Abstract: A method and system are provided for reducing noise in a time domain waveform of a signal under test (SUT). The method includes performing cross-correlation of multiple first complex signals and multiple second complex signals, respectively, from the SUT to provide multiple cross-correlated signals, respectively, where the cross-correlated signals have amplitude components and no phase components from the SUT, and where the first and second complex signals include uncorrelated noise, respectively. The method further includes determining an average of the cross-correlated signals to provide an average cross-correlated signal with reduced uncorrelated noise; obtaining a representative phase component from one of the first complex signals or the second complex signals; and combining the representative phase component with the average cross-correlated signal to provide a representative complex signal corresponding to the SUT with reduced uncorrelated noise.

Abstract: A measurement instrument and associated method: receive at a first input an aggressor signal (e.g., a supply voltage) from a device under test (DUT); capture samples of the aggressor signal; receive at a second input a victim signal from the DUT, wherein the received victim signal includes jitter induced thereon from the aggressor signal; capture samples of the received victim signal; apply the captured samples of the aggressor signal and the captured samples of the received victim signal to a predetermined model, which represents the jitter induced onto the received victim signal from the aggressor signal, to produce a system of equations; ascertain a plurality of unknown parameters in the predetermined model from the system of equations; and apply the predetermined model with the ascertained parameters to the captured samples of the aggressor signal to estimate the jitter induced onto the received victim signal from the aggressor signal.

Abstract: A measurement instrument and associated method: receive at a first input an aggressor signal (e.g., a supply voltage) from a device under test (DUT); capture samples of the received supply voltage; receive at a second input a victim signal from the DUT, wherein the received victim signal includes a crosstalk voltage induced thereon from the supply voltage; capturing samples of the received victim signal; applying the captured samples of the received supply voltage and the received victim signal to a predetermined model which represents crosstalk voltage induced onto the received victim signal from the supply voltage waveform, to produce a system of equations, wherein the model includes a plurality of unknown parameters; ascertain the plurality of unknown parameters in the predetermined model from the system of equations; and apply the predetermined model with the ascertained parameters to the captured samples of the received supply voltage to estimate the crosstalk voltage.

Abstract: A measurement instrument and associated method: receive at a measurement instrument at least one victim signal from a device under test (DUT), the victim signal including crosstalk interference from one or more aggressor signals which are not received by the measurement instrument; extract from the victim signal an ideal data pattern for the received victim signal, where the ideal data pattern does not include intersymbol interference (ISI), a noise component, or crosstalk interference to the victim signal; ascertain from the received victim signal and the ideal data pattern the ISI for the victim signal; produce a difference signal as a difference between: (1) the received victim signal; and (2) a sum of the ideal data pattern and the ISI; and ascertain from the difference signal a sum of the noise component and the crosstalk interference from one or more aggressor signals which are not received by the measurement instrument.

Abstract: Equalized Acquisition Record are prepared from Original Acquisition Records reflecting Total Jitter and from an existing description of DDJ. Removal of timing DDJ alters the locations of edges associated with data events. Voltage DDJ adjusts the asserted voltage in the central portion of a Unit Interval. One technique for equalizing timing jitter variably interpolates along the existing Original Acquisition Record to discover plausible new voltage values to assign to existing sample locations along the time axis. Another technique construes the desired amount of correction for each data event as an impulse that is applied to a Finite Impulse Response Filter whose output is a Voltage Correction Waveform having a smoothed voltage excursion. Time variant voltage values output from the Finite Impulse Response Filter are collected into a Voltage Correction Waveform Record having entry times found in the Original Acquisition Record.

Abstract: Separation and analysis of measured Total Jitter (TJ) begins with a suitably long arbitrary digital test pattern, from which an Acquisition Record is made. A Time Interval Error (TIE) or Voltage Level Error (VLE) Record is made of the Acquisition Record. A Template defines a collection of associated bit value or transitions that are nearby or otherwise related to a bit location of interest, and has associated therewith a collection of Descriptors and their respective Metrics. Each Descriptor identifies one of the various different patterns of bit value or transitions that fit the Template. The TIE/VLE Record is examined, and a parameter is measured for each instance of each Descriptor for the Template. The collection of measured parameters for each particular Descriptor are combined (e.g., averaging) to produce the Metric for that Descriptor.

Abstract: Measurement of jitter in a system uses a digital test sequence comprising many repetitions of a test pattern. An Acquisition Record is made of the entire test sequence. A complete Time Interval Error Record is made of the Acquisition Record. The complete TIE Record is separated into a collection of Component TIE Records, one for each transition in the test pattern, and that collectively contain all the different instances in the test sequence of that transition in the test pattern. An FFT is performed on each component TIE Record, and the collected DC contributions of those FFTs are combined to produce indications of Data Dependent Jitter, both as a function of bit position within the test pattern, and for the test sequence as a whole. The various spectral content of the FFTs for the component TIE Records are combined to produce an indication of Random Jitter and Periodic Jitter, which can then be used in finding Deterministic Jitter and Total Jitter.

Abstract: A method and apparatus for analyzing jitter in a signal. The signal is buffered to form a sequence of signal vectors and a time interval error function is calculated for each the signal vector. A time interval error spectrum is then calculated by transforming the time interval error function using a discrete Fourier transform. An average time interval error spectrum and an average power spectral density function are then calculated as averages of the amplitude of the time interval error spectrum and its amplitude squared, respectively. Parameters of the signal jitter are estimated from the average time interval error spectrum and the average power spectral density function.