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.
I was at a dance
When he caught my eye
Standin' all alone
Lookin' sad and shy
We began to dance
Swayin' to and fro
And soon I knew I'd never let him go
(Chorus)
Blame it on the bossa nova
With it's magic spell
Blame it on the bossa nova
That he did so well
Oh it all began with just one little dance
But soon it ended up a big romance
Blame it on the bossa nova
The dance of love
Now was it the moon
No no the bossa nova
Or the stars above
No no the bossa nova
Now was it the tune
Yea yea the bossa nova
The dance of love
Now I'm glad to say
I'm his bride to be
And we're gonna raise a family
And when our kids ask
How it came about
I gonna say to them with out a doubt