Abstract: A remote node capable of reducing the effect of an increase in a processing time that occurs when a C-RAN structure is applied and efficiently performing scheduling of radio resources is provided. A remote node 10 according to the present disclosure includes a scheduler 11 configured to perform scheduling for a first radio resource among radio resources available for radio communication, the first radio resource being a radio resource designated in advance by a center node 20, and a communication unit 12 configured to perform radio communication with a communication terminal 30 by using the first radio resource or a second radio resource among the radio resources available for radio communication, the second radio resource being a radio resource for which scheduling has been performed by the center node 20.

Abstract: A remote node capable of reducing the effect of an increase in a processing time that occurs when a C-RAN structure is applied and efficiently performing scheduling of radio resources is provided. A remote node 10 according to the present disclosure includes a scheduler 11 configured to perform scheduling for a first radio resource among radio resources available for radio communication, the first radio resource being a radio resource designated in advance by a center node 20, and a communication unit 12 configured to perform radio communication with a communication terminal 30 by using the first radio resource or a second radio resource among the radio resources available for radio communication, the second radio resource being a radio resource for which scheduling has been performed by the center node 20.

Abstract: Transmission channel estimation is performed for NT×NR reception signals and estimated transmission channel values are thereby output. The estimated transmission channel values are divided into N groups of NT×M estimated transmission channel values and a covariance matrix with M rows and N columns is obtained for each of the estimated transmission channel value groups. The N covariance matrixes are averaged over a predetermined range in terms of at least a time or a frequency (first averaging). Eigenvectors are generated based on respective N averaging outputs. Transmission channels between base station antennas and terminal antennas are generated from the eigenvectors and the estimated transmission channel values. Covariance matrixes are obtained for the generated transmission channels. The covariance matrixes are averaged over a different range from the range used in the first averaging (second averaging) and a beam forming weight is obtained by combining the generated eigenvectors.

Abstract: Described herein is a multi-antenna signal receiving device that includes a plurality of reception antennas that is capable of maximizing a diversity gain while eliminating a multi-path interference (MPI). The device receives a first received signal of a first antenna that includes components corresponding to a plurality of first paths and the device receives a second received signal of a second antenna that includes components corresponding to a plurality of second paths. The multi-antenna signal receiving device detects a component corresponding to a first path among the plurality of first paths, and a component corresponding to a second path among the plurality of second paths.

Abstract: Transmission channel estimation is performed for NT×NR reception signals and estimated transmission channel values are thereby output. The estimated transmission channel values are divided into N groups of NT×M estimated transmission channel values and a covariance matrix with M rows and N columns is obtained for each of the estimated transmission channel value groups. The N covariance matrixes are averaged over a predetermined range in terms of at least a time or a frequency (first averaging). Eigenvectors are generated based on respective N averaging outputs. Transmission channels between base station antennas and terminal antennas are generated from the eigenvectors and the estimated transmission channel values. Covariance matrixes are obtained for the generated transmission channels. The covariance matrixes are averaged over a different range from the range used in the first averaging (second averaging) and a beam forming weight is obtained by combining the generated eigenvectors.

Abstract: A cooperative communication system and method is provided. A cooperative communication relay station includes a signal receiving unit which receives a source signal from a source node and a multiple relaying signal relayed by a neighboring relay station, a signal generation unit which generates a first relay signal and a second relay signal, the first relay signal being generated by performing a decode-and forward scheme with respect to the multiple relaying signal and the second relay signal being generated by performing an amplify-and-forward scheme with respect to the source signal, and a signal transmission unit which transmits the first relay signal and the second relay signal to a destination node.

Abstract: A wireless communication device and method are capable of detecting a receive timing of a direct wave at higher precision without increasing transmit power. A signal receiver receives a signal having a center frequency changed in a predetermined rule at predetermined time intervals. A time-frequency transformer transforms the received signal from a time domain to a frequency domain. A filter removes frequency-domain signal components unused during reception, based on the predetermined rule, from the frequency-domain signal. A reverse modulator performs a reverse modulation process on the remaining signal components. A signal adder generates an added signal by performing accumulative addition on the signal components that underwent the reverse modulation process in the reverse modulator for a predetermined period. A direct wave arrival time determiner determines an arrival time of a direct wave according to an impulse response obtainable from an output of the frequency-time transformer.

Abstract: Provided are a multiple antenna receiver and a method of receiving a signal. A multiple antenna receiver includes a plurality of antennas to receive a plurality of received symbols, a QR decomposition unit to perform QR decomposition for a channel matrix, a Q-received symbol generator to generate Q-received symbols corresponding to the plurality of antennas, a subtractor to remove a component corresponding to at least one neighbor symbol from a target received symbol corresponding to one of the Q-received symbols, an adder to add a signal component to the target received symbol, a first FDE to perform frequency domain equalization for an output of the subtractor, and a second FDE to perform frequency domain equalization for an output of the adder.

Abstract: A wireless communication device and method are capable of detecting a receive timing of a direct wave at higher precision without increasing transmit power. A signal receiver receives a signal having a center frequency changed in a predetermined rule at predetermined time intervals. A time-frequency transformer transforms the received signal from a time domain to a frequency domain. A filter removes frequency-domain signal components unused during reception, based on the predetermined rule, from the frequency-domain signal. A reverse modulator performs a reverse modulation process on the remaining signal components. A signal adder generates an added signal by performing accumulative addition on the signal components that underwent the reverse modulation process in the reverse modulator for a predetermined period. A direct wave arrival time determiner determines an arrival time of a direct wave according to an impulse response obtainable from an output of the frequency-time transformer.

Abstract: Described herein is a multi-antenna signal receiving device that includes a plurality of reception antennas that is capable of maximizing a diversity gain while eliminating a multi-path interference (MPI). The device receives a first received signal of a first antenna that includes components corresponding to a plurality of first paths and the device receives a second received signal of a second antenna that includes components corresponding to a plurality of second paths. The multi-antenna signal receiving device detects a component corresponding to a first path among the plurality of first paths, and a component corresponding to a second path among the plurality of second paths.

Abstract: The invention provides a spectrum analyzing method, a distortion detector and a distortion compensation amplifying device for performing time/frequency conversion processing at high speed, and reducing a convergent time of a compensation coefficient. The distortion detector for detecting distortion in a frequency area with respect to an input signal includes a time window processing section for multiplying the input signal by a time window; an averaging processing section for averaging an output of the time window processing section; an FFT processing section for converting an output of the averaging processing section from a time area to a frequency area; and a distortion extracting section for extracting a distortion component from an output of the FFT processing section.

Abstract: A cooperative communication system and method is provided. A cooperative communication relay station includes a signal receiving unit which receives a source signal from a source node and a multiple relaying signal relayed by a neighboring relay station, a signal generation unit which generates a first relay signal and a second relay signal, the first relay signal being generated by performing a decode-and forward scheme with respect to the multiple relaying signal and the second relay signal being generated by performing an amplify-and-forward scheme with respect to the source signal, and a signal transmission unit which transmits the first relay signal and the second relay signal to a destination node.

Abstract: A multicarrier receiver that receives N carrier frequencies therein comprises N A/D converters each of which analog-digital converts a receive signal at a sample rate fs for each