Mitsubishi Electric Corporation

Oki Electric Industry Co., Ltd.

Kaoru Tsukamoto

Hiroshi Nishimoto

Akihiro Okazaki

Tomohiro Iwanaga

Naohiro Shinoda

Shusaku Umeda

Yusuke Kinoshita

Kanako Yamaguchi

Kimito Horie

Toshiharu Okada

Yoji Hamano

Hiroto Miyahara

Masao Tomizawa

A reception device includes: a reception unit receiving transmission signals; a splitting unit splitting received signals into real component and imaginary component; a narrowing unit narrowing down possible signal point candidates of real component of the signal and imaginary component of the signal to signal point candidates based on the real component and the imaginary component of the split received signal; a signal point candidate hypothesizing unit hypothesizing one signal point candidate of real component from the signal point candidates of real component obtained by narrowing-down and hypothesizing one signal point candidate of imaginary component from the signal point candidates of imaginary component obtained by narrowing-down; and a signal estimation value calculating unit estimating real component of the signal based on the one hypothesized real component signal point candidate and estimating imaginary component of the signal based on the one hypothesized imaginary component signal point candidate.

Reception device, reception method, and communication system

A distributed antenna system includes a plurality of antenna groups which includes first antennas and second antennas. The first antennas form beams in a first direction along a mobile station track and transmit identical signals at identical frequencies. The second antennas form beams in a second direction opposite to the first direction and transmit identical signals at identical frequencies. The antenna groups are installed on one side of the mobile station track. A frequency of signals transmitted by the first antennas belonging to the same antenna group is different from a frequency of signals transmitted by the first antennas belonging to another antenna group adjacent thereto, a frequency of signals transmitted by the second antennas belonging to the same antenna group is different from a frequency of signals transmitted by the second antennas belonging to another antenna group adjacent thereto, and the signals from the first antennas and the signals from the second antennas are transmitted using two frequencies in total.

Distributed antenna system

There are provided a signal transmitter that generates a signal indicating execution of distance measurement and transmits the signal to a plurality of antennas, a combiner that adds a plurality of received signals that are radio signals including a response signal from the mobile station and each of which is correspondingly received by each of the antennas, a timing detector that detects a timing at which reception power for a signal added by the combiner is maximized and determines a reception timing of the response signal, a base station time calculator that determines a round trip time from transmission of the signal indicating execution of distance measurement to reception of the response signal on the basis of the reception timing and a timing of the transmission of the signal indicating execution of distance measurement, a power detector that identifies one of the antennas that has received a received signal with highest reception power among the plurality of received signals, and a distance calculator that calculates a distance between the distributed antenna base station and the mobile station on the basis of the round trip time, a delay in signal transmission to the antenna identified by the power detector, and a distance to the identified antenna.

Distributed antenna base station, mobile station, and method of distance measurement

An OFDM transmission apparatus performs transmission using an orthogonal frequency division multiplexing scheme in one or a plurality of frequency bands and includes a symbol multiplexing unit to multiply a column vector containing a first number of modulated symbols generated by primary modulation in a frequency domain, by a precoding matrix having as many rows and columns as the first number to generate a multiplexed symbol group containing the first number of multiplexed symbols each containing a second number of the modulated symbols that are multiplexed, where the first number is two or more, and the second number is equal to or more than two and equal to or less than the first number; and a subcarrier allocation unit to allocate the multiplexed symbols contained in the multiplexed symbol group to different subcarriers.

Transmission apparatus and transmission method

A distributed antenna system includes a plurality of first antenna groups and a plurality of second antenna groups. The first antenna groups include a plurality of first antennas which forms beams in a first direction along a mobile station track and transmits identical signals at identical frequencies. The second antenna groups include a plurality of second antennas which forms beams in a second direction and transmits identical signals at identical frequencies. The first antennas and the second antennas are installed to face each other across the mobile station track. Each of the first antenna groups uses a frequency different from a frequency used in another first antenna group adjacent thereto, each of the second antenna groups uses a frequency different from a frequency used in another second antenna group adjacent thereto, and two frequencies are used by the first antenna groups and the second antenna groups in total.

A mobile station that communicates with a base station includes, a distance calculation unit that calculates the distance between the mobile station and the base station, a reception power measurement unit that measures a reception power of a reception signal received from the base station; a rain state determination unit that determines a transmission-path quality on the basis of a reception-power theoretical value corresponding to the distance and a reception power measured by the reception power measurement unit and selects a communication parameter on the basis of the determined transmission-path quality, and a modulation unit that generates a transmission signal to be transmitted to the base station by using a communication parameter.

Mobile station, base station, wireless communication system, and communication method

A control station serving as a base-station control device that issues an operation instruction to each of base stations in a wireless communication system in which a plurality of base stations perform transmission at the same time and the same frequency, wherein a frequency offset of a reception signal from a mobile station that is detected by each of the base stations is collected, and a phase rotation amount that is a rotation amount when the base stations rotate a phase of a transmission signal is determined for each of the base stations so that frequency offsets of the respective transmission signals having been subjected to phase rotation by the respective base stations are the same.

Base-station control device, wireless communication system, and base station

A music player has sequencers each including a reading and restoring function unit for reading music information including header information, a delta time, and a message and restoring running status of the message; a message analyzing and processing function unit for analyzing the header information, consuming a period of time according to the delta time, and processing the message to generate sound source drive information; a writing function unit for writing the sound source drive information into an output memory; and a sequencer controlling function unit for controlling the reading and restoring function unit to read and restore the music information, controlling the message analyzing and processing function unit to analyze the header information, and controlling the message analyzing and processing function unit and the writing function unit to consume the period of time, generate the sound source drive information, and write the sound source drive information.

Music player

A play data editing device edits play data according to a characteristic of a speaker. The play data editing device includes a dividing unit () for dividing first play data into second play data per channel; a classifying unit () for classifying the second play data into a rhythm part, a melody part, and a base part; a chord processing unit () for converting a number of chords of the second play data corresponding to the melody part according to the characteristic of the speaker; a velocity processing unit () for converting a velocity of the second play data corresponding to the rhythm part according to the characteristic of the speaker; and a sound range processing unit () for shifting a sound range of the second play data corresponding to the base part according to the characteristic of the speaker.

Play data editing device and method of editing play data

A music playback unit corrects the frequency characteristics of a speaker installed in a portable telephone, without using an equalizer. The musical score data is stored in a first memory, and data for correcting the velocity of musical score data for each velocity of each note is stored in a second memory. The sound generator driver reads the musical score data from the first memory, and reads the correction data from the second memory, and also corrects the velocity of the musical score data by substituting the musical score data and correction data in a predetermined calculation formula. The musical score data after the velocity is corrected is played by the MIDI sound generator, amplifier and speaker.

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Tokyo, Japan

Kaoru Tsukamoto