Simplified encoding apparatus and method for pilot tone modulation in automatic-track-following

A 24/25 modulation encoding device for generating a power spectrum of a binary sequence using spectrum peak and notch power monitoring (SPNPM) modulation, comprising:

• means for generating digitized step functions for replacing sine and cosine functions required by said SPNPM modulation;
• a bit shifter and an accumulator for generating an estimator of expectation for approximating a real and an imaginary part of a work value for obtaining said power spectrum required by said SPNPM modulation;
• an absolute accumulator for receiving said estimator of expectation approximating said real and imaginary parts of said work value and for generating an absolute work value to replace a work-square value required for generating said power spectrum;
• a linear sum circuit with an input terminal designated as a DC terminal looping back for extra-weighting an input therefrom;
• and
• a comparator coupled to said linear sum circuit for determining a smaller sum value for monitoring a notch required by said SPNPM modulation for reducing circuit complexity of said encoding device.

A method for performing 24/25 modulation encoding by generating a power spectrum of a binary sequence using spectrum peak and notch power monitoring (SPNPM) modulation, comprising the steps of:

• generating digitized step functions for replacing sine and cosine functions required by said SPNPM modulation;
• employing a bit shifter and an accumulator for generating an estimator of expectation for approximating a real and an imaginary part of a work value for obtaining said power spectrum required by said SPNPM modulation;
• employing an absolute accumulator for receiving said estimator of expectation approximating said real and imaginary parts of said work value and for generating an absolute work value to replace a work-square value required for generating said power spectrum;
• employing a linear sum circuit with an input terminal designated as a DC terminal looping back for extra-weighting an input therefrom;
• and
• employing a comparator coupled to said linear sum circuit for determining a small sum value for monitoring a notch required by said SPNPM modulation for simplifying said encoding method.