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: 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: 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: A radio apparatus includes a first receiver that is a processing unit for amplifying and frequency converting a radio signal received via an antenna, thereby outputting an IF signal; a detector unit for detecting a preamble signal from the IF signal; a second receiver for amplifying and quadrature demodulating the radio signal, thereby generating an I-signal and a Q-signal; a demodulator unit for demodulating the I-signal and Q-signal to generate a data signal; and a control unit for halting the operation of the first receiver and further activating the second receiver when the detector unit detects the preamble signal and for activating the first receiver and halting the operation of the second receiver when the demodulator unit completes the demodulation of the I-signal and Q-signal.

Abstract: A radio apparatus includes an antenna; an amplifier that amplifies a radio signal, received via the antenna; a first mixer that frequency converts the amplified radio signal to generate a first analog signal; a first A/D converter that converts the first analog signal to generate a first digital signal; a second mixer that frequency converts the amplified signal to generate a second analog signal; a second A/D converter means that converts the second analog signal to generate a second digital signal; a demodulator means that demodulates the first and second digital signals to generate a demodulated signal; a detector that detects a preamble from the first digital signal; and a control means that halts the second mixer and second A/D converter during the wait for the radio signal and that activates the second mixer and second A/D converter when the detector detects the preamble.

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 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: 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 serial transmission device includes a transmitting unit that transmits data, a receiving unit that receives the data, and a plurality of serial transmission paths that connect the transmitting unit with the receiving unit and are used to transmit data. The receiving unit includes an inter-lane skew information generation unit that generates inter-lane skew information about skew of each of the serial transmission paths and transmits the generated inter-lane skew information to the transmitting unit. The transmitting unit includes a data conversion rule generation unit that generates a conversion rule used to determine distribution of the data to each of the serial transmission paths based on the inter-lane skew information.

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 generates transmission signal including first and second pilot signal sequences allocated to first and second frequencies symmetrically located in relation to a center frequency, and third and fourth pilot signal sequences allocated to third and fourth frequencies symmetrically located in relation to the center frequency, quadrature-modulates the transmission signal, to obtain a quadrature modulation signal, quadrature-demodulates the quadrature modulation signal, to obtain a reception signal, extracts first to fourth pilot signal sequences from the reception signal, estimates a first transfer characteristic concerning first and second frequency by using first and second pilot signal sequences, estimates a second transfer characteristic concerning third and fourth frequencies using third and the fourth pilot signal sequences, generates a third transfer characteristic from which an influence of transmission IQ imbalance is removed by using first and second transfer characteri

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.