Communicating over power distribution media

• US 8,680,706 B2
• Filed: 08/03/2012
• Issued: 03/25/2014
• Est. Priority Date: 05/30/2008
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Zyren, James
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US13/566,811
• Publication Number:
  US 20130202053A1
• Time in Patent Office: 599 Days
• Field of Search: 307/1, 307/3, 307/4
• US Class Current: 307/4
• CPC Class Codes: H04B 2203/5433 Remote metering
• CPC Class Codes: H04B 2203/5458 Monitor sensor; Alarm systems
• CPC Class Codes: H04B 2203/547 via DC power distribution
• CPC Class Codes: H04B 3/546 Combination of signalling, telemetering, protection circuits for remote indication of supply or distribution network condition H02J13/00
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

A system includes a first communication module to be coupled to a first transmission medium for distributing power using a voltage waveform having a first amplitude; and a second communication module to be coupled to a second transmission medium for distributing power using a voltage waveform having a second amplitude different from the first amplitude, the second transmission medium being coupled to the first transmission medium. Each of the first and second communication modules is configured to use signals that propagate between the first and second transmission media.

Claims

1. A first device comprising:

a network interface; and

a first communication module configured to couple with a first transmission medium for distributing power using a first voltage waveform having a first amplitude in a network that also comprises a second transmission medium for distributing power using a second voltage waveform having a second amplitude different from the first amplitude, wherein the first transmission medium is coupled with the second transmission medium;

the first communication module further configured to;

utilize signals that propagate between the first and second transmission media for communication with a second communication module of a second device coupled with the second transmission medium; and

implement a modulation scheme that enables propagation of the signals from the first transmission medium to the second transmission medium, wherein the modulation scheme further configures the first communication module to select a pair of subcarrier frequencies for Frequency Shift Keying (FSK) modulation from a plurality of subcarrier frequencies used for Orthogonal Frequency Division (OFDM) modulation.

2. The first device of claim 1, wherein the first transmission medium is coupled with the second transmission medium by a transformer.

3. The first device of claim 1, wherein the first communication module is configured to implement the modulation scheme that enables propagation of the signals from the first transmission medium to the second communication module of the second device coupled with the second transmission medium via a transformer.

4. The first device of claim 3, wherein the second communication module of the second device is coupled with a thermostat and is configured to use signals to control the thermostat.

5. The first device of claim 1, wherein the first communication module is coupled to a power line.

6. The first device of claim 5, wherein the first communication module includes a smart meter coupled to a Smart Power Grid.

7. The first device of claim 6, wherein the first transmission medium includes an Alternating Current (AC) domestic power distribution medium.

8. The first device of claim 1, wherein the first amplitude is in a range of 100-240 Volts rms, and the second amplitude is 24 Volts rms.

9. The first device of claim 1, wherein the first and the second voltage waveforms have a frequency in a range of about 50-60 Hz.

10. The first device of claim 1, wherein the first communication module configured to select the pair of subcarrier frequencies comprises the first communication module configured to select a plurality of pairs of subcarrier frequencies.

11. The first device of claim 1, wherein the first communication module is further configured to transmit a signal using FSK modulation on a plurality of pairs of subcarrier frequencies from the plurality of subcarrier frequencies used for OFDM modulation.

12. The first device of claim 11, wherein the plurality of pairs of subcarrier frequencies are separated from each other by a minimum number of intervening frequencies of subcarriers that are not used to transmit signals.

13. The first device of claim 11, wherein the first communication module configured to select the pair of subcarrier frequencies comprises the first communication module configured to select the plurality of pairs of subcarrier frequencies, and wherein the first communication module is further configured to spread the plurality of pairs of subcarrier frequencies from each other over the plurality of subcarrier frequencies used for OFDM modulation to compensate for frequency selective fading on the first transmission medium.

