Multi-carrier transmission systems

• US 6,366,554 B1
• Filed: 06/01/1999
• Issued: 04/02/2002
• Est. Priority Date: 09/02/1996
• Status: Expired due to Term

• Current Assignee: STMicroelectronics NV
• Original Assignee: STMicroelectronics NV
• Inventors: Stefansson, Tomas, Wen, Ye, Ohman, Hans, Bahlenberg, Gunnar, Isaksson, Anders, Okvist, Goran, Ljunggren, Lis-Marie, Isaksson, Mikael, Nordstrom, Tomas, Johansson, Magnus, Isaksson, Lars-Ake, Tonvall, Harry, Bengtsson, Daniel, Olsson, Lennart, Hakansson, Siwert
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): PHAN, MAN U
• Application Number:
  US09/147,759
• Time in Patent Office: 1,036 Days
• Field of Search: 370/206, 370/207, 370/208, 370/210, 370/203, 370/260, 370/484, 370/480, 370/515, 375/260, 375/221, 375/355, 375/222, 375/231, 375/347, 375/261, 375/298
• US Class Current: 370/206
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 2025/0349 as a feedback filter
• CPC Class Codes: H04L 2025/037 Detection of convergence state
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence
• 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 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated

Abstract

A multi-carrier transmission system, for example a DMT system. Channel information is transmitted between two transceivers using a plurality of subcarriers. Each subcarrier, or symbol, has a parameter associated with it. The transceivers are adapted to transmit the channel information as a sequence of n groups in which each of the n groups contains information concerning the number of adjacent subcarriers which have the same value as the parameter, together with the actual value of the parameter. The parameter which may have a plurality of discrete values, may be a bit-loading value, or a QAM constellation identifier.

Claims

1. A multi-carrier transmission system in which channel information is transmitted between two transceivers using a plurality of sub-carriers, characterised in that each sub-carrier, or symbol, has a parameter associated therewith, and in that said transceivers are configured to transmit said channel information as a sequence of a number of groups, in which each of said groups contains information concerning the number of adjacent sub-carriers which have the same value as said parameter, together with the actual value of the parameter, wherein the number of information bits required to be transmitted is substantially reduced in comparison to known systems, thereby effecting a saving in transmission capacity, and wherein said parameter has a plurality of discrete values, in that the number of information bits transmitted will be reduced if

2. A multi-carrier transmission system as claimed in claim 1, characterised in that said parameter has a plurality of discrete values.

3. A multi-carrier transmission system as claimed in claim 1, or claim 2, characterised in that said parameter is a bit-loading value.

4. A multi-carrier transmission system as claimed in claim 1, or claim 2, characterised in that said parameter is a QAM constellation identifier.

5. A multi-carrier transmission system as claimed in claim 1, characterised in that N equals 1024 n equals 4 and m equals 10.

6. A multi-carrier transmission system as claimed in claim 5, characterised in that P equals 50 groups and in that the number of bits to be transmitted is reduced by 83%.

7. A multi-carrier transmission system as claimed in claim 5, characterised in that P is less that 200 groups and in that the number of bits to be transmitted is reduced by at least 32%.

8. A multi-carrier transmission system as claimed in claim 5, characterised in that P is less that 100 groups and in that the number of bits to be transmitted is reduced by at least 66%.

23. A multi-carrier transmission system, transmitter, transceiver, or method as claimed in any previous claims, characterised in that said system is a DMT system.

24. A multi-carrier transmission system, transmitter, transceiver, or method as claimed in any previous claims, characterised in that said system is a DMT-based VDSL system.

9. A transmitter for a multi-carrier transmission system in which channel information is transmitted between two transceivers using a plurality of sub-carriers, characterised in that each sub-carrier, or symbol, has a parameter associated therewith, and in that said transmitter is configured to transmit said channel information as a sequence of n groups, in which each of said n groups contains information concerning the number of adjacent sub-carriers which have the same value of said parameter, together with the actual value of the parameter, wherein said parameter has a plurality of discrete values, in that the number of information bits transmitted will be reduced if

10. A transmitter as claimed in claim 9, characterised in that said parameter has a plurality of discrete values.

11. A transmitter as claimed in claim 9, or claim 10, characterised in that said parameter is a bit-loading value.

12. A transmitter as claimed in claim 9, or claim 11, characterised in that said parameter is a QAM constellation identifier.

