A method is provided for equalizing an amplitude modulated compatible
digital broadcasting signal which includes an amplitude modulated radio
frequency signal having a first frequency spectrum, the amplitude
modulated radio frequency signal having a first carrier modulated by an
analog program signal, a plurality of digitally modulated carrier signals
positioned within a bandwidth which encompasses the first frequency
spectrum, a first group of the digitally modulated carrier signals
including complementary signals and lying within the first frequency
spectrum, and second and third groups of the digitally modulated carrier
signals including non-complementary signals and lying outside of the first
frequency spectrum. The method includes the steps of producing a first
signal representative of in-phase components of the amplitude modulated
compatible digital broadcasting signal; producing a second signal
representative of quadrature-phase components of the amplitude modulated
compatible digital broadcasting signal; using the first and second signals
as the real and imaginary inputs to take the Fast Fourier Transform of the
first and second signals to produce a plurality of transformed signals
representative of frequency domain data; processing the transformed
signals by multiplying the transformed signals by an equalization vector,
with the equalization vector comprising a plurality of equalizer
coefficients; and updating the equalizer coefficients used for the
complementary signals by interpolating coefficients of the vector for the
non-complementary signals. The invention also encompasses the operation of
radio frequency receivers which utilize the above method, as well as
apparatus that performs the above method and radio frequency receivers
which utilize the above equalization method.