Dynamic error quantizer tuning systems and methods
AssigneeMaxim Integrated Products, Inc.
InventorCharles Razzell
Life of this patent
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Abstract
Dynamic error-quantizer tuning systems and methods prevent misconvergence to local minima by using a dynamic quantizer circuit that controls reference voltages of three or more comparators that are independently adjusted to modify the transfer function of the dynamic quantizer circuit. A weighted sum of the comparator outputs is subtracted from the input to form an error signal in a control loop. The ratio of the reference voltages is chosen to reduce or eliminate local minima during a convergence of the control loop and is set to values that minimize a mean squared error signal with respect to discrete modulation states of the input after the convergence of the control loop is complete.
Claims20
A dynamic quantizer circuit for preventing misconvergence of a decision-feedback control loop to a local minimum, the dynamic quantizer circuit comprising:
- an input;
- a control circuit that controls one or more reference voltages in a set of reference voltages;
- and
- comparators coupled to the input, each comparator having an output and being associated with at least one of the one or more reference voltages, the reference voltages of at least two of the comparators being independently adjustable to adjust a transfer function of the dynamic quantizer circuit,
- wherein a weighted sum of the outputs of the comparators is subtracted from the input to form an error signal in a control loop,
- the ratio of at least two voltages in the set of reference voltages being chosen to reduce or eliminate local minima during a convergence of the control loop, and
- the ratio of at least two voltages in the set of reference voltages being set to values to minimize a mean squared error signal with respect to discrete modulation states of the input after the convergence of the control loop is complete.
A dynamic error-quantizer tuning method for preventing misconvergence of a control loop to a local minimum, the method comprising:
- using a control circuit that controls one or more reference voltages in a set of reference voltages to adjust reference voltages of at least two comparators to adjust a transfer function of a dynamic quantizer circuit, each comparator being coupled to an input, having an output, and being associated with at least one of the one or more reference voltages;
- subtracting from the input a weighted sum of the outputs of the comparators to obtain an error signal in a control loop;
- selecting a ratio of at least two voltages in the set of reference voltages such as to reduce or eliminate local minima during a convergence of the control loop;
- and
- setting the ratio of at least two voltages in the set of reference voltages to values to minimize a mean squared error signal with respect to discrete modulation states of the input after the convergence of the control loop is complete.
Dependencies are inferred from the claim text.