Patent ID: 6377312
Filing Date: 2002-04-23
Classification: H04N

Abstract:
A digital television receiver for receiving a digital television signal sent at a prescribed symbol rate from a transmitter, said digital television receiver improved to include therewithin a combination comprising:demodulation circuitry for demodulating said digital television signal to supply digital samples of demodulated signal at a sample rate that is higher than said prescribed symbol rate, such that said symbol rate is a rational fraction of said sampling rate; an equalizer filter connected after said demodulation circuitry for supplying an equalizer filter response to said digital samples of demodulated digital television signal supplied by said demodulation circuitry, said equalizer filter response supplied at said sample rate that is higher than said prescribed symbol rate, said equalizer filter including filter coefficient registers and having filtering parameters that are adjustable in response to filter coefficients as received from time to time for temporary storage in said filter coefficient registers; a rate-reduction filter connected after said equalization filter for generating a rate-reduction filter output signal at symbol rate responsive to said equalizer filter response at said sample rate that is higher than said prescribed symbol rate; a quantizer connected after said rate-reduction filter for quantizing said rate-reduction filter output signal to generate estimates of the digital television signal as transmitted by said transmitter, said estimates being generated at symbol rate as a quantizer output signal; a first interpolation filter connected after said quantizer for re-sampling said quantizer output signal to said sample rate that is higher than said prescribed symbol rate, thereby to generate a first interpolation filter response; an error detector connected for comparing said equalizer filter response with said first interpolation filter response to generate a decision-feedback error signal at said sample rate that is higher than said prescribed symbol rate; and calculation apparatus connected to respond to said decision-feedback error signal for updating the filter coefficients temporarily stored in said filter coefficient registers of said equalizer filter.