Repeater system for strong signal environments

• US 6,993,287 B2
• Filed: 03/04/2004
• Issued: 01/31/2006
• Est. Priority Date: 03/04/2003
• Status: Active Grant

• Current Assignee: Cufer Asset Ltd LLC (Intellectual Ventures LLC)
• Original Assignee: Four Bars Clarity, LLC
• Inventors: O 'Neill, Frank P.
• Primary Examiner(s): Gesesse, Tilahun
• Assistant Examiner(s): Lee, John J.
• Application Number:
  US10/794,458
• Publication Number:
  US 20040176027A1
• Time in Patent Office: 698 Days
• Field of Search: 455/9, 455/11.1, 455/14, 455/15, 455/7, 455/25, 455/562.1, 455/422.1, 455/424, 455/509, 455/450, 455/452.1, 455/503, 455/63.1, 455/63.4, 455/67.11, 455/445, 455/446
• US Class Current: 455/11.1
• CPC Class Codes: H04B 7/15535 Control of relay amplifier gain amplifier gain control in general H03G3/00; gain control reducing self - or loop interference H04B7/15578
• CPC Class Codes: H04B 7/15571 by signal isolation, e.g. isolation by frequency or by antenna pattern, or by polarization
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A repeater system combines co-located antennas, limited and controlled downlink signal amplification, stability management and an amplification indicator to create a user-installed solution to co-channel interference within cellular systems, in strong signal environments such as elevated locations or high-rise building. The invention may be particularly relevant to cellular systems, such as CDMA, that allow limited imbalance between uplink and downlink path losses, thus enabling the design of an inexpensive downlink repeater which creates moderate signal amplification for selected line-of-sight signals, defeating co-channel interference over a small area. Signal amplification is maintained at a level below the capacity of the system to support imbalance, guaranteeing reliable cellular calls.

Claims

1. A repeater for a mobile communication system having a plurality of base stations and subscriber units that communicate via RF signals, comprising:

a receive antenna that is directed toward one of the base stations to receive transmitted RF signals from the base station, the receive antenna generating a received signal therefrom;

an amplifier receptive of the received signal, the amplifier amplifying the level of the received signal to generate an amplified signal; and

a transmit antenna located proximate to the receive antenna, the transmit antenna being receptive of the amplified signal, the transmit antenna transmitting RF signals within a local area to subscriber units located nearby;

wherein the repeater operates in the downlink direction between the base station and the subscriber units near the repeater and the presence of the repeater in the downlink direction causes an intentional imbalance in total losses between the downlink and the uplink directions.

2. A repeater as defined in claim 1, wherein the RF signals received by the receive antenna and the RF signals transmitted by the transmit antenna are at substantially the same frequency.

3. A repeater as defined in claim 1, further including a repeater housing in which the receive and transmit antennas are located.

4. A repeater as defined in claim 1, wherein the receive and transmit antennas are located within two meters of each other.

5. A repeater as defined in claim 1, wherein the amplifier provides an external indication of the magnitude of amplification.

6. A repeater as defined in claim 1, wherein the amplifier includes circuitry therein to substantially prevent saturation.

7. A repeater as defined in claim 6, wherein the circuitry substantially prevents saturation by periodically incrementing the magnitude of amplification toward an oscillation condition and testing for same.

8. A repeater as defined in claim 7, wherein the circuitry resets the magnitude of amplification to a smaller level during periodic testing for oscillation, and to a much smaller level for sudden occurrences of oscillation, in order to minimize the length of time for which steady amplification is interrupted.

9. A repeater as defined in claim 1, wherein the subscriber can optimally position the receive and transmit antennas of the repeater.

10. A repeater as defined in claim 9, wherein the subscriber uses received audio quality when using the subscriber unit to optimally position the receive and transmit antennas of the repeater.

11. A repeater as defined in claim 9, wherein the amplifier provides an external indication of the magnitude of amplification and wherein the subscriber uses the external indication to optimally position the receive and transmit antennas of the repeater.

12. A repeater as defined in claim 9, wherein the subscriber units include an indication of received signal strength and wherein the subscriber uses the indication to optimally position the receive and transmit antennas of the repeater.

13. A repeater as defined in claim 1, wherein the repeater is effective in substantially eliminating co-channel interference in the vicinity of the repeater.

14. A repeater as defined in claim 1, wherein the repeater is effective in substantially eliminating co-channel interference within ten meters of the repeater.

15. A repeater as defined in claim 1, wherein the subscriber units and the receive and transmit antennas of the repeater are all located in the vicinity of each other and all are in an environment receiving signals of adequate signal strength from multiple base stations.

16. A repeater as defined in claim 15, wherein the amplifier includes circuitry therein to substantially prevent saturation.

17. A repeater as defined in claim 1, wherein the mobile telecommunication system includes a downlink direction in which signals are transmitted from the base stations to the subscriber units and an uplink direction in which signals are transmitted from the subscriber units to the base stations and wherein the repeater system is employed in the downlink direction only.

