Abstract: Device and methods for real-time polarization-dependent loss monitoring at coherent transceivers. In one embodiment, there is provided a method of monitoring a polarization dependent loss (PDL) of a signal during transmission through an optical communication link, the method comprising: receiving the signal by a coherent receiver, the received signal being subjected to one or more impairments in Amplifier Gain Control (AGC) mode, the one or more impairments including PDL; estimating an AGC gain effect of the AGC mode; compensating for the AGC gain effect in the received signal; determining the PDL from the compensated signal; and reporting the PDL.

Abstract: A sliced graphics processing unit (GPU) architecture in processor-based devices is disclosed. In some aspects, a GPU based on a sliced GPU architecture includes multiple hardware slices. The GPU further includes a command processor (CP) circuit and an unslice primitive controller (PC_US). Upon receiving a graphics instruction from a central processing unit (CPU), the CP circuit determines a graphics workload, and transmits the graphics workload to the PC_US. The PC_US then partitions the graphics workload into multiple subbatches and distributes each subbatch to a PC_S of a hardware slice for processing.

Abstract: A sliced graphics processing unit (GPU) architecture in processor-based devices is disclosed. In some aspects, a GPU based on a sliced GPU architecture includes multiple hardware slices. The GPU further includes a command processor (CP) circuit and an unslice primitive controller (PC_US). Upon receiving a graphics instruction from a central processing unit (CPU), the CP circuit determines a graphics workload, and transmits the graphics workload to the PC_US. The PC_US then partitions the graphics workload into multiple subbatches and distributes each subbatch to a PC_S of a hardware slice for processing.

Abstract: The disclosed systems and methods for frequency domain (FD) local oscillator frequency offset (LOFO) compensation. The method comprising: i) compensating, by an integer Fast Fourier Transform (FFT) bins-based oscillator, LOFO in a received signal by an integer number of FFT bins; and ii) compensating, by a fractional FFT bins-based oscillator, LOFO in the compensated signal by the integer FFT bins-based oscillator with a fine compensation resolution of a fractional number of FFT bins.

Abstract: This application relates to a power consumption grading method for a network-based power supply system. The method includes: when it is detected that power overload protection is not triggered, starting a plurality of power modules of a powered device one by one in a specific order until all the plurality of power modules are started or it is detected that the power overload protection is triggered after a specific power module is started; when it is detected that the power overload protection is triggered, selecting, according to the specific order and based on the specific power module, one or more of the plurality of power modules as a power module combination of the powered device; and determining a load power of the powered device and a corresponding power consumption level based on the power module combination.

Abstract: The invention belongs to the field of amorphous alloys, and more specifically, relates to a method for calibrating the internal temperature field of amorphous alloy prepared by spark plasma sintering. First, the part required for temperature field calibration inside the bulk amorphous alloy sample obtained by spark plasma sintering is cut into a series of small amorphous alloy samples, and the isothermal crystallization treatment is performed to obtain the crystallization time of different parts of the sample. An annealing-isothermal crystallization experiment is performed on the adopted amorphous alloy powder at different annealing temperatures, and the functional relationship between the annealing temperature and the crystallization time is obtained.

Abstract: Apparatuses and methods for far-end monitoring of transmitter IQ skew in a DSCM system are described. Soft symbols for a given subchannel and a corresponding mirror subchannel are used as joint inputs to a MIMO equalizer. The hard decision symbols for the given subchannel and mirror subchannel are used as references to compute the equalizer coefficients. An estimated phase or estimated transmitter IQ skew is computed for at least the given subchannel using the equalizer coefficients. The computation is repeated to obtain estimated phase or estimated transmitter skew for all subchannels. The transmitter IQ skew is computed using the estimates from all subchannels. The computation is performed for each polarization. The computed transmitter IQ skew is communicated back to the transmitter via optical path (for correcting the skew).

