Method and apparatus for filtering digital television signals

Abstract

A system for filtering digital television signals is provided. The system comprises a generator for providing a first data sequence to a private data packetizer, and a transmitter for transmitting the packetized first data sequence in a data channel of a digital television signal. The system further includes a receiver for receiving the digital television signal and recovering the first data sequence. The receiver includes a channel estimator for providing an estimate of channel characteristics, such as estimated channel impulse estimate and estimated noise variance. The receiver further includes an adaptive equalizer filter having an input for receiving the digital television signal and an input for receiving adaptive filter coefficients. The receiver further includes a coefficient processor for calculating adaptive filter coefficients based on the channel estimate, and providing the adaptive filter coefficients to the adaptive equalizer filter. The digital television signal is thus filtered to remove undesired channel effects.

Description

[0001]This is a continuation of application Ser. No. 10 / 728,934 filed Dec. 5, 2003, abandoned, which is a continuation of application Ser. No. 10 / 247,455 filed Sep. 19, 2002, abandoned, which is a reissue of application Ser. No. 09 / 206,409, filed Dec. 7, 1998, Pat. No. 6,122,015.BACKGROUND OF THE INVENTION[0002]This invention relates in digital television and, more particularly, to methods and apparatus for filtering digital television signals to remove multipath and other undesirable effects upon a digital television signal as the signal propagates through a channel.[0003]Digital television is an emerging technology that is the subject of much research both in the United States and Japan. Because of the potential advantages of digital television and the many technical problems associated therewith, research into improved systems and methods for transmitting and receiving digital television signals is increasing.[0004]One of the most important prevalent problems associated with digi...

AI Technical Summary

Benefits of technology

[0009]A method of filtering a digital television transmission comprises the steps of generating a first data sequence at a transmitter and periodically inserting the first data sequence into a digital television bit stream to be transmitted. The method further comprises the steps of transmitting the digital television bit stream through a channel to a receiver, receiving the digital television bit stream and extracting the first data sequence from the digital television bit stream. The extracted first data sequence includes channel induced noise. The method further includes the steps of comparing the extracted first data sequence, including channel induced noise, to a second data sequence. The second data...

Problems solved by technology

One of the most important prevalent problems associated with digital television signals is the problem of multipath effects.

Even microreflections in cabling can cause multipath conditions.

Images