Video receiver with DC offset cancellation

An integrated circuit device, coupled to a signal source that receives a broadcast spectrum from an electrically or optically conductive medium, to output formatted video signals corresponding to a selected channel which is one of a plurality of channels of the broadcast spectrum, the integrated circuit device comprising:

• tuner circuitry, coupled to the signal source, to receive a broadcast-frequency analog video signal, having timing information embedded therein, and to output a baseband video signal which corresponds to the selected channel of the broadcast spectrum, the tuner circuitry including:
• amplifier circuitry, coupled to the signal source, to output a first signal which is an amplified representation of at least a portion of the broadcast-frequency analog video signal;
• local oscillator circuitry, coupled to the amplifier circuitry, to generate and output a local oscillator signal, wherein the local oscillator signal includes a frequency which is associated with the selected channel;
• detector circuitry, coupled to the local oscillator circuitry, to generate and output a second signal using the first signal, the local oscillator signal and a cancellation signal, wherein the second signal includes an in-phase component and a quadrature component;
• cancellation circuitry, coupled to the detector circuitry, to dynamically generate the cancellation signal which is associated with the selected channel, wherein the cancellation signal is a substantially time-invariant signal;
• baseband demodulator circuit, coupled to the detector circuitry, to output a baseband video signal, which corresponds to the selected channel, using the second signal;
• and
• video decoder circuitry, coupled to the receiver circuitry, to receive the baseband video signal and output the first formatted video signal corresponding to the selected channel of the broadcast spectrum, the video decoder circuitry including:
• processing circuitry, coupled to the baseband demodulator circuit, to process the baseband video signal, the processing circuitry including:
• luma circuitry to generate a third signal using the baseband video signal, wherein the third signal is representative of a luma signal corresponding to the selected channel;
• and
• chroma circuitry to generate a fourth signal using the baseband video signal, wherein the fourth signal is representative of a chroma signal corresponding to the selected channel;
• timing recovery circuitry, coupled to the tuner circuitry, to generate a timing signal using the timing information within the broadcast-frequency analog video signal;
• and
• format circuitry, coupled to the processing circuitry, to generate and output the formatted video signal, corresponding to the selected channel, using the third signal, fourth signal and timing signal,
• wherein the cancellation circuitry (i) is coupled to the timing recovery circuitry to receive the timing signal and (ii) dynamically generates the cancellation signal, using the timing signal, for each selected channel of the plurality of channels of the broadcast spectrum.

A system, coupled to a signal source that receives a broadcast spectrum from an electrically or optically conductive medium, to output formatted video signals corresponding to a selected channel which is one of a plurality of channels of the broadcast spectrum, the system comprising:

• filter circuitry, coupled to the signal source, to receive a broadcast-frequency analog video signal and to generate a filtered representation of the broadcast-frequency analog video signal;
• and
• an integrated circuit, coupled to the filter circuitry, comprising:
• tuner circuitry, coupled to the filter circuitry, to receive the filtered representation of the broadcast-frequency analog video, having timing information embedded therein, and to output a baseband video signal which corresponds to the selected channel of the broadcast spectrum, the tuner circuitry including:
• amplifier circuitry, coupled to the filter source, to output a first signal which is an amplified representation of at least a portion of the filtered representation of the broadcast-frequency analog video signal;
• local oscillator circuitry, coupled to the amplifier circuitry, to generate and output a local oscillator signal, wherein the local oscillator signal includes a frequency which is associated with the selected channel;
• detector circuitry, coupled to the local oscillator circuitry, to generate and output a second signal using the first signal, the local oscillator signal and a cancellation signal, wherein the second signal includes an in-phase component and a quadrature component, the detector circuitry including:
• a mixer circuit to mix the first signal and the local oscillator signal to generate a frequency-shifted analog video signal;
• cancellation circuitry, coupled to the detector circuitry, to generate and output the cancellation signal which is associated with the selected channel, wherein the cancellation signal is a substantially time-invariant signal;
• baseband demodulator circuit, coupled to the detector circuitry, to output a baseband video signal, which corresponds to the selected channel, using the second signal;
• and
• video decoder circuitry, coupled to the receiver circuitry, to receive the baseband video signal and output the first formatted video signal corresponding to the selected channel of the broadcast spectrum, the video decoder circuitry including:
• processing circuitry, coupled to the baseband demodulator circuit, to process the baseband video signal, the processing circuitry including:
• luma circuitry to generate a third signal using the baseband video signal, wherein the third signal is representative of a luma signal corresponding to the selected channel;
• timing recovery circuitry, coupled to the tuner circuitry, to generate a timing signal using the timing information within the broadcast-frequency analog video signal, the timing recovery circuitry is configured to provide the timing signal to the cancellation circuitry;
• and
• format circuitry, coupled to the processing circuitry, to generate and output the formatted video signal, corresponding to the selected channel, using the third signal and timing signal.

