RFID readers and tags transmitting and receiving waveform segment with ending-triggering transition

• US 7,049,964 B2
• Filed: 08/10/2004
• Issued: 05/23/2006
• Est. Priority Date: 08/10/2004
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Hyde, John D., Diorio, Christopher J.
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US10/915,930
• Publication Number:
  US 20060033622A1
• Time in Patent Office: 651 Days
• Field of Search: 340/572.1, 340/572.4, 340/505, 340/5.23, 340/5.25, 340/5.6, 340/10.1, 340/10.51, 340/10.52, 235/432, 235/472.01, 375/336, 375/355, 704/260
• US Class Current: 340/572.1
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00

Abstract

RFID readers exchange information with RFID tags. The information is encoded for transmission and decoded upon reception. Encoding is in binary bits, which are in turn encoded in waveform segments. The last transmitted waveform incorporates an ending-triggering transition, and terminates in a preset manner with respect to when the ending-triggering transition occurs. Parsing while decoding can happen by waiting for the ending-triggering transition, and then waiting according to the preset manner. This way there is no ambiguity in the ending of the waveform, and no End Frame is necessary.

Claims

1. An RFID reader capable of:

encoding information in terms of RFID symbols;

encoding the RFID symbols into successive waveform segments that individually correspond to the RFID symbols, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition; and

transmitting a signal wave having a waveform made from the segments.

2. The reader of claim 1, further capable of:

transmitting a preamble to the signal wave.

3. The reader of claim 1, further capable of:

then transmitting a wave that encodes neither information, nor that the last segment has been transmitted.

4. The reader of claim 1, wherein

the preset manner is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

5. The reader of claim 1, wherein

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

6. The reader of claim 1, wherein

the preset manner is that the last segment terminates a preset time interval after the transition occurs.

7. The reader of claim 6, wherein

the interval is a preset fraction of a symbol period.

8. The reader of claim 1, wherein

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

9. The reader of claim 1, wherein

one of the symbols is encoded by one of a plurality of different waveform segments depending on whether there is a next symbol.

10. The reader of claim 1, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

11. An RFID reader capable of:

receiving a signal wave having a waveform made from successive waveform segments, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner wit respect to the occurrence of the ending-triggering transition;

after receiving the last segment, receiving a wave tat encodes neither information nor that the last segment has been received;

parsing the waveform segments according to the preset manner and the ending-triggering transition;

decoding RFID symbols from the parsed waveform segments; and

decoding information from the decoded RFID symbols.

12. The reader of claim 11, further capable of:

receiving a preamble to the signal wave.

13. The reader of claim 11, wherein

the preset manner is that the last segment terminates a preset number of additional transitions alter the ending-triggering transition occurs.

14. The reader of claim 11, wherein

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

15. The reader of claim 11, wherein

the preset manner is tat the last segment terminates a preset time interval after the transition occurs.

16. The reader of claim 15, wherein

the interval is a preset fraction of a symbol period.

17. The reader of claim 11, wherein

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

18. The reader of claim 11, wherein

one of the symbols is decoded from different waveform segments depending on whether there is a next symbol.

19. The reader of claim 11, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

20. An RFID tag capable of:

encoding information in terms of RFID symbols;

encoding the RFID symbols into successive waveform segments that individually correspond to the RFID symbols, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition; and

transmitting a signal wave having a waveform made from the segments.

21. The tag of claim 20, further capable of:

transmitting a preamble to the signal wave.

22. The tag of claim 20, further capable of:

then transmitting a wave that encodes neither information, nor that the last segment has been transmitted.

23. The tag of claim 20, wherein

the preset manner is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

24. The tag of claim 20, wherein

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

25. The tag of claim 20, wherein

the preset manner is that the last segment terminates a preset time interval after the transition occurs.

26. The tag of claim 25, wherein

the interval is a preset fraction of a symbol period.

27. The tag of claim 20, wherein

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

28. The tag of claim 20, wherein

one of the symbols is encoded by one of a plurality of different waveform segments depending on whether there is a next symbol.

29. The tag of claim 20, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

30. An RFID tag capable of:

receiving a signal wave having a waveform made from successive waveform segments, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition;

after receiving the last segment, receiving a wave tat encodes neither information nor that the last segment has been received;

parsing the waveform segments according to the preset manner and the ending-triggering transition;

decoding RFID symbols from the parsed waveform segments; and

decoding information from the decoded RFID symbols.

31. The rag of claim 30, further capable of:

receiving a preamble to the signal wave.

32. The tag of claim 30, wherein

the preset manner is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

33. The tag of claim 30, wherein

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

34. The tag of claim 30, wherein

the preset maimer is that the last segment terminates a preset time interval after the transition occurs.

35. The tag of claim 34, wherein

the interval is a preset fraction of a symbol period.

36. The tag of claim 30, wherein

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

37. The tag of claim 30, wherein

one of the symbols is decoded from different waveform segments depending on whether there is a next symbol.

38. The tag of claim 30, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

39. A device comprising:

means for encoding information in terms of RFID symbols;

means for encoding the RFID symbols into successive waveform segments tat individually correspond to the RFID symbols, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition; and

means for transmitting a signal wave having a waveform made from the segments.

40. The device of claim 39, further comprising:

means for transmitting a preamble to the signal wave.

41. The device of claim 39, further comprising:

means for then transmitting a wave tar encodes neither information, nor that the last segment has been transmitted.

42. The device of claim 39, wherein

the preset manner is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

43. The device of claim 39, wherein

the preset manner is tat the last segment terminates upon the occurrence of the ending-triggering transition.

