Circuitry for generating reference signal for delta encoding systems
AssigneeDeltaLab Research, Inc.
InventorRichard E. DeFreitas
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Abstract
In an electrical system of the type in which a digitally encoded signal is determined at least in part by the difference between a present value of an input signal and a reference signal representative of a past value of the input signal, improved circuitry for generating the reference signal. The improved circuitry comprises extraction means including a filter for extracting from the pattern of bits in the digitally encoded signal information relating to the time derivative of the present value of the input signal and an envelope detector for processing the output of the filter to provide a control signal, and integrating means responsive to the control signal to provide the reference signal.
Claims29
In an electrical system of the type in which a digitally encoded signal is determined at least in part by the difference between a present value of an input signal and a reference signal representative of a past value of said input signal, improved circuitry for generating said reference signal, comprising extraction means for extracting from the pattern of bits in said digitally encoded signal information relating to the time derivative of said present value to provide a corresponding control signal, said extraction means including a filter, and an envelope detector, said control signal from said extractioon means being fed to an integrating means, said integrating means being responsive to said control signal to provide said reference signal.
In an electrical system of the type in which a digitally encoded signal is determined at least in part by the difference between a present value of an input signal and a reference signal representative of a past value of said input signal, improved circuitry for generating said reference signal, comprising
- extraction means including a filter for extracting from the pattern of bits in said digitally encoded signal information relating to the time derivative of said present value to provide a corresponding control signal,
- integrating means responsive to said control signal to provide said reference signal,
- modulating means for feeding back to an input of said filter a modulated signal comprising said control signal modulated by said encoded signal, and
- means for providing as an input to said filter a mixture of said modulated signal and said digitally encoded signal, said mixture being selected to provide tracking at low slew rates between said input and the decoded output while maintaining dynamic range.
Dependencies are inferred from the claim text.