Amplitude Distributions of Television Channel Noise and a Model for Impulse Noise

Noise on telephone channels has been measured for years with instruments which are constructed to enable reasonably good correlations between the reading obtained and the annoyance of the noise during a telephone conversation.1 Fluctuations of the meter pointer during a measurement are either ignored or mentally averaged by the observer, depending upon their frequency of occurrence and their magnitude. With the introduction of data transmission on the telephone network, the relatively frequent high amplitude excursions of the noise waveform were viewed as a "new" kind of noise, primarily because they were generally not annoying in voice communication and it was recognized that no meaningful measure of them could be obtained with the standard noise measuring sets. The term "impulse noise" was applied to these high excursions and new instruments were designed to measure them. 2 The significance of impulse noise in data transmission has given rise to a great deal of effort devoted to its measurement, characterization, and evaluation as a transmission impairment. 3-6 (For an extensive bibliography, see lief. 3.) Several models have been suggested to describe the erratic behavior and clustering phenomena associated with 3243