High data-rate powerline network system and method

• US 20020039388A1
• Filed: 02/27/2001
• Published: 04/04/2002
• Est. Priority Date: 02/29/2000
• Status: Abandoned Application

• Current Assignee: Thomson Licensing SA (Vantiva SA)
• Original Assignee: Thomson Licensing SA (Vantiva SA)
• Inventors: Smart, Kevin J., Stoddard, Trenton D., Haab, Dan B.
• Application Number:
  US09/794,761
• Publication Number:
  US 20020039388A1
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2075 in which the data are represented by the change in carrier phase
• CPC Class Codes: H04L 27/2637 with direct modulation of individual subcarriers
• CPC Class Codes: H04L 27/2653 with direct demodulation of individual subcarriers
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26

Abstract

A powerline network physical layer that allows multiple nodes to communicate digital data at high speed, with low error rates, using electrical powerlines in a home or office is described. The physical layer provides multiple channels by using Frequency Division Multiplexing (FDM). Each FDM channel is independent and separately modulated to carry data using Differential Binary Phase Shift Keying (DBPSK) or Differential Quadrature Phase Shift Keying (DQPSK). The error rate on each FDM channel is monitored and the separate channel are used according to an error rate criterion. If a channel is presenting an error rate that is too high, the channel is either disabled, ignored, or reconfigured into a reduced-capacity mode that provides an acceptable error rate.

Claims

1. A powerline network physical layer that allows multiple nodes to exchange digital data at high speed, comprising:

a transceiver, said transceiver comprising;

a data separator configured to separate an input data stream into a plurality of channel data streams, said data separator further configured to produce channel control data for each of said channel data streams;

a plurality of modulators, each of said modulators configured to receive a received channel data stream and said channel control data corresponding to the received channel data stream, each modulator configured to produce a modulated data output; and

a combiner, said combiner configured to combine a plurality of said modulated data outputs to produce a combined transmission stream; and

an analog front end configured to couple said combined transmission stream onto a powerline, said analog front end further configured to; and

comprising;

receive signals from said powerline to produce a combined receive stream;

a channel separator configured to separate said combined receive stream into a plurality of channel streams;

a plurality of demodulators configured to demodulate said plurality of channel streams into a plurality of demodulated data streams, each demodulator configured to demodulate a single channel stream; and

a data combiner configured to combine said plurality of demodulated data streams into an output data stream.

2. The communication system of claim 1, wherein said physical layer provides point-to-point communication.

3. The communication system of claim 1, wherein said physical layer provides point-to-multipoint communication.

4. A powerline network transmitter comprising:

a data separator configured to separate an input data stream into a plurality of channel data streams, said data separator further configured to produce channel control data for each of said channel data streams;

a plurality of modulators, each of said modulators configured to modulate a selected channel data stream according to channel control data corresponding to said selected channel data, each modulator configured to produce a modulated data output; and

a combiner, said combiner configured to combine a said modulated data outputs to produce a combined transmission stream.

5. A communication system comprising a transmitter for sending data over a first communication channel carried by a communication medium, said transmitter configured to encode data for transmission over said channel using a first symbol time and a second symbol time, said first symbol time being relatively longer than said second symbol time, said first symbol time used during time periods when said first communication channel is more noisy, said second symbol time used during time periods when said communication channel is less noisy.

6. The communication system of claim 5, wherein said communication medium comprises a powerline.

7. The communication system of claim 5, wherein said communication medium comprisesis a coaxial cable.

8. The communication system of claim 5, wherein said communication channel medium is a radio frequency signal and said medium is air or vacuum.

9. The communication system of claim 5, wherein said communication medium comprises a twisted-pair cable.

10. The communication system of claim 5, wherein said communication medium comprises a fiber-optic cable.

11. The communication system of claim 5, wherein data is modulated onto said first channel using differential Binary Phase Shift Keying.

12. The communication system of claim 5, wherein data is modulated onto said first channel using differential Quadrature Phase Shift Keying.

13. The communication system of claim 5, wherein data is modulated onto said first channel using Quadrature Amplitude Modulation.

14. The communication system of claim 5, wherein data is modulated onto said first channel using Frequency Shift Keying.

15. The communication system of claim 5, further comprising a second channel carried by said medium, said transmitter further configured to use a third symbol time.

16. The communication system of claim 5, wherein said third symbol time is substantially equal to said first symbol time.

17. The communication system of claim 5, wherein said second channel is time-division multiplexed with said first channel.

18. The communication system of claim 5, wherein said second channel is frequency-division multiplexed with said first channel.

19. The communication system of claim 5, wherein said second channel is orthogonal frequency-division multiplexed with said first channel.

20. The communication system of claim 5, wherein said second channel is orthogonal frequency-division multiplexed with said first channel using a programmable block length.

21. The communication system of claim 5, wherein said second channel is aggregated with said first channel.

22. The communication system of claim 5, wherein a first error rate on said first channel is monitored and a second error rate on said second channel is monitored.

23. The communication system of claim 5, wherein a first error rate on said first channel is monitored and said first channel is disabled if said first error rate exceeds a specified value.

24. The communication system of claim 5, wherein said transmitter sends a first data stream on both said first channel and said second channel, and wherein a single-channel receiver receives said data stream by selecting either said first channel or said second channel.

