Patent ID: 7539255
Filing Date: 2009-05-26
Classification: H04L

Abstract:
1. A method of synchronizing timing at a receiver of multichannel modulation signals over a transmission facility, relative to a transmitter, comprising the steps of: receiving a multichannel modulation signal comprised of a plurality of pilot tones, each pilot tone at one of a plurality of subchannel frequencies of the multichannel modulation signal; converting the multichannel modulation signal into a digital signal; demodulating the digital signal including the received plurality of pilot tones over at least one frame; selecting a first subset of the plurality of pilot tones; for a second subset of the plurality of pilot tones, the second subset not including any of the plurality of pilot tones in the first subset, deriving a summed phase error estimate based on a phase error estimate of each of the demodulated plurality of pilot tones in the second subset relative to a reference signal, the step of deriving a summed phase error estimate comprising; controlling the converting of subsequent frames responsive to the summed phase error estimate; and for each of the first subset of the plurality of pilot tones, adjusting an associated reference signal.