System and method of radio transmission between a radio transmitter and radio receiver

• US 6,169,485 B1
• Filed: 08/25/1999
• Issued: 01/02/2001
• Est. Priority Date: 12/06/1995
• Status: Expired due to Term

• Current Assignee: NTP Incorporated
• Original Assignee: NTP Incorporated
• Inventors: Campana, Thomas J. Jr.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US09/382,777
• Time in Patent Office: 496 Days
• Field of Search: 340/573.1, 340/573.3, 340/573.4, 340/572.4, 455/296, 342/118, 342/147
• US Class Current: 340/573.4
• CPC Class Codes: G08B 21/0222 Message structure or message content, e.g. message protocol
• CPC Class Codes: G08B 21/0227 System arrangements with a plurality of child units
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions
• CPC Class Codes: G08B 21/0247 System arrangements wherein the alarm criteria uses signal strength
• CPC Class Codes: G08B 21/0263 System arrangements wherein the object is to detect the direction in which child or item is located
• CPC Class Codes: G08B 25/007 Details of data content structure of message packets; data protocols
• CPC Class Codes: H04B 17/18 Monitoring during normal operation
• CPC Class Codes: H04B 17/23 Indication means, e.g. displays, alarms, audible means
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence

Abstract

An antenna assembly providing selectable omnidirectional or directional reception of radio transmissions in a frequency band in accordance with the invention includes an electrically conductive reflector (432) defining a cavity (702) having a bottom (708), an opening (714) and a surface (704 and 706) extending from the bottom to the opening and an electrical output (763); an electrically conductive loop (431) coupled to ground and having an electrical outlet (766) for coupling to an RF amplifier (407), the loop being positioned between the bottom opening of the cavity; a RF switch (406) having an input (760) and first and second outputs (762 and 764), the RF switch having a first switching state electrically connecting the input to the first output and a second switching state electrically connecting the input to the second output, the first switch output being electrically coupled to ground and the second switch output being electrically coupled to the output of the electrically conductive loop; and wherein the first switching state provides the directional reception and the second switching state provides the omnidirectional reception of the radio transmissions.

Claims

1. A system comprising:

at least one transmitter, each transmitter periodically transmitting transmissions containing an identification thereof; and

a receiver which receives the periodic transmissions from the at least one transmitter, the receiver in response to identifying the periodic transmissions from the at least one transmitter processes signal fluctuations in each received periodic transmission to produce a signal having the fluctuations removed therefrom and processes a plurality of the signals having the fluctuations removed to produce a composite signal.

2. A system in accordance with claim 1 wherein:

the periodic transmissions are by a radio carrier from the at least one transmitter to the radio receiver.

3. A system in accordance with claim 2 wherein:

the radio carrier during the periodic transmissions hops to different frequencies.

4. A system in accordance with claim 3 wherein:

the processing of the signal fluctuations is an integration; and

the processing of the plurality of signals to produce the composite signal is an integration of the plurality of signals.

5. A system in accordance with claim 4 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

6. A system in accordance with claim 4 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

7. A system in accordance with claim 3 wherein:

the processing of the signal fluctuations is an averaging process; and

the processing of the plurality of signals to produce the composite signal is an averaging of the plurality of signals.

8. A system in accordance with claim 7 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

9. A system in accordance with claim 7 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

10. A system in accordance with claim 3 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

11. A system in accordance with claim 3 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

12. A system in accordance with claim 3 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

13. A system in accordance with claim 2 wherein:

the processing of the signal fluctuations is an integration; and

the processing of the plurality of signals to produce the composite signal is an integration of the plurality of signals.

14. A system in accordance with claim 13 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

15. A system in accordance with claim 13 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

16. A system in accordance with claim 2 wherein:

the processing of the signal fluctuations is an averaging process; and

the processing of the plurality of signals to produce the composite signal is an averaging of the plurality of signals.

