Patent ID: 6968002

Claim:
A method for time aligning first and second signals, comprising the steps of: modulating said second signal by said first signal to provide a third signal; and determining frequency component strengths of said third signal, said frequency component strengths being indicative of time alignment between said first signal and said second signal, wherein said step of determining frequency component strengths of said third signal comprises: filtering said third signal to provide a filtered signal while sweeping said second signal through a time delay; and detecting a level of said filtered signal, said level being indicative of time alignment between said first signal and said second signal, said step of detecting a level of said filtered signal comprises: first detecting when said filtered signal is at a minimum level during said sweeping, said minimum level occurring at a first time delay value; second detecting when said filtered signal is next at said minimum level during said sweeping, said next minimum level occurring at a second time delay value; and setting a time delay value for said second signal at a delay value between said first time delay value and said second time delay value; wherein said first signal comprises a data signal encoded in a predetermined bit pattern in a Non-Return-to-Zero signal format, said second signal comprises a Return-to-Zero pulse signal having a frequency equal to a data interval of said first signal, and said third signal comprises a data signal in which data is encoded in a Return-to Zero signal format.