Patent ID: 7324903

Claim:
An apparatus for measuring a quality of a signal passing through a channel, the apparatus comprising: an eye pattern detection unit, which detects eye pattern signals representing time changes of a waveform of the signal passing through the channel; and a signal quality generation unit, which generates a signal quality value of the signal passing through the channel based on an eye depth measured from the eye pattern signals, wherein the signal quality generation unit comprises: a histogram generation unit which generates a histogram of the eye pattern signals; a level section determination unit which determines a number of level sections, a size of each level section and a corresponding main level value for each level section based on the histogram; and an eye depth generation unit, which generates the eye depth for each determined level section, wherein the histogram generation unit obtains unit sections having a maximum or a minimum unit section value based on the histogram, and wherein, if an absolute value of a difference between adjacent minimum and maximum unit section values is smaller than a predetermined threshold value, the level section determination unit excludes the unit section having the smaller difference value as one of the boundary unit sections for the level section.