17. A system in accordance with claim 16 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

18. A system in accordance with claim 16 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

19. A system in accordance with claim 2 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

20. A system in accordance with claim 2 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

21. A system in accordance with claim 2 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

22. A system in accordance with claim 1 wherein:

the processing of the signal fluctuations is an integration; and

the processing of the plurality of signals to produce the composite signal is an integration of the plurality of signals.

23. A system in accordance with claim 22 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

24. A system in accordance with claim 22 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

25. A system in accordance with claim 22 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

26. A system in accordance with claim 1 wherein:

the processing of the signal fluctuations is an averaging process; and

the processing of the plurality of signals to produce the composite signal is an averaging of the plurality of signals.

27. A system in accordance with claim 26 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

28. A system in accordance with claim 26 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

29. A system in accordance with claim 26 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

30. A system in accordance with claim 1 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

31. A system in accordance with claim 30 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

32. A system in accordance with claim 1 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

33. A system in accordance with claim 32 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

34. A system in accordance with claim 1 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

35. In a system having at least one transmitter with each transmitter periodically transmitting transmissions containing an identification of the transmitter and a receiver which receives the periodic transmissions, the receiver comprising:

at least one processor, the at least one processor identifies the periodic transmissions and in response to identifying the periodic transmissions from the at least one transmitter processes signal fluctuations in each received periodic transmission to produce a signal having the fluctuations removed therefrom and processes a plurality of the signals having the fluctuations removed to produce a composite signal.

36. A receiver in accordance with claim 35 wherein:

the periodic transmissions are by a radio carrier from the at least one transmitter to the radio receiver.

37. A receiver in accordance with claim 36 wherein:

the radio carrier during the periodic transmission hops to different frequencies.

38. A receiver in accordance with claim 37 wherein:

the processing of the signal fluctuations is an integration; and

the processing of the plurality of signals having the fluctuations removed is an integration of the plurality of signals.

39. A receiver in accordance with claim 38 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

40. A receiver in accordance with claim 38 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

41. A receiver in accordance with claim 37 wherein:

the processing of the signal fluctuations is an averaging process; and

the processing of the plurality of signals having the fluctuations removed is an averaging of the plurality of signals.

42. A receiver in accordance with claim 41 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

43. A receiver in accordance with claim 41 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

44. A receiver in accordance with claim 37 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

45. A receiver in accordance with claim 37 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

46. A receiver in accordance with claim 37 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

47. A receiver in accordance with claim 36 wherein:

the processing of the signal fluctuations is an integration; and

the processing of the plurality of signals having the fluctuations removed is an integration of the plurality of signals.

48. A receiver in accordance with claim 47 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

49. A receiver in accordance with claim 47 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

50. A receiver in accordance with claim 36 wherein:

the processing of the signal fluctuations is an averaging process; and

the processing of the plurality of signals having the fluctuations removed is an averaging of the plurality of signals.

51. A receiver in accordance with claim 50 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

52. A receiver in accordance with claim 50 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

53. A receiver in accordance with claim 36 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

54. A receiver in accordance with claim 36 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

55. A receiver in accordance with claim 36 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

56. A receiver in accordance with claim 35 wherein:

the processing of the signal fluctuations is an integration; and

the processing of the plurality of signals having the fluctuations removed is an integration of the plurality of signals.

57. A receiver in accordance with claim 56 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

58. A receiver in accordance with claim 56 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

59. A receiver in accordance with claim 56 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

60. A receiver in accordance with claim 35 wherein:

the processing of the signal fluctuations is an averaging process; and

the processing of the plurality of signals having the fluctuations removed is an averaging of the plurality of signals.

61. A receiver in accordance with claim 60 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

62. A receiver in accordance with claim 60 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

63. A receiver in accordance with claim 60 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.

64. A receiver in accordance with claim 35 wherein:

the composite signal is used by the receiver to determine a range of the at least one transmitter from the receiver.

65. A system in accordance with claim 35 wherein:

the composite signal is used by the receiver to determine a direction of the at least one transmitter relative to the receiver.

66. A receiver in accordance with claim 35 wherein:

the plurality of signals having the fluctuations removed are produced by processing successive periodic transmissions.