Generating sine wave from noisy pulsed signal
If the waveform in your picture is precisely the waveform that you wish to convert to a clock then use a high speed comparator - maybe the MAX999 will be adequate. If the signal is dancing around DC wise then you can feed the MAX999 +input with the actual signal and low pass filter the signal and feed it to the -input. A simple RC network will do that.

It's called a data slicer: -



You can take it much further when the average level is moving about a fair bit. The circuit below does peak detection of most positive and most negative parts of the waveform and produces a "mid-rail" that both tracks the average (even quite fast moving average values) and also compensates for magnitude shifts of the signal: -



I've done the same but at 80.19MHz - don't ask why it was 80.19MHz - it is a long story.