Abstract: A digitizing instrument is used for modifying pattern data and jitter and noise components of a communication signal. In a typical implementation, the midpoints of a rising edge slope and horizontal portion of the communication signal are determined and multiple digital data records are acquired at the midpoints. The data sample records are transformed to frequency components and the random jitter and noise, and periodic jitter and noise components are determined. A correlated pattern data and the jitter and noise components are matrix elements in a simulated signal channel having communication system elements. Each correlated pattern data and jitter and noise component may be modified for each of the communication system element. The selectively modified correlated pattern data and jitter and noise components are combined to produce a modified communication signal that is displayed as a numeric table, eye diagram or bit error rate presentation.

Abstract: A digitizing instrument is used for modifying pattern data and jitter and noise components of a communication signal. In a typical implementation, the midpoints of a rising edge slope and horizontal portion of the communication signal are determined and multiple digital data records are acquired at the midpoints. The data sample records are transformed to frequency components and the random jitter and noise, and periodic jitter and noise components are determined. A correlated pattern data and the jitter and noise components are matrix elements in a simulated signal channel having communication system elements. Each correlated pattern data and jitter and noise component may be modified for each of the communication system element. The selectively modified correlated pattern data and jitter and noise components are combined to produce a modified communication signal that is displayed as a numeric table, eye diagram or bit error rate presentation.

Abstract: A digitizing instrument is used for modifying pattern data and jitter and noise components of a communication signal. In a typical implementation, the midpoints of a rising edge slope and horizontal portion of the communication signal are determined and multiple digital data records are acquired at the midpoints. The data sample records are transformed to frequency components and the random jitter and noise, and periodic jitter and noise components are determined. A correlated pattern data and the jitter and noise components are matrix elements in a simulated signal channel having communication system elements. Each correlated pattern data and jitter and noise component may be modified for each of the communication system element. The selectively modified correlated pattern data and jitter and noise components are combined to produce a modified communication signal that is displayed as a numeric table, eye diagram or bit error rate presentation.

Abstract: The distribution with respect to time of an event defined by the waveform of a repetitive input signal having a magnitude that lies within a predetermined range of values is observed by generating a sample signal at least once during each repetition of the input signal, generating an n-bit digital timing signal representative of the time of occurrence of a sample signal relative to the time of occurrence of the trigger signal, and sampling the repetitive input signal and generating a memory enable signal in the event that the magnitude of the input signal at the time of sampling falls within the predetermined range of values. The memory locations of a memory having 2.sup.n separately addressable memory locations are allocated respectively to the 2.sup.