System and method for impulse radio power control

• US 6,539,213 B1
• Filed: 06/14/1999
• Issued: 03/25/2003
• Est. Priority Date: 06/14/1999
• Status: Expired due to Term

• Current Assignee: Alereon Incorporated (PNG Telecommunications, Inc.)
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Cowie, Ivan A., Fullerton, Larry W., Richards, James L.
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Ferguson, Keith
• Application Number:
  US09/332,501
• Time in Patent Office: 1,380 Days
• Field of Search: 455/226.3, 455/522, 455/63, 455/69, 455/550, 455/517, 455/68, 455/70, 455/67.3, 455/232.1, 455/422, 455/450, 455/509
• US Class Current: 455/226.3
• CPC Class Codes: H04B 1/7163 using impulse radio
• CPC Class Codes: H04B 1/7183 Synchronisation
• CPC Class Codes: H04B 2001/6908 using time hopping
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

A system and method for impulse radio power control wherein a first transceiver transmits an impulse radio signal to a second transceiver. A power control update is calculated according to a performance measurement of the signal received at the second transceiver. The transmitter power of either transceiver, depending on the particular embodiment, is adjusted according to the power control update. Various performance measurements are employed according to the current invention to calculate a power control update, including bit error rate, signal-to-noise ratio, and received signal strength, used alone or in combination. Interference is thereby reduced, which is particularly important where multiple impulse radios are operating in close proximity and their transmission interfere with one another. Reducing the transmitter power of each radio to a level that produces satisfactory reception increases the total number of radios that can operate in an area without saturation. Reducing transmitter power also increases transceiver efficiency.

Claims

1. A method for power control in an ultra wideband (UWB) impulse radio system, comprising the steps of:

transmitting an impulse radio signal from a first transceiver;

receiving said impulse radio signal at a second transceiver;

determining at least one performance measurement of said received impulse radio signal;

calculating a power control update according to said at least one performance measurement of said received impulse radio signal; and

controlling the output power of at least one of said first transceiver and said second transceiver according to said power control update.

2. The method of claim 1, wherein said at least one performance measurement is selected from the group consisting of bit error rate, signal-to-noise ratio, and received signal strength.

3. The method of claim 1, further comprising the step of summing said power control update with at least one additional power control update to produce a power control command, and wherein said step of controlling comprises controlling the output power of at least one of said first transceiver and said second transceiver according to said power control command.

4. The method of claim 1, wherein said step of calculating is performed at said second transceiver.

5. The method of claim 4, wherein said step of controlling comprises controlling said output power of said second transceiver according to said power control update.

6. The method of claim 5, further comprising the step of transmitting a further impulse radio signal from said second transceiver, and wherein said step of controlling said output power of said second transceiver comprises controlling the integration gain of said further impulse radio signal according to said power control update.

7. The method of claim 5, further comprising the step of transmitting a further impulse radio signal from said second transceiver, and wherein said step of controlling said output power of said second transceiver comprises controlling the pulse peak power of said further impulse radio signal according to said power control update.

8. The method of claim 5, further comprising the step of transmitting a further impulse radio signal from said second transceiver, and wherein said step of controlling said output power of said second transceiver comprises controlling the pulse height of said further impulse radio signal according to said power control update.

9. The method of claim 5, wherein said step of transmitting said impulse radio signal comprises transmitting a pulse train including a quantity N_train of pulses for each bit of information,

further comprising the step of transmitting a further impulse radio signal from said second transceiver, wherein said step of transmitting said further impulse radio signal comprises transmitting a pulse train including a quantity N_train2 of pulses for each bit of information, and

wherein said step of controlling said output power of said second transceiver comprises controlling said quantity N_train2 of pulses according to said power control update.

10. The method of claim 9, further comprising the step of providing said second transceiver with information related to said quantity N_train of pulses by including said information in a header of said impulse radio signal.

11. The method of claim 9, further comprising the step of providing said second transceiver with information related to said quantity N_train of pulses by including said information in control signals transmitted by said first transceiver.

