Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
138 words
In a data transmission system wherein data signals are pulse amplitude modulated, transmitted, received, demodulated and applied to a data sink, apparatus for controlling the phase of a clock signal, comprising: means for producing said clock signal, subtraction means for receiving said data and demodulated signals and producing a difference signal having amplitudes which characterize the amplitude differences between said data and said demodulated signals at predetermined sampling instants, means for generating a slope signal having a value indicative of the slope of said demodulated signal, multiplier means coupled to said subtraction means and said generating means for producing a signal having amplitudes which are the products of the amplitudes of said difference and said slope signals and means for receiving said clock signal and adjusting the phase position of said clock signal responsive to said product signal.
Claim 2
Dependent Claim
138 words
In a data transmission system wherein data signals are pulse amplitude modulated, transmitted, received, demodulated and applied to a data sink, apparatus for controlling the phase of a clock signal, comprising: means for producing said clock signal, subtraction means for receiving said data and demodulated signals and producing a difference signal having amplitudes which characterize the amplitude differences between said data and said demodulated signals at predetermined sampling instants, means for generating a slope signal having a value indicative of the slope of said demodulated signal, multiplier means coupled to said subtraction means and said generating means for producing a signal having amplitudes which are the products of the amplitudes of said difference and said slope signals and means for receiving said clock signal and adjusting the phase position of said clock signal responsive to said product signal.
Claim 3
Dependent Claim
107 words
The apparatus defined in claim 1 wherein said means for producing said clock signal is an oscillator coupled to a frequency altering means, said apparatus further comprising: integrating means for producing a signal whose value is the integral of said product signal, sign circuit means for receiving said integral signal and producing a signal which is indicative of the polarity of said integral signal, and, means for supplying said integral signal and said polarity indicating signal to said altering means, said frequency altering means altering the spacing between segments of said clock signal in dependence upon the values of said integral signal and said polarity indicating signal.
Claim 4
Dependent Claim
67 words
The apparatus defined in claim 1 wherein said means for generating a slope signal comprises: first and second sampling means for receiving said demodulated signal and sampling it at succeeding different instants of time and for producing outputs indicating the amplitudes of said demodulated signal at said instants of time and differentiating circuit means for producing said slope signal from said first and second sampling means outputs.
Claim 5
Dependent Claim
40 words
The apparatus defined in claim 3 further comprising: third sampling means including equalizer means for counteracting the linear distortions occurring in the transmission of said data signal and for coupling at least partially equalized data signals to said subtracting means.