Abstract: The invention belongs to the field of amorphous alloys, and more specifically, relates to a method for calibrating the internal temperature field of amorphous alloy prepared by spark plasma sintering. First, the part required for temperature field calibration inside the bulk amorphous alloy sample obtained by spark plasma sintering is cut into a series of small amorphous alloy samples, and the isothermal crystallization treatment is performed to obtain the crystallization time of different parts of the sample. An annealing-isothermal crystallization experiment is performed on the adopted amorphous alloy powder at different annealing temperatures, and the functional relationship between the annealing temperature and the crystallization time is obtained.

Abstract: A construction method of fast-setting polymer grouting for rapid control of slope erosion and landslide.

Abstract: The disclosed systems and methods for detecting mirror crosstalk between frequency bands equally above and below the center frequency of a Digital Subcarrier Multiplexing system include: a transmitter configured to insert zero-power symbols on half the frequency bands below center frequency, and insert other zero-power symbols, partially overlapping in time with the first zero-power symbols, on the other half of the frequency bands above center frequency. A receiver zeroes out ASE and other noises during the overlapping portion of all the zero-power symbols, then uses the power detected during the remaining portion of each zero-power symbol in each frequency band to accurately evaluate the mirror crosstalk from the corresponding frequency band on the opposite side of center frequency.

Abstract: Methods and devices for IQ time skew and conjugation compensation and calibration of a coherent transmitter or transceiver are described. A pilot tone is combined with a digital data signal such that relative powers of the pilot tone in each of two frequency bands of the transmitted data signal may be detected by a pilot tone detector and used to calculate the time skew between I and Q modulation channels of the transmitter. A transmitter DSP applies IQ time skew bias to the data signal to compensate for any calculated IQ time skew. The pilot tone detector also provides the transmitter DSP with the information necessary to detect phase conjugation of the optical signal, which can be corrected by inverting the polarity of the data signal or changing the phase bias point of the optical modulator.

Abstract: Methods and systems for performing signal pre-correction of a transmission signal comprising a sequence of symbols using a Pattern Dependent Look-up Table (PDLUT) containing one or more distortion correction values. Upon accessing a distortion correction value from the PDLUT for a symbol of the sequence of symbols, the accessed distortion correction value is quantized into one or more quantized values according to one or more quantizations, thereby reducing the bit-width of the distortion correction value. The transmission signal and the distortion correction value with reduced bit-width may undergo linear correction compensation, such as through a finite impulse response (FIR) filter, independent of one another, where the one or more quantized correction values with reduced bit-width reduce a number of calculation steps performed during linear correction compensation resulting in power savings.

Abstract: Methods and systems for performing signal pre-correction of a transmission signal comprising a sequence of symbols using a Pattern Dependent Look-up Table (PDLUT) containing one or more distortion correction values. Upon accessing a distortion correction value from the PDLUT for a symbol of the sequence of symbols, the accessed distortion correction value is quantized into one or more quantized values according to one or more quantizations, thereby reducing the bit-width of the distortion correction value. The transmission signal and the distortion correction value with reduced bit-width may undergo linear correction compensation, such as through a finite impulse response (FIR) filter, independent of one another, where the one or more quantized correction values with reduced bit-width reduce a number of calculation steps performed during linear correction compensation resulting in power savings.

Abstract: Methods and apparatus for coherent transmitter calibration are provided that employ direct detection (DD) using one single photodetector (PD). The provided method and apparatus do not require hardware for coherent reception, or additional ADCs for quality control. An additional optical tone is added to a QAM optical signal that is outside the band of the QAM optical signal. The result of this is that after direct detection, there is a correlation between the real and imaginary parts, and the imaginary part can be recovered with a Hilbert transform. The estimated QAM optical signal obtained by direct detection is used to perform a transmitter factory calibration method to calibrate for one or more transmitter impairments and/or to perform in-line self-calibration.

