Fujitsu Corporation

Katsuhiro Ikeda

Takatoshi Nakamura

An optical transmitter includes an optical modulator including a first modulator, a second modulator, and a phase shifter that provides a predetermined optical phase difference between the first modulator and the second modulator, a light source that makes light enter the optical modulator, and a voltage controller that detects a distortion of light power characteristics from output light of the optical modulator in a state where no data signal is input to the optical modulator to determine a bias voltage to be set in the optical modulator while reducing the distortion.

Optical transmitter, optical transmission apparatus, and method of controlling optical transmitter

A radio device including: a processor configured to execute a procedure including a difference calculating process which calculates, when a plurality of transmission symbols are one symbol with different assignment positions of one of a frequency area and a time area, a difference between an assignment position of one reference symbol and an assignment position of another symbol among the plurality of transmission symbols, and a shift process which generates a symbol by shift processing of one of the frequency area and the time area with respect to the reference symbol, which is assigned to the an assignment position and subjected to an orthogonal transform processing, according to the difference; and a transmitter configured to performs transmitting processing based on the reference symbol which is subjected to the orthogonal transform processing and the generated symbol by the shift processing.

Radio device, radio communication system, and radio control method

By using a discrete Fourier transform equation that is used to transform N data values (N is an integer equal to or greater than one) to N transformation values, a wireless communication apparatus calculates three continuous transformation values from the N data values. Then, the wireless communication apparatus obtains a fixed change in the phase difference from the three calculated transformation values; multiplies the calculated transformation value by a twiddle factor that is obtained from the change in the phase difference; and calculates not-yet calculated transformation values.

Wireless communication apparatus and wireless communication method

Channel estimates calculated by a channel estimator () are linearly interpolated (). When transmissions from transmitting antennas are stopped due to a deterioration of the propagation environment, since a larger amount of computing resources become available for use, a channel estimate selectorselects the linearly interpolated channel estimates and supplies them to an MIMO demultiplexerwhich can thus cope with fast fading.

Growing community of inventors

Yokosuka, Japan

Katsuhiro Ikeda