Bit allocation among carriers in multicarrier communications

• US 7,801,225 B2
• Filed: 10/05/2004
• Issued: 09/21/2010
• Est. Priority Date: 11/25/1998
• Status: Expired due to Fees

• Current Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Original Assignee: Daphimo Co BV LLC (Intellectual Ventures LLC)
• Inventors: Tzannes, Marcos C., Sandberg, Stuart D., Shapiro, Jerome M.
• Primary Examiner(s): Corrielus; Jean B
• Application Number:
  US10/957,612
• Publication Number:
  US 20050058213A1
• Time in Patent Office: 2,177 Days
• Field of Search: 375259-260, 375225-227, 375219-220, 370/342, 370/252, 714/786, 714/752, 714/746
• US Class Current: 375/260
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 5/0044 allocation of payload

Abstract

A technique is provided that may be employed in multicarrier communications to improve the efficiency of error correction using symbol-oriented error correction methodologies, by reducing the number of error correction code symbols (102, 104 . . . ) that are received in error that result from a single channel error. More specifically, in this technique, bits from the symbols are allocated among the channels in such a way as to minimize the number of respective channels that are allocated bits belonging to more that one respective symbol during a respective transmission period.

Claims

1. A multicarrier data modulation method, comprising:

allocating a plurality of data bit signals of a serial input data stream among a plurality of carrier signals, wherein the plurality of data signals are modulated over the plurality of carrier signals by a modulation apparatus, wherein a predetermined number of the plurality of data bit signals are included in each one of a plurality of error correction symbols, wherein a number of the plurality of data bit signals modulated on at least one carrier signal is fewer than the predetermined number of data bit signals included in each of the plurality of error correction symbols, wherein each of said plurality of carrier signals is associated with a respective transmission channel, and wherein the allocating of the plurality of data bit signals among the carrier signals reduces a number of carrier signals that modulate data bit signals belonging to different error correction symbols during a transmission period.

2. The method according to claim 1, wherein each of the plurality of error correction symbols is a forward error correction coding symbol.

3. The method according to claim 1, wherein each of the plurality of error correction symbols has a size of one byte.

4. The method according to claim 1, wherein, during the transmission period, all of the data bit signals allocated to a one of the plurality of carrier signals are mapped to one error correction symbol.

5. The method according to claim 1, wherein the allocating the plurality of data bit signals among the plurality of carrier signals comprises determining numbers of data bit signals for transmission via the channels without exceeding a predetermined probability of bit transmission error, and allocating the plurality of data bit signals to the plurality of carrier signals in accordance with a carrier signal allocation sequence order, the order being such that the number of carrier signals that modulate data bit signals belonging to different error correction symbols is reduced.

6. The method according to claim 1, wherein the allocating the plurality of data bit signals among the plurality of carrier signals further comprises adjusting a transmission gain of at least one channel to change a data bit signal capacity of the at least one channel.

7. The method according to claim 5, wherein the allocating the plurality of data bit signals among the plurality of carrier signals further comprises adjusting a transmission gain of at least one channel to change a data bit signal capacity of the at least one channel.

8. A computer-readable memory comprising stored computer-executable program instructions that, in response to execution by a processor of an apparatus, enable the apparatus to:

provide a plurality of carrier signals for use in modulating a plurality of data bit signals of a serial input data stream, wherein a predetermined number of the plurality of data bit signals is included in each one of a plurality of error correction symbols before the plurality of data bit signals are modulated on the plurality of carrier signals, wherein a number of the plurality of data bit signals modulated on at least one carrier signal is fewer than the predetermined number of data bit signals included in each error correction symbol, and wherein each of said plurality of carrier signals is associated with a respective transmission channel; and

determine an allocation of the plurality of data bit signals among the plurality of carrier signals, wherein the allocation of the plurality of data bit signals among the plurality of carrier signals reduces a number of carrier signals that modulate data bit signals belonging to different error correction symbols during a transmission period.

9. The computer-readable memory according to claim 8, wherein each of the plurality of error correction symbols is a forward error correction coding symbol.

10. The computer-readable memory according to claim 8, wherein each of the plurality of error correction symbols has a size of one byte.

11. The computer-readable memory according to claim 8, wherein the allocation includes an allocation of only a set of data bit signals to a one of the plurality of carrier signals, wherein the set of data bit signals are mapped to only one error correction symbol.

12. The computer-readable memory according to claim 8, wherein the allocation comprises a determination of maximum numbers of bit signals transmittable via the channels without exceeding a desired maximum probability of bit transmission error, and an allocation of the maximum numbers of data bit signals to the plurality of carrier signals in accordance with a carrier signal allocation sequence order, the order being such that the number of carrier signals that are allocated data bit signals belonging to more than one error correction symbol during the transmission period is reduced.

13. The computer-readable memory according to claim 8, wherein the allocation comprises an adjustment of a transmission gain of at least one channel to change a data bit signal capacity of the at least one channel.

14. The computer-readable memory according to claim 12, wherein the allocation comprises an adjustment of a transmission gain of at least one channel to change a data bit signal capacity of the at least one channel.

15. A multicarrier data modulation system, comprising:

a transceiver adapted to generate a plurality of carrier signals for use in modulating a plurality of data bit signals of a serial input data stream; and

a processor adapted to;

include a predetermined number of the plurality of data bit signals in each one of a plurality of error correction symbols before the plurality of data bit signals are modulated on the plurality of carrier signals, wherein a number of plurality of data bit signals configured to be modulated on at least one carrier signal is fewer than the predetermined number of the plurality of data bit signals that are included in each error correction symbol, and wherein each of said plurality of carrier signals is associated with a respective transmission channel, and

allocate the plurality of data bit signals among the plurality of carrier signals in a way that reduces the number of carrier signals that modulate data bit signals belonging to different error correction symbols during a transmission period.

