Patent ID: 7664169

Claim:
A method to control performance of a modem wherein each tone of a plurality of tones has an associated tone gain value and a maximum reachable tone gain value, and each tone of the plurality of tones is used in the modem to carry a bitstream, the method comprising: configuring the modem to: perform at least one of: selectively swapping bits between at least two tones in said plurality of tones, and selectively changing at least one tone gain value to optimize an error parameter; determine current tone gain values for said plurality of tones; determine gain margins between said maximum reachable tone gain values and said current tone gain values, respectively; and perform, to optimize said error parameter as a function of said gain margins, at least one of: varying a number of bits allocated to said plurality of tones, the varying including taking away one bit from a first tone of the plurality of tones in which the first tone has a minimum gain margin value of said gain margins, and adding one bit to a second tone of the plurality of tones in which the second tone has a higher gain margin of the gain margins, and performing a transmitted power variation by varying at least one of the current tone gain values.