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US 6,583,822 B1Granted
Timing recovery device of digital TV
AssigneeLG Electronics Inc.
InventorJung Sig Jun
Life of this patent
Estimating the term…
Abstract
A timing recovery device in a digital television receiver using a VSB system is disclosed. In the present invention, the timing recovery device independently determines whether the detected hsync signal is reliable and operates if the detected hsync signal is reliable.
Claims6
A method for recovering the timing in a digital TV, comprising:
- activating a timing error detector when a control signal indicating a hsync signal section of an input digital signal is received from a sync signal recovery unit and if the detected hsync signal is reliable, and extracting a timing error information from the input digital signal;
- filtering a low frequency signal component of the timing error information;
- and
- converting an output frequency in accordance with the low frequency signal component of the timing error information to adjust a sampling timing the input digital signal,
- wherein said control signal is output by determining a correlation relation of the input digital signal with a predetermined hsync signal pattern, adding the determined correlation relation for a period of 832 symbols to distinguish the hsync signal section from the digital signal, comparing the added value with a first predetermined threshold value and outputting a signal indicating the hsync signal section if the added value is over the first predetermined threshold value, and checking the reliability of the signal indicating the hsync signal section and outputting the control signal if the checked reliability is above a second predetermined value;
- and
- wherein the correlation relation is output to the timing error detector, and the timing error detector is activated when the control signal is received and if the correlation relation is above a third predetermined value.
4 more elements
A digital TV receiver comprising:
- a timing recovery unit which extracts a timing error information from an input digital signal when a control signal indicating a hsync signal section of the input digital signal is received from a sync signal recovery unit and if the detected hysnc signal is reliable, filters a low frequency signal component of the timing error information, and converts an output frequency in accordance with the low frequency signal component of the timing error information to adjust a sampling timing the input digital signal;
- and
- a sync signal recovery unit which determines a correlation relation of the input digital signal with a predetermined hsync signal pattern, adds the correlation relation for a period of preset symbols to distinguish the hsync signal section from the digital signal, compares the added value with a first predetermined threshold value and outputs a signal indicating the hsync signal section if the added value is over the first predetermined threshold value, and checks the reliability of the hsync signal section and outputs the control signal indicating the hsync signal section if the checked reliability is above a second predetermined value,
- wherein said sync signal recovery unit includes:
- a correlating detector which determines the correlation relation;
- an integrator which adds an output of the correlating detector for a period of 832 symbols to distinguish the hsync signal section from the digital signal;
- a slicer which compares an output value of the integrator with the first predetermined threshold value and outputs the signal indicating the hsync signal section if the output value is over the first predetermined threshold value;
- and
- a confidence counter which checks the reliability of the hsync signal section output by the slicer and outputs the control signal if the checked reliability is above the second predetermined value;
- and
- wherein the correlating detector outputs the correlation relation to the timing error detector, and the timing error detector is activated when the control signal is received and if the correlation relation is above a third predetermined value.
8 more elements
Dependencies are inferred from the claim text.