Equalizer status monitor
First Claim
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1. An apparatus for determining convergence of an equalizer, comprising:
- an equalizer output signal;
a nearest element decision device, the nearest element decision device receiving the equalizer output signal and creating a decision device output signal containing permissible symbol values; and
a monitoring circuit, the monitoring circuit receiving the decision device output signal and applying a test criterion to data contained in the decision device output signal so as to determine equalizer convergence.
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Abstract
A system for monitoring the output of an adaptive channel equalizer in order to determine if convergence has been achieved. A slicer samples data from the equalizer during a predetermined period. The output data from the slicer is forwarded to a microprocessor in order to apply a test standard to the slicer data. For example, if one of every possible transmitted symbol is detected by the microprocessor, convergence is assumed to have occurred. If the test criterion is not met, a reset signal is sent to the equalizer.
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23 Claims
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1. An apparatus for determining convergence of an equalizer, comprising:
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an equalizer output signal;
a nearest element decision device, the nearest element decision device receiving the equalizer output signal and creating a decision device output signal containing permissible symbol values; and
a monitoring circuit, the monitoring circuit receiving the decision device output signal and applying a test criterion to data contained in the decision device output signal so as to determine equalizer convergence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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- 12. An equalizer status monitoring device for use in a digital communication system, the device including an adaptive channel equalizer, a slicer and a monitoring circuit, wherein the digital communications system receives a vestigial sideband modulated signal containing high definition video information represented by a multiple level symbol constellation, the data having a data frame format constituted by a succession of data frames, the adaptive channel equalizer generating a first output signal which is input to the slicer, the slicer generating a second output signal which is input to the monitoring circuit, the monitoring circuit applying a test criteria to the second output signal to determine convergence of the adaptive channel equalizer.
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19. In a digital communications receiver including an adaptive equalization filter that desirably achieves a state of convergence and which undesirably achieves a state of divergence or an invalid state, a method of monitoring the state of the equalization filter comprising the steps of:
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coupling an output signal from the equalization filter to a monitoring circuit;
causing the monitoring circuit to examine data contained within the output signal for a finite time period;
causing the monitoring circuit to apply a test protocol to the examined data; and
causing the monitoring circuit to reset the equalization filter when the test protocol detects a state of divergence. - View Dependent Claims (20, 21, 22, 23)
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Specification