System and method for providing slicer level adaption
The present invention relates in general to a method, apparatus, and article of manufacture for providing high-speed digital communications through a communications channel. In one aspect, the present invention employs an automatic slicer level adaption to enhance the performance of a high speed communications system.
1. A reference generator circuit for a receiver module coupled to a digital communications channel, the reference generator circuit comprising:
a reference level generation module that generates an adjustable reference level within the receiver module;
an error measurement module, coupled to the reference level generation module, to determine an error statistic based upon a comparison between a received signal and a desired signal, wherein the error statistic is collected using a sign of a recovered datum and a sign of an error; and
wherein the reference level generation module uses the error statistic to control the magnitude of the adjustable reference level.
2. The reference generator circuit according to claim 1 , wherein a range of signal values is determined as corresponding to the received signal using a maximum reference level and minimum reference level; and
the maximum reference level and minimum reference level are adjusted using the error statistic collected by the error measurement module.
3. The reference generator circuit according to claim 2 , wherein adaption of the maximum reference level and minimum reference level can be performed without training data during an initialization process.
4. The reference generator circuit according to claim 2 , wherein the maximum reference level and minimum reference level magnitude are externally set to a predetermined value.
5. A reference generator circuit according to claim 2 , wherein spacing between reference levels is non-uniform.
6. The reference generator circuit according to claim 5 , wherein a performance criteria for setting non-uniformity between ranges of signal values is a measure of a bit-error rate (BER) for the receiver module.
7. The reference generator circuit according to claim 1 , wherein a summation is determined that includes a product of the sign of the recovered datum and the sign of the error.
8. The reference generator circuit according to claim 1 , wherein
the reference level generation module generates a plurality of adjustable reference levels and
spacing between reference levels is non-uniform.
9. The reference generator according to claim 8 , wherein the non-uniformity is asymmetric.
10. A method for a reference generator circuit for a receiver module coupled to a digital communications channel, comprising:
generating an adjustable reference level, within the receiver module, using a reference level generation module;
determining an error statistic, within an error measurement module coupled to the reference level generation module, based upon a comparison between a received signal and a desired signal, wherein the error statistic is collected using a sign of a recovered datum and a sign of an error; and
adjusting the magnitude of the adjustable reference level in response to the error statistic.
11. The method of claim 10 , further comprising:
determining a range of signal values as corresponding to the received signal using a maximum reference level and minimum reference level; and
adjusting the maximum reference level and minimum reference level using the error statistic collected by the error measurement module.