13. A transceiver for a multi-carrier transmission system, characterised in that said transceiver includes a receiver and a transmitter as claimed in any one of claims 9 to 12.

14. A multi-carrier transmission system including two transceivers as claimed in claim 13.

15. In a multi-carrier transmission system in which channel information is transmitted between two transceivers using a plurality of sub-carriers, a method for transmitting channel information, characterised in that each sub-carrier, or symbol, has a parameter associated therewith, said method being characterised by the step of transmitting said channel information as a sequence of n groups, in which each of said n groups contains information concerning the number of adjacent sub-carriers which have the same value as said parameter, together with the actual value of the parameter, wherein said parameter is a QAM constellation identifier and has a plurality of discrete values, in that the number of information bits transmitted will be reduced if

16. A method as claimed in claim 15, characterised in that said parameter has a plurality of discrete values.

17. A method as claimed in claim 15, or claim 16, characterised in that said parameter is a bit-loading value.

18. A method as claimed in claim 15, or claim 16, characterised in that said parameter is a QAM constellation identifier.

19. A method as claimed in claim 15, characterized in that N equals 1024, n equals 4 and m equals 10.

20. A method as claimed in claim 19, characterised in that P equals 50 groups and in that the number of bits to be transmitted is reduced by 83%.

21. A method as claimed in claim 19, characterised in that P is less that 200 groups and in that the number of bits to be transmitted is reduced by at least 32%.

22. A method as claimed in claim 19, characterised in that P is less that 100 groups and in that the number of bits to be transmitted is reduced by at least 66%.

25. A multi-carrier transmission system, comprising:

a first transceiver configured to transmit and receive information using a plurality of sub-carriers, each of the plurality of sub-carriers having a channel information parameter associated therewith, wherein

the plurality of sub-carriers are categorized into a plurality of groups, each group including at least one of the plurality of sub-carriers, the channel information parameter associated with each of the at least one of the plurality of sub-carriers included in a particular group having a common value,

the first transceiver transmits channel information to another transceiver via a communications channel as a sequence of blocks of information, each block of information corresponding to a group and including

a quantity of sub-carriers included in the group, and

the common value of the channel information parameter corresponding to the group,

wherein transmitting the channel information as blocks of information requires substantially fewer bits than transmitting each channel information parameter individually, and wherein

26. The multi-carrier transmission system of claim 25, wherein each channel information parameter has a value of one of a plurality of discrete values.

27. The multi-carrier transmission system of claim 25, wherein the channel information parameter comprises a bit-loading value.

28. The multi-carrier transmission system of claim 25, wherein the channel information parameter comprises a QAM constellation identifier.

29. The multi-carrier transmission system of claim 25, wherein N is equal to 1024, n is equal to 4, and m is equal to 10.

30. The multi-carrier transmission system of claim 29, wherein

P is equal to 50, and

a number of bits required to transmit channel information is 83% fewer than would be required by transmitting each channel information parameter individually.

31. The multi-carrier transmission system of claim 29, wherein

P is less than 200, and

a number of bits required to transmit channel information is at least 32% fewer than would be required by transmitting each channel information parameter individually.

32. The multi-carrier transmission system of claim 29, wherein

P is less than 100, and

a number of bits required to transmit channel information is at least 66% fewer than would be required by transmitting each channel information parameter individually.

47. The multi-carrier transmission system of claim 25, wherein the system comprises a DMT system.

48. The multi-carrier transmission system of claim 25, wherein the system comprises a DMT-based VDSL sytstem.

33. A transmitter for a multi-carrier transmission system, comprising:

a first mechanism configured to transmit information using a plurality of sub-carriers, each of the plurality of subcarriers having a channel information parameter associated therewith, wherein

the plurality of sub-carriers are categorized into a plurality of groups, each group including at least one of the plurality of sub-carriers, the channel information parameter associate with each of the at least one of the plurality of sub-carriers included in a particular group having a common value,

the transmitter transmits channel information to a transceiver via a communications channel as a sequence of blocks of information, each block of information corresponding to a group and including

a quantity of sub-carriers included in the group, and

the common value of the channel information parameter corresponding to the group,

wherein transmitting the channel information as blocks of information requires substantially fewer bits than transmitting each channel information parameter individually, and wherein

 

P(m+n)<

N×

n,

34. The transmitter of claim 33, wherein each channel information parameter has a value of one of a plurality of discrete values.

