Flexible data transmission scheme adaptive to communication channel quality

A BASE-T Ethernet integrated circuit comprising:

• a transmit circuit including
• a link quality detector operable to detect a link quality metric;
• and
• logic operable to select a symbol transmission rate and a data modulation scheme based on the detected link quality metric,
• wherein the selected symbol transmission rate and the selected modulation scheme together represent a selectable data rate from a selection of data rates;
• and
• wherein, for a selected symbol transmission rate, if the detected link quality metric is less than a link quality threshold, then the logic is to select the data modulation scheme such that a data bit per symbol value represented by the selected data modulation scheme is decrease by at least ½ data bit per symbol.

A BASE-T Ethernet integrated circuit comprising:

• a receive circuit including
• a receiver operable to receive data symbols;
• and
• an LLR calculator to calculate log-likelihood-ratios (LLRs) for each data bit represented in a respective data symbol from both axes PAM data associated with a selected data modulation scheme, wherein the selected data modulation scheme is Neo-128DSQ or Neo-32DSQ, and wherein the calculation of LLRs comprises an adjustment factor;
• and
• wherein, if the selected data modulation scheme is Neo-32DSQ, the LLR calculator is to:
• perform modulo function on a Superset constellation to identify a 2DSQ Coset;
• perform transformation for each dimension of the 2DSQ Coset of the Superset separately;
• and
• use the transformed dimensions for LLR calculations.

A method of transferring data along a link with a BASE-T transceiver, the method comprising:

• detecting a link quality metric;
• selecting a symbol transmission rate and a data modulation scheme based on the detected link quality metric,
• wherein the selected symbol transmission rate and the selected data modulation scheme together represent a selectable data rate from a selection of data rates;
• and
• wherein selecting a symbol transmission rate and a data modulation scheme comprises selecting a data transmission scheme from the group comprising standard 10 GBASE-T at 800 MBaud and using 128DSQ, 400 MBaud using 1D-PAM16 with 4 bits in each PAM16 symbol being LDPC encoded, 200 MBaud using 1D-PAM16 with 4 bits in each PAM16 symbol being LDPC encoded, and 1 GBASE-T at 125 MBaud using PAM5.