Abstract: A sampling method that determines the deterministic and random components of a signal when the magnitude of the signal exceeds the range of the sampler.

Abstract: A signal sampling system includes an input signal and a plurality of samplers. The plurality of samplers produces a plurality of sample output signals. Each sampler from the plurality of samplers samples the input signal to produce a corresponding sample output signal from the plurality of sample output signals. Each sampler samples the input signal with a sampling pulse having a sampling aperture. A first sampling aperture used by a first sampler from the plurality of samplers to sample the input signal differs in duration from a second sampling aperture used by a second sampler from the plurality of samplers to sample the input signal.

Abstract: A signal sampling system includes a plurality of samplers that sample a signal. A signal processor processes samples acquired by the plurality of samplers in order to characterize jitter present in the signal. A set of samples is taken for a periodically repeating signal edge. The set of samples includes one sample from each sampler in the plurality of samplers. Each sample in the set of samples is taken at a different time. The signal processor evaluates values of samples within the set of samples to characterize jitter.

Abstract: A signal sampling system is presented. A first sampler samples a signal under test. At least one signal generator generates an asynchronous signal that is asynchronous to the signal under test. A second sampler samples a synchronous signal that is synchronous to the signal under test. A third sampler samples the synchronous signal. In response to the at least one asynchronous signal, the first sampler obtains a first sample, the second sampler obtains a second sample and the third sampler obtains a third sample. The first sample is a data sample of the signal under test. The second sample and the third sample are used to provide timing information about the data sample.

Abstract: A signal sampling system includes an input signal and a plurality of samplers. The plurality of samplers produces a plurality of sample output signals. Each sampler from the plurality of samplers samples the input signal to produce a corresponding sample output signal from the plurality of sample output signals. Each sampler samples the input signal with a sampling pulse having a sampling aperture. A first sampling aperture used by a first sampler from the plurality of samplers to sample the input signal differs in duration from a second sampling aperture used by a second sampler from the plurality of samplers to sample the input signal.

Abstract: A Decision-Feedback Equalizer Simulator (“DFES”) for predicting a bit-error rate (“BER”) of a transmitted signal through a channel, wherein the transmitted signal includes a repeating pattern having a length of N bits and wherein the transmitted signal is sampled by a bit-error rate tester (“BERT”) that produces a BER value as a function of a decision threshold ? of the BERT (“BERT(?)”). The DFES may include a decision-feedback equalizer (“DFE”) having a symbol detector, and a processor configured to define a vector of random variables (“X”) in response to determining the BER value, wherein {right arrow over (X)} has the same length of N bits as the repeating pattern of the transmitted signal, and determine the BER value in the DFE as a function of a DFE decision threshold z (“BER(z)”) of the symbol detector utilizing {right arrow over (X)}.

Abstract: A system and method for characterizing components for generating or communicating signals. A predefined test signal, such as a repeating sequence of symbols, or a pseudo-random binary sequence, is generated by a signal transmitter. A reference waveform is generated from the test signal. An acquired waveform is generated by collecting the test signal at a port of the device under test (DUT). A reference spectrum and an acquired spectrum are generated using a discrete Fourier transform. The acquired spectrum is divided by the reference spectrum to generate a scattering parameter spectrum that characterizes the DUT.

Abstract: A method and system characterize a random component of the jitter by designating an edge in the repetitive pattern, determining a slope of the designated edge, and acquiring a set of amplitude values at a different occurrences of the designated edge. A frequency domain representation of the set of amplitude values is then obtained, and identified peaks in the frequency domain representation are truncated. An RMS value, or other measure of random variations of the truncated representation is extracted and converted, based on the slope of the designated edge, to a corresponding RMS time jitter that represents the random component of the jitter. A periodic component of the jitter is characterized by determining the peak amplitude deviation of the acquired set of amplitude values, and then determining a periodic amplitude variation based on the RMS value, the peak amplitude deviation and the number of amplitude values in the set of amplitude values.

Abstract: A direct determination equalizer system (“DDES”) for compensating for the deterministic effects of a transmission channel and a data source is disclosed. The DDES may include an equalizer having equalizer-tap coefficients, a cross-correlator configured to receive the first sampled signal and an ideal signal and in response produce a cross-correlated signal, and a processor in signal communication with the equalizer and the cross-correlator. The equalizer is configured to receive a first sampled signal and in response produce an equalized output data signal sequence and the processor is configured to determine the equalizer-tap coefficients from the cross-correlated signal.

Abstract: A method establishes a reference bit in a bit pattern. The method includes (a) identifying a series of bit sequences in the bit pattern including all bit sequences having the largest number of consecutive bits with a common logic state and (b) assigning a reference bit based on one bit sequence in the series when the series includes only one bit sequence. The method includes (c) identifying a series of bit sequences in the bit pattern that includes all bit sequences that have the largest number of consecutive bits with an alternative logic state from a last prior identified series of bit sequences, and that are adjacent to each bit sequence in the last prior identified series of bit sequences. The method assigns a reference bit based on one bit sequence in the series identified in (c) when the series identified in (c) includes only one bit sequence.

Abstract: A method and system characterize jitter of an applied signal. The characterization includes acquiring a set of pseudo-randomly timed samples at a designated position on the signal, assigning a jitter value to each of the pseudo-randomly timed samples in the acquired set, and selecting a frequency from an array of frequencies based on a correlation of the assigned jitter values with the frequencies in the array. The periodic jitter associated with the signal is designated to have the frequency within the array of frequencies that has the highest correlation to the assigned jitter values.

Abstract: A method and system characterize jitter of an applied signal. The characterization includes acquiring a set of pseudo-randomly timed samples at a designated position on the signal, assigning a jitter value to each of the pseudo-randomly timed samples in the acquired set, and selecting a frequency from an array of frequencies based on a correlation of the assigned jitter values with the frequencies in the array. The periodic jitter associated with the signal is designated to have the frequency within the array of frequencies that has the highest correlation to the assigned jitter values.

Abstract: A method and system characterize a random component of the jitter by designating an edge in the repetitive pattern, determining a slope of the designated edge, and acquiring a set of amplitude values at a different occurrences of the designated edge. A frequency domain representation of the set of amplitude values is then obtained, and identified peaks in the frequency domain representation are truncated. An RMS value, or other measure of random variations of the truncated representation is extracted and converted, based on the slope of the designated edge, to a corresponding RMS time jitter that represents the random component of the jitter. A periodic component of the jitter is characterized by determining the peak amplitude deviation of the acquired set of amplitude values, and then determining a periodic amplitude variation based on the RMS value, the peak amplitude deviation and the number of amplitude values in the set of amplitude values.