Abstract: There is proved an optical transmission system including: a transmitter configured to transmit an optical signal modulated with a discrete multi-tone (DMT) drive signal; a filter capable of changing a wavelength of the optical signal input from the transmitter; a monitor configured to monitor a power of the optical signal passed through the filter; and at least one processor configured to: set a center wavelength of the filter, shift the center wavelength, detect a change in the power monitored by the monitor, identify a carrier component of the optical signal based on the change in the power, and control a relative relationship between a transmission characteristic of the filter and a wavelength of the carrier component so that the carrier component is included in the optical signal and one of an upper sideband and a lower sideband of the optical signal is at least partially removed by the filter.

Abstract: A transmission apparatus including: a waveform shaper that performs spectrum correction on an optical signal converted from an electrical signal encoded by OFDM (Orthogonal Frequency Division Multiplexing); a converter that converts the optical signal on which the waveform shaper has performed the spectrum correction, into the electrical signal; and a nonlinear compensator that compensates for a nonlinear distortion with respect to the electrical signal converted by the converter.

Abstract: A bit allocation method is used in an optical transmission system that transmits multicarrier signals of different wavelengths in wavelength division multiplexing. Frequency characteristics of subcarriers included in the multicarrier signals are different between the respective multicarrier signals. The method includes: measuring transmission characteristics of the subcarriers included in corresponding multicarrier signals at different subcarrier frequencies; and determining a number of bits to be allocated to each of the subcarriers included in each of the multicarrier signals based on the transmission characteristics measured at the different subcarrier frequencies.

Abstract: A banknote handling apparatus that performs a depositing handling or a depositing/dispensing handling by transporting banknotes along a transport path includes a recognizing unit that recognizes an inserted banknotes; a deposit acceptability judging unit that determines, based on a recognition result obtained by the recognizing unit, whether the banknotes is acceptable for deposit; a reject reason identifying unit that identifies a reject reason of rejected banknotes that is determined to be unacceptable for deposit by the deposit acceptability judging unit; and a dispensing handling unit that sorts and dispenses the rejected banknotes based on the reject cause identified by the reject cause identifying unit.

Abstract: A transmission device connects a plurality of transmission device by a ring network. The transmission device includes a generating unit, a transmission unit, a determination unit, and a setting unit. The generating unit generates a test signal. The transmission unit transmits the generated test signal to a first transmission device provided immediately downstream in the ring network. The determination unit determines whether a transmission characteristic of the own device on the basis of the test signal measured by the first transmission device is acquired from a second transmission device provided immediately upstream by rounding the ring network. The setting unit sets, on the basis of the acquired transmission characteristic when the transmission characteristic of the own device is acquired, a control level related to the transmission performed by the transmission unit.

Abstract: An optical transmitter includes: a digital signal process unit that generates a drive signal for generating multi-carrier signals through a plurality of independent digital signal processes, the multi-carrier signals having a cyclic prefix and to be transmitted by a parallel transmission; a synchronization unit that synchronizes clocks of the plurality of digital signal processes; and an adjust unit that reduces a delay difference of the cyclic prefix between the multi-carrier signals after the parallel transmission.

Abstract: An optical communication system includes an optical transmitter that sends an optical signal; and an optical receiver that receives the optical signal. The optical transmitter controls a transmission rate of the optical signal to a first transmission rate corresponding to first reception light power lower than target reception light power of the optical receiver in response to transmission light power control for the optical signal corresponding to the target reception light power.

Abstract: A multilevel-intensity modulation and demodulation system includes: a digital-to-analog conversion unit to convert an output level value of a digital signal into an analog signal; a multilevel-intensity-modulated light transmission unit to transmit an optical signal multilevel-intensity modulated based on the analog signal; a multilevel-intensity-modulated light reception unit to receive the optical signal multilevel-intensity modulated, and convert the received optical signal into an analog reception electrical signal; an analog-to-digital conversion unit to convert the analog reception electrical signal into a reception level value; and a controller to convert a transmission multiple gradation level being one of a plurality of multiple gradation levels of multilevel-intensity modulation to which the digital signal is mapped, into the output level value so as to cause the reception level value to be in a desired reception state, and to receive a digital signal corresponding to a reception multiple-gradation-

Abstract: An optical transmitter transmits to an optical receiver a multi-carrier modulated signal light by driving a light source with a modulated signal modulated with a multi-carrier modulation scheme. The optical receiver monitors reception characteristic of any of subcarrier signals included in the modulated signal and transmits a monitor result to the optical transmitter. The optical transmitter controls drive conditions of the light source based on the monitor result received from the optical receiver.

Abstract: A receiving device includes an optical filter, an acquisition unit, a first determination unit, and a filter setting unit. The optical filter transmits an optical DMT signal received from a sending device. The acquisition unit acquires the transmission characteristics of the optical DMT signal received from the sending device. The first determination unit determines a filter frequency of the optical filter that removes a dip from the optical DMT signal on the basis of the acquired transmission characteristics. The filter setting unit sets the determined filter frequency in the optical filter.

Abstract: A transmission apparatus includes: an assigning unit that assigns an information signal to a subcarrier with a frequency different from a frequency of a received radio signal; a creating unit that creates a multi-carrier signal, in which information signals are multiplexed, each of the information signals being assigned to one subcarrier by the assigning unit; and a multiplexing unit that frequency-multiplexes the received radio signal to the multi-carrier signal created by the creating unit and outputs a resulting frequency-multiplexed signal.

