signals having said

first polarization and being arranged in a predetermined pattern to define a second transmit coverage area overlapping said first transmit coverage area and to thereby provide polarization isolation from said second plurality of receive antenna elements;

polarization diversity receiver means connected to said first and second pluralities of receive antenna elements for processing respective first and second receive signals received from a mobile station to generate an enhanced quality output receive signal based upon polarization diversity reception; and

alternating polarization transmitter means connected to said first and second pluralities of transmitter antenna elements for alternately transmitting signals at respective alternating first and second polarizations to provide enhanced received signal quality at a mobile station.

33. A base station according to claim 32 wherein said polarization diversity receiver means further comprises means for separating said first and second receive signals into a plurality of respective individual channels based upon frequency and for processing each of said individual channels to generate a respective enhanced quality output receive signal.

34. A base station according to claim 32 wherein said polarization diversity receiver means further comprises means for separating said first and second receive signals into a plurality of respective individual channels based upon time slot and for processing each of said individual channels to generate a respective enhanced quality output receive signal.

35. A base station according to claim 32 further comprising transmitter coding means connected to said alternating polarization transmitter means for generating coded and interleaved time division multiple access signals transmitted from said first and second antenna arrays to a mobile station.

36. A base station according to claim 32 wherein said first antenna array comprises an elongate substrate carrying said first plurality of receive antenna elements and said first plurality of transmit antenna elements extending in a vertical direction;

and wherein said second antenna array comprises a second elongate substrate adjacent said first elongate substrate and carrying said second plurality of receive antenna elements and said second plurality of transmit antenna elements extending in a vertical direction.

37. A base station according to claim 36 wherein a respective one of said receive antenna elements of said first antenna array and a respective one of said transmit antenna elements of said first antenna array are provided on a common patch antenna for receiving signals having said first polarization and transmitting signals having said second polarization.

38. A method for operating a cellular base station for communicating with at least one mobile station, the method comprising the steps of:

receiving a first signal from a mobile station at a first polarization;

receiving a second signal from said mobile station at a polarization different from said first polarization;

processing said first and second receive signals to generate an enhanced quality output receive signal based upon polarization diversity reception wherein said step of receiving said first signal comprises receiving same via a first plurality of receive antenna elements arranged in a predetermined pattern, and wherein said step of receiving said second signal comprises receiving same via a second plurality of receive antenna elements arranged in a predetermined pattern;

transmitting signals having said second polarization from adjacent said first plurality of receive antenna elements to thereby provide polarization isolation; and

transmitting signals having said first polarization from adjacent said second plurality of receive antenna elements to thereby provide polarization isolation.

39. A method according to claim 38 wherein said step of processing comprises determining signal-to-noise ratios of said first and second receive signals, and weighting said first and second receive signals based upon said respective signal-to-noise ratios thereof to generate the enhanced quality output receive signal.

40. A method according to claim 38 further comprising the step of separating said first and second receive signals into a plurality of respective individual channels based upon frequency and processing each of said individual channels to generate a respective enhanced quality output receive signal.

41. A method according to claim 38 further comprising the step of separating said first and second receive signals into a plurality of respective individual channels based upon time slot and processing each of said individual channels to generate a respective enhanced quality output receive signal.

42. A method according to claim 38 wherein said step of receiving said first signal comprises receiving same via a first plurality of receive antenna elements arranged in a predetermined pattern, and wherein said step of receiving said second signal comprises receiving same via a second plurality of receive antenna elements arranged in a predetermined pattern.

43. A method according to claim 38 further comprising the step of alternately transmitting signals at respective alternating first and second polarizations to provide enhanced received signal quality at a mobile station.

44. A method according to claim 43 further comprising the step of generating coded and interleaved time division multiple access signals transmitted to said mobile station.

45. A method according to claim 38 wherein said step of receiving said first polarization comprises receiving right-hand-circular polarization, and wherein said step of receiving said second polarization comprises receiving left-hand-circular polarization.

