VERIFIED DISTANCE RANGING

• US 20070285306A1
• Filed: 04/16/2007
• Published: 12/13/2007
• Est. Priority Date: 04/18/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ekbal, Amal, Lee, Chong, Julian, David
• Granted Patent: US 8,552,903 B2
• Time in Patent Office: Days
• US Class Current: 342/118
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/284 using coded pulses
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Various techniques are described relating to verifying a distance between devices. A distance between two devices may be verified by requiring one of the devices to take one or more actions that generate a result that is only possible if the device is at most a given distance from the other device. In some aspects verified ranging is accomplished through the use of a ranging signal and a responsive signal. In some aspects the ranging signal may comprise a random, pseudorandom, or deterministic sequence. A responding device may operate on a ranging signal in accordance with a known function to generate a responsive signal. A ranging device also may perform operations to determine the likelihood that a responding device properly operated on a ranging signal that the ranging device transmitted to the responding device.

Claims

1. A method of verifying a distance, comprising:

transmitting a first set of at least one first signal to a second device;

receiving a second set of at least one second signal transmitted by the second device in response to the first set of at least one first signal; and

determining, based on characteristics of the first set of at least one first signal and the second set of at least one second signal, whether a distance between a first device and the second device is valid or allowable.

2. The method of claim 1, wherein the determination comprises determining whether the second set of at least one second signal is received within a defined time period after the transmission of the first set of at least one first signal.

3. The method of claim 2, wherein the defined time period corresponds to an expected distance between the first device and the second device.

4. The method of claim 1, wherein the determination comprises determining whether the second set of at least one second signal corresponds to a defined signal response scheme applied to the first set of at least one first signal.

5. The method of claim 4, wherein the defined signal response scheme comprises application of a function to a defined sequence and to the first set of at least one first signal.

6. The method of claim 5, wherein the defined sequence comprises a random or pseudorandom sequence.

7. The method of claim 5, wherein the defined sequence is generated in accordance with at least one cryptographic key associated with at least one of the first device and the second device.

8. The method of claim 5, wherein the function comprises XORing.

9. The method of claim 5, wherein the function comprises determining whether or not a signal is transmitted.

10. The method of claim 4, wherein the determination of whether the second set of at least one second signal corresponds to the defined signal response scheme applied to the first set of at least one first signal comprises performing a statistical analysis on the second set of at least one second signal.

11. The method of claim 1, wherein:

the characteristics of the first set of at least one first signal comprise at least one of the group consisting of;

time, frequency, phase, and amplitude;

the first device varies at least one of the characteristics of the first set of at least one first signal; and

at least one of the characteristics of the second set of at least one second signal is functionally based on the at least one of the characteristics that is varied by the first device.

12. The method of claim 11, wherein the varying by the first device comprises varying, in a random or pseudorandom manner, the at least one of the characteristics of the first set of at least one first signal.

13. The method of claim 11, wherein the varying by the first device comprises varying, in a deterministic manner, the at least one of the characteristics of the first set of at least one first signal.

14. The method of claim 1, wherein the second device transmits the second set of at least one second signal within a defined time period after the second device receives the first set of at least one first signal.

15. The method of claim 14, wherein the defined time period comprises 10 microseconds.

16. The method of claim 1, further comprising determining the distance between the first device and the second device, wherein the determination of whether the distance between the first and second devices is valid or allowable comprises determining whether the determined distance is accurate based on the characteristics of the first set of at least one first signal and the second set of at least one second signal.

17. The method of claim 16, further comprising comparing the determined distance to a threshold value, wherein the first set of at least one first signal is transmitted if the comparison indicates that the determined distance is equal to or less than the threshold value.

18. The method of claim 16, wherein the distance determination comprises using a time of arrival measurement scheme.

19. The method of claim 1, wherein the first set of at least one first signal comprises a modulated signal.

20. The method of claim 19, wherein the modulated signal comprises a phase shift keying modulated signal, an on/off keying modulated signal, a frequency shift keying modulated signal, or a time shift keying modulated signal.

21. The method of claim 1, wherein the first set of at least one first signal comprises at least one random or pseudorandom signal.

22. The method of claim 1, wherein the first set of at least one first signal comprises a defined sequence of pulses.

23. The method of claim 1, wherein the first set of at least one first signal comprises at least one ultra-wideband pulse.

