Mitsubishi Electric Corporation

Hiroki Iura

Akinori Taira

Shigeru Uchida

Fumihiro Hasegawa

Noriyuki Fukui

Akihiro Okazaki

Koji Tomitsuka

Mitsuru Mochizuki

Hiroshi Nishimoto

Hikaru Watanabe

Tadahiro Shimoda

Masataka Otsuka

Kazunari Kihira

Manabu Sakai

Makoto Matsuki

A base station includes: a control unit that allocates one or more layers per terminal for transmission to one or more terminals, and configures positions in a frequency domain and a time domain of reference signals of each of the layers on the basis of at least one of information indicating a position of each of the terminals and information indicating condition of each of channel between the transmission device and the one or more terminals; a processing unit that arranges the reference signals of each of the layers in the frequency domain and the time domain on the basis of the positions in the frequency domain and the time domain configured by the control unit; and a precoding unit and a transmitting unit that perform space-division multiplexing on signals of one or more layers arranged by the processing unit, and transmit the multiplexed signals.

Transmission device, communication system, and transmission method

An interference cancellation device includes a data symbol extraction unit that extracts a data symbol portion from a received signal, a null symbol extraction unit that extracts a null symbol portion from the received signal, a data symbol power calculation unit that calculates a data symbol power estimated value, a null symbol power calculation unit that calculates a null symbol power estimated value, a null symbol spectrum calculation unit that calculates a null symbol spectrum from a null symbol signal, and an interference center frequency estimation unit that eliminates the effect of an image for an interference in calculation of an interference bandwidth when is calculating an interference center frequency estimated value, using a data symbol signal, the data symbol power estimated value, the null symbol power estimated value, and the null symbol spectrum.

Interference cancellation device, control circuit, storage medium, and interference center frequency estimation method

The base station allocates, to one terminal, at least one transmission layer and allocates at least one resource block that is a minimum allocation unit of a communication resource in each transmission layer, to transmit a signal to the terminal, and includes processing units each associated with one of the transmission layers, the processing units being equal in number to the transmission layers. Each processing unit includes a reference signal generation unit to generate a reference signal to be used by the terminal in demodulation processing on a received signal, and an information processing unit to determine an arrangement of the resource block in which to transmit the reference signal to the terminal, based on at least one of a state of a channel between the base station and the terminal or information on the resource block to be used in transmission of the reference signal in an adjacent cell.

Transmitting apparatus and receiving apparatus

A base station () according to the present invention includes: a control unit () that allocates one or more layers per terminal for transmission to one or more terminals, and configures positions in a frequency domain and a time domain of reference signals of each of the layers on the basis of at least one of information indicating a position of each of the terminals and information indicating condition of each of channel between the transmission device and the one or more terminals; a processing unit (-to-N) that arranges the reference signals of each of the layers in the frequency domain and the time domain on the basis of the positions in the frequency domain and the time domain configured by the control unit (); and a precoding unit () and a transmitting unit () that perform space-division multiplexing on signals of one or more layers arranged by the processing unit (-to-N), and transmit the multiplexed signals.

Transmission device, communication system, and transmission method that configure positions of reference signals in frequency and time domains for each of a plurality of layers

A base station serving as a transmission apparatus includes a plurality of transmission antennas capable of forming beams directed to a plurality of terminals, which are reception apparatus, and a precoder configured to perform outer precoding on transmission signals transmitted from the plurality of transmission antennas. The plurality of terminals include at least one first reception apparatus, which are transmission destinations of the transmission signals, and second reception apparatus, which are reception apparatus other than the first reception apparatus. The precoder performs outer precoding on the transmission signals transmitted from the plurality of transmission antennas so that received power in the second reception apparatus among the plurality of reception apparatus is equal to or less than a threshold.

Transmission apparatus, reception apparatus, control station, communication system, and transmission precoding method

A wireless device according to the present invention is configured to execute a beamforming weight training function for acquiring in advance, by mutual communication between a base station and a terminal station, transmission quality information at a time when a combination of a base station beamforming weight and a terminal station beamforming weight is used, and identifying a suitable beamforming weight, and is configured to search for, based on the transmission quality information identified in the training step, a suitable beamforming weight while performing mutual communication, and execute processing of updating the suitable beamforming weight.

Wireless device and wireless communication control method

A sub-array number determinator is provided to determine a number of sub-arrays to be allocated to each of user terminals detected by a terminal position detector on a basis of relation between positions of the user terminals and a position of an antenna apparatus. An antenna selector selects sub-arrays for the number determined by the sub-array number determinator from among the sub-arrays and allocates the selected sub-arrays for the determined number to each of the user terminals. This structure is capable of preventing interference among beams for user terminals and providing excellent communication quality to the user terminals even in condition where the user terminals are adjacent to each other.

Antenna apparatus

A wireless communication apparatus configured to select an allocation system for transmission symbols on the basis of transmission line situations between the wireless communication apparatus and terminals includes a channel estimator to estimate transmission line coefficients between communication target terminals and sub-arrays, a resource scheduler to generate, on the basis of the transmission line coefficients, mapping information and transmission weight information by spatial multiplexing and frequency multiplexing and select and output the mapping information and the transmission weight information by one of the multiplexing systems, a symbol mapper to map transmission symbols on a frequency axis on the basis of the mapping information from the resource scheduler, and a pre-coder to perform, on the basis of the transmission weight information from the resource scheduler, a weighting operation concerning a signal mapped by the symbol mapper.

Wireless communication apparatus and wireless communication method

A radio transmission apparatus includes a plurality of antennas each having an amplifier, a transmission signal generation unit (modulation units, S/P units, and FFT units) which generates a signal to be transmitted to a terminal via the antennas, and a weighting processing unit (a precoder unit, a maximum power calculation unit, and multipliers) which executes a weighting process on a signal to be transmitted to the terminal, which has been generated by the transmission signal generation unit, based on channel state information between the radio transmission apparatus and the terminal and an output limit value of the amplifier.

Radio transmission apparatus

A signal generating device includes a first digital filter unit outputting a first interpolated signal by interpolating an input signal, a second digital filter unit outputting a second interpolated signal by interpolating the first interpolated signal, a phase calculation unit calculating a phase of a digital signal, a phase-accuracy conversion unit calculating first phase signal and second phase signal, a first memory storing filter coefficients, a first coefficient readout unit reading filter coefficients from the first memory and switching filter coefficients of the first digital filter unit, a phase-error calculation unit calculating a phase error signal, a second memory storing filter coefficients, a second coefficient readout unit reading filter coefficients from the second memory, and a gain normalization unit normalizing a gain of the filter coefficients to maintain a constant sum of the filter coefficients and switching filter coefficients of the second digital filter unit.

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Tokyo, Japan

Hiroki Iura