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In telecommunication, an eye pattern, also known as an eye diagram, is an oscilloscope display in which a digital signal from a receiver is repetitively sampled and applied to the vertical input, while the data rate is used to trigger the horizontal sweep. It is so called because, for several types of coding, the pattern looks like a series of eyes between a pair of rails. It is an experimental tool for the evaluation of the combined effects of channel noise and intersymbol interference on the performance of a baseband pulse-transmission system. It is the synchronised superposition of all possible realisations of the signal of interest viewed within a particular signalling interval. Several system performance measures can be derived by analyzing the display. If the signals are too long, too short, poorly synchronized with the system clock, too high, too low, too noisy, or too slow to change, or have too much undershoot or overshoot, this can be observed from the eye diagram. An open eye pattern corresponds to minimal signal distortion. Distortion of the signal waveform due to intersymbol interference and noise appears as closure of the eye pattern.〔Christopher M. Miller "High-Speed Digital Transmitter Characterization Using Eye Diagram Analysis". (1266 Hewlett-Packard Journal 45(1994) Aug., No,4 ), pp. 29-37.〕〔John G Proakis, Digital Communications 3rd ed, 2001〕 ==Example== Image:Binary PSK eye diagram.svg|The eye diagram of a binary PSK system Image:Multipath system eye diagram.svg|The eye diagram of the same system with multipath interference(MI) effects added Image:Eye diagram.png|Eye diagram of a 4 level PAM signal 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Eye pattern」の詳細全文を読む スポンサード リンク
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