Abstract: Methods and apparatuses for IQ time skew calibration in a coherent transceiver are described. A four-channel signal is received. A set of inputs is constructed for a 4×8 MIMO equalizer by converting the four-channel signal into four complex inputs that each have a phase shift corresponding to an estimated carrier frequency offset. The set of inputs further includes conjugate replicas of the four complex inputs. Using output from the 4×8 MIMO equalizer, equalizer coefficients are calculated by minimizing error between the MIMO output and a reference signal. Receiver and transmitter IQ skew are estimated using the equalizer coefficients, by converting the equalizer coefficients form the time domain to the frequency domain to determine receiver and transmitter IQ differential phase responses, which are indicative of respective receiver and transmitter IQ skew in the time domain. Skew compensation is then performed.

Abstract: Methods and devices for power imbalance compensation and calibration of a coherent transmitter or transceiver are described. A pilot tone is combined with a digital data signal such that relative amplitudes of the pilot tone in each of four transmitted optical data channels may be detected by a pilot tone detector and used to calculate any power imbalances between I/Q phase channels and/or X/Y polarized channels of the transmitter. The pilot tone detector applies gain to the data signal of the transmitter to compensate for any calculated power imbalances. Because the pilot tone is combined with the digital data signal, its amplitude in each received channel is proportional to the data signal power of that channel.

Abstract: The present disclosure relates to methods and apparatus for graphics processing. An example method generally includes receiving, at a graphics processing unit (GPU), a plurality of commands corresponding to a plurality of draws across a frame, each of the plurality of commands indicating a depth test direction with respect to a low-resolution depth (LRZ) buffer for the corresponding draw. The method generally includes maintaining, at the GPU, a LRZ status buffer to store a corresponding depth test direction for a first command in time of the plurality of commands processed by the GPU. The method generally includes disabling, at the GPU, use of the LRZ buffer for depth testing for any of the plurality of commands remaining unprocessed after processing a command of the plurality of commands having a different depth test direction than the corresponding depth test direction stored in the LRZ status buffer.

Abstract: Optical transmitters, receivers, and methods are described in an optical network. An optical transmitter comprises an encoder configured to receive an input data stream and to encode the input data stream into a signal. The signal is defined as a sequence of regular units, and a rotator is configured to receive each unit of the signal and to output, for each given input unit with an input state of polarization (SOP), a respective given output unit associated with an output SOP. The output SOP of the given output unit is different from a corresponding output SOP of each other output unit that is immediately adjacent to the given output unit. The output SOPs of the units in a transmitted signal may form an alternating pattern (or other repeating pattern), which may help to lower the average BER, in particular, due to forward error correction (FEC).

Abstract: Methods and apparatuses for IQ time skew calibration in a coherent transceiver are described. A four-channel signal is received. A set of inputs is constructed for a 4×8 MIMO equalizer by converting the four-channel signal into four complex inputs that each have a phase shift corresponding to an estimated carrier frequency offset. The set of inputs further includes conjugate replicas of the four complex inputs. Using output from the 4×8 MIMO equalizer, equalizer coefficients are calculated by minimizing error between the MIMO output and a reference signal. Receiver and transmitter IQ skew are estimated using the equalizer coefficients, by converting the equalizer coefficients form the time domain to the frequency domain to determine receiver and transmitter IQ differential phase responses, which are indicative of respective receiver and transmitter IQ skew in the time domain. Skew compensation is then performed.

Abstract: The disclosed systems, apparatuses and methods are directed to controlling a difference between a first center frequency of a first optical subcarrier and a second center frequency of a second optical subcarrier of an optical super-channel signal in an optical network. The method comprises modulating the first optical subcarrier at a first optical side component frequency with a first side modulation frequency and modulating the second optical subcarrier at a second optical side component frequency with a second side modulation frequency. The method further comprises detecting a radio-frequency (RF) power at a modulated beat frequency tone in the modified optical signal.