18. A repeater as defined in claim 17, wherein the amplifier includes circuitry therein to substantially prevent saturation.

19. A repeater as defined in claim 18, wherein the amplifier provides an external indication of the magnitude of amplification.

20. A repeater as defined in claim 1, wherein the receive and transmit antennas are isolated from each other using cross-polarization achieved by mechanical orientation or by electrical rotation.

21. A repeater as defined in claim 1, wherein the receive and transmit antennas are isolated from each other using a metallic chassis.

22. A repeater as defined in claim 1, wherein the amplification is limited in magnitude to maintain the capacity of the mobile communications system to support link imbalance.

23. A repeater for a mobile communication system having a plurality of base stations and subscriber units that communicate via RF signals, comprising:

a receive antenna located in an environment receiving signals of adequate signal strength from multiple base stations, the receive antenna being directed toward one of the base stations to receive transmitted RF signals from the base station, the receive antenna generating a received signal therefrom;

an amplifier receptive of the received signal, the amplifier amplifying the level of the received signal to generate an amplified signal; and

a transmit antenna located proximate to the receive antenna and also located in an environment receiving signals of adequate signal strength from multiple base stations, the transmit antenna being receptive of the amplified signal, the transmit antenna transmitting RF signals within a local area to subscriber units located nearby and also receiving signals of adequate signal strength from multiple base stations;

wherein the mobile telecommunication system includes a downlink direction in which signals are transmitted from the base stations to the subscriber units and an uplink direction in which signals are transmitted from the subscriber units to the base stations, and wherein the presence of the repeater in the downlink direction causes an intentional imbalance in total losses between the downlink and the uplink directions.

24. A repeater as defined in claim 23, wherein the amplifier includes circuitry therein to substantially prevent saturation.

25. A repeater as defined in claim 23, wherein the amplification is limited in magnitude to maintain the capacity of the mobile communications system to support link imbalance.

26. A repeater for a mobile communication system having a plurality of base stations and subscriber units that communicate via RF signals, comprising:

a receive antenna located in an environment receiving signals of adequate signal strength from multiple base stations, the receive antenna being directed toward one of the base stations to receive transmitted RF signals from the base station, the receive antenna generating a received signal therefrom;

an amplifier receptive of the received signal, the amplifier amplifying the level of the received signal to generate an amplified signal; and

a transmit antenna located proximate to the receive antenna and also located in an environment receiving signals of adequate signal strength from multiple base stations, the transmit antenna being receptive of the amplified signal, the transmit antenna transmitting RF signals within a local area to subscriber units located nearby and also receiving signals of adequate signal strength from multiple base stations;

wherein the mobile telecommunication system includes a downlink direction in which signals are transmitted from the base stations to the subscriber units and an uplink direction in which signals are transmitted from the subscriber units to the base stations and wherein the repeater system is employed in the downlink direction only.

27. A repeater for a mobile communication system having a plurality of base stations and subscriber units that communicate via RF signals, comprising:

a receive antenna that is directed toward one of the base stations to receive transmitted RF signals from the base station, the receive antenna generating a received signal therefrom;

an amplifier receptive of the received signal, the amplifier amplifying the level of the received signal to generate an amplified signal; and

a transmit antenna located proximate to the receive antenna, the transmit antenna being receptive of the amplified signal, the transmit antenna transmitting RF signals within a local area to subscriber units located nearby;

wherein the receive and transmit antennas are located within two meters of each other;

wherein the mobile telecommunication system includes a downlink direction in which signals are transmitted from the base stations to the subscriber units and an uplink direction in which signals are transmitted from the subscriber units to the base stations and wherein the repeater system is employed in the downlink direction only.

28. A repeater as defined in claim 27, wherein the RF signals received by the receive antenna and the RF signals transmitted by the transmit antenna are at substantially the same frequency.

29. A repeater as defined in claim 27, further including a repeater housing in which the receive and transmit antennas are located.

30. A repeater as defined in claim 27, wherein the presence of the repeater in the downlink direction causes an intentional imbalance in total losses between the downlink and the uplink directions.

31. A repeater as defined in claim 30, wherein the amplifier includes circuitry therein to substantially prevent saturation.

32. A repeater as defined in claim 30, wherein the amplification is limited in magnitude to maintain the capacity of the mobile communication system to support link imbalance.

33. A repeater as defined in claim 27, wherein the amplifier includes circuitry therein to substantially prevent saturation.

34. A repeater as defined in claim 27, wherein the amplifier provides an external indication of the magnitude of amplification.

35. A repeater as defined in claim 27, wherein the subscriber can optimally position the receive and transmit antennas of the repeater.

36. A repeater as defined in claim 35, wherein the subscriber uses received audio quality when using the subscriber unit to optimally position the receive and transmit antennas of the repeater.

