Fujitsu Corporation

Tomoki Katou

Manabu Yamazaki

Kazuhiko Hatae

Nobukazu Koizumi

Masashi Sato

Masato Oota

Hisao Nakashima

Yasuo Ohtomo

Daisuke Sasaki

Koji Nakamuta

Nobuaki Kawasoe

Akiko Furuya

Hiromi Fukino

Yusuke Ujiie

Shuhei Hatae

A drive circuit for supplying a drive current to light emitting elements includes an output circuit that sets a magnitude of the drive current based on an assumed value of a threshold current being a threshold value of the drive current, an acquisition circuit that acquires an optical-output monitor value indicating a magnitude of an optical output of the light emitting elements, a first calculation circuit that calculates an average value of the drive current in a predetermined period in a frame period as an average drive current value for each of the predetermined period, a second calculation circuit that calculates an average value of the optical-output monitor values in the predetermined period as an average optical-output monitor value, and an adjustment circuit that adjusts the assumed value of the threshold current value based on the average drive current value and the average optical-output monitor value.

Drive circuit and image projection apparatus

A circuit includes a calculation circuit configured to calculate a noise power of a predetermined-training-sequence pattern repeatedly included in a first signal input into an adaptive equalizer, based on a second signal obtained by compensating the first signal by a compensation circuit, a channel-estimation value based on the second signal, and the predetermined-training-sequence pattern; and an average circuit configured to obtain an average value of estimation values of frequency offsets based on the predetermined-training-sequence pattern having the noise power equal to or smaller than a predetermined power, among estimation values of frequency offsets based on the predetermined-training-sequence pattern, wherein the compensation circuit is configured to compensate a frequency offset of the predetermined-training sequence pattern based on the average value and thereby obtain the second signal, and the adaptive equalizer is configured to perform adaptive-equalization processing of the first signal with a setting value based on the second signal.

Adaptive equalization circuit, digital coherent receiver, and adaptive equalization method

A signal processing apparatus includes: a filter; and a filter control circuit, wherein the filter control circuit is configured to: detect a power of signals output from the filter; determine one of a plurality of numerical ranges to which the power belongs; update a filter coefficient of the filter according to a determination result; count a number of the signals having the power of a first value or more; set an invalid area which becomes a target not to be determined for each of one or more boundaries between the plurality of numerical ranges when the number of the signals becomes a second value or more; and control a width of the invalid area based on the number of signals.

Signal processing apparatus, signal processing method, and signal processing system

A receiving device that converts, to a digital signal, a signal in which signal light from an optical transmission path and local oscillation light are mixed, so as to perform digital signal processing, the optical communication receiving device comprising: a frequency offset compensation unit configured to calculate a frequency offset of the digital signal and to, based on the frequency offset, compensate for a phase of the digital signal; a carrier phase recovery unit configured to calculate a carrier phase of the digital signal whose phase is compensated for in the frequency offset compensation unit; and a residual frequency offset detection unit configured to calculate an average of differences in the carrier phase, and to output the average as a residual frequency offset, wherein the frequency offset compensation unit is configured to correct the frequency offset using the residual frequency offset output by the residual frequency offset detection unit.

Optical communication receiving device and frequency offset compensation method

A transposing apparatus is configured by a computer controlling a computing device having computing elements arranged into a matrix and memory devices connected to the computing elements. The computing device executes an electromagnetic field analysis process on latticed three-dimensional analysis subject data present in a three-dimensional coordinate system. The computer is configured to detect the number of lined-up lattices in a direction of a first axis, in a direction of a second axis, and in a direction of a third axis of the coordinate system, through detection on the three-dimensional analysis subject data; transpose a group of lattices of the three-dimensional analysis subject data, based on the detected numbers of lined-up lattices and on the number of lined-up computing elements in a row direction and in a column direction; and output to the computing device, the three-dimensional analysis subject data transposed.

Transposing apparatus, transposing method, and computer product

An optical receiving device includes: an adaptive equalizer that includes a position estimation unit configured to estimate, based on a first signal component and a second signal component of a reception signal generated by reception of a training sequence pattern transmitted from an optical transmitter, a symbol position of the reception signal, and generates an estimated symbol position, a delay unit configured to provide a delay difference between the first signal component and the second signal component, a control unit configured to set a plurality of symbol displacement amount candidates of displacement amounts for the estimated symbol position, causes the delay unit to generate a plurality of delay differences, and generates a channel estimation symbol position used for channel estimation, and an error rate calculation unit configured to calculate an error rate of the signal restored by an adaptive equalization unit.

Optical receiving device

A method includes: calculating a position-dependent processing load to be caused by a process that depends on a position of a cell, for each of cells into which a spatial area specified as a target of an analysis to be executed by processing devices that are included in a first number of processing devices and synchronize for each unit in time domain is divided; and assigning the cells to a second number of processing devices which are part or all of the first number of processing devices, under a condition where a criterion determined with respect to uniformity in a total processing time among processing devices used for the analysis is met. The total processing time of each processing device includes a length of time to be taken to execute each process depending on the position of each of cell(s) to be assigned to this processing device.

Growing community of inventors

Kawasaki, Japan

Tomoki Katou