Mitsubishi Electric Corporation

Agc Inc.

Tsukishima Kikai Co., Ltd.

Nippon Steel Sumitomo Metal Corporation

Primetals Technologies Japan, Ltd.

Keisuke Matsuda

Tsuyoshi Yoshida

Masashi Binkai

Keisuke Dohi

Tatsuya Kobayashi

Hiroshi Miura

Takashi Sugihara

Ryosuke Matsumoto

Kiyoshi Onohara

Hiroshi Aruga

Takaaki Murakami

Kazuo Kubo

Toshiyuki Ando

Satoshi Suwa

Keita Mochizuki

Naoki Suzuki

Tomoyuki Kobayashi

Kenji Horii

Hiroki Goto

Toshinari Watanabe

Eisuke Haraguchi

Masaki Kataoka

Yuko Tachibana

Yoichi Haraguchi

Yuji Ikemoto

Kazuaki Kobayashi

Tomofumi Hosho

Seiki Nakamura

Shota Koshikawa

Yuuki Tateyama

An optical space communications transmission and reception terminal includes: an optical transceiver to convert transmission data into a transmission optical signal modulated at a symbol rate synchronized with a transmission clock signal and output it, and generate received data from a reception optical signal; an intensity modulation unit to generate an intensity-modulated transmission optical signal; a transmission clock source to supply a transmission clock signal; a fiber coupling unit) to output the intensity-modulated transmission optical signal as collimated light and couple the input optical signal to an optical fiber; an optical fiber amplifier to amplify the optical signal coupled to the optical fiber; a tracking mirror to output the optical signal to the fiber coupling unit and output the transmission optical signal to space; and an angle sensor to output a clock signal extracted from the optical signal divided by a beam splitter to the optical transceiver.

Optical space communications transmission and reception terminal and optical space communications system

An optical space communication transmitting terminal includes: a plurality of transmitters that form a plurality of groups and transmit optical signals having wavelengths different from each other; multiplexers that are provided to each of the groups and outputs optical signals wavelength-multiplexed by multiplexing the optical signals transmitted from the transmitters belonging to the group; optical amplifiers that are provided to each of the groups and amplifies the wavelength-multiplexed optical signals; and optical antennas that are provided to each of the groups and transmits the amplified optical signals into space, in which the optical antennas of the groups transmit the optical signals in the same direction.

Receiver, optical space communication system, and optical space communication reception method

A signal processing device processes reception signals of optical signals received by a receiver when the optical signals transmitted from a transmitter are propagated to the receiver via a plurality of paths, and includes: a signal-to-noise ratio calculating unit that calculates signal-to-noise ratios of the optical signals that have been propagated through the respective paths, from propagation distances of the optical signals in the respective paths, intensities of the optical signals transmitted from the transmitter, and intensities of noise with respect to the optical signals transmitted from the transmitter; an amplitude adjusting unit that adjusts amplitudes of the reception signals of the optical signals that have been propagated through the respective paths, using the corresponding signal-to-noise ratios calculated by the signal-to-noise ratio calculating unit; and a signal combining unit that combines the reception signals whose amplitudes have been adjusted by the amplitude adjusting unit.

Signal processing device, signal processing method, receiver, and optical communication system

A receiver is configured to extract a clock signal superimposed on a detection signal of light propagated to determine whether or not SNR of the detection signal is lower than SNR at which the detection signal can be demodulated; compensate a signal value of the detection signal by using a filter coefficient and output a detection signal after signal value compensation; and calculate, as the filter coefficient, a filter coefficient in which a signal value of a detection signal output from the adaptive filter is a reference value when it is determined that there is no SNR degradation, and changes the filter coefficient to a stored filter coefficient when it is determined that SNR degradation occurs.

Receiver

The object of the present invention is to provide an optical laminate capable of reducing reflectance not only with respect to light incident vertically but also light incident obliquely, and further capable of obtaining a neutral reflected color tone even when light is incident obliquely. The optical laminate includes a base material, an antireflection film provided on one surface of the base material, and a light shielding film provided on the other surface of the base material. The optical laminate satisfies all of the following characteristics (i) to (iii):0.5&#x3c;(&#x3bb;,&#x3b8;)/(&#x3bb;,&#x3b8;)&#x3c;1.5;&#x2003;&#x2003;(i)(&#x3b8;)&#x2264;3%; and&#x2003;&#x2003;(ii)(&#x3b8;)&#x2264;10%;&#x2003;&#x2003;(iii)in which R (&#x3bb;, &#x3b8;) designates reflectance when light of a wavelength of &#x3bb; nm is incident at an angle of &#x3b8;, provided that &#x3bb;=380 nm, &#x3b8;=60&#xb0; and &#x3bb;=650 nm, &#x3b8;=60&#xb0;; and

Optical laminate having antireflection film and light shielding film

A spatial optical transmitter modulates an optical signal of a single wavelength in accordance with a signal to be transmitted, divides the modulated optical signal into two, rotates polarizations of the two divided optical signals, and transmits the two optical signals as optical signals of two orthogonal polarizations to space.

Spatial optical transmitter and spatial optical communication system

A coherent receiver performing coherent detection on polarization multiplex light into which first polarization light and second polarization light are multiplexed, and splitting the polarization multiplex light into the first polarization light and the second polarization light, an adaptive equalizer compensating the waveform distortion of a signal superimposed onto the first polarization light by using a first FIR filter, compensating the waveform distortion of a signal superimposed onto the second polarization light by using a second FIR filter, and by decoding each of the signals whose waveform distortion has been compensated, generating their respective decoded data, an error ratio calculator calculating the bit error ratio of each decoded data generated by the adaptive equalizer, a margin calculator calculating a margin from the bit error ratio of an error correction limit in each bit error ratio calculated by the error ratio calculator, and a tap number controller setting up the numbers of taps of the first and second FIR filters by referring to the respective margins calculated by the margin calculator are included.

