Power-line carrier communications system

• US 6,288,631 B1
• Filed: 12/08/1999
• Issued: 09/11/2001
• Est. Priority Date: 12/08/1998
• Status: Expired due to Term

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Shinozaki, Satoshi, Maki, Masahiro, Igata, Yuji
• Primary Examiner(s): Wu, Daniel J.
• Assistant Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US09/456,495
• Time in Patent Office: 643 Days
• Field of Search: 340/310.01, 340/310.02, 340/310.03, 340/310.06, 375/259, 375/262, 371/43
• US Class Current: 375/260
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/04 using frequency diversity
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

An object of the present invention is to provide a reliable power-line carrier communications system having a resistance to high-level impulse noise synchronized with power-cycle frequency in virtue of redundancy on both time and frequency axes.

An interleave part (11) shuffles, in n interleaving ways, transmitting symbols in a unit of symbol stream of the same length as a noise cycle. A modulation part (12) modulates the n-type symbol streams with n-piece carriers. A demodulation part (22) extracts amplitude/phase information from each of the n-piece carriers, and then outputs the information as amplitude/phase information streams. A de-interleave part (23) unshuffles the amplitude/phase information streams. A determination part (24) determines a symbol value from amplitude/phase information values in the same timing in the amplitude/phase information streams, and then outputs the values in a receiving symbol stream.

Claims

1. A power-line carrier communications system in which a power-line is used for a transmission path, and a symbol is transmitted from a transmitting apparatus to a reception apparatus, wherein

said transmission apparatus comprises:

interleave means for shuffling m symbols (where m is an integer of 2 or more) in a unit of symbol stream in n ways (where n is an integer of 2 or more) and generating n-type symbol streams in which 1st to mth symbols are shuffled;

modulation means for subjecting said n-type symbol streams generated by said interleave means to amplitude-modulation and/or phase-modulation in such a manner as to randomly distribute each symbol on both time and frequency axes by using predetermined carriers each corresponding thereto, and outputting the same as modulated signals; and

transmission amplifier means for amplifying said modulated signals to be in a predetermined amplitude, and outputting the same to said transmission path, and

said reception apparatus comprises;

reception amplifier means for amplifying, to be in a predetermined amplitude, and outputting the modulated signals received through said transmission path;

demodulation means for subjecting the modulated signals outputted from said reception amplifier means to amplitude-modulation and/or phase-demodulation by using predetermined reference carriers each corresponding thereto, and then generating n-type amplitude/phase information streams;

de-interleave means for unshuffling the symbols in said n-type amplitude/phase information streams generated by said demodulation means in an inverse manner to the interleave means, and then outputting the unshuffled n-type amplitude/phase information streams; and

determination means for determining a value respectively for said 1st to mth symbols according to each information on said unshuffled n-type amplitude/phase information streams outputted from said de-interleave means.

2. The power-line carrier communications system as claimed in claim 1, wherein said determination means calculates an average value of amplitude information and/or phase information within a predetermined threshold value from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in said unshuffled n-type amplitude/phase information streams, and then determining a value of a kth symbol according to the average value.

3. The power-line carrier communications system as claimed in claim 1, wherein, from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in said unshuffled n-type amplitude/phase information streams, said determination means

calculates an amplitude average value of the amplitude/phase information streams transmitted with the same carrier,

calculates relative amplitude information for said amplitude average value,

determines a degree of reliability based on whether or not a value of said relative amplitude information is within a predetermined range, and

calculates an average value by using only reliable amplitude information and/or phase information, and then

determines a value of a kth symbol according to the average value.

4. The power-line carrier communications system as claimed in claim 1, wherein, from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in said unshuffled n-type amplitude/phase information streams, said determination means

calculates amplitude average and distribution values of the amplitude/phase information streams transmitted with the same carrier,

calculates relative amplitude information for said amplitude average value,

determines a degree of reliability based on whether or not an absolute value of said relative amplitude information is smaller than an absolute value obtained by multiplying said distribution value by a predetermined constant, and

calculates an average value by using only reliable amplitude information and/or phase information, and then determines a value of a kth symbol according to the average value.

5. The power-line carrier communications system as claimed in claim 1, wherein, from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in said unshuffled n-type amplitude/phase information streams, said determination means

determines a degree of reliability whether or not a difference between an amplitude value of symbol the amplitude/phase information streams transmitted and an amplitude value of a preceding symbol, with the same carrier, is within a predetermined value, and

calculates an average value by using only reliable amplitude information and/or phase information, and then determines a value of a kth symbol according to the average value.

6. The power-line carrier communications system as claimed in claim 1, wherein said symbol stream having 1st to mth symbols in said interleave means is equal to or less than a half power-supply cycle time.

7. The power-line carrier communications system as claimed in claim 2, wherein said symbol stream having 1st to mth symbols in said interleave means is equal to or less than a half power-supply cycle time.

8. The power-line carrier communications system as claimed in claim 3, wherein said symbol stream having 1st to mth symbols in said interleave means is equal to or less than a half power-supply cycle time.

9. The power-line carrier communications system as claimed in claim 4, wherein said symbol stream having 1st to mth symbols in said interleave means is equal to or less than a half power-supply cycle time.

10. The power-line carrier communications system as claimed in claim 5, wherein said symbol stream having 1st to mth symbols in said interleave means is equal to or less than a half power-supply cycle time.

