Systems and methods for retransmission return channel error detection

• US 8,677,226 B2
• Filed: 03/22/2010
• Issued: 03/18/2014
• Est. Priority Date: 05/04/2009
• Status: Expired due to Fees

• Current Assignee: Ikanos Communications Incorporated (Qualcomm, Inc.)
• Original Assignee: Ikanos Communications Incorporated (Qualcomm, Inc.)
• Inventors: Pons, Julien D., Alloin, Laurent Francis, Sorbara, Massimo, Venkatesan, Vinod
• Primary Examiner(s): Bhatia, Ajay
• Assistant Examiner(s): NGUYEN, THIEN DANG
• Application Number:
  US12/728,758
• Publication Number:
  US 20100281349A1
• Time in Patent Office: 1,457 Days
• Field of Search: 714/801, 714/807, 714/799, 714/E11.032, 375/340
• US Class Current: 714/801
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/1505 Golay Codes
• CPC Class Codes: H03M 13/251 with block coding
• CPC Class Codes: H03M 13/256 with trellis coding, e.g. with convolutional codes and TCM
• CPC Class Codes: H03M 13/353 Adaptation to the channel
• CPC Class Codes: H03M 13/616 Matrix operations, especially for generator matrices or check matrices, e.g. column or row permutations
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0073 Special arrangements for feedback channel
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal

Abstract

A method implemented in a digital subscriber line (DSL) system is described for minimizing a misdetection probability at a far-end coded message receiver during transmission of a coded message. The method comprises jointly determining, at the far-end coded message receiver, a P matrix and a modulation scheme. The method further comprises encoding a message into a coded message with a systematic linear block code, the systematic linear block code having a generator matrix [I P], where I represents a linear block code component identity matrix and P represents the determined P matrix. The method also comprises modulating the encoded message to one or more tones forming a discrete multi-tone (DMT) symbol according to the determined modulation scheme.

Claims

1. A system comprising:

a transmitter for transmitting a coded message to a far-end coded message receiver, the transmitter comprising;

an encoder configured to encode a message into a coded message having information bits and redundancy bits, the encoder using a generator matrix [I P], where I is an identity matrix that passes the information bits from the message into the encoded message and P represents a matrix that generates the redundancy bits in the encoded message from the information bits in the message; and

a modulator configured to modulate the encoded message to one or more tones forming a discrete multi-tone (DMT) symbol using a modulation scheme comprising a constellation size, wherein the P matrix and the constellation size of the modulation scheme are jointly determined so that the combination of the determined P matrix and constellation size of the modulation scheme together minimize a misdetection probability at the far-end coded message receiver.

2. The system of claim 1, wherein the transmitter is configured to minimize the misdetection probability by selecting the modulation scheme to minimize the message error probability and then selecting the P matrix that maximizes both Hamming and Euclidean minimum distances on the coded message.

3. The system of claim 1, wherein the transmitter is configured to minimize the misdetection probability by first selecting a modulation scheme to minimize the message error probability.

4. The system of claim 3, wherein the message error probability is minimized by modulating the coded message to tones with a signal-to-noise ratio (SNR) higher than the minimum required SNR.

5. The system of claim 3, wherein upon selecting a modulation scheme, the transmitter then selects the P matrix that maximizes a Hamming minimum distance and minimizes multiplicities associated with smallest Euclidean distances of a Euclidean distance spectrum computed for the coded message.

6. The system of claim 1, wherein the linear block code P matrix is communicated by the far-end coded message receiver.

7. The system of claim 1, wherein configuration of the modulator is specified by the far-end message receiver.

8. The system of claim 1, wherein the joint determination of the P matrix and modulation scheme is performed according to a noise environment.

9. The system of claim 7, wherein the configuration of the modulator comprises bit-to-tone loading information.

10. The system of claim 1, wherein the modulator operates based on a trellis coded modulation (TCM) scheme, wherein the message error probability is minimized by modulating the coded message including the TCM redundancy to a first trellis section of a TCM trellis diagram.

19. A system according to claim 1,

wherein the identity matrix I is a 12*12 identity matrix, and

wherein the P matrix is:

11. A system comprising:

a receiver for receiving a coded message from a far-end coded message transmitter, the receiver comprising;

an error detector configured to determine a level of correctness of the received message encoded to include information bits and redundancy bits, the encoding having been performed using a generator matrix [I P], where I is an identity matrix that passes the information bits into the encoded message and P represents a matrix that generates the redundancy bits in the encoded message; and

a demodulator configured to demodulate the encoded message from one or more tones forming a discrete multi-tone (DMT) symbol using a demodulation scheme comprising a constellation size; and

wherein the receiver is further configured to transmit modulation information associated with the coded message to the far-end message transmitter, and wherein the receiver jointly determines the P matrix and modulation information including the constellation size so that the combination of the determined P matrix and constellation size together minimize a misdetection probability.

12. The system of claim 11, wherein the P matrix is communicated to the far-end coded message transmitter.

13. The system of claim 11, wherein the demodulator comprises a trellis coded modulation (TCM) scheme decoder.

14. The system of claim 13, wherein the receiver minimizes the message error probability by transmitting to the far-end transmitter, modulation information to modulate the coded message including the TCM redundancy to a first trellis section of a TCM trellis diagram.

15. The system of claim 11, wherein the receiver minimizes the message error probability by transmitting to the far-end transmitter, modulation information to modulate the coded message to tones with a signal-to-noise ratio (SNR) higher than the minimum required SNR.

16. The system of claim 11, wherein the receiver minimizes the misdetection probability by first selecting a modulation scheme that minimizes the message error probability.

17. The system of claim 16, wherein upon selecting a modulation scheme, the receiver then selects the P matrix that maximizes both Hamming and Euclidean minimum distances computed for the coded message.

18. The system of claim 16, wherein upon selecting a modulation scheme, the receiver then selects the P matrix that maximizes the Hamming minimum distance and minimizes multiplicities associated with smallest Euclidean distances of a Euclidean distance spectrum computed for the coded message.

20. A system according to claim 11,

wherein the identity matrix I is a 12*12 identity matrix, and

wherein the P matrix is:

21. A method implemented in a digital subscriber line (DSL) system for minimizing a misdetection probability at a far-end coded message receiver during transmission of a coded message, comprising:

jointly determining, at the far-end coded message receiver, a P matrix and a modulation scheme comprising a constellation size, wherein jointly determining includes determining a combination of P matrix and constellation size that together minimize the misdetection probability;

encoding a message into a coded message having information bits and redundancy bits using a generator matrix [I P], where I is an identity matrix that passes the information bits from the message into the encoded message and P represents the determined P matrix that generates the redundancy bits from the information bits in the message; and

modulating the encoded message to one or more tones forming a discrete multi-tone (DMT) symbol according to the determined modulation scheme.

22. The method of claim 21, wherein jointly determining a P matrix and a modulation scheme comprises:

selecting a modulation scheme; and

upon selecting the modulation scheme, selecting the P matrix that maximizes both Hamming and Euclidean minimum distances, wherein the minimum Euclidean distance is computed for the coded message.