Patent ID: 7646804

Claim:
A system for bit-loading in a discrete multitone (DMT)-based digital subscriber line (DSL) modem, comprising: a model generator configured to generate a model containing a calculated total loading for an assumed gross coding gain and estimated total bit loadings for a plurality of other assumed gross coding gains, wherein said model generator estimates said estimated total bit loadings by adding a total numbers of estimated bits loaded on all subchannels at said assumed gross coding gains by taking one-bit loading at one coding gain and estimating total bit loadings at said assumed gross coding gains and said total numbers of estimated bits loaded on all subchannels depends upon signal-to-noise ratios, bit caps and numbers of unloaded subchannels, wherein said model generator pre-computes three threshold arrays subscripted by said assumed gross coding gains based on an output of a single-bit loading, wherein the three arrays represent a number of loaded subchannels, a number of one bit subchannels for use in estimating a number of trellis bits, and a total number of loaded bits, all at the indexed gross coding gain; and a bit loader associated with said model generator and configured to load bits in accordance with said model.