Patent ID: 6980618

Claim:
A method of correcting for a phase offset between a subscriber and a service provider, comprising: sending a training signal from the subscriber to the service provider, the service provider being synchronized to a network clock, receiving the training signal at the service provider, calculating the phase offset between the subscriber and the service provider based upon the received training signal, transmitting the calculated phase offset from the service provider to the subscriber, and pre-adjusting a new signal transmitted from the subscriber to the service provider based upon the transmitted phase offset; wherein the calculating step further comprises modulating the received training signal by a cosine function to generate a signal Rx and modulating the received training signal by a sine function to generate a signal Ry wherein, R(t)=the received training signal, ω 0 =the base frequency of the training signal, and Rx = ∫ T ⁢ R ⁢ ⁢ ( t ) * cos ⁢ ⁢ ( ω 0 ⁢ ⁢ t ) ⁢ ⁢ ⅆ t , wherein T=2Π/ω 0 .