Transition based feedforward equalization method and apparatus implemented with lookup table circuits
AssigneeMellanox Technologies Denmark Aps
InventorsJuan Jose Vegas-Olmos, Steen Christensen, Johan Jacob Mohr
Life of this patent
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Abstract
Embodiments are disclosed for equalizing input signals for communication systems. An example method includes receiving an input signal. The input signal encodes a plurality of bits in a number of amplitude levels. The example method further includes converting the input signal to an equalized output signal using a plurality of lookup table circuits. The equalized output signal encodes a plurality of symbols in a number of amplitude levels. The example method further includes feeding the equalized output signal to an output driver circuit.
Claims14
A feedforward equalization method for equalizing input signals for communication systems, comprising:
- receiving an input signal, wherein the input signal encodes a plurality of bits in a number of amplitude levels, and wherein the plurality of bits in the input signal comprises a plurality of fixed tap bits and a plurality of floating tap bits;
- using a plurality of selector circuits in a plurality of lookup table circuits to select a plurality of bits from the plurality of floating tap bits;
- using a plurality of floating tap bits processing lookup table circuits in the plurality of lookup table circuits to convert the plurality of selected floating tap bits;
- using a plurality of fixed tap bits processing lookup table circuits in the plurality of lookup table circuits to convert the plurality of fixed tap bits;
- using a plurality of summer circuits in the plurality of lookup table circuits to add the plurality of converted selected floating tap bits and the plurality of converted fixed tap bits to generate a plurality of outputs of the lookup table circuits;
- using a plurality of multiplexers to multiplex the plurality of outputs of the lookup table circuits;
- using a plurality of variable gain amplifiers to amplify a plurality of outputs of the multiplexers;
- and
- feeding a plurality of outputs of the multiplexers to an output driver circuit.
A transmitter-side feedforward equalizer used in communication systems, wherein the transmitter-side equalizer is configured to:
- receive an input signal, wherein the input signal encodes a plurality of bits in a number of amplitude levels, and wherein the plurality of bits in the input signal comprises a plurality of fixed tap bits and a plurality of floating tap bits;
- use a plurality of selector circuits in a plurality of lookup table circuits to select a plurality of bits from the plurality of floating tap bits;
- use a plurality of floating tap bits processing lookup table circuits in the plurality of lookup table circuits to convert the plurality of selected floating tap bits;
- use a plurality of fixed tap bits processing lookup table circuits in the plurality of lookup table circuits to convert the plurality of fixed tap bits;
- use a plurality of summer circuits in the plurality of lookup table circuits to add the plurality of converted selected floating tap bits and the plurality of converted fixed tap bits to generate a plurality of outputs of the lookup table circuits;
- use a plurality of multiplexers to multiplex the plurality of outputs of the lookup table circuits;
- use a plurality of variable gain amplifiers to amplify a plurality of outputs of the multiplexers;
- and
- feed a plurality of outputs of the multiplexers to an output driver circuit.
Dependencies are inferred from the claim text.