Patent ID: 7177350

Claim:
A method for generating a signal for use in a power saving mode in a digital subscriber line transmission system comprising: determining a combination of constellation points representing a signal having a peak-to-average ratio within a threshold, each constellation point representing a symbol transmitting during a payload data carrying mode comprising the step of performing the peak-to-average ratio minimization method on one or more combinations of constellation points representing symbols transmitting during the payload data carrying mode, wherein the peak-to-average ratio minimization method is an optimum subset rotation method comprising the steps of dividing selected constellation points from candidate sets for each bin used during the payload data carrying mode into a number of subsets; generating a time-domain signal for each subset from the selected constellation points for each subset; adjusting a phase of each of the time-domain signals for each subset; combining the time domain signals for each subset into a resulting signal; and determining whether the resulting signal satisfies the peak-to-average ratio threshold; and determining a set of input bits corresponding to each of the constellation points in the combination.