12. The method of claim 9, wherein said step of controlling said quantity N_train2 comprises calculating said quantity N_train2 of pulses according to:

13. The method of claim 9, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses,

wherein said quantity N_train2 of pulses comprises a quantity N_period2 of periods, and wherein each period comprises a quantity N_{pulses-per-period2} of pulses, and

wherein said step of controlling said quantity N_train2 of pulses comprises controlling said quantity N_{pulses-per-period2} of pulses.

14. The method of claim 9, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses,

wherein said quantity N_train2 of pulses comprises a quantity N_period2 of periods, and wherein each period comprises a quantity N_{pulses-per-period2} of pulses, and

wherein said step of controlling said quantity N_train2 of pulses comprises controlling said quantity N_period2 of periods.

15. The method of claim 1, wherein said step of calculating is performed at said second transceiver,

further comprising the step of transmitting said power control update from said second transceiver to said first transceiver between said calculating step and said controlling step, and

wherein said controlling step comprises controlling said output power of said first transceiver according to said power control update.

16. The method of claim 1, further comprising the step of transmitting said at least one performance measurement from said second transceiver to said first transceiver between said determining step and said calculating step,

wherein said calculating step is performed at said first transceiver, and

wherein said controlling step comprises controlling said output power of said first transceiver according to said power control update.

17. The method of claim 1, wherein said controlling step comprises controlling said output power of said first transceiver according to said power control update.

18. The method of claim 17, further comprising the step of transmitting a further impulse radio signal from said first transceiver, and wherein said step of controlling said output power of said first transceiver comprises controlling a number of pulses of said further impulse radio signal according to said power control update.

19. The method of claim 17, further comprising the step of transmitting a further impulse radio signal from said first transceiver, and wherein said step of controlling said output power of said first transceiver comprises controlling the pulse peak power of said further impulse radio signal according to said power control update.

20. The method of claim 17, further comprising the step of transmitting a further impulse radio signal from said first transceiver, and wherein said step of controlling said output power of said first transceiver comprises controlling the pulse height of said further impulse radio signal according to said power control update.

21. The method of claim 17, wherein said step of transmitting said impulse radio signal comprises transmitting a pulse train including a quantity N_train of pulses for each bit of information,

further comprising the step of transmitting a further impulse radio signal from said first transceiver, wherein said step of transmitting said further impulse radio signal comprises transmitting a pulse train including a quantity N_train2 of pulses for each bit of information, and

wherein said step of controlling said output power of said first transceiver comprises controlling said quantity N_train2 of pulses according to said power control update.

22. The method of claim 21, further comprising the step of providing said second transceiver with information related to said quantity N_train of pulses by including said information in a header of said impulse radio signal.

23. The method of claim 21, further comprising the step of providing said second transceiver with information related to said quantity N_train of pulses by including said information in control signals transmitted by said first transceiver.

24. The method of claim 21, wherein said step of controlling said quantity N_train2 comprises calculating said quantity N_train2 according to:

25. The method of claim 21, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses,

wherein said quantity N_train2 of pulses comprises a quantity N_period2 of periods, and wherein each period comprises a quantity N_{pulses-per-period2} of pulses, and

wherein said step of controlling said quantity N_train2 of pulses comprises controlling said quantity N_{pulses-per-period2} of pulses.

26. The method of claim 21, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses,

wherein said quantity N_train2 of pulses comprises a quantity N_period2 of periods, and wherein each period comprises a quantity N_{pulses-per-period2} of pulses, and

wherein said step of controlling said quantity N_train2 of pulses comprises controlling said quantity N_peroid2 of periods.