37. A repeater as defined in claim 35, wherein the amplifier provides an external indication of amplification and wherein the subscriber uses the external indication to optimally position the receive and transmit antennas of the repeater.

38. A repeater as defined in claim 35, wherein the subscriber units include an indication of received signal strength and wherein the subscriber uses the indication to optimally position the receive and transmit antennas of the repeater.

39. A repeater as defined in claim 27, wherein the repeater is effective in substantially eliminating co-channel interference in the vicinity of the repeater.

40. A repeater as defined in claim 27, wherein the repeater is effective in substantially eliminating co-channel interference within ten meters of the repeater.

41. A repeater as defined in claim 27, wherein the subscriber units and the receive and transmit antennas of the repeater are all located in the vicinity of each other and all are receiving signals of adequate signal strength from multiple base stations.

42. A repeater as defined in claim 27, wherein the receive and transmit antennas are isolated from each other using cross-polarization achieved by mechanical orientation or by electrical rotation.

43. A repeater as defined in claim 27, wherein the receive and transmit antennas are isolated from each other using a metallic chassis.

44. A repeater for a mobile communication system having a plurality of base stations and subscriber units that communicate via RF signals, comprising:

a receive antenna that is directed toward one of the base stations to receive transmitted RF signals from the base station, the receive antenna generating a received signal therefrom;

an amplifier receptive of the received signal, the amplifier amplifying the level of the received signal to generate an amplified signal, the amplifier including circuitry therein to substantially prevent saturation by periodically incrementing the magnitude of amplification toward an oscillation condition and testing for same; and

a transmit antenna located proximate to the receive antenna, the transmit antenna being receptive of the amplified signal, the transmit antenna transmitting RF signals within a local area to subscriber units located nearby.

45. A repeater as defined in claim 44, wherein the RF signals received by the receive antenna and the RF signals transmitted by the transmit antenna are at substantially the same frequency.

46. A repeater as defined in claim 44, further including a repeater housing in which the receive and transmit antennas are located.

47. A repeater as defined in claim 44, wherein the receive and transmit antennas are located within two meters of each other.

48. A repeater as defined in claim 44, wherein the mobile telecommunication system includes a downlink direction in which signals are transmitted from the base stations to the subscriber units and an uplink direction in which signals are transmitted from the subscriber units to the base stations, and wherein the presence of the repeater in the downlink direction causes an intentional imbalance in total losses between the downlink and the uplink directions.

49. A repeater as defined in claim 48, wherein the amplification is limited in magnitude to maintain the capacity of the mobile communication system to support link imbalance.

50. A repeater as defined in claim 44, wherein the amplifier provides an external indication of the magnitude of amplification.

51. A repeater as defined in claim 44, wherein the subscriber can optimally position the receive and transmit antennas of the repeater.

52. A repeater as defined in claim 51, wherein the subscriber uses received audio quality when using the subscriber unit to optimally position the receive and transmit antennas of the repeater.

53. A repeater as defined in claim 51, wherein the amplifier provides an external indication of amplification and wherein the subscriber uses the external indication to optimally position the receive and transmit antennas of the repeater.

54. A repeater as defined in claim 51, wherein the subscriber units include an indication of received signal strength and wherein the subscriber uses the indication to optimally position the receive and transmit antennas of the repeater.

55. A repeater as defined in claim 44, wherein the repeater is effective in substantially eliminating co-channel interference in the vicinity of the repeater.

56. A repeater as defined in claim 44, wherein the repeater is effective in substantially eliminating co-channel interference within ten meters of the repeater.

57. A repeater as defined in claim 44, wherein the subscriber units and the receive and transmit antennas of the repeater are all located in the vicinity of each other and all are receiving signals of adequate signal strength from multiple base stations.

58. A repeater as defined in claim 44, wherein the mobile telecommunication system includes a downlink direction in which signals are transmitted from the base stations to the subscriber units and an uplink direction in which signals are transmitted from the subscriber units to the base stations and wherein the repeater system is employed in the downlink direction only.

59. A repeater as defined in claim 44, wherein the receive and transmit antennas are isolated from each other using cross-polarization achieved by mechanical orientation or by electrical rotation.

60. A repeater as defined in claim 44, wherein the receive and transmit antennas are isolated from each other using a metallic chassis.

61. A repeater as defined in claim 44, wherein the saturation-prevention circuitry resets the magnitude of amplification to a smaller level during periodic testing for oscillation, and to a much smaller level for sudden occurrences of oscillation, in order to minimize the length of time for which steady amplification is interrupted.

62. A method for substantially eliminating co-channel interference in a local area containing subscriber units receiving adequate signals from a plurality of base stations, comprising:

co-locating a transmit antenna and a receive antenna within an environment receiving signals of adequate signal strength from multiple base stations to provide downlink-only amplification;

further including substantially preventing saturation by periodically testing for oscillation with a minimum of service interruption and then setting the amplification to a maximum magnitude.