14. The first device of claim 1, wherein the pair of subcarrier frequencies are adjacent frequencies separated by a frequency that is an inverse of a symbol time containing a whole number of periods of a sinusoidal waveform of each of multiple mutually orthogonal subcarriers.

15. The first device of claim 14, wherein the symbol time is used for generating symbols within the signals sent between the first communication module and the second communication module.

16. The first device of claim 15, wherein the signals sent between the first communication module and the second communication module use FSK modulation.

17. The first device of claim 1, wherein a modulation index for the pair of subcarrier frequencies is on an order of one.

18. The first device of claim 1, wherein a modulation index for the pair of subcarrier frequencies is between 0.6 and about 1.5.

19. The first device of claim 1, wherein the first communication module configured to implement the modulation scheme further comprises the first communication module configured to use FSK modulation for communication with the second communication module of the second device and use OFDM modulation for communication with a third communication module coupled with the first transmission medium.

20. The first device of claim 1, wherein the first communication module configured to implement the modulation scheme further comprises the first communication module configured to use a first pair of subcarrier frequencies for FSK modulation for communication with the second communication module and use a different second pair of subcarrier frequencies for FSK modulation for communication with a third communication module coupled with the second transmission medium.

21. The first device of claim 1, wherein the first communication module configured to implement the modulation scheme further comprises the first communication module configured to use FSK modulation for communication with the second communication module and use OFDM modulation for communication over a distribution cable from an AC domestic power grid.

22. A method comprising:

configuring a first communication module coupled to a first transmission medium to use signals that propagate between the first transmission medium and a second transmission medium for communication with a second communication module coupled with the second transmission medium, the first transmission medium for distributing power using a first voltage waveform having a first amplitude and the second transmission medium for distributing power using a second voltage waveform having a second amplitude different from the first amplitude, wherein the first transmission medium is coupled with the second transmission medium; and

implementing a modulation scheme at the first communication module that enables propagation of the signals from the first transmission medium to the second transmission medium, wherein the modulation scheme includes selecting a pair of subcarrier frequencies for Frequency Shift Keying (FSK) modulation from a plurality of subcarrier frequencies used for Orthogonal Frequency Division (OFDM) modulation.

23. The method of claim 22, wherein said implementing the modulation scheme at the first communication module comprises implementing the modulation scheme that enables propagation of the signals from the first transmission medium to the second communication module coupled with the second transmission medium via a transformer.

24. The method of claim 22, wherein said selecting the pair of subcarrier frequencies includes selecting a plurality of pairs of subcarrier frequencies.

25. The method of claim 22, further comprising transmitting a signal from the first communication module using FSK modulation on a plurality of pairs of subcarrier frequencies from the plurality of subcarrier frequencies used for OFDM modulation.

26. The method of claim 25, wherein the plurality of pairs of subcarrier frequencies are separated from each other by a minimum number of intervening frequencies of subcarriers that are not used to transmit signals.

27. The method of claim 22, wherein said selecting the pair of subcarrier frequencies comprises selecting a plurality of pairs of subcarrier frequencies, and wherein the method further comprises spreading the plurality of pairs of subcarrier frequencies from each other over the plurality of subcarrier frequencies used for OFDM modulation to compensate for frequency selective fading on the first transmission medium.

28. The method of claim 22, wherein the pair of subcarrier frequencies are adjacent frequencies separated by a frequency that is an inverse of a symbol time containing a whole number of periods of a sinusoidal waveform of each of multiple mutually orthogonal subcarriers.

29. The method of claim 28, wherein the symbol time is used for generating symbols within signals sent between the first communication module and the second communication module.

30. The method of claim 29, wherein the signals sent between the first communication module and the second communication module use FSK modulation.

31. The method of claim 22, wherein said implementing the modulation scheme at the first communication module comprises using FSK modulation for communication with the second communication module and using OFDM modulation for communication with a third communication module coupled with the first transmission medium.