24. The method of claim 23, wherein each ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

25. The method of claim 1, wherein the transmission of the first set of at least one first signal and the reception of the second set of at least one second signal are via an air interface of a personal area network or an air interface of a body area network.

26. An apparatus for verifying a distance, comprising:

a transmitter adapted to transmit a first set of at least one first signal to a device;

a receiver adapted to receive a second set of at least one second signal transmitted by the device in response to the first set of at least one first signal; and

a verifier adapted to determine, based on characteristics of the first set of at least one first signal and the second set of at least one second signal, whether a distance between the apparatus and the device is valid or allowable.

27. The apparatus of claim 26, wherein the verifier is further adapted to determine whether the second set of at least one second signal is received within a defined time period after the transmission of the first set of at least one first signal.

28. The apparatus of claim 27, wherein the defined time period corresponds to an expected distance between the apparatus and the device.

29. The apparatus of claim 26, wherein the verifier is further adapted to determine whether the second set of at least one second signal corresponds to a defined signal response scheme applied to the first set of at least one first signal.

30. The apparatus of claim 29, wherein the defined signal response scheme comprises application of a function to a defined sequence and to the first set of at least one first signal.

31. The apparatus of claim 30, wherein the defined sequence comprises a random or pseudorandom sequence.

32. The apparatus of claim 30, wherein the defined sequence is generated in accordance with at least one cryptographic key associated with at least one of the apparatus and the device.

33. The apparatus of claim 30, wherein the function comprises XORing.

34. The apparatus of claim 30, wherein the function comprises determining whether or not a signal is transmitted.

35. The apparatus of claim 29, wherein the verifier is further adapted to perform a statistical analysis on the second set of at least one second signal to determine whether the second set of at least one second signal corresponds to the defined signal response scheme applied to the first set of at least one first signal.

36. The apparatus of claim 26, further comprising a signal generator adapted to vary at least one of the characteristics of the first set of at least one first signal, wherein:

the characteristics of the first set of at least one first signal comprise at least one of the group consisting of;

time, frequency, phase, and amplitude; and

at least one of the characteristics of the second set of at least one second signal is functionally based on the at least one of the characteristics that is varied by the signal generator.

37. The apparatus of claim 36, wherein the signal generator is further adapted to vary, in a random or pseudorandom manner, the at least one of the characteristics of the first set of at least one first signal.

38. The apparatus of claim 36, wherein the signal generator is further adapted to vary, in a deterministic manner, the at least one of the characteristics of the first set of at least one first signal.

39. The apparatus of claim 26, wherein the device transmits the second set of at least one second signal within a defined time period after the device receives the first set of at least one first signal.

40. The apparatus of claim 39, wherein the defined time period comprises 10 microseconds.

41. The apparatus of claim 26, further comprising a distance determiner adapted to determine the distance between the apparatus and the device, wherein the verifier is further adapted to determine whether the determined distance is accurate based on the characteristics of the first set of at least one first signal and the second set of at least one second signal.

42. The apparatus of claim 41, further comprising a comparator adapted to compare the determined distance to a threshold value, wherein the transmitter is further adapted to transmit the first set of at least one first signal if the comparison indicates that the determined distance is equal to or less than the threshold value.

43. The apparatus of claim 41, wherein the distance determiner is further adapted to use a time of arrival measurement scheme.

44. The apparatus of claim 26, wherein the first set of at least one first signal comprises a modulated signal.

45. The apparatus of claim 44, wherein the modulated signal comprises a phase shift keying modulated signal, an on/off keying modulated signal, a frequency shift keying modulated signal, or a time shift keying modulated signal.

46. The apparatus of claim 26, wherein the first set of at least one first signal comprises at least one random or pseudorandom signal.

47. The apparatus of claim 26, wherein the first set of at least one first signal comprises a defined sequence of pulses.

48. The apparatus of claim 26, wherein the first set of at least one first signal comprises at least one ultra-wideband pulse.

49. The apparatus of claim 48, wherein each ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

50. The apparatus of claim 26, wherein the transmitter is adapted to transmit via an air interface of a personal area network or an air interface of a body area network and the receiver is adapted to receive via the air interface of the personal area network or the air interface of the body area network.

51. An apparatus for verifying a distance, comprising:

means for transmitting a first set of at least one first signal to a device;

means for receiving a second set of at least one second signal transmitted by the device in response to the first set of at least one first signal; and

means for determining, based on characteristics of the first set of at least one first signal and the second set of at least one second signal, whether a distance between the apparatus and the device is valid or allowable.

