Timing data reproduction system

A system for providing a sampling clock reference signal for information encoded in a digital data signal having a given pulse repetition rate and pulse width, comprising:

• means including a variable frequency or phase oscillator for sampling said digital data signal at successive time intervals determined by the frequency of the oscillator output signal, said frequency being on the order of twice said given pulse repetition rate, so that said sampling time intervals are on the order of one-half said digital data signal pulse width;
• a shift register coupled to said sampling means for storing successive groups of samples of said digital data signal, each group comprising at least two successive samples thereof;
• oscillator control means including a logic circuit for converting the pattern of digital data signal samples stored in said shift register into a control signal, the value of which is indicative of whether the phase of said digital data signal leads or lags the phase of said oscillator,
• said oscillator control means further including means for varying the frequency or phase of the output signal of said oscillator in accordance with said control signal so that the phase of said oscillator is maintained in coincidence with the phase of said digital data signals;
• and
• frequency divider means for synchronously dividing the frequency of the oscillator output signal in half to provide said sampling clock reference signal.