Patent ID: 6384858
Filing Date: 2002-05-07
Classification: H04N

Abstract:
A method for extracting training signal from data field synchronizing signals included in the initial data segments of data fields in a digital television signal, which digital television signal is received as carrier modulation by a digital television receiver provided with an equalizer filter, the weighting coefficients of which equalizer filter are adjusted responsive to said training signal as extracted by said method, said carrier modulation subject to being accompanied at times by co-channel analog television signal, said method comprising the steps of:demodulating said digital television signal to generate a baseband signal, which baseband signal is accompanied by undesirable demodulation artifacts at said times that said carrier modulation is accompanied by said co-channel analog television signal; determining the occurrence of the initial data segments of data fields in said digital television signal, as demodulated to baseband to generate said baseband signal; extracting said training signal by combining the initial data segments of a prescribed number of data fields in said digital television signal as demodulated to baseband to generate said baseband signal, said prescribed number being chosen to reduce the energy of said undesirable demodulation artifacts as compared to the energy of said training signal as so extracted.