Abstract: A method and system for removing the effect of intersymbol interference (ISI) from a data record indicating times of logic level transitions exhibited by a data signal that has been distorted by ISI exhibited by a system having a particular step response may perform the following acts. The data record may be received, and a transition from within the data may be selected record for removal of ISI. Preceding transitions within the data record are then inspected. A time defect is obtained, based at least in part upon the inspected preceding transitions. Finally, the data record is adjusted, based upon the time defect, to indicate a new time of transition for the selected transition, thereby removing the effect of ISI for the selected transition.

Abstract: A method, apparatus, and article of manufacture for analyzing a measurable distribution having random components and deterministic components. The method includes the steps of collecting data, constructing a probability density function based on the data such that the probability density function is a convolution of deterministic functions and random functions, constructing a probability density function based on a deterministic and random convolution model having three or more parameters wherein at least one of the parameters are unknown, and determining unknown parameters by using a deconvolution process.

Abstract: A method for measuring a bit error rate in a communication system that includes a transmitter, a medium, and a receiver. The method may include identifying a plurality of causes of bit errors. For each cause, the communication system is measured to determine a corresponding probability density function. Each of the corresponding probability density functions is integrated over an interval representing a range in which the corresponding cause creates a bit error, thereby generating a plurality of integrated quantities. The integrated quantities are summed to arrive at a bit error rate for the communication system. An apparatus may be programmed to execute the foregoing method.

Abstract: A system for determining a response characteristic of an nth order linear system, such as a phase locked loop, is disclosed. An input signal is supplied to the linear system, and the system measures an output signal produced by the linear system. A variance record is constructed for a measurable quantity, such as jitter, extracted from the output signal. The response characteristic of the linear system is then obtained from the variance record. The response characteristic, such as the transfer function, noise processes, and/or power spectral density (PSD), may be found through a numerical or analytical solution to a mathematical relationship between a response function of the nth order linear system and the variance record.

Abstract: A method, apparatus, and article of manufacture for analyzing measurements. The invention provides a method for separating and analyzing the components of a distribution, such as deterministic and random components. The method performs the steps of collecting data from a measurement apparatus, constructing a histogram based on the data such that the histogram defines a distribution, fitting tails regions wherein deterministic and random components and associated statistical confidence levels are estimated.

Abstract: A method and apparatus for measuring characteristics in an electromagnetic or optical system. A modulation signal is provided to a device under test to provide a first signal and to a reference device which provides a second signal, and a tine domain optical analyzer measures the transitions of the first signal and the transitions of the second signal to determine characteristics of the device under test. In one embodiment, the characteristics of the reference device are determined with a modulated light source having two or more known wavelengths that provides a first signal, and a second signal is provided to a reference device to create a third signal. A time domain optical analyzer measures the transitions of the first signal and the transitions of the third signal for two or more wavelengths to determine reference device signal delay time characteristics as a function of wavelength.

Abstract: A method, apparatus, and article of manufacture for analyzing a measurable distribution having random components and deterministic components. The method includes the steps of collecting data, constructing a probability density function based on the data such that the probability density function is a convolution of deterministic functions and random functions, constructing a probability density function based on a deterministic and random convolution model having three or more parameters wherein at least one of the parameters are unknown, and determining unknown parameters by using a deconvolution process.

Abstract: A system for determining a response characteristic of an nth order linear system, such as a phase locked loop, is disclosed. An input signal is supplied to the linear system, and the system measures an output signal produced by the linear system. A variance record is constructed for a measurable quantity, such as jitter, extracted from the output signal. The response characteristic of the linear system is then obtained from the variance record. The response characteristic, such as the transfer function, noise processes, and/or power spectral density (PSD), may be found through a numerical or analytical solution to a mathematical relationship between a response function of the nth order linear system and the variance record.

Abstract: A system that measures a segment of a waveform by isolating the segment by virtue of gating. A waveform anomaly may be gated. The gated waveform is supplied to a plurality of frequency information extractors, which yield information regarding the frequency content of the gated waveform at individual frequencies. Distortion introduced into the gated waveform may be measured by applying the same gating function to a reference waveform. The system may measure or gate an incoming waveform at time intervals dictated by a clock signal recovered from the incoming waveform. A segment of the waveform to be measured may be circulated through a fiber loop, with a fraction of the circulated signal split off for presentation to a measurement system with each circulation. The point in time at which the waveform crosses a threshold may be determined by straddle sampling.

Abstract: A method, apparatus, and article of manufacture for analyzing measurements. The invention provides a method for separating and analyzing the components of a distribution, such as deterministic and random components. The method performs the steps of collecting data from a measurement apparatus, constructing a histogram based on the data such that the histogram defines a distribution, fitting tails regions wherein deterministic and random components and associated statistical confidence levels are estimated.

Abstract: A method, apparatus, and article of manufacture for analyzing measurements. The invention provides a method for separating and analyzing the components of a distribution, such as deterministic and random components. The method performs the steps of collecting data from a measurement apparatus, constructing a histogram based on the data such that the histogram defines a distribution, fitting tails regions wherein deterministic and random components and associated statistical confidence levels are estimated.