52. The apparatus of claim 51, wherein the means for determining determines whether the second set of at least one second signal is received within a defined time period after the transmission of the first set of at least one first signal.

53. The apparatus of claim 52, wherein the defined time period corresponds to an expected distance between the apparatus and the device.

54. The apparatus of claim 51, wherein the means for determining determines whether the second set of at least one second signal corresponds to a defined signal response scheme applied to the first set of at least one first signal.

55. The apparatus of claim 54, wherein the defined signal response scheme comprises application of a function to a defined sequence and to the first set of at least one first signal.

56. The apparatus of claim 55, wherein the defined sequence comprises a random or pseudorandom sequence.

57. The apparatus of claim 55, wherein the defined sequence is generated in accordance with at least one cryptographic key associated with at least one of the apparatus and the device.

58. The apparatus of claim 55, wherein the function comprises XORing.

59. The apparatus of claim 55, wherein the function comprises determining whether or not a signal is transmitted.

60. The apparatus of claim 54, wherein the means for determining performs a statistical analysis on the second set of at least one second signal to determine whether the second set of at least one second signal corresponds to the defined signal response scheme applied to the first set of at least one first signal.

61. The apparatus of claim 51, further comprising means for varying at least one of the characteristics of the first set of at least one first signal, wherein:

the characteristics of the first set of at least one first signal comprise at least one of the group consisting of;

time, frequency, phase, and amplitude; and

at least one of the characteristics of the second set of at least one second signal is functionally based on the at least one of the characteristics that is varied by the means for varying.

62. The apparatus of claim 61, wherein the means for varying varies, in a random or pseudorandom manner, the at least one of the characteristics of the first set of at least one first signal.

63. The apparatus of claim 61, wherein the means for varying varies, in a deterministic manner, the at least one of the characteristics of the first set of at least one first signal.

64. The apparatus of claim 51, wherein the device transmits the second set of at least one second signal within a defined time period after the device receives the first set of at least one first signal.

65. The apparatus of claim 64, wherein the defined time period comprises 10 microseconds.

66. The apparatus of claim 51, further comprising means for determining the distance between the apparatus and the device, wherein the means for determining whether a distance between the apparatus and the device is valid or allowable determines whether the determined distance is accurate based on the characteristics of the first set of at least one first signal and the second set of at least one second signal.

67. The apparatus of claim 66, further comprising means for comparing the determined distance to a threshold value, wherein the means for transmitting transmits the first set of at least one first signal if the comparison indicates that the determined distance is equal to or less than the threshold value.

68. The apparatus of claim 66, wherein the means for determining the distance uses a time of arrival measurement scheme.

69. The apparatus of claim 51, wherein the first set of at least one first signal comprises a modulated signal.

70. The apparatus of claim 69, wherein the modulated signal comprises a phase shift keying modulated signal, an on/off keying modulated signal, a frequency shift keying modulated signal, or a time shift keying modulated signal.

71. The apparatus of claim 51, wherein the first set of at least one first signal comprises at least one random or pseudorandom signal.

72. The apparatus of claim 51, wherein the first set of at least one first signal comprises a defined sequence of pulses.

73. The apparatus of claim 51, wherein the first set of at least one first signal comprises at least one ultra-wideband pulse.

74. The apparatus of claim 73, wherein each ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

75. The apparatus of claim 51, wherein the means for transmitting transmits and the means for receiving receives via an air interface of a personal area network or an air interface of a body area network.

76. A computer-program product for verifying a distance, comprising:

computer-readable medium comprising codes executable by at least one computer to;

transmit a first set of at least one first signal to a second device;

receive a second set of at least one second signal transmitted by the second device in response to the first set of at least one first signal; and

determine, based on characteristics of the first set of at least one first signal and the second set of at least one second signal, whether a distance between a first device and the second device is valid or allowable.

77. A headset for processing signals, comprising:

a transmitter adapted to transmit a first set of at least one first signal to a device;

a receiver adapted to receive a second set of at least one second signal transmitted by the device in response to the first set of at least one first signal;

a verifier adapted to determine, based on characteristics of the first set of at least one first signal and the second set of at least one second signal, whether a distance between the headset and the device is valid or allowable; and

a transducer adapted to provide an audible output based on a signal received via the receiver.

