Patent ID: 6292511
Filing Date: 2001-09-18
Classification: H04H,H04L

Abstract:
A method of equalizing an amplitude modulated compatible digital broadcasting signal including 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, said method comprising 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 said plurality of transformed signals by multiplying said plurality of transformed signals by an equalization vector, said equalization vector comprising a plurality of equalizer coefficients; andupdating said equalizer coefficients used for the complementary signals by interpolation using coefficients of said vector for the non-complementary signals.