35. The transmitter of claim 33, wherein the channel information parameter comprises a bit-loading value.

36. The transmitter of claim 33, wherein the channel information parameter comprises a QAM constellation identifier.

37. A transceiver for a multi-carrier transmission system, comprising:

a transmitter configured to transmit information using a plurality of sub-carriers, each of the plurality of sub-carriers having a channel information parameter associated therewith; and

a receiver configured to receive information using the plurality of sub-carriers, wherein

the plurality of sub-carriers are categorized into a plurality of groups, each group including at least one of the plurality of sub-carriers, the channel information parameter associated with each of the at least one of the plurality of sub-carriers included in a particular group having a common value,

the transceiver transmits channel information to another transceiver via a communications channel as a sequence of blocks of information, each block of information corresponding to a group and including

a quantity of sub-carriers included in the group, and

the common value of the channel information parameter corresponding to the group,

wherein transmitting the channel information as blocks of information requires substantially fewer bits than transmitting each channel information parameter individually, and wherein

38. A multi-carrier transmission system, comprising:

a first transceiver, including

a first transmitter configured to transmit information using a plurality of sub-carriers, each of the plurality of sub-carriers having a channel information parameter associated therewith, and

a first receiver configured to receive information using the plurality of sub-carriers; and

a second transceiver, including

a second transmitter configured to transmit information using the plurality of sub-carriers, and

a second transmitter configured to receive information using the plurality of sub-carriers,

wherein the plurality of sub-carriers are categorized into a plurality of groups, each group including at least one of the plurality of sub-carriers, the channel information parameter associated with each of the at least one of the plurality of sub-carriers included in a particular group having a common value,

the first transceiver transmits channel information to the second transceiver via a communications channel as a sequence of blocks of information, each block of information corresponding to a group and including

a quantity of sub-carriers included in the group, and

the common value of the channel information parameter corresponding to the group,

wherein transmitting the channel information as blocks of information requires substantially fewer bits than transmitting each channel information parameter individually, and wherein

39. A method for transmitting channel information in a multi-carrier transmission system, comprising the steps of:

transmitting channel information from a first transceiver to a second transceiver via a communications channel as a sequence of blocks of information, wherein

the first transceiver and the second transceiver are configured to transmit information using a plurality of sub-carriers, each of the plurality of sub-carriers having a channel information parameter associated therewith,

the plurality of sub-carriers are categorized into a plurality of groups, each group including at least one of the plurality of sub-carriers, the channel information parameter associated with each of the at least one of the plurality of sub-carriers included in a particular group having a common value, and

each block of information corresponding to a group and including

a quantity of sub-carriers included in the group, and

the common value of the channel information parameter corresponding to the group,

wherein transmitting the channel information as blocks of information requires substantially fewer bits than transmitting each channel information parameter individually, and wherein

40. The method of claim 39, wherein each channel information parameter has a value of one of a plurality of discrete values.

41. The method of claim 39, wherein the channel information parameter comprises a bit-loading value.

42. The method of claim 39, wherein the channel information parameter comprises a QAM constellation identifier.

43. The method of claim 39, wherein N is equal to 1024, n is equal to 4, and m is equal to 10.

44. The method of claim 43, wherein

P is equal to 50, and

a number of bits required to transmit channel information is 83% fewer than would be required by transmitting each channel information parameter individually.

45. The method of claim 43, wherein

P is less than 200, and

a number of bits required to transmit channel information is at least 32% fewer than would be required by transmitting each channel information parameter individually.

46. The method of claim 43, wherein

P is less than 100, and

a number of bits required to transmit channel information is at least 66% fewer than would be required by transmitting each channel information parameter individually.