Abstract: A digital signal processor (DSP), may identify symbol values associated with a 5 quadrature amplitude modulation (5QAM) signal. The DSP may determine a first bit set based on the symbol values and a first particular bit value. The DSP may determine a second bit set based on the symbol values and a second particular bit value. The DSP may compute a first distance based on the first bit set and the symbol values. The DSP may compute a second distance based on the second bit set and the symbol values. The DSP may determine that the first distance is less than the second distance. The first distance being less than the second distance may indicate that the first bit set is a correctly decoded bit set. The DSP may provide an output associated with the correctly decoded bit set.

Abstract: An optical receiver may include a digital signal processor to receive an input sample that includes transmitted data, transmitted by an optical transmitter, and nonlinear distortion. The digital signal processor may process the input sample to generate an estimated data value. The estimated data value may be an estimate of the transmitted data. The digital signal processor may remove the estimated data value from the input sample to generate a noise sample. The digital signal processor may determine a nonlinear distortion value based on the input sample, the estimated data value, and the noise sample. The nonlinear distortion value may be an estimate of the nonlinear distortion included in the input sample. The digital signal processor may remove the nonlinear distortion value from the input sample to generate an output sample, and may output the output sample.

Abstract: A digital signal processor (DSP) may receive a signal that has an x-polarization (x-pol) and a y-polarization (y-pol). The DSP may equalize the x-pol of the signal and the y-pol of the signal based on filter coefficients determined using a constant modulus algorithm (CMA). The DSP may perform phase correction on the equalized x-pol signal and the equalized y-pol signal. The DSP may identify a first frame header pattern within the phase-corrected x-pol signal, and may identify a second frame header pattern within the phase-corrected y-pol signal. The DSP may determine, based on the first frame header pattern and the second frame header pattern, a quantity of lock-in differential group delay (DGD). The device may adjust one or more of the filter coefficients to remove the quantity of lock-in DGD and to permit an amount of polarization mode dispersion to be determined based on the filter coefficients.

Abstract: A digital signal processor (DSP) may receive a signal that has an x-polarization (x-pol) and a y-polarization (y-pol). The DSP may equalize the x-pol of the signal and the y-pol of the signal based on filter coefficients determined using a constant modulus algorithm (CMA). The DSP may perform phase correction on the equalized x-pol signal and the equalized y-pol signal. The DSP may identify a first frame header pattern within the phase-corrected x-pol signal, and may identify a second frame header pattern within the phase-corrected y-pol signal. The DSP may determine, based on the first frame header pattern and the second frame header pattern, a quantity of lock-in differential group delay (DGD). The device may adjust one or more of the filter coefficients to remove the quantity of lock-in DGD and to permit an amount of polarization mode dispersion to be determined based on the filter coefficients.

Abstract: A digital signal processor (DSP), may identify symbol values associated with a 5 quadrature amplitude modulation (5QAM) signal. The DSP may determine a first bit set based on the symbol values and a first particular bit value. The DSP may determine a second bit set based on the symbol values and a second particular bit value. The DSP may compute a first distance based on the first bit set and the symbol values. The DSP may compute a second distance based on the second bit set and the symbol values. The DSP may determine that the first distance is less than the second distance. The first distance being less than the second distance may indicate that the first bit set is a correctly decoded bit set. The DSP may provide an output associated with the correctly decoded bit set.

Abstract: An apparatus and method for removing solids and particulates from fluid by magnetic separation. First and second spaced rotatable drums move a closed loop belt. A portion of the belt is disposed in contact with the fluid flowing through a fluid passage disposed adjacent to a circumferential portion of the first rotatable drum where solids and particulates in the fluid are attracted to the belt by magnetic attraction from a magnetic source within the first rotatable drum. A wiper scrapes the solids deposited on the belt.

Abstract: A method of data symbol recovery in a coherent receiver of an optical communications system. Two or more SYNC bursts, having a known symbol sequence and periodicity, are processed to derive an estimate of a frequency offset ?f between a transmit laser and a Local Oscillator (LO) of the receiver. A phase rotation ?(n) is computed based on the estimate of the frequency offset ?f, and applied to a plurality of data symbol estimates to generate corresponding rotated symbol estimates. The rotated symbol estimates are then filtered to generate corresponding decision values of each data symbol.

Abstract: A method of data symbol recovery in a coherent receiver of an optical communications system. Two or more SYNC bursts, having a known symbol sequence and periodicity, are processed to derive an estimate of a frequency offset ?f between a transmit laser and a Local Oscillator (LO) of the receiver. A phase rotation ?(n) is computed based on the estimate of the frequency offset ?f, and applied to a plurality of data symbol estimates to generate corresponding rotated symbol estimates. The rotated symbol estimates are then filtered to generate corresponding decision values of each data symbol.