Patent ID: 6970528
Filing Date: 2005-11-29
Classification: H04L

Abstract:
1. A method of measuring jitter in a device under test comprising the steps of: providing a coherent sample signal to the device under test; to capture data unwrapping the data from the device; performing FFT (Fast Fourier Transform) of the unwrapped data; removing a DC harmonic and a fundamental frequency from the FFT of the unwrapped data; performing an inverse FFT of the FFT of the unwrapped data with the DC harmonic and fundamental frequency removed to get a code error; adjusting the code error to a predetermined phase; determining the variance of the code error at a low slew rate; determining the variance of the code error at a high slew rate; and calculating the jitter on each angle from the variance of the code error determined at the high slew rate and the variance of the code error determined at the low slew rate.