VSB reset to minimize data loss
AssigneeZenith Electronics Corporation
InventorVictor G. Mycynek
Life of this patent
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Abstract
A receiver for VSB signals includes tuner channel changing circuitry. AGC circuitry, an IF FPLL and confidence counters, for indicating when signal acquisition or loss occurs. When a loss of signal indication is generated, the IF FPLL is reset, but not the tuner channel changing circuitry and the AGC circuitry, in order to quickly reacquire the signal. If the loss of signal indication persists for a predetermined time or for a predetermined number of loss of signal indications, the IF FPLL, the tuner channel changing circuitry and the AGC circuitry are all reset to reacquire the signal.
Claims12
A method of operating a VSB receiver having AGC circuitry, tuner channel changing circuitry signal acquisition means for indicating when a VSB signal has been acquired, and IF FPLL circuitry, comprising:
- resetting the IF FPLL circuitry, but not the tuner channel changing circuitry and the AGC circuitry, to attempt signal reacquisition upon an indication from the signal acquisition means that a loss of signal has occurred;
- and
- resetting the tuner channel changing circuitry, the AGC circuitry and the IF FPLL circuitry upon a subsequent indication from the signal acquisition means that the loss of signal continues.
A method of operating a VSB receiver having tuner channel changing circuitry, AGC circuitry, signal acquisition means, including confidence circuitry for indicating the status of signal acquisition, and IF FPLL circuitry, comprising:
- resetting the IF FPLL circuitry, but not the tuner channel chancing circuitry and the AGC circuitry, to attempt signal reacquisition upon an indication from the signal acquisition means that a loss of signal has occurred;
- repeating the step of resetting the IF FPLL circuitry, but not the tuner channel changing circuitry and the AGC circuitry, for a predetermined number of indications of signal loss;
- and
- resetting the tuner channel changing circuitry, the AGC circuitry and the IF FPLL circuitry after the predetermined number of indications of signal loss.
A VSB receiver having tuner channel changing circuitry, AGC circuitry, signal acquisition means for determining when a VSB signal has been acquired and IF FPLL circuitry, comprising:
- means for indicating a loss of signal;
- means for resetting said IF FPLL circuitry, but not said tuner channel changing circuitry and said AGC circuitry, to attempt signal reacquisition;
- and
- means, effective upon a subsequent indication that said loss of signal continues, for resetting said tuner channel changing circuitry, said AGC circuitry and said IF FPLL circuitry.
A VSB receiver having tuner channel changing circuitry, AGC circuitry, signal acquisition means, including confidence circuitry for indicating the status of signal acquisition, for determining When a VSB signal has been acquired, and IF FPLL circuitry, comprising:
- means, responsive to a loss of signal indication from said confidence circuitry signifying that a loss of signal has occurred, for resetting said IF FPLL circuitry, but not said tuner channel changing circuitry and said AGC circuitry, to attempt signal reacquisition;
- and
- said resetting means, after a predetermined number of said loss of signal indications from said confidence circuitry, resetting said tuner channel changing circuitry, said AGC circuitry and said IF FPLL circuitry.
Dependencies are inferred from the claim text.