Broadcast signal recognition system and method

A method for the automatic electronic recognition of a program unit broadcast by radio waves which includes:

• a. processing said program unit to obtain a plurality of digitized reference signal segments, the processing of said program unit including prefiltering to select a preferred signal in a frequency portion of the audio spectrum with a stable characteristic, forming an envelope from said prefiltered signal to provide an envelope reference signal, filtering the envelope reference signal to obtain a stable, narrow bandwidth reference signal, and digitizing said narrow bandwidth reference signal to obtain a digitized reference signal,
• b. successively processing a broadcast signal to generate successive digitized broadcast signal segments, the processing of said broadcast signal including prefiltering to select a prefiltered broadcast signal in a frequency portion of the audio spectrum with a stable characteristic, forming an envelope from said prefiltered broadcast signal to provide an envelope broadcast signal, filtering the envelope broadcast signal to obtain a stable, narrow bandwidth broadcast signal and digitizing said narrow bandwidth broadcast signal to obtain a digitized broadcast signal,
• c. correlating a plurality of successive digitized broadcast signal segments with an equal number of digitized reference signal segments to obtain correlation function peaks for each resultant correlation segment, and
• d. comparing the spacing between correlation function peaks for each correlation segment to determine whether such spacing is substantially equal to the reference signal segment length.

A method for the automatic electronic recognition of a program unit broadcast by radio waves which includes:

• a. processing said program unit to obtain a plurality of digitized reference signal segments by digitizing and dividing said reference signal into a plurality of reference segments of equal length to obtain a plurality of digitized reference segments, normalizing said digitized reference segments to obtain the RMS power value for each reference segment, and storing each such RMS power value for each reference segment, zero filling each such normalized reference segment to obtain a plurality of zero filled reference segments of equal length, successively subjecting each said zero filled reference segment to a Fourier transformation and the performance of a complex conjugate to obtain a frequency domain complex spectra for each such zero filled reference segment, and storing the resultant frequency domain complex spectra reference signal segments;
• b. successively processing a broadcast signal to generate successive digitized broadcast signal segments;
• c. correlating a plurality of successive digitized broadcast signal segments with an equal number of digitized reference signal segments to obtain correlation function peaks for each resultant correlation segment, and
• d. comparing the spacing between correlation function peaks for each correlation segment to determine whether such spacing is substantially equal to the reference signal segment length.

A method for the automatic electronic recognition of a program unit broadcast by radio waves which includes:

• a. processing said program unit to obtain a plurality of digitized reference signal segments including at least two groups of successive digitized reference signal segments, the speed of one of said groups being varied with relation to the speed of the remaining group,
• b. successively processing a broadcast signal to generate successive digitized broadcast signal segments;
• c. correlating a plurality of successive digitized broadcast signal segments with an equal number of digitized reference signal segments to obtain correlation function peaks for each resultant correlation segment, and
• d. comparing the spacing between correlation function peaks for each correlation segment to determine whether such spacing is substantially equal to the reference signal segment length.

A method for the automatic, electronic recognition of a program unit broadcast by radio waves which includes:

• a. obtaining a plurality of reference signal segments from said program unit;
• b. processing said plurality of reference signal segments to obtain digitized reference signal segments;
• c. obtaining the RMS power value of each reference signal segment;
• d. successively processing a broadcast signal to generate successive digitally sampled broadcast signal segments;
• e. correlating a plurality of successive broadcast signal segments with an equal number of digitized reference signal segments to obtain correlation function peaks for each resultant correlation segment;
• f. obtaining an RMS power value coincident with each correlation function peak, and
• g. comparing the pattern of the RMS power values from said reference signal segments with the pattern of the RMS power values coincident with an equal number of said correlation function peaks.