Digital signal peaking apparatus with controllable peaking level

Digital signal processing apparatus comprising:

• a source for providing digital input signals to be processed;
• digital filtering means coupled to said source for developing filtered digital signals including relatively higher frequency components of said digital input signals;
• multiplying means coupled to said digital filtering means for controllably scaling the magnitudes of said filtered digital signals in accordance with the value of a multiplier coefficient to develop scaled digital signais;
• first detecting means coupled to said digital filtering means for developing a detected signal repres entative of the peak magnitude of said filtered digital signals;
• second detecting means coupled to said first detecting means for developing first signals indicating that said detected signal exceeds a range of values in a first sense and developing second signals indicating that said detected signals exceed said range of values in a second sense;
• control means coupled to said second detection means for developing said multiplier coefficient having first and second values in response to said first and second signals, respectively, and developing said multiplier coefficient having values intermediate said first and second values in response to said detected signal;
• and
• combining means coupled to said source and to said multiplying means for combining said digital input signals and said scaled digital signals to produce processed digital signals.

A digital signal peaking system for controllably peaking relatively higher frequency signal components of digital input signals comprising:

• a digital filter means to which said digital input signals are applied for producing filtered digital signals including said relatively higher frequency signal components;
• peak detector means coupled to said digital filter means for developing a peak-level signal representative of the peak magnitude of said filtered digital signals;
• digital counter means for producing a multiplier coefficient factor in accordance with a digital count stored therein;
• first detector means, coupled to said peak detector means and to said digital counter means, for setting the stored digital count to a first predetermined value in response to said peak-level signal being greater than a first control value;
• second detector means, coupled to said peak detector means and to said digital counter means, for setting the stored digital count to a second predetermined value in response to said peak level signal being less than a second control value;
• third detector means, coupled to said peak detector means and to said digital counter means, for changing the stored digital count to a value intermediate said first and second predetermined values in accordance with the value of said peak-level signal intermediate said first and second control values;
• digital multiplier means, coupled to said digital filter means and to said digital counter means, for scaling said filtered digital signals in accordance with said multiplier coefficient factor produced by said digital counter means;
• delay means to which said digital input signals are applied for producing delayed digital signals in temporal alignment with corresponding scaled digital signals produced by said digital multiplier means;
• and
• digital combining means, coupled to said digital multiplier means and to said delay means, for combining said delayed digital signals and said scaled digital signals to develop peaked digital signals.