11. The power-line carrier communications system as claimed in claim 1, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

12. The power-line carrier communications system as claimed in claim 2, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

13. The power-line carrier communications system as claimed in claim 3, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

14. The power-line carrier communications system as claimed in claim 4. wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

15. The power-line carrier communications system as claimed in claim 5, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

16. The power-line carrier communications system as claimed in claim 6, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

17. The power-line carrier communications system as claimed in claim 7, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

18. The power-line carrier communications system as claimed in claim 8, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

19. The power-line carrier communications system as claimed in claim 9, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

20. The power-line carrier communications system as claimed in claim 10, wherein said modulation means modulates in an OFDM scheme, and

said demodulation means demodulates in the OFDM scheme.

21. A power-line carrier communications system in which a power-line is used for a transmission path, and a symbol is transmitted from a transmission apparatus to a reception apparatus, wherein:

said transmission apparatus comprises;

interleave device operable to shuffle m symbols (where m is an integer of 2 or more) in a unit of symbol stream in n ways (where n is an integer of 2 or more) and generate n-type symbol streams in which 1st to mth symbols are shuffled;

modulation device operable to subject the n-type symbol streams generated by said interleave device to amplitude-modulation and/or phase-modulation in such a manner as to randomly distribute each symbol on both time and frequency axes by using predetermined carriers each corresponding thereto, and outputting the same as modulated signals; and

transmission amplifier device operable to amplify the modulated signals to be in a predetermined amplitude, and output the same to said transmission path; and

said reception apparatus comprises;

reception amplifier device operable to amplify, to be in a predetermined amplitude, and output the modulated signals received through said transmission path;

demodulation device operable to subject the modulated signals outputted from said reception amplifier device to amplitude-modulation and/or phase-demodulation by using predetermined reference carriers each corresponding thereto, and then generating n-type amplitude/phase information streams;

de-interleave device operable to unshuffle the symbols in the n-type amplitude/phase information streams generated by said demodulation device in an inverse manner to the interleave device, and then output the unshuffled n-type amplitude/phase information streams; and

determination device operable to determine a value respectively for the 1st to mth symbols according to each information on the unshuffled n-type amplitude/phase information streams outputted from said de-interleave device.

22. The power-line carrier communications system as claimed in claim 21, wherein said determination device is operable to calculate an average value of amplitude information and/or phase information within a predetermined threshold value from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in the unshuffled n-type amplitude/phase information streams, and then determine a value of a kth symbol according to the average value.

23. The power-line carrier communications system as claimed in claim 21, wherein, from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in the unshuffled n-type amplitude/phase information streams, said determination device is operable to:

calculate an amplitude average value of the amplitude/phase information streams transmitted with the same carrier,

calculate relative amplitude information for the amplitude average value;

determine a degree of reliability based on whether or not a value of the relative amplitude information is within a predetermined range; and

calculate an average value by using only reliable amplitude information and/or phase information, and then determine a value of a kth symbol according to the average value.

24. The power-line carrier communications system as claimed in claim 21, wherein, from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in the unshuffled n-type amplitude/phase information streams, said determination device is operable to:

calculate amplitude average and distribution values of the amplitude/phase information streams transmitted with the same carrier;

calculate relative amplitude information for the amplitude average value;

determine a degree of reliability based on whether or not an absolute value of the relative amplitude information is smaller than an absolute value obtained by multiplying the distribution value by a predetermined constant; and

calculate an average value by using only reliable amplitude information and/or phase information, and then determine a value of a kth symbol according to the average value.

25. The power-line carrier communications system as claimed in claim 21, wherein, from kth (where k is an integer equal to or less than m) amplitude information and/or phase information in the unshuffled n-type amplitude/phase information streams, said determination device is operable to:

determine a degree of reliability whether or not a difference between an amplitude value of symbol the amplitude/phase information streams transmitted and an amplitude value of a preceding symbol, with the same carrier, is within a predetermined value; and

calculate an average value by using only reliable amplitude information and/or phase information, and then determine a value of a kth symbol according to the average value.

26. The power-line carrier communications system as claimed in claim 21, wherein the symbol stream having 1st to mth symbols in said interleave device is equal to or less than a half power-supply cycle time.

27. The power-line carrier communications system as claimed in claim 22, wherein the symbol stream having 1st to mth symbols in said interleave device is equal to or less than a half power-supply cycle time.

28. The power-line carrier communications system as claimed in claim 23, wherein the symbol stream having 1st to mth symbols in said interleave device is equal to or less than a half power-supply cycle time.

29. The power-line carrier communications system as claimed in claim 24, wherein the symbol stream having 1st to mth symbols in said interleave device is equal to or less than a half power-supply cycle time.

30. The power-line carrier communications system as claimed in claim 25, wherein the symbol stream having 1st to mth symbols in said interleave device is equal to or less than a half power-supply cycle time.

31. The power-line carrier communications system as claimed in claim 21, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

32. The power-line carrier communications system as claimed in claim 22, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

33. The power-line carrier communications system as claimed in claim 23, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

34. The power-line carrier communications system as claimed in claim 24, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

35. The power-line carrier communications system as claimed in claim 25, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

36. The power-line carrier communications system as claimed in claim 26, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

37. The power-line carrier communications system as claimed in claim 27, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

38. The power-line carrier communications system as claimed in claim 28, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

39. The power-line carrier communications system as claimed in claim 29, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.

40. The power-line carrier communications system as claimed in claim 30, wherein said modulation device is operable to modulate in an OFDM scheme;

and

said demodulation device is operable to demodulate in the OFDM scheme.