27. The method of claim 1, wherein said step of determining comprises determining the signal strength of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

28. The method of claim 1, wherein said step of determining comprises determining the signal-to-noise ratio of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

29. The method of claim 1, wherein said step of determining comprises determining the bit error rate of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

30. The method of claim 1, wherein said step of determining comprises determining the bit error rate and the signal strength of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

31. The method of claim 1, wherein said step of determining comprises determining the bit error rate and the signal-to-noise ratio of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

32. The method of claim 1, wherein said step of determining comprises determining the signal-to-noise ratio and the signal strength of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

33. The method of claim 1, wherein said step of determining comprises determining the bit error rate of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

34. The method of claim 1, wherein said step of determining comprises determining the bit error rate and the signal strength of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

35. The method of claim 1, wherein said step of determining comprises determining the bit error rate and the signal-to-noise ratio of said received impulse radio signal, and wherein said step of calculating comprises calculating said power control update according to:

36. A method for power control in a UWB impulse radio system, comprising the steps of:

transmitting an impulse radio signal from a first transceiver;

receiving said impulse radio signal at a second transceiver;

determining at least one signal performance measurement based on said received impulse radio signal;

determining a power control update based on said at least one signal performance measurement;

determining a power control command based on at least said power control update; and

controlling the output power of at least one of said first transceiver and said second transceiver according to said power control command.

37. The method of claim 36, wherein said step of controlling the output power comprises controlling the output power according to:

38. The method of claim 36, wherein said step of controlling the output power comprises controlling the output power according to:

39. The method of claim 36, wherein said step of controlling the output power comprises controlling the output power according to:

40. A UWB impulse radio transceiver, wherein said transceiver communicates with a second UWB impulse radio transceiver, said impulse radio transceiver comprising:

an impulse radio transmitter;

an impulse radio receiver, wherein said receiver receives an impulse radio signal from the second impulse transceiver;

a power adjuster that calculates a power control update according to at least one performance measurement of said received impulse radio signal; and

a power controller that controls the output power of said impulse radio transmitter according to said power control update.

41. The transceiver of claim 40, further comprising a signal evaluator for determining said at least one performance measurement of said received impulse radio signal.

42. The transceiver of claim 40, wherein said at least one performance measurement is selected from the group of bit error rate, signal-to-noise ratio, and received signal power.

43. The transceiver of claim 40, further comprising an integrator for summing said power control update with at least one additional power control update to produce a power control command, and wherein said power controller controls the output power of said impulse radio transmitter according to said power control command.

44. The transceiver of claim 40, wherein said power controller controls the output power by controlling the integration gain of said impulse radio transmitter according to said power control update.

45. The transceiver of claim 40, wherein said power controller controls the output power by controlling the pulse peak power of impulse signals transmitted by said impulse radio transmitter, and wherein said controller controls the pulse peak power according to said power control update.

46. The transceiver of claim 40, wherein said power controller controls the output power by controlling the pulse height of impulse signals transmitted by said impulse radio transmitter, and wherein said controller controls the pulse height according to said power control update.

47. The transceiver of claim 40, wherein said impulse radio transmitter transmits a pulse train including a quantity N_train of pulses for each bit of information, and wherein said power controller controls the output power by controlling said quantity N_train of pulses according to said power control update.

48. The transceiver of claim 47, wherein said power controller calculates said quantity N_train according to:

49. The transceiver of claim 47, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses, and wherein said power controller controls the output power by controlling said quantity N_{pulses-per-period} of pulses according to said power control update.

50. The transceiver of claim 47, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses, and wherein said power controller controls the output power by controlling said quantity N_period of pulses according to said power control update.

51. The transceiver of claim 40, wherein said at least one performance measurement comprises the signal strength of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

52. The transceiver of claim 51, further comprising a signal evaluator to determine the signal strength of said received impulse radio signal.

53. The transceiver of claim 40, wherein said at least one performance measurement comprises the signal-to-noise ratio of said received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

54. The transceiver of claim 40, wherein said at least one performance measurement comprises the bit error rate of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

55. The transceiver of claim 40, wherein said at least one performance measurement comprises the bit error rate and the signal strength of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

 

P_ref=K₂(BER_S1−

BER_ref)

56. The transceiver of claim 40, wherein said at least one performance measurement comprises the bit error rate and the signal-to-noise ratio of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

57. The transceiver of claim 40, wherein said at least one performance measurement comprises the signal-to-noise ratio and the signal strength of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

58. The transceiver of claim 40, wherein said at least one performance measurement comprises the bit error rate of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