A system, coupled to a signal source that receives a broadcast spectrum from an electrically or optically conductive medium, to output formatted video signals corresponding to a selected channel which is one of a plurality of channels of the broadcast spectrum, the system comprising:

• filter circuitry, coupled to the signal source, to receive a broadcast-frequency analog video signal and to generate a filtered representation of the broadcast-frequency analog video signal, wherein the filter circuitry includes a pass-band filter having a pass-band that corresponds to the selected channel of the broadcast spectrum;
• and
• tuner circuitry, connected to the filter circuitry, to receive the filtered representation of the broadcast-frequency analog video, having timing information embedded therein, and to output the baseband video signal which corresponds to the selected channel of the broadcast spectrum, the tuner circuitry including:
• amplifier circuitry, coupled to the filter source, to output a first signal which is an amplified representation of at least a portion of the filtered representation of the broadcast-frequency analog video signal;
• local oscillator circuitry, coupled to the amplifier circuitry, to generate and output a local oscillator signal, wherein the local oscillator signal includes a frequency which is associated with the selected channel;
• detector circuitry, coupled to the local oscillator circuitry, to generate and output a second signal using the first signal, the local oscillator signal and a cancellation signal, wherein the second signal includes an in-phase component and a quadrature component, the detector circuitry including:
• a mixer circuit to mix the first signal and the local oscillator signal to generate a frequency-shifted analog video signal;
• and
• summing circuitry, coupled to the mixer circuit and the cancellation circuitry, to sum the cancellation signal with the frequency-shifted analog video signal to reduce the substantially time-invariant offset of the second signal;
• cancellation circuitry, coupled to the detector circuitry, to generate and output the cancellation signal which is associated with the selected channel, wherein the cancellation signal is a substantially time-invariant signal;
• baseband demodulator circuit, coupled to the detector circuitry, to output a baseband video signal, which corresponds to the selected channel, using the second signal;
• and
• video decoder circuitry, coupled to the receiver circuitry, to receive the baseband video signal and output the first formatted video signal corresponding to the selected channel of the broadcast spectrum, the video decoder circuitry including:
• processing circuitry, coupled to the baseband demodulator circuit, to process the baseband video signal, the processing circuitry including:
• luma circuitry to generate a third signal using the baseband video signal, wherein the third signal is representative of a luma signal corresponding to the selected channel;
• timing recovery circuitry, coupled to the tuner circuitry, to generate a timing signal using the timing information within the broadcast-frequency analog video signal, the timing recovery circuitry is configured to provide the timing signal to the cancellation circuitry;
• and
• format circuitry, coupled to the processing circuitry, to generate and output the formatted video signal, corresponding to the selected channel, using the third signal, fourth signal and timing signal.

An integrated circuit device, coupled to a signal source that receives a broadcast spectrum from an electrically or optically conductive medium, to output formatted video signals corresponding to a selected channel which is one of a plurality of channels of the broadcast spectrum, the integrated circuit device comprising:

• means for receiving a broadcast-frequency analog video signal, having timing information embedded therein, and for outputting a baseband video signal which corresponds to the selected channel of the broadcast spectrum, including:
• means for outputting a first signal which is an amplified representation of at least a portion of the broadcast-frequency analog video signal;
• means for generating and outputting a local oscillator signal, wherein the local oscillator signal includes a frequency which is associated with the selected channel;
• means for generating and outputting a second signal using the first signal, the local oscillator signal and a cancellation signal, wherein the second signal includes an in-phase component and a quadrature component;
• means for dynamically generating the cancellation signal which is associated with the selected channel, wherein the cancellation signal is a substantially time-invariant signal;
• means for outputting a baseband video signal, which corresponds to the selected channel, using the second signal;
• and
• means for receiving the baseband video signal and for outputting the first formatted video signal corresponding to the selected channel of the broadcast spectrum, including:
• means for processing the baseband video signal, including:
• means for generating a third signal using the baseband video signal, wherein the third signal is representative of a luma signal corresponding to the selected channel;
• and
• means for generating a fourth signal using the baseband video signal, wherein the fourth signal is representative of a chroma signal corresponding to the selected channel;
• means for generating a timing signal using the timing information within the broadcast-frequency analog video signal;
• and
• means for generating and outputting the formatted video signal, corresponding to the selected channel, using the third signal, fourth signal and timing signal.