Patent ID: 6272176
Filing Date: 2001-08-07
Classification: H04H

Abstract:
A method for adding a binary code bit to a block of a signal varying within a predetermined signal bandwidth, the method comprising the following steps:a) selecting a reference frequency within the predetermined signal bandwidth, and associating therewith both a first code frequency having a first predetermined offset from the reference frequency and a second code frequency having a second predetermined offset from the reference frequency;b) measuring the spectral power of the signal within the block in a first neighborhood of frequencies extending about the first code frequency and in a second neighborhood of frequencies extending about the second code frequency;c) increasing the spectral power at the first code frequency so as to render the spectral power at the first code frequency a maximum in the first neighborhood of frequencies; and,d) decreasing the spectral power at the second code frequency so as to render the spectral power at the second code frequency a minimum in the second neighborhood of frequencies.