Method for synchronizing seamless rate adaptation

• US 8,045,601 B2
• Filed: 12/11/2009
• Issued: 10/25/2011
• Est. Priority Date: 03/12/1999
• 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.
• Primary Examiner(s): Torres, Juan A
• Application Number:
  US12/636,416
• Publication Number:
  US 20100111148A1
• Time in Patent Office: 683 Days
• Field of Search: 375/219, 375/222
• US Class Current: 375/219
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0016 involving special memory structures, e.g. look-up tables
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• 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 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0075 Transmission of coding parameters to receiver H04L1/0023 takes precedence
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/18 End to end
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• 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 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 5/1446 of transmission speed
• CPC Class Codes: H04M 11/062 : using different frequency bands for speech and other data
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A Discrete Multitone Modulation (DMT) system and method with the capability to adapt the system bit rate on-line in a seamless manner. The DMT system provides a robust and fast protocol for completing this seamless rate adaptation. The DMT system also provides a framing and encoding method with reduced overhead compared to conventional DMT systems. The DMT system and method provide seamless rate adaptation with the provision of different power levels. This framing and encoding method enables a system with seamless rate adaptation capability. The system and method of the invention can be implemented in hardware, or alternatively in a combination of hardware and software.

Claims

1. An apparatus, comprising:

a physical communications interface; and

a transceiver coupled to the physical communications interface, and configured to;

transmit or receive a message during data communications to change from a first data rate to a second data rate; and

transition, during the data communications, from transmission of a plurality of codewords at the first data rate to transmission of the plurality of codewords at the second data rate, wherein the transition is based at least on a sync symbol or a phase-shifted sync symbol, and wherein the plurality of codewords includes bits associated with application data before and after the transition.

2. The apparatus of claim 1, wherein the plurality of codewords has a specified codeword size and a specified number of parity bits for forward error correction.

3. The apparatus of claim 1, wherein the transceiver is further configured to:

transmit or receive the sync symbol or the phase-shifted sync symbol; and

transition to transmission of the plurality of codewords at the second data rate on a next immediate frame after transmit or receipt of the sync symbol or the phase-shifted sync symbol.

4. The apparatus of claim 1, wherein the transceiver is configured to retain a pre-transition codeword size, a pre-transition interleaver depth, and a pre-transition frame size after transitioning to transmission of a plurality of codewords by use of at least one changed transmission parameter.

5. The apparatus of claim 1, wherein the sync symbol or the phase-shifted sync symbol comprises a predefined pseudorandom noise sequence modulated across a plurality of carriers of a communications system.

6. An apparatus, comprising:

a physical communications interface; and

a transceiver coupled to the physical communications interface, and configured to;

transmit or receive a message during data communications to change from a first data rate to a second data rate; and

transition, during the data communications, from reception of a plurality of codewords at the first data rate to reception of the plurality of codewords at the second data rate, wherein the transition is based at least on a sync symbol or a phase-shifted sync symbol, and wherein the plurality of codewords includes bits associated with application data before and after the transition.

7. The apparatus of claim 6, wherein the plurality of codewords has a specified codeword size and a specified number of parity bits for forward error correction.

8. The apparatus of claim 6, wherein the receiver is further configured to:

transmit or receive the sync symbol or the phase-shifted sync symbol; and

transition to reception of the plurality of codewords at the second data rate on a next immediate frame after transmit or receipt of the sync symbol or the phase-shifted sync symbol.

9. The apparatus of claim 6, wherein the transceiver is configured to retain a pre-transition codeword size, a pre-transition interleaver depth, and a pre-transition frame size after the transition to reception of a plurality of codewords by use of at least one changed reception parameter.

10. The apparatus of claim 6, wherein the sync symbol or the phase-shifted sync symbol comprises a predefined pseudorandom noise sequence modulated across a plurality of carriers of a communications system.

11. An apparatus, comprising:

a physical communications interface; and

a transceiver coupled to the physical communications interface, and configured to, during data communications;

select a new bit rate;

send a message to another transceiver that the new bit rate will be used; and

transition to use of the new bit rate for communication with the other transceiver based at least on receipt of a sync symbol or a phase-shifted sync symbol, wherein the transceiver is further configured to retain at least one of a pre-transition codeword size, a pre-transition interleaver depth, and a pre-transition frame size upon the transition to use of the new bit rate.