Optical receiver, light signal receiving method, and data reproduction device

Provided is an optical transmission/reception device () for transmitting or receiving an optical signal via a communication path () in which a phase change of the optical signal is suppressed. The optical transmission/reception device () includes: a transmission device () including a framer generation unit (), a symbol mapping unit (), and an optical modulation unit (); and a reception device () including an optical reception front end unit (), an A/D conversion unit (), a polarization separation unit (), and a phase estimating unit () for estimating a phase of at least one of a plurality of polarizations from a plurality of polarization signals separated by the polarization separation unit () and estimating a phase of a remaining polarization on the basis of the estimated phase. The optical transmission/reception device (), therefore, has a small circuit scale and allows a digital coherent reception system to be applied to free space optics or a communication system with a short communication distance such as an access network.

Optical transmission/reception device and optical transmission/reception method

A producing method of a base member provided with a printed layer, the method including: disposing a printing plate including a screen plate having an opening pattern and a frame body supporting the screen plate so that the printing plate is opposed to a printing target surface of the base member having at least one bent portion; disposing a squeegee so as to be opposed to a plate surface of the screen plate opposite to the base member; and forming the printed layer by extruding a printing material onto the printing target surface by the squeegee via the opening pattern of the screen plate in a state where the frame body is supported so as to be relatively movable with respect to the printing target surface in a normal direction of the printing target surface.

Producing method of base member provided with printed layer and base member provided with printed layer

Each of a first filter to a fourth filter is an FIR filter having one tap. Each of a fifth filter and a sixth filter is an FIR filter having less than 46 taps. As a result, it is possible to obtain an adaptive equalization filter having a smaller total number of taps than an adaptive equalization filter using an FIR filter having 24 taps as each of the first to fourth filters.

Adaptive equalization filter and signal processing device

A transmitter generates a burst signal obtained by multiplexing signals of a first polarization and a second polarization orthogonal to each other, and including, at the beginning thereof, a pilot sequence in which the first and the second polarizations each have single frequency components of a first frequency and a second frequency different from each other. A coherent light reception unit performs conversion into an electrical signal by allowing received light and local light to interfere with each other. A pilot sequence detection unit detects a pilot sequence from the converted electrical signal. The polarization estimation unit estimates polarization states of the first polarization and the second polarization at a receiver from frequency components corresponding to the first frequency, and the second frequency. An equalizer demultiplexes the first polarization and the second polarization on the basis of the estimated polarization states.

Optical communication device

An optical transmitter includes: a bit converter that processes input bits in units of four bits, and generates an output bit sequence having eight bits based on one of a first conversion table, a second conversion table, and a third conversion table; and a symbol mapper that allocates the output bit sequence to an X-polarization and to a Y-polarization of each of two consecutive time slots. The bit converter performs a process of generating the output bit sequence based on the first conversion table, the second conversion table, and the third conversion table. The bit converter performs the process such that a sequence of two most significant bits and a sequence of two least significant bits of the output bit sequence are respectively associated with values that are allocated respectively to two constellation points having phases different by 180 degrees on a complex plane.

Optical transmitter, optical receiver, and optical communication system

A likelihood generation device is included in a receiving apparatus that receives a code-modulated signal including n&#x2212;k information bits and k parity bits in N-dimensional arrangement, where N is a natural number greater than or equal to four, and n and k are natural numbers with k&#x3c;n. The likelihood generation device includes: a temporary likelihood determination unit to determine, by using a table that includes an L-dimensional address space and stores a likelihood in each of the L-dimensional address spaces, likelihoods of an information bit and a parity bit that are transmitted by the code-modulated signal received, where L is a natural number with L&#x3c;N; and a likelihood correction unit to update, among the likelihoods determined by the likelihood derivation unit, the likelihood of the information bit on a basis of a rule for generation of the parity bit.

Likelihood generation device, receiving apparatus, likelihood generation method, and optical transmission system

A symbol mapping device includes a transmission data processing unit receiving two transmission data having the same length, and if the length is a first length, uses the two transmission data as two output data without change, and if the length is less than the first length, adds dummy data to the two transmission data to generate two output data, each data having the first length; a parity addition unit generating two parity-added transmission data based on the two output data, where the two parity-added transmission data each contain parity data added to the transmission data and each have a second length; a shuffle unit extracting two modulation data, being data to be mapped, from the two parity-added transmission data generated by the parity addition unit; and a mapping processing unit mapping the two modulation data to two time slots of constellation points.

Symbol mapping device

An optical communication apparatus receives a signal in which optical signals each including multiplexed subcarriers are frequency multiplexed, and includes: transceivers to perform reception process on a processing target band in which any one of the optical signals is included and to calculate a frequency offset amount between local light and a reception target optical signal that is included in the processing target band and calculate a carrier frequency interval between the local light and an optical signal adjacent to the reception target optical signal; and a frequency control unit to calculate an adjustment amount when an optical communication apparatus that is a source of the optical signals adjusts the frequencies of the optical signals based on the frequency offset amount and the carrier frequency interval calculated by the transceivers and to transmit the calculated adjustment amount to the optical communication apparatus that is a source of the optical signals.

Growing community of inventors

Tokyo, Japan

Keisuke Matsuda