ADC having adjustable threshold levels for PAM signal processing
AssigneeSitrus Technology Corporation
InventorsMichael Q. Le, Mrunmay Talegaonkar
Life of this patent
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Abstract
An ADC system dynamically adjusts threshold levels used to resolve PAM signal amplitudes into digital values. The ADC circuitry includes an analog front end to receive and condition the PAM signal, a low-resolution ADC to digitize the conditioned signal according to a first set of threshold values, and a high-resolution ADC to subsample the conditioned signal to generate subsampled signals. A microprocessor in communication with the low-resolution ADC and the high-resolution ADC derives a statistical value from the subsampled signals, determines an updated set of threshold values, and dynamically replaces the first set of threshold values for the low-resolution ADC with the updated set of threshold values.
Claims18
A method to improve signal to noise ratio due to signal impairment by an optical or electrical medium, the method comprising:
- receiving an incoming signal from the optical or the electrical medium and conditioning the incoming signal to form an analog conditioned signal;
- sampling the analog conditioned signal using a first number of bits per sample according to a first set of threshold values;
- sub sampling the analog conditioned signal using a second number of bits per sample to obtain a plurality of sub sampled signals, the second number of bits being greater than the first number of bits to provide higher resolution for detection of errors from the plurality of sub sampled signals than the sampling using the first number of bits per sample;
- deriving one or more statistical values based on the errors from the plurality of sub sampled signals;
- determining a set of updated threshold values from the one or more statistical values;
- and
- dynamically replacing the first set of threshold values with the updated set of threshold values.
Dependencies are inferred from the claim text.