78. A watch for processing signals, comprising:

a transmitter adapted to transmit a first set of at least one first signal to a device;

a receiver adapted to receive a second set of at least one second signal transmitted by the device in response to the first set of at least one first signal;

a verifier adapted to determine, based on characteristics of the first set of at least one first signal and the second set of at least one second signal, whether a distance between the watch and the device is valid or allowable; and

a display adapted to provide a visual output based on a signal received via the receiver.

79. A medical device for processing signals, comprising:

a transmitter adapted to transmit a first set of at least one first signal to a device;

a receiver adapted to receive a second set of at least one second signal transmitted by the device in response to the first set of at least one first signal;

a verifier adapted to determine, based on characteristics of the first set of at least one first signal and the second set of at least one second signal, whether a distance between the medical device and the device is valid or allowable; and

a sensor adapted to generate sensed data to be transmitted via the transmitter.

80. A method of responding to a signal, comprising:

receiving a first set of at least one first signal at a first device from a second device, wherein the first set of at least one first signal is received at a first time;

generating a second set of at least one second signal by applying a function to data represented by the first set of at least one first signal, based on a signal response scheme known to the first device and the second device; and

transmitting the second set of at least one second signal to the second device at a second time that is within a defined time period after the first time.

81. The method of claim 80, wherein the generation of the second set of at least one second signal comprises applying the function to a defined sequence known to the first device and the second device.

82. The method of claim 81, wherein the defined sequence comprises a random or pseudorandom sequence.

83. The method of claim 81, wherein the defined sequence is generated in accordance with at least one cryptographic key associated with at least one of the first device and the second device.

84. The method of claim 80, wherein the function comprises XORing.

85. The method of claim 80, wherein the function comprises determining whether or not a signal is transmitted.

86. The method of claim 80, wherein:

the first time is associated with receipt of a specified signal from the first set of at least one first signal; and

a specified signal from the second set of at least one second signal is transmitted at the second time.

87. The method of claim 80, wherein the defined time period comprises 10 microseconds.

88. The method of claim 80, wherein the first set of at least one first signal comprises at least one phase shift keying modulated signal, at least one on/off keying modulated signal, at least one frequency shift keying modulated signal, or at least one time shift keying modulated signal.

89. The method of claim 80, wherein the first set of at least one first signal comprises at least one random or pseudorandom signal.

90. The method of claim 80, wherein the first set of at least one first signal comprises a defined sequence of pulses.

91. The method of claim 80, wherein the first set of at least one first signal comprises ultra-wideband pulses.

92. The method of claim 91, wherein each ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

93. The method of claim 80, wherein the reception of the first set of at least one first signal and the transmission of the second set of at least one second signal are via an air interface of a personal area network or an air interface of a body area network.

94. An apparatus for responding to a signal, comprising:

a receiver adapted to receive a first set of at least one first signal, wherein the first set of at least one first signal is received at a first time;

a signal generator adapted to generate a second set of at least one second signal by applying a function to data represented by the first set of at least one first signal, based on a signal response scheme known to the apparatus and a device; and

a transmitter adapted to transmit the second set of at least one second signal to the device at a second time that is within a defined time period after the first time.

95. The apparatus of claim 94, wherein the signal generator is further adapted to apply the function to a defined sequence known to the apparatus and the device to generate the second set of at least one second signal.

96. The apparatus of claim 95, wherein the defined sequence comprises a random or pseudorandom sequence.

97. The apparatus of claim 95, wherein the defined sequence is generated in accordance with at least one cryptographic key associated with at least one of the apparatus and the device.

98. The apparatus of claim 94, wherein the function comprises XORing.

99. The apparatus of claim 94, wherein the function comprises determining whether or not a signal is transmitted.

100. The apparatus of claim 94, wherein:

the first time is associated with receipt of a specified signal from the first set of at least one first signal; and

the transmitter is further adapted to transmit a specified signal from the second set of at least one second signal at the second time.

101. The apparatus of claim 94, wherein the defined time period comprises 10 microseconds.

102. The apparatus of claim 94, wherein the first set of at least one first signal comprises at least one phase shift keying modulated signal, at least one on/off keying modulated signal, at least one frequency shift keying modulated signal, or at least one time shift keying modulated signal.

103. The apparatus of claim 94, wherein the first set of at least one first signal comprises at least one random or pseudorandom signal.

104. The apparatus of claim 94, wherein the first set of at least one first signal comprises a defined sequence of pulses.

