Digital signal demodulation using weighted peak sample averaging

A method for performing demodulation of servo bursts pre-recorded in quadrature along laterally offset locations from a centerline of a track of a rotating data medium, comprising:

• reading analog signals along said centerline representing said servo bursts on each side of said centerline;
• performing an analog-to-digital conversion of the analog signals at predetermined sample intervals to produce digital words indicative of instantaneous magnitudes of the servo bursts;
• determining digital peaks of said digital words of said analog signals on opposite sides of said centerline from value s at said predetermined sample intervals;
• weighing said digital peaks different than nonpeaks;
• and
• subtracting adjacent ones of said determined digital peaks to determine an alignment of a head along said centerline of said track.

A circuit for demodulating servo bursts detected from a data medium, comprising:

• an A/D converter to receive said detected servo bursts to convert said servo bursts into digital data words at predefined sample times;
• a peak detector for determining respective peaks of said digital data words;
• a circuit for applying different weighting to said peaks of said digital data words with predefined weights than to nonpeaks of the digital data words;
• and
• accumulating said weighted peaks;
• a circuit for determining a sum of said weights applied to said digital data words;
• and a circuit for dividing said accumulated weighted peaks by said sum of said weights.