Abstract: An optical reception apparatus may include a receiver, a monitor, and a controller. The optical reception apparatus receives multi-carrier modulated signal light modulated by a multi-carrier modulation scheme. The multi-carrier modulation scheme is available to allocate different transmission conditions for each of a plurality of subcarriers in accordance with transmission characteristics of the subcarriers. The receiver may receive from an optical transmission line a training signal light allocated with the same transmission conditions for each of the subcarriers. The monitor may monitor the transmission characteristics of the training signal light to detect a frequency at which a dip of the transmission characteristics occurs. The controller may control, based on the frequency detected by the monitor, a dispersion compensation for the multi-carrier modulated signal light having received a dispersion from the optical transmission line.

Abstract: An optical transmitter includes a DMT modulating unit that allocates information signals to SCs and that generates a DMT signal by performing multi-level modulation on each of the information signals allocated to each of the SCs. The optical transmitter includes a mixer that shifts, on the basis of the probe result of the DMT signal and frequency information on a wireless signal that is input, the carrier frequency of the wireless signal so as not to overlap the SC to which the information signal in the DMT signal is allocated. Furthermore, the optical transmitter includes a multiplexing unit that multiplexes the DMT signal received from the DMT modulating unit and the wireless signal in which the carrier frequency has been shifted and outputs the multiplexed signal.

Abstract: A transmission device includes: a plurality of modulators that respectively generate multicarrier signals from given data; a distributor that distributes input data to the modulators; an optical circuit that multiplexes the multicarrier signals to generate a WDM optical signal; and a controller that obtains allocation information from a receiver of the WDM optical signal and generates a distribution instruction to control the distributor and a bit allocation instruction to control the modulators according to the allocation information. The allocation information is calculated based on transmission characteristics of each subcarrier of the respective multicarrier signals and the allocation information indicates a number of bits of data allocated to each of the subcarriers. The distributor distributes the input data to the modulators according to the distribution instruction.

Abstract: A cooling device includes a power module incorporating chips that generate heat and having chip arrangement in which a first chip having the largest amount of heat generation and second chips having the second largest amount of heat generation are not adjacent to each other and the first chip is adjacent to any two of third chips having the smallest amount of heat generation, a heat sink, to a base surface of which the power module is closely attached, and flat first and second anisotropic high heat conductors having a thermal conductivity higher than a main body disposed on the surface of the heat sink. The first and second anisotropic high heat conductors are separated into two and disposed under the first chip and under the second chips.

Abstract: A drive circuit for a power semiconductor element includes: a voltage-command generation unit that generates a voltage command VGEref, which is a charge command between the gate and emitter terminals of a power semiconductor element; and a subtracter that calculates a deviation voltage Verr between the voltage command VGEref and the voltage between the gate and emitter terminals. The drive circuit also includes: a gate current controller that is input with the deviation voltage Verr and calculates a gate-current command voltage VIGref for determining the gate current that is caused to flow to the gate terminal of the power semiconductor element; a gate-current command limiter that limits the gate-current command voltage VIGref; and a gate-current supply device that is input with an actual gate-current command voltage VIGout and that supplies a gate current to the gate terminal of the power semiconductor element.

Abstract: The invention is related to a device for detecting insulation degradation in an inverter-driven load device, in particular a motor, the device including: zero-phase current measuring means for measuring a zero-phase current in power-feed lines, provided in the power-feed lines between an inverter device and the motor; and command control means for putting rotation of the motor on standby; wherein the zero-phase current measuring means measures the total of phase currents fed into respective phases so as not to rotate a shaft even when an external force is applied to the shaft during the rotation being on standby, whereby allowing regular detection of insulation degradation without switching over the power-feed lines connected with the load device.

Abstract: An optical transmitter includes a discrete multi-tone (DMT) modulation unit that modulates a carrier signal having a specific frequency with an information signal and a carrier signal having a frequency different from the specific frequency with a monitor signal, to generate a DMT modulation signal that multiplexes the information signal and the monitor signal. The optical transmitter includes a laser diode (LD) unit that optically converts the DMT modulation signal to a corresponding optical DMT modulation signal, a frequency extraction unit that extracts a harmonic distortion component of the monitor signal from the optical DMT modulation signal, and a frequency analysis unit. The optical transmitter includes a bias control unit that controls a bias supply unit that adjusts a bias value to be supplied to the LD unit such that the extracted harmonic distortion component of the monitor signal is reduced.

Abstract: A monolithic-capacitor-mounted structure satisfies Lc>Wc and Lx/Wx<Lc/Wc, where Lx denotes a distance between a first-lengthwise outermost portion of a first-lengthwise outermost one of first through fourth pads and a second-lengthwise outermost portion of a second-lengthwise outermost one of the pads; Wx denotes a distance between a first-widthwise outermost portion of a first-widthwise outermost one of the pads and a second-widthwise outermost portion of a second-widthwise outermost one of the pads; Lc denotes a distance between a first-lengthwise outermost portion of a first-lengthwise outermost one of external electrodes and a second-lengthwise outermost portion of a second-lengthwise outermost one of the external electrodes; and Wc denotes a distance between a first-widthwise outermost portion of a first-widthwise outermost one of the external electrodes and a second-widthwise outermost portion of a second-widthwise outermost one of the external electrodes.

Abstract: The embodiments of the present invention provide a method and an apparatus for compensating nonlinear distortions in an intensity modulation-direct detection (IM-DD) system; wherein the method comprises: calculating, according to nonlinear coefficients and differences between values of an input signal at different time, nonlinear distortions of the input signal, so as to eliminate the nonlinearity distortions. By applying the method and the apparatus provided by the embodiments of the present invention, nonlinear cost of the IM-DD system can be effectively reduced, thereby improving the system capacity.