12. The apparatus of claim 11, wherein the transceiver is further configured to transition to a new Bit Allocation Table associated with the new bit rate, and wherein the transceiver is further configured to transmit the new Bit Allocation Table to the other transceiver.

13. The apparatus of claim 11, wherein the transceiver is further configured to transition to a new Bit Allocation Table associated with the new bit rate, and wherein the transceiver is further configured to build the new Bit Allocation Table based at least on communication capabilities of the other transceiver.

14. The apparatus of claim 13, wherein the communication capabilities of the other transceiver include at least a maximum and a minimum number of bits per Discrete Multitone Modulation symbol.

15. The apparatus of claim 11, wherein the transceiver is further configured to transition to a new Bit Allocation Table associated with the new bit rate, and wherein the new Bit Allocation Table is one of a plurality of predefined Bit Allocation Tables.

16. The apparatus of claim 11, wherein the transceiver is further configured to transition to use of the new data rate for communication with the other transceiver in a frame immediately after receipt or transmit of the sync symbol or the phase-shifted sync symbol.

17. An apparatus, comprising:

a physical communications interface; and

a transceiver coupled to the physical communications interface, and configured to, during data communications;

transmit a plurality of codewords, wherein the plurality of codewords includes a specified codeword size and a specified number of parity bits for forward error correction;

transmit or receive a message to change a bit rate; and

seamlessly transition to a transmission of the plurality of codewords at the changed bit rate based on a sync symbol or an inverted sync symbol, and wherein the plurality of codewords includes bits associated with application data before and after the transition.

18. The apparatus of claim 17, wherein the transceiver is further configured to:

transmit or receive the sync symbol or the inverted sync symbol; and

utilize the changed bit rate on a frame, wherein the frame immediately succeeds the transmission or the reception of the sync symbol or the inverted sync symbol.

19. The apparatus of claim 17, wherein the transceiver is further configured to keep an interleaver depth and a frame size unchanged before and after the seamless transition.

20. The apparatus of claim 17, wherein the sync symbol or the inverted sync symbol comprises a predefined pseudorandom noise sequence modulated across a plurality of carriers.

21. An apparatus, comprising:

a physical communications interface; and

a transceiver coupled to the physical communications interface, and configured to, during data communications;

receive a plurality of codewords, wherein the plurality of codewords include a specified codeword size and a specified number of parity bits for forward error correction;

transmit or receive a message to change a bit rate; and

seamlessly transition to reception of the plurality of codewords at the changed bit rate based on a sync symbol or an inverted sync symbol, and wherein the plurality of codewords includes bits associated with application data before and after the transition.

22. The apparatus of claim 21, wherein the transceiver is further configured to:

transmit or receive the sync symbol or the inverted sync symbol; and

utilize the changed bit rate on a frame, wherein the frame immediately succeeds the transmission or the reception of the sync symbol or the inverted sync symbol.

23. The apparatus of claim 21, wherein the transceiver is further configured to keep an interleaver depth and a frame size unchanged before and after the seamless transition.

24. The apparatus of claim 21, wherein the sync symbol or the inverted sync symbol comprises a predefined pseudorandom noise sequence modulated across a plurality of carriers.

25. An apparatus, comprising:

a physical communications interface; and

means for transitioning, during data communications, a data rate of a transmission of a plurality of codewords from a first data rate to a second data rate, wherein the transitioning is based at least on a sync symbol or a phase-shifted sync symbol, and wherein the plurality of codewords includes bits associated with application data before and after transitioning to the second data rate.

26. The apparatus of claim 25, wherein the plurality of codewords has a specified codeword size and a specified number of parity bits for forward error correction.

27. An apparatus, comprising:

a physical communications interface; and

means for transitioning, during data communications, a data rate of a reception of a plurality of codewords from a first data rate to a second data rate, wherein the transitioning is based at least on a sync symbol or a phase-shifted sync symbol, and wherein the plurality of codewords includes bits associated with application data before and after the transitioning.

28. The apparatus of claim 27, wherein the plurality of codewords has a specified codeword size and a specified number of parity bits for forward error correction.