44. The device of claim 39, wherein

the preset manner is that the last segment terminates a preset lime interval after the transition occurs.

45. The device of claim 44, wherein

the interval is a preset fraction of a symbol period.

46. The device of claim 39, wherein

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

47. The device of claim 39, wherein

one of the symbols is encoded by one of a plurality of different waveform segments depending on whether there is a next symbol.

48. The device of claim 39, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

49. An article comprising:

a storage medium, the storage medium having instructions stored thereon, in which when the instructions are executed by at least one device, they result in;

encoding information in terms of RFID symbols; and

encoding the RFID symbols into successive waveform segments for transmission as a signal wave, the segments individually corresponding to the RFID symbols, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition.

50. The article of claim 49, in which

the preset manner is tat the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

51. The article of claim 49, in which

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

52. The article of claim 49, in which

the preset manner is that the last segment terminates a preset time interval after the transition occurs.

53. The article of claim 52, in which

the interval is a preset fraction of a symbol period.

54. The article of claim 49, in which

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

55. The article of claim 49, in which

one of the symbols is encoded by one of a plurality of different waveform segments depending on whether there is a next symbol.

56. The article of claim 49, in which

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

57. A method comprising:

encoding information in terms of RFID symbols;

encoding the RFID symbols into successive waveform segments that individually correspond to the RFID symbols, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition; and

transmitting a signal wave having a waveform made from the segments.

58. The method of claim 57, further comprising:

transmitting a preamble to the signal wave.

59. The method of claim 57, further comprising:

then transmitting a wave that encodes neither information, nor that the last segment has been transmitted.

60. The method of claim 57, wherein

the preset manner is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

61. The method of claim 57, wherein

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

62. The method of claim 57, wherein

the preset manner is that the last segment terminates a preset time interval after the transition occurs.

63. The method of claim 62, wherein

the interval is a preset fraction of a symbol period.

64. The method of claim 57, wherein

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

65. The method of claim 57, wherein

one of the symbols is encoded by one of a plurality of different waveform segments depending on whether there is a next symbol.

66. The method of claim 57, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

67. A device comprising:

means for receiving a signal wave having a waveform made from successive waveform segments, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition;

means for after receiving the last segment, receiving a wave that encodes neither information nor that the last segment has been received;

means for parsing the waveform segments according to the preset manner and the ending-triggering transition;

means for decoding RFID symbols from the parsed waveform segments; and

means for decoding information from the decoded RFID symbols.

68. The device of claim 67, further comprising:

means for receiving a preamble to the signal wave.

69. The device of claim 67, wherein

the preset manner is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

70. The device of claim 67, wherein

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

71. The device of claim 67, wherein

the preset manner is that the last segment terminates a preset time interval after the transition occurs.

72. The device of claim 71, wherein

the interval is a preset fraction of a symbol period.

73. The device of claim 67, wherein

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

74. The device of claim 67, wherein

one of the symbols is decoded from different waveform segments depending on whether there is a next symbol.

75. The device of claim 67, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

76. An article comprising:

a storage medium, the storage medium having instructions stored thereon, in which when the instructions are executed by at least one device, they result in;

parsing successive waveform segments of a received signals wave having a waveform, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition, wherein alter the signal wave another wave has been received that encodes neither information nor that the last segment has been received, wherein parsing is performed according to the preset maimer and the ending-triggering transition;

decoding RFID symbols from the parsed waveform segments; and

decoding information from the decoded RFID symbols.

77. The article of claim 76, in which executing the instructions further results in:

decoding a received preamble to the wave.

78. The article of claim 76, in which

the preset manner is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

79. The article of claim 76, in which

the preset manner is that the last segment terminates upon the occurrence of the ending-triggering transition.

80. The article of claim 76, in which

the preset manner is that the last segment terminates a preset time interval after the transition occurs.

81. The article of claim 80, in which

the interval is a preset fraction of a symbol period.

82. The article of claim 76, in which

the segments belong in a segment set, and

at least some but not all of the segments in the set incorporate the ending-triggering transition.

83. The article of claim 76, in which

one of the symbols is decoded from different waveform segments depending on whether there is a next symbol.

84. The article of claim 76, in which

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.

85. A method comprising:

receiving a signal wave having a waveform made from successive waveform segments, the last one of the segments incorporating an ending-triggering transition and terminating in a preset manner with respect to the occurrence of the ending-triggering transition;

after receiving the last segment, receiving a wave that encodes neither information nor that the last segment has been received;

parsing the waveform segments according to the preset manner and the ending-triggering transition;

decoding RFID symbols from the parsed waveform segments; and

decoding information from the decoded RFID symbols.

86. The method of claim 85, further comprising:

receiving a preamble to the signal wave.

87. The method of claim 85, wherein

the preset maimer is that the last segment terminates a preset number of additional transitions after the ending-triggering transition occurs.

88. The method of claim 85, wherein

the preset manner is tat the last segment terminates upon the occurrence of the ending-triggering transition.

89. The method of claim 85, wherein

the preset manner is that the last segment terminates a preset time interval after the transition occurs.

90. The method of claim 89, wherein

the interval is a preset fraction of a symbol period.

91. The method of claim 85, wherein

the segments belong in a segment set, and

at least same but not all of the segments in the set incorporate the ending-triggering transition.

92. The method of claim 85, wherein

one of the symbols is decoded from different waveform segments depending on whether there is a next symbol.

93. The method of claim 85, wherein

the segments belong in a segment set, and

all of the segments in the set incorporate the ending-triggering transition.