25. The communication system of claim 5, wherein said first channel is uncorrelated with respect to said second channel.

26. The communication system of claim 5, wherein a phase of said first channel is uncorrelated with respect to said second channel.

27. The communication system of claim 5, wherein said first channel is correlated with respect to said second channel.

28. The communication system of claim 5, wherein a phase of said first channel is randomized with respect to said second channel.

29. The communication system of claim 5, wherein said first channel is synchronous with respect to said second channel.

30. The communication system of claim 5, wherein said first channel is asynchronous with respect to said second channel.

31. The communication system of claim 5, wherein said communication channel comprises a point-to-point channel.

32. The communication system of claim 5, wherein said communication channel comprises a point-to-multipoint channel.

33. The communication system of claim 5, wherein said communication channel comprises a point-to-point radio channel.

34. The communication system of claim 5, wherein said communication channel comprises a point-to-multipoint radio channel.

35. The communication system of claim 5, wherein said symbol is coded by phase transitions.

36. The communication system of claim 5, wherein a first symbol is used to energize said first channel.

40. The method of claim 39, further comprising the steps of:

using a bit-based Barker code to provide a relatively high correlation peak.

37. A method for demodulating data for transmission on a noisy channel, comprising the steps of:

selecting a programmable symbol time;

using said symbol time to control a delay tap on a programmable delay;

using said symbol time to select a decimation rate of an output decimator;

providing a modulated signal to an input of said programmable delay; and

providing an output of said programmable delay to said output decimator.

38. A method for demodulating data comprising the steps of:

sub-sampling an intermediate frequency signal to produce an aliased image signal;

delaying said aliased image signal by a one symbol delay to produce a delayed image; and

calculating a phase difference by multiplying said aliased image signal by a complex conjugate said delayed image.

39. A method for symbol synchronization comprising the steps of:

receiving a received signal having a first symbol time;

demodulating said received signal using a second symbol time to produce a demodulator output;

correlating said demodulator output against a known symbol sequence and searching for a correlation peak; and

synchronizing using said correlation peak.

41. A hunting receiver for receiving control information, said hunting receiver comprising a single-channel receiver configured to search for a desired signal on a plurality of channels by separately examining each channel of said plurality of channels, said single channel receiver configured to select a desired channel from said plurality of channels and receive data from said desired channel.

42. A method for sending data on a plurality of channels comprising the steps of:

selecting a first initial phase state for a first channel;

encoding data for modulation onto said first channel based on a phase difference between said first initial phase state and a second phase state;

selecting a second initial phase state for a second channel; and

encoding data for modulation onto said second channel based on a phase difference between said second initial phase state and a third phase state.

43. An apparatus for communicating data over a noisy medium comprising:

means for modulating data onto at least one of a plurality of channels carried by said medium;

means for demodulating data received from a least one of said plurality of channels.

44. An apparatus for communicating data over powerlines comprising:

means for modulating data into at least one of a plurality of channels;

means for coupling said plurality of channels onto a powerline;

means for obtaining a first channel from said powerline; and

means for demodulating data from said first channel.

46. The digital demodulator of claim 45, further comprising:

phase shifting means for adjusting a phase of said phase-difference stream to produce a phase stream;

integrating means for integrating said phase stream;

synchronizing means for synchronizing said phase stream to produce synchronized stream; and

decimating means for decimating said synchronized stream to produce a bit stream.

47. The digital demodulator of claim 46, wherein said synchronizing means is programmable.

48. The digital demodulator of claim 46, wherein said synchronizing means synchronizes at symbol boundaries.

45. A digital demodulator comprising:

correlating means for autocorrelating a digital data stream to produce a correlated stream;

first decimating means for decimating said correlated stream to produce a decimated stream;

delaying means for producing a one-symbol delayed stream from said decimated stream; and

multiplying means for multiplying said correlated stream with a complex conjugate of said delayed stream to produce a phase-difference stream.

49. An apparatus for sending data from a first phase line of a powerline to a second phase line of the powerline, comprising:

means for plugging into a two-phase outlet of said powerline; and

means for coupling data from said first phase line to said second phase line.

50. An apparatus for sending data from a first phase of a powerline to a second phase of the powerline, comprising;

a plug configured to plug into a two-phase power outlet, said plug comprising a first prong configured to contact said first phase and a second prong configured to contact said second phase; and

a coupler comprising a first port and a second port, said first port provided to said first prong, and said second port provided to said second prong.

51. The apparatus of claim 50, wherein said coupler comprises a capacitor.

52. A method for demodulating data for transmission on a noisy channel wherein said noise is characterized by noise bursts separated by less noisy intervals, comprising the steps of:

selecting a programmable symbol time such that a packet comprising a desired number of symbols is shorter than an expected interval between noise bursts;

using said symbol time to control a delay tap on a programmable delay;

using said symbol time to select a decimation rate of an output decimator;

providing a modulated signal to an input of said programmable delay; and

providing an output of said programmable delay to said output decimator.

53. A computer power supply comprising a data coupler configured to provide a modulated signal onto a powerline.

54. A computer power supply comprising a data coupler configured to extract at least a portion of a modulated signal from a powerline.

55. A computer power supply comprising a powerline network interface, said power supply configured to provide one or more direct current voltages to a computer system, said powerline network interface comprising:

a first circuit configured to extract at least a portion of modulated data signal from a powerline; and

a second circuit configured to demodulate said modulated data signal.