Abstract: Embodiments are disclosed for generating a lookup table value for calibrating a lookup table circuit in an optical transmitter. The example method includes generating a calibration signal. The calibration signal encodes a plurality of bits in a number of amplitude levels. The example method further includes transmitting the calibration signal to a module under calibration and transmitting a symbol sequence of defined length to a reference module. The reference module compares the symbol sequence with a distorted signal received from the module under calibration to generate a set of condition count statistics. The example method further includes receiving the set of condition count statistics from the receiver in the reference module and calculating a lookup table value based on the set of condition count statistics. The example method further includes transmitting the lookup table value to a transmitter associated with the module under calibration.

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.

Abstract: Embodiments are disclosed for equalizing a pulse amplitude modulation signal for a receiver in a communication system. An example method includes receiving an electronic signal. The electronic signal encodes a plurality of symbols in a number of amplitude levels in a plurality of pulses in the electronic signal. The example method further includes estimating multiple symbol values using all possible values of an immediately preceding symbol for each symbol in the electronic signal. Each estimated symbol value is determined using one of the possible values of the immediately preceding symbol. The example method further includes receiving an actual value of the immediately preceding symbol and selecting an actual estimated symbol value from the multiple symbol values based on the actual value of the immediately preceding symbol. The actual estimated symbol value may be used as the actual value for selecting an estimated symbol value of an immediately subsequent symbol.

Abstract: Embodiments are disclosed for equalizing a pulse amplitude modulation signal for a receiver in a communication system. An example method includes receiving an electronic signal. The electronic signal encodes a plurality of symbols in a number of amplitude levels in a plurality of pulses in the electronic signal. The example method further includes estimating multiple symbol values using all possible values of an immediately preceding symbol for each symbol in the electronic signal. Each estimated symbol value is determined using one of the possible values of the immediately preceding symbol. The example method further includes receiving an actual value of the immediately preceding symbol and selecting an actual estimated symbol value from the multiple symbol values based on the actual value of the immediately preceding symbol. The actual estimated symbol value may be used as the actual value for selecting an estimated symbol value of an immediately subsequent symbol.

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.