Patent application number | Description | Published |
20080303609 | POWER LINE COMMUNICATION SYSTEM AND CAPACITIVE SIGNAL COUPLING UNIT - In power line communications using carrier waves of high frequencies in the MHz range such as 2 to 30 MHz, when a coaxial cable for performing transmission of signals and a power line are signal-coupled using a capacitive signal coupling unit, even if an impedance matching circuit is installed in the capacitive signal coupling unit, we have found that leakage current of levels that cannot be neglected from leakage noise considerations flows through the outer sheath of the coaxial cable that transmits the signals, and, accordingly, leaking electromagnetic waves induced by the leakage current flowing through the coaxial cable due to impedance mismatch between the power line and the capacitive signal coupling unit are reduced by an impedance member showing high impedances at high frequencies in the MHz range. | 12-11-2008 |
20120020677 | RECEIVING DEVICE AND DEMODULATION DEVICE - To adequately perform sampling, a receiving device that solves problems that involve an increase in circuit area and an increase in cost, is provided. | 01-26-2012 |
20120237202 | COHERENT OPTICAL RECEIVER, APPARATUS AND METHOD FOR DETECTING INTER-CHANNEL SKEW IN COHERENT OPTICAL RECEIVER - In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an inter-channel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source, a 90° hybrid circuit, an optoelectronic converter, an analog to digital converter, and a digital signal processing unit; wherein the 90° hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog to digital converter quantizes the detected electrical signals and outputs quantized signals; the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and an FFT operation unit for performing a fast Fourier transform process on the quantized signals; and wherein the difference in propagation delay is calculated on the basis of a plurality of peak values with a central focus on one peak value in the results of performing the fast Fourier transform process. | 09-20-2012 |
20120269513 | OPTICAL RECEPTION DEVICE AND OPTICAL RECEPTION CONTROL METHOD - An optical reception device ( | 10-25-2012 |
20120280844 | DIGITAL RECEIVER AND OPTICAL COMMUNICATION SYSTEM THAT USES SAME - A digital receiver includes: an analog-to-digital (AD) converter ( | 11-08-2012 |
20130051790 | COHERENT OPTICAL RECEIVER, APPARATUS AND METHOD FOR DETECTING INTERCHANNEL SKEW IN COHERENT OPTICAL RECEIVER - In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an interchannel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source; a 90-degree hybrid circuit; an optoelectronic converter; an analog-to-digital converter; and a digital signal processing unit, wherein the 90-degree hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog-to-digital converter quantizes the detected electrical signals and outputs quantized signals; and the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and a demodulation unit for demodulating the quantized signals. | 02-28-2013 |
20130251082 | DIGITAL RECEIVER AND WAVEFORM COMPENSATION METHOD - An objective is to provide a digital receiver and a method of compensating waveform that are capable of compensating waveform distortion without increasing the circuit size. A digital receiver | 09-26-2013 |
20130266308 | COHERENT OPTICAL RECEIVER, DEVICE AND METHOD FOR DETECTING INTER-LANE SKEW IN COHERENT OPTICAL RECEIVER - The disclosed coherent optical receiver includes a local light source; a 90-degree hybrid circuit; an optoelectronic converter; an analog-to-digital converter; a skew addition unit; and a FFT operation unit. The 90-degree hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs multiple optical signals separated into a plurality of signal components. The optoelectronic converter detects the optical signal and outputs a detected electrical signal. The analog-to-digital converter digitizes the detected electrical signal and outputs a detected digital signal. The skew addition unit adds to the detected digital signal an additional skew amount whose absolute value is equal to, whose sign is opposite to a skew amount of a difference in propagation delay in each lane connected to each output channel of the 90-degree hybrid circuit. The FFT operation unit performs a fast Fourier transform on the output from the skew addition unit. | 10-10-2013 |
20130302041 | OPTICAL RECEIVER AND METHOD FOR OPTICAL RECEPTION - In order to improve degradation of receiving sensitivity caused by analog characteristics degradation in an optical receiver, the optical receiver includes: the first coefficient computing unit for computing the first equalization filter coefficient for compensating the first waveform distortion caused and formed by an optical transmission path; the second coefficient calculating unit for predetermining the second equalization filter coefficient for compensating the second waveform distortion caused and formed by an analog characteristics degradation of components; a coefficient operating unit for performing operation to the first equalization filter coefficient and the second equalization filter coefficient and outputting the third equalization filter coefficient; and a waveform equalization processing unit including a waveform equalization filter for performing an equalization process to an input signal including the first waveform distortion and the second waveform distortion based on the third equalization filter coefficient, correcting each of the first waveform distortion and the second waveform distortion and outputting an output signal. | 11-14-2013 |