32. The method of claim 22, wherein said implementing the modulation scheme at the first communication module comprises using a first pair of subcarrier frequencies for FSK modulation for communication with the second communication module and using a different second pair of subcarrier frequencies for FSK modulation for communication with a third communication module coupled with the second transmission medium.

33. The method of claim 22, wherein said implementing the modulation scheme at the first communication module comprises using FSK modulation for communication with the second communication module and using OFDM modulation for communication over a distribution cable from an AC domestic power grid.

34. A system comprising:

a first communication module configured to couple with a first transmission medium for distributing power using a first voltage waveform having a first amplitude; and

a second communication module configured to be coupled to a second transmission medium for distributing power using a second voltage waveform having a second amplitude different from the first amplitude, wherein the second transmission medium is coupled to the first transmission medium;

wherein each of the first and second communication modules is configured to use signals that propagate between the first and second transmission media, wherein the first communication module is configured to implement a modulation scheme that enables propagation of the signals from the first transmission medium to the second transmission medium and select a pair of subcarrier frequencies for Frequency Shift Keying (FSK) modulation from a plurality of subcarrier frequencies used for Orthogonal Frequency Division (OFDM) modulation.

35. The system of claim 34, wherein the first communication module is configured to implement the modulation scheme that enables propagation of the signals from the first transmission medium to the second communication module coupled with the second transmission medium via a transformer.

36. The system of claim 35, wherein the second communication module is coupled with a thermostat and is configured to use signals to control the thermostat.

37. The system of claim 34, wherein the first transmission medium includes an Alternating Current (AC) domestic power distribution medium.

38. The system of claim 34, wherein the first communication module configured to select the pair of subcarrier frequencies includes the first communication module configured to select a plurality of pairs of subcarrier frequencies.

39. The system of claim 38, wherein the first communication module is further configured to transmit a signal using FSK modulation on the plurality of pairs of subcarrier frequencies.

40. The system of claim 39, wherein the plurality of pairs of subcarrier frequencies are separated from each other by a minimum number of intervening frequencies of subcarriers that are not used to transmit signals.

41. The system of claim 34, wherein the first communication module configured to select the pair of subcarrier frequencies comprises the first communication module configured to select a plurality of pairs of subcarrier frequencies, and wherein the first communication module is further configured to spread the plurality of pairs of subcarrier frequencies from each other over the plurality of subcarrier frequencies used for OFDM modulation to compensate for frequency selective fading on the first transmission medium.

42. The system of claim 34, wherein the pair of subcarrier frequencies are adjacent frequencies separated by a frequency that is an inverse of a symbol time containing a whole number of periods of a sinusoidal waveform of each of multiple mutually orthogonal subcarriers.

43. The system of claim 34, wherein the first communication module configured to implement the modulation scheme further comprises the first communication module configured to use FSK modulation for communication with the second communication module and use OFDM modulation for communication with a third communication module coupled with the first transmission medium.

44. The system of claim 34, wherein the first communication module configured to implement a modulation scheme further comprises the first communication module configured to use a first pair of subcarrier frequencies for FSK modulation for communication with the second communication module and use a different second pair of subcarrier frequencies for FSK modulation for communication with a third communication module coupled with the second transmission medium.

45. The system of claim 34, further comprising a third communication module coupled to the second transmission medium to use signals that propagate between the first transmission medium and the second transmission medium.

46. The system of claim 45, further comprising communicating in parallel between the first and second communication modules and between the first and third communication modules.

47. The system of claim 45, wherein the first communication module configured to implement the modulation scheme further comprises the first communication module configured to use a first pair of subcarrier frequencies for Frequency Shift Keying (FSK) modulation for communication with the second communication module and using a different second pair of subcarrier frequencies for Frequency Shift Keying (FSK) modulation for communication with the third communication module.

48. The system of claim 34, wherein the first communication module configured to implement the modulation scheme further comprises the first communication module configured to use FSK modulation for communication with the second communication module and use OFDM modulation for communication over a distribution cable from an AC domestic power grid.