46. A cellular base station for communicating with at least one mobile station in a cellular communications system over one of a plurality of cellular communications channels, said base station comprising:

a plurality of receive antennas, a first one of said receive antennas for receiving signals having a first polarization from the mobile station over the cellular communications channel and defining a first receive coverage area, and a second one of said receive antennas adjacent said first receive antenna for receiving signals having a second polarization from the mobile station over the cellular communications channel and defining a second receive coverage area;

support means for supporting said plurality of antennas such that said first and second receive antennas are oriented so that said first and second receive coverage areas overlap thereby defining an overlap receive coverage area; and

a plurality of polarization diversity receivers, each of said polarization diversity receivers being connected to at least two adjacent receive coverage antennas, a first one of said polarization diversity receivers being connected to said first and second receive antennas for processing respective first and second receive signals having said first and second polarizations and received from the mobile station in said overlap receive coverage area to generate an enhanced quality output receive signal based upon polarization diversity reception;

a plurality of transmit antennas, a first one of said transmit antennas for transmitting signals having said second polarization to the mobile station over the cellular communications channel and defining a first transmit coverage area, and a second one of said transmit antennas for transmitting signals having said first polarization to the mobile station over the cellular communications channel and defining a second transmit coverage area, wherein said support means supports said first and second transmit antennas so that said first and second transmit coverage areas overlap, so that said first receive coverage area and said first transmit coverage area overlap, and so that said second receive coverage area and said second transmit coverage area overlap.

47. A base station according to claim 46 wherein said first polarization comprises right hand circular polarization and said second polarization comprises left hand circular polarization.

48. A cellular base station according to claim 46 wherein said first receive antenna and said first transmit antenna are provided as a first transmit and receive antenna, and wherein said second receive antenna and said second transmit antenna are provided as a second transmit and receive antenna.

49. A base station for communicating with at least one mobile station in a cellular communications system, said base station comprising:

a plurality of antennas, a first one of said antennas receiving signals having a first polarity and transmitting signals having a second polarity and defining a first coverage area, and a second one of said antennas receiving signals having said second polarity and transmitting signals having said first polarity and defining a second coverage area;

support means for supporting said plurality of antennas such that said first and second coverage areas overlap thereby defining an overlap coverage area; and

a plurality of polarization diversity receivers, each of said polarization diversity receivers being connected to at least two antennas, one of said polarization diversity receivers being connected to said first and second antennas for processing respective first and second receive signals having said first and second polarizations and received from a mobile station in said overlap coverage area to generate an enhanced quality output receive signal based upon polarization diversity reception.

50. A base station according to claim 49 further comprising:

transmit means connected to each of said antennas, said transmit means providing said first transmit signals having said second polarity to said first antenna and providing said second transmit signals having said first polarity to said second antenna; and

control means connected to said transmit means for alternately providing said first transmit signal to said first antenna and said second transmit signal to said second antenna so that a mobile station in said overlap coverage area alternately receives said first transmit signal having said second polarity and said second transmit signal having said second polarity.

51. A base station according to claim 50 wherein said control means alternately provides said first transmit signal to said first antenna and said second transmit signal to said second antenna based on said first and second receive signals received by said polarization diversity receiver connected to said first and second antennas.

52. A cellular base station for communicating with at least one mobile station in a cellular communications system over one of a plurality of cellular communications channels, said base station comprising:

a first antenna defining a first coverage area, wherein said first antenna receives signals having a first polarization from the mobile station over the cellular communications channel and transmits signals having a second polarization to the mobile station over the cellular communications channel to thereby provide polarization isolation;

a second antenna adjacent said first antenna defining a second coverage area, wherein said second antenna receives signals having said second polarization from the mobile station over the cellular communications channel and transmits signals having said first polarization to the mobile station over the cellular communications channel to thereby provide polarization isolation; and

support means for supporting said first and second receive antennas so that said first and second coverage areas overlap thereby defining an overlap coverage area.

53. A cellular base station according to claim 52 further comprising a polarization diversity receiver connected to said first and second antennas for processing respective first and second receive signals having said first and second polarizations and received from the mobile station in said overlap coverage area to generate an enhanced quality output receive signal based upon polarization diversity reception.

54. A cellular base station according to claim 52 further comprising alternating polarization transmitter means operatively connected to said first and second antennas for alternately transmitting signal segments from said first and second antennas to the mobile station to provide enhanced received signal quality at the mobile station.