20140028319 | TANK-TYPE SWITCHING DEVICE - A discharge location determination unit includes: discharge detection circuits connected to metal electrodes, respectively, and to which a signal due to discharge is input; and a calculation circuit to which signals output from the discharge detection circuits are input, wherein, if the intensity difference or intensity ratio between the two output signals is within a predetermined value, the calculation circuit determines that the discharge location is inside a tank, otherwise the calculation circuit determines that the discharge location is outside the tank. | 01-30-2014 |
20140079386 | COHERENT OPTICAL RECEIVER, APPARATUS AND METHOD FOR DETECTING INTERCHANNEL SKEW IN COHERENT OPTICAL RECEIVER - In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an interchannel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source; a 90-degree hybrid circuit; an optoelectronic converter; an analog-to-digital converter; and a digital signal processing unit, wherein the 90-degree hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog-to-digital converter quantizes the detected electrical signals and outputs quantized signals; and the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and a demodulation unit for demodulating the quantized signals. | 03-20-2014 |
20140140690 | COHERENT OPTICAL RECEIVER, APPARATUS AND METHOD FOR DETECTING INTER-CHANNEL SKEW IN COHERENT OPTICAL RECEIVER - In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an inter-channel skew arises, therefore, a method for detecting inter-channel skew in a coherent optical receiver according to an exemplary aspect of the invention includes the steps of: outputting a plurality of optical signals separated into a plurality of signal components by making a test light from a test light source interfere with a local light from a local light source; detecting the optical signals and outputting detected electrical signals; quantizing the detected electrical signals and outputting quantized signals; performing a fast Fourier transform process on the quantized signals; and calculating a difference in propagation delay between the plurality of signal components on the basis of a plurality of peak values in the results of performing the fast Fourier transform process. | 05-22-2014 |
20140147112 | TRANSMISSION DEVICE, TRANSMISSION METHOD, AND COMMUNICATION SYSTEM - In order to provide a transmission device which can resolve the deterioration in transmission characteristics due to lack of the resolution of a D/A converter in a high speed and large capacity digital communication, a transmission device according to an exemplary aspect of the present invention includes an encoding unit encoding input data; an unequal-interval quantization unit quantizing an output signal from the encoding unit by a quantization level number based on a resolution of a subsequent digital-to-analog conversion unit by using an unequally spaced quantization level interval based on the output signal; the digital-to-analog conversion unit converting an output signal from the unequal-interval quantization unit into an analog signal; an output level adjustment unit adjusting an output level of the digital-to-analog conversion unit so as to compensate a difference between a predetermined initial transfer function and a transfer function of the unequal-interval quantization unit; and a modulation unit generating a transmission signal based on an output signal of the digital-to-analog conversion unit adjusted by the output level adjustment unit. | 05-29-2014 |
20140166622 | TANK-TYPE CIRCUIT BREAKER - Capacitors ( | 06-19-2014 |
20140379771 | DIGITAL FILTER CIRCUIT AND DIGITAL FILTER PROCESSING METHOD - A digital filter circuit includes an FFT circuit ( | 12-25-2014 |
20150019608 | DIGITAL FILTER CIRCUIT, DIGITAL FILTER PROCESSING METHOD AND DIGITAL FILTER PROCESSING PROGRAM STORAGE MEDIUM - Reduction of a circuit size and power consumption for performing digital filtering processing in a frequency domain is realized. The digital filter circuit includes: a complex conjugate generation unit for generating a second complex number signal including conjugate complex numbers of all complex numbers included in a first complex number signal of the frequency domain generated by converting a complex number signal of a time domain by Fourier transform; a filter coefficient generation unit for generating a first and a second frequency domain filter coefficient of a complex number from a first, a second and a third input filter coefficient of a complex number having been inputted; a first filtering unit for performing filtering processing to the first complex number signal by the first frequency domain filter coefficient, and outputting a third complex number signal; a second filtering unit for performing filtering processing to the second complex number signal by the second frequency domain filter coefficient, and outputting a fourth complex number signal; and a complex conjugate combining unit for combining the third complex number signal and the fourth complex number signal, and generating a fifth complex number signal. | 01-15-2015 |