59. The transceiver of claim 40, wherein said at least one performance measurement comprises the bit error rate and the signal strength of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

60. The transceiver of claim 40, wherein said at least one performance measurement comprises the bit error rate and the signal-to-noise ratio of the received impulse radio signal, and wherein said power adjuster calculates said power control update according to:

61. A UWB impulse radio transceiver, wherein said transceiver communicates with a second UWB impulse radio transceiver, said impulse radio transceiver comprising:

an impulse radio transmitter, wherein said transmitter transmits an impulse radio signal to the second impulse transceiver;

an impulse radio receiver, wherein said receiver receives information related to said transmitted impulse radio signal from the second transceiver; and

a power controller that controls the output power of said impulse radio transmitter according to said information related to said transmitted impulse radio signal.

62. The transceiver of claim 61, wherein said information related to said transmitted impulse radio signal comprises a power control update, and wherein said power controller controls the output power of said impulse radio transmitter according to said power control update.

63. The transceiver of claim 61, wherein said information related to said transmitted impulse radio signal comprises at least one performance measurement related to said transmitted impulse radio signal, further comprising a power adjuster that calculates a power control update according to said at least one performance measurement, and wherein said power controller controls the output power of said impulse radio transmitter according to said power control update.

64. The transceiver of claim 63, wherein said at least one performance measurement is selected from the group consisting of bit error rate, signal-to-noise ratio, and received signal power.

65. The transceiver of claim 63, wherein said power controller controls the output power by controlling the integration gain of said impulse radio transmitter according to said power control update.

66. The transceiver of claim 63, wherein said power controller controls the output power by controlling the pulse peak power of impulse signals transmitted by said impulse radio transmitter, and wherein said controller controls the pulse peak power according to said power control update.

67. The transceiver of claim 63, wherein said power controller controls the output power by controlling the pulse height of impulse signals transmitted by said impulse radio transmitter, and wherein said controller controls the pulse height according to said power control update.

68. The transceiver of claim 63, wherein said impulse radio transmitter transmits a pulse train including a quantity N_train of pulses for each bit of information, and wherein said power controller controls the output power by controlling said quantity N_train of pulses according to said power control update.

69. The transceiver of claim 68, wherein said power controller calculates said quantity N_train according to:

70. The transceiver of claim 68, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses, and wherein said power controller controls the output power by controlling said quantity N_{pulses-per-period} of pulses according to said power control update.

71. The transceiver of claim 68, wherein said quantity N_train of pulses comprises a quantity N_period of periods, and wherein each period comprises a quantity N_{pulses-per-period} of pulses, and wherein said power controller controls the output power by controlling said quantity N_period of pulses according to said power control update.

72. The transceiver of claim 63, wherein said at least one performance measurement comprises the signal strength of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

73. The transceiver of claim 63, wherein said at least one performance measurement comprises the signal-to-noise ratio of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

74. The transceiver of claim 63, wherein said at least one performance measurement comprises the bit error rate of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

 

dP=K(BER_s1−

BER_ref)

where dP is said power control update, K is a gain constant, BER_S1 is the bit error rate of said transmitted impulse radio signal, and BER_ref is a bit error rate reference.

75. The transceiver of claim 63, wherein said at least one performance measurement comprises the bit error rate and the signal strength of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

76. The transceiver of claim 63, wherein said at least one performance measurement comprises the bit error rate and the signal-to-noise ration of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

77. The transceiver of claim 63, wherein said at least one performance measurement comprises the signal-to-noise ratio and the signal strength of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

 

P_ref=K₂(SNR_ref−

SNR_S1)

78. The transceiver of claim 63, wherein said at least one performance measurement comprises the bit error rate of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

79. The transceiver of claim 63, wherein said at least one performance measurement comprises the bit error rate and the signal strength of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

80. The transceiver of claim 63, wherein said at least one performance measurement comprises the bit error rate and the signal-to-noise ratio of said transmitted impulse radio signal, and wherein said power adjuster calculates said power control update according to:

 

SNR_ref=K₂(log(BER_s1)−

log(BER_ref))