Method and apparatus for selection of ARQ parameters and estimation of improved communications

1. A method of approximating a bit error rate applicable to a multicarrier communications channel, including:

measuring an average signal to noise ratio across effective subcarriers of the channel; and

analytically approximating a bit error rate from at least the average signal to noise ratio, an average bit loading of the effective subcarriers, and forward error correction and automatic repeat request parameters.

2. A method of approximating a signal to noise ratio gain resulting from application of an automatic repeat request protocol with a particular maximum number of transmissions allowed, to a forward error correction encoded multicarrier communications channel, including:

measuring an initial average signal to noise ratio across the effective subcarriers of the channel; and

analytically approximating a signal to noise ratio gain from at least the initial average signal to noise ratio, an average bit loading of the effective subcarriers, forward error correction parameters and a parameter for the particular maximum number of transmissions allowed.

3. A method of selecting communication parameters to be applied to a multicarrier communications channel, including:

measuring an initial signal to noise ratio across effective subcarriers of the channel;

accessing previously recorded analytical approximations of one or more bit error rates resulting from application of one or more communication parameters to a range of signal to noise ratios including the measured initial signal to noise ratio, wherein the previously recorded analytical approximations derived from:

selecting a range of signal to noise ratios applicable to the effective subcarriers of the channel;

selecting a set of alternative communication parameters describing an average bit loading of the subcarriers and forward error correction and automatic repeat request handling; and

analytically approximating a bit error rate for the range of SNRs and the set of alternative communication parameters; and

selecting the communication parameters to be applied based at least in part on the measured initial signal to noise ratio and the previously recorded analytical approximations.

4. The method of claim 3 , wherein the approximations are recorded as splines.

5. The method of claim 3 , wherein the approximations are recorded as interpolation tables.

6. A method of selecting communication parameters to be applied to a multicarrier communications channel, including:

measuring an initial signal to noise ratio across effective subcarriers of the channel;

accessing previously recorded analytical approximations of one or more signal to noise ratio gains resulting from application of one or more communication parameters to a range of signal to noise ratios including the measured initial signal to noise ratio, wherein the previously recorded analytical approximations derived from analytically approximating a signal to noise ratio gain from at least an initial signal to noise ratio, an average bit loading of the effective subcarriers, forward error correction parameters and a parameter for the particular maximum number of transmissions allowed; and

selecting the communication parameters to be applied based at least in part on the previously recorded analytical approximations.

7. The method of claim 6 , wherein the approximations are recorded as splines.

8. The method of claim 6 , wherein the approximations are recorded as interpolation tables.

9. A method of selecting forward error correction parameters for use in a communications session having multiple communications channels, including the steps:

measuring an average signal to noise ratio of effective subcarriers of the channel and counting the effective subchannels to be loaded with data; and

selecting from stored communication parameters associated with predicted net signal to noise ratio gains for the communication parameters, wherein the predicted net signal to noise ratio gains were previously derived at least for pairs of forward error correction parameters S and R/S across a range of average signal to noise ratios and a range of number of effective subcarriers to be loaded with data bits, wherein S is the number of symbol sets per codeword and R/S is a number redundancy symbols per codeword divided by S.

10. The method of claim 9 , wherein the predicted net signal to noise ratio gains are recorded as splines.

11. The method of claim 9 , wherein the predicted net signal to noise ratio gains are recorded as interpolation tables indexed by the measured initial signal to noise ratio and a count of the effective subcarriers.