16. The multicarrier data modulation system according to claim 15, wherein each of the plurality of error correction symbols is a forward error correction coding symbol.

17. The multicarrier data modulation system according to claim 16, wherein each of the plurality of error correction symbols has a size of one byte.

18. The multicarrier data modulation system according to claim 15, wherein, all the data bit signals allocated to a one of the plurality of carrier signals are mapped to only one error correction symbol.

19. The multicarrier data modulation system according to claim 15, wherein the processor is adapted to determine a maximum number of data bit signals transmittable via the channels without exceeding a desired maximum probability of bit transmission error, and to allocate the maximum number of data bit signals to the carrier signals in accordance with a carrier signal allocation sequence order, the order being such that the number of carrier signals that are allocated data bit signals belonging to different error correction symbols during transmission period is reduced.

20. The multicarrier data modulation system according to claim 15, wherein the processor is further adapted to adjust a transmission gain of at least one channel to change a data bit signal capacity of the at least one channel.

21. The multicarrier data modulation system according to claim 19, wherein the processor is further adapted to adjust a transmission gain of at least one channel to change a data bit signal capacity of the at least one channel.

22. A multicarrier data modulation method, comprising:

modulating, over a plurality of carrier signals, a plurality of data bit signals of a serial input data stream, wherein a predetermined number of the plurality of data bit signals is included in each one of a plurality of error correction symbols before the plurality of data bit signals are modulated on the plurality of carrier signals, wherein a number of data bit signals that are modulable on at least one carrier signal is fewer than the predetermined number of the plurality of data bit signals included in each error correction symbol, and wherein each of said plurality of carrier signals is associated with a respective transmission channel; and

allocating the plurality of data bit signals among the plurality of carrier signals, wherein the allocating of the plurality of data bit signals among the plurality of carrier signals reduces or minimizes the number of carrier signals that modulate data bit signals belonging to different error correction symbols during a transmission period.

23. The multicarrier data modulation method according to claim 22, wherein the allocating of the plurality of data bit signals comprises adjusting a signal-to-noise margin of at least one channel.

24. The multicarrier data modulation method according to claim 23, wherein the said adjusting is carried out in such a way so as to permit the at least one channel to be assigned data bit signals from only a single error correction symbol during the transmission period.

25. The multicarrier data modulation method according to claim 23, wherein the plurality of data bit signals are allocated among the plurality of carrier signals in accordance with a carrier signal allocation sequence order, the order being such that the number of carrier signals that modulate data bits signals belonging to different error correction symbols is reduced.

26. The multicarrier data modulation method according to claim 22, wherein the plurality of data bit signals are allocated among the plurality of carrier signals in accordance with a carrier signal allocation sequence order, the order being such that the number of carrier signals that modulate data bits signals belonging to different error correction symbols is reduced.

27. The multicarrier data modulation method according to claim 23, wherein a signal-to-noise ratio (SNR) of the at least one channel is approximately the sum of the SNR margin and a minimum required SNR for the at least one channel, wherein the data bit signals to be transmitted via the at least one channel belong to more than one error correction symbol during the transmission period, and wherein said adjusting comprises increasing the SNR margin so as to reduce the number of data bit signals transmittable by the at least one channel while decreasing an error rate probability associated with bit signal transmission via the at least one channel.

28. A method for modulating data bit signals over a transmission channel having a plurality of subchannels, comprising:

including a predetermined number of data bit signals of an input data stream to each of a plurality of error correction symbols;

modulating, over the plurality of subchannels, a plurality of data bit signals, including modulating over at least one of the plurality of subchannels fewer than the predetermined number of data bit signals included in each error correction symbol;

placing the plurality of subchannels into groups comprised of one or more subchannels based on data bit signal capacities of the subchannels, wherein a collective data bit signal capacity of each group comprises the predetermined number of data bit signals; and

allocating the plurality of data bit signals among the groups of subchannels such that data bit signals included in different error correction symbols are not modulated on the same subchannel, thereby reducing the number of error correction symbols that are affected by an error occurring on any given subchannel during a transmission period.

29. The method of claim 28, further comprising determining a subchannel order in which to allocate the plurality of data bit signals of the plurality of error correction symbols to the subchannels.

30. The method of claim 29, further comprising adjusting the number of data bit signals transmittable by a given subchannel.

31. The method of claim 30, wherein adjusting the number of data bit signals comprises adjusting a transmission gain for the given subchannel.

32. The method of claim 30, wherein adjusting the number of data bit signals comprises adjusting a signal-to-noise ratio for the given subchannel.

33. The method of claim 29, wherein the subchannel order is based upon the bit size of the error correction symbol and the number of data bit signals modulable on each subchannel.

34. The method of claim 28, further comprising adjusting the number of data bit signals transmittable by a given subchannel.

35. The method of claim 34, wherein adjusting the number of data bit signals comprises adjusting a transmission gain for the given subchannel.

36. The method of claim 34, wherein adjusting the number of data bit signals comprises adjusting a signal-to-noise ratio for the given subchannel.

37. The method of claim 28, wherein the allocating occurs during initialization of a multicarrier transceiver.