Patent ID: 6295317
Filing Date: 2001-09-25
Classification: H04L

Abstract:
A method of demodulating and equalizing an amplitude modulated compatible digital broadcasting signal including an amplitude modulated radio frequency signal having a first carrier modulated by an analog program signal in a first frequency spectrum, 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 carrier signals and lying within the first frequency spectrum, and second and third groups of the digitally modulated carrier signals including non-complementary carrier signals and lying outside of the first frequency spectrum, said method comprising the steps of:taking the Fast Fourier Transform of the amplitude modulated compatible digital broadcasting signal to produce a first transformed signal representative of the non-complementary carriers;processing said first transformed signal to produce a first equalized signal by multiplying said first transformed signal by a first equalization vector, said first equalization vector comprising a first plurality of equalizer coefficients;updating said first plurality of equalizer coefficients used for the non-complementary signals;taking the Fast Fourier Transform of the amplitude modulated compatible digital broadcasting signal to produce a second transformed signal representative of the complementary carriers;determining a second equalization vector comprising a second plurality of equalizer coefficients, said second plurality of equalizer coefficients being determined by interpolation using coefficients of said first plurality of equalizer coefficients; andprocessing said second transformed signal to produce a second equalized signal by multiplying said second transformed signal by said second equalization vector.