Abstract: According to one embodiment, a wireless communication apparatus includes a calculator and a controller. The calculator multiplies a first weighting factor by a first data signal to be transmitted on a first channel, the first weighting factor is based on a second weighting factor multiplied by a second data signal received on the first channel. The controller controls a transmission to transmit to a destination device a control signal if the first data signal transmitted to the partner device exists, and no second data signal to be transmitted on the first channel exists in the device.

Abstract: A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.

Abstract: According to one embodiment, an allocating unit of a wireless communication device finds for each user an unallocated radio channel having maximum communication quality as a first radio channel, and calculates a first metric matching a communication state using communication quality in the first radio channel, selects one user from the plurality of users based on the first metric and allocates the first radio channel to the selected user. Further, the allocating unit repeats allocating an unallocated radio channel adjacent to a radio channel allocated to the selected user on a frequency domain until predetermined conditions are satisfied.

Abstract: According to one embodiment, a communication device communicates with N remote units. Each remote unit includes a plurality of antennas, wireless transmitting units, and wireless receiving units. The communication device is provided with a received signal processing unit, to which received signals by a plurality of the wireless receiving units are combined and input, and which specifies the remote unit subjected to interference, and a switch which decreases a reception gain of the wireless receiving unit included in N?1 remote units out of the N remote units in a predetermined measurement section. The received signal processing unit calculates a correlation value between the combined received signals and a reference signal transmitted by a user terminal connected to another base station system in the measurement section and specifies the remote unit subjected to the interference by the second user terminal based on the correlation value.

Abstract: One embodiment provides a signal processor configured to cooperate with a first apparatus having first and second antennas and a second apparatus having third and fourth antennas, including: first and second calculators for calculating first and second coefficient, respectively; first and second estimators for estimating first and second transfer functions of a path between the first and second apparatuses based on first and second weights; and a third calculator for calculating a third coefficient. The third coefficient is used with the first and second transfer functions for making a transfer function ratio regarding the first antenna, a transfer function ratio regarding the second antenna, a transfer function ratio regarding the third antenna and a fourth transfer function ratio regarding the fourth antenna same as one another.

Abstract: According to one embodiment, a wireless transmission method is disclosed. The method can perform feedback loop processing including subtracting a feedback data signal obtained by multiplying a feedback processing data signal by a gain from an input data signal to generate the feedback processing data signal. The method can perform beam forming processing with respect to the feedback processing data signal and at least one pilot signal for channel estimation to generate a beam-formed signal. In addition, the method can transmit the beam-formed signal by a plurality of antennas. Precoding processing performed on the pilot signal is only beam forming processing.

Abstract: A first extended base station that forms a first cell and a second extended base station that forms a second cell operate for a cooperative communication of transmitting same data to a user terminal located in the first cell. A second signal processor that corresponds to the second extended base station generates a training signal specific to the first extended base station and the first extended base station and the second extended base station transmit same data and same training signals. Thus, a cooperative communication can be realized in a system that uses a training signal specific to a base station.

Abstract: In one embodiment, there is provided a communication device configured to add a first perturbation signal corresponding to an integer multiple of a first basic signal, to a first information signal having first information, which is to be transmitted to a plurality of destination terminals, and transmit a wireless signal having the first information to the plurality of destination terminals by a spatial multiplexing method. The device includes: a determination unit configured to set a magnitude of the first basic signal to N times of one side of a basic lattice, wherein the basic lattice is determined according to a modulation method of the first information signal, and N is real number of one or more; an adder configured to add the first perturbation signal to the first information signal to output a second information signal; and a multiplier configured to multiply the second information signal by a weight.

Abstract: A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.

Abstract: A wireless communication apparatus includes a first storage unit configured to store each of a plurality of upper limit values of absolute values of additional signals that are set for a corresponding one of a plurality of first wireless communication apparatuses and are added when a plurality of modulation symbols to be transmitted to the first wireless communication apparatuses are precoded, a coding unit configured to decide each of a plurality of first values of the additional signals for a corresponding one of the first wireless communication apparatuses within ranges defined by the upper limit values, and precode the modulation symbols using the first values to obtain a plurality of transmission signals, and a first transmission unit configured to transmit, using multi-user MIMO (Multiple Input Multiple Output), the transmission signals to the first wireless communication apparatuses.

Abstract: In one embodiment, a wireless relay apparatus for replaying a signal processed by first encoding from a transmitting apparatus to a receiving apparatus is disclosed. The apparatus includes a demodulation unit, a decoding unit, a detection unit, an extraction unit, and an encoding unit. The demodulation unit demodulates a received signal. The decoding unit performs error correction decoding corresponding to the first encoding on the demodulated signal. The detection unit detects an error in a decoded signal. The extraction unit extracts a portion pertaining to information data from the demodulated signal by hard decision, if the detection unit detects an error. The encoding unit performs error correcting coding on the extracted portion pertaining to the information data with an error. The information data encoded by the encoding unit is transmitted.

Abstract: A wireless communication apparatus includes an M-number of (M is an integer of 2 or more) receiving portions connected to respective antennas, a frame analyzing section configured to analyze a reception signal received by the M-number of receiving portions, and a selecting section configured to select a receiving portion to be in service from the M-number of receiving portions. The selecting section selects a P-number of (P is an integer of from 0 to M) receiving portions from the M-number of receiving portions, based on an analysis result obtained by the frame analyzing section.

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.

Abstract: A radio communication apparatus includes: generation units generating first to mth signals; a storage storing allocation information defining that beams of different quality levels are allocated to first to mth communication apparatuses for each of first to nth subcarriers so that frequencies of respective quality levels are substantially uniform over all the subcarriers among the apparatuses; determining units determining transmission weights by which the signals are multiplied so that the beams according to the allocation information are formed for the apparatuses for each of the subcarriers; generation units performing multiplication processing by using the signals and the weights for each of the subcarriers to generate first to hth weighted signals for each of the subcarriers; transform units performing inverse Fourier transform on the weighted signals for each of the subcarriers to generate first to hth transformed signals; and transmission processing units transmitting the transformed signals via first

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.

Abstract: A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.

Abstract: According to one embodiment, a wireless communication apparatus includes a perturbation vector addition unit, a weight multiplication unit and a normalization coefficient multiplication unit. The perturbation vector addition unit is configured to add a perturbation vector only to a first data signal of a first transmission signal containing a first pilot signal and the first data signal, and obtain a second transmission signal containing a second pilot signal and a second data signal. The weight multiplication unit is configured to multiply each of the second pilot signal and the second data signal by a weight for removing interference on a reception side, and obtain a third transmission signal containing a third pilot signal and a third data signal. The normalization coefficient multiplication unit is configured to multiply each of the third pilot signal and the third data signal by a common normalization coefficient for normalizing a total transmission power.

Abstract: A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.

Abstract: A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.

Abstract: A receiver of an OFDM signal includes a reception unit to receive an OFDM signal formed by a plurality of OFDM symbols respectively including data subcarriers to which data signals are allocated and pilot subcarriers to which cyclically shifted pilot signals are allocated in frequency domain, an estimator to estimate phase errors of the pilot signals to generate first estimated values related to an offset of the OFDM symbol corresponding to each two or more OFDM symbols in the OFDM signal, a weighting adder to perform weighting additions on the first estimated values to obtain one second estimated value related to the offset, a compensator to compensate the offset by using the second estimated value to obtain a compensated OFDM signal, and a decoder to decode the compensated OFDM signal to reproduce the data signals.