Patent ID: 7656985

Claim:
Apparatus for synchronizing a local clock at a receiver with a clock at a transmitter, where indications of transmitter clock signals are communicated to the receiver as timestamps, comprising: a phase detector operable to compute an error signal indicative of differences between the timestamps and a local clock signal; a loop filter operable to reduce jitter and noise in the error signal, and thereby produce a first control signal in a first frequency domain; a mapping function to scale the first control signal from the first frequency domain to a second control signal in a second frequency domain, wherein the mapping function is based on the inverse of the magnitude of the nominal sampling interval between receipt of timestamps; a digital oscillator operable to oscillate at a frequency based at least in-part on the second control signal, and thereby produce a digital oscillator output signal; and a timestamp counter operable to count pulses in the digital oscillator output signal, and output the local clock signal.