105. The apparatus of claim 94, wherein the first set of at least one first signal comprises ultra-wideband pulses.

106. The apparatus of claim 105, wherein each ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

107. The apparatus of claim 94, wherein the transmitter is adapted to transmit via an air interface of a personal area network or an air interface of a body area network and the receiver is adapted to receive via the air interface of the personal area network or the air interface of the body area network.

108. An apparatus for responding to a signal, comprising:

means for receiving a first set of at least one first signal, wherein the first set of at least one first signal is received at a first time;

means for generating a second set of at least one second signal by applying a function to data represented by the first set of at least one first signal, based on a signal response scheme known to the apparatus and a device; and

means for transmitting the second set of at least one second signal to the device at a second time that is within a defined time period after the first time.

109. The apparatus of claim 108, wherein the means for generating applies the function to a defined sequence known to the apparatus and the device to generate the second set of at least one second signal.

110. The apparatus of claim 109, wherein the defined sequence comprises a random or pseudorandom sequence.

111. The apparatus of claim 109, wherein the defined sequence is generated in accordance with at least one cryptographic key associated with at least one of the apparatus and the device.

112. The apparatus of claim 108, wherein the function comprises XORing.

113. The apparatus of claim 108, wherein the function comprises determining whether or not a signal is transmitted.

114. The apparatus of claim 108, wherein:

the first time is associated with receipt of a specified signal from the first set of at least one first signal; and

the means for transmitting transmits a specified signal from the second set of at least one second signal at the second time.

115. The apparatus of claim 108, wherein the defined time period comprises 10 microseconds.

116. The apparatus of claim 108, wherein the first set of at least one first signal comprises at least one phase shift keying modulated signal, at least one on/off keying modulated signal, at least one frequency shift keying modulated signal, or at least one time shift keying modulated signal.

117. The apparatus of claim 108, wherein the first set of at least one first signal comprises at least one random or pseudorandom signal.

118. The apparatus of claim 108, wherein the first set of at least one first signal comprises a defined sequence of pulses.

119. The apparatus of claim 108, wherein the first set of at least one first signal comprises ultra-wideband pulses.

120. The apparatus of claim 119, wherein each ultra-wideband pulse has a fractional bandwidth on the order of 20% or more, has a bandwidth on the order of 500 MHz or more, or has a fractional bandwidth on the order of 20% or more and has a bandwidth on the order of 500 MHz or more.

121. The apparatus of claim 108, wherein the means for transmitting transmits and the means for receiving receives via an air interface of a personal area network or an air interface of a body area network.

122. A computer-program product for responding to a signal, comprising:

computer-readable medium comprising codes executable by at least one computer to;

receive a first set of at least one first signal, wherein the first set of at least one first signal is received at a first time;

generate a second set of at least one second signal by applying a function to data represented by the first set of at least one first signal, based on a signal response scheme known to a first device and a second device; and

transmit the second set of at least one second signal to the second device at a second time that is within a defined time period after the first time.

123. A headset for processing signals, comprising:

a receiver adapted to receive a first set of at least one first signal, wherein the first set of at least one first signal is received at a first time;

a signal generator adapted to generate a second set of at least one second signal by applying a function to data represented by the first set of at least one first signal, based on a signal response scheme known to the headset and a device;

a transmitter adapted to transmit the second set of at least one second signal to the device at a second time that is within a defined time period after the first time; and

a transducer adapted to provide an audible output based on a signal received via the receiver.

124. A watch for processing signals, comprising:

a receiver adapted to receive a first set of at least one first signal, wherein the first set of at least one first signal is received at a first time;

a signal generator adapted to generate a second set of at least one second signal by applying a function to data represented by the first set of at least one first signal, based on a signal response scheme known to the watch and a device;

a transmitter adapted to transmit the second set of at least one second signal to the device at a second time that is within a defined time period after the first time; and

a display adapted to provide a visual output based on a signal received via the receiver.

125. A medical device for processing signals, comprising:

a receiver adapted to receive a first set of at least one first signal, wherein the first set of at least one first signal is received at a first time;

a signal generator adapted to generate a second set of at least one second signal by applying a function to data represented by the first set of at least one first signal, based on a signal response scheme known to the medical device and a device;

a transmitter adapted to transmit the second set of at least one second signal to the device at a second time that is within a defined time period after the first time; and

a sensor adapted to generate sensed data to be transmitted via the transmitter.