1
William G Rhind, Norman G Carder: Non-intrusive channel-impairment analyzer. Hewlett-Packard, Karl E Bring, January 15, 1991: US04985900 (74 worldwide citation)

A non-intrusive channel-impairment analyzer is provided for measuring at least one quasi-static impairment characteristic of a band-limited data communications channel. The analyzer comprises a data receiver section and a measurement section. The data receiver section is arranged to receive data mod ...


2
Norman G Carder: Waveform measurement. Hewlett Packard Company, June 10, 1997: US05637994 (8 worldwide citation)

The characteristics of an a.c. waveform are determined by measuring the time interval between the instant when the waveform crosses a first reference threshold and the instant when it crosses another threshold. The second threshold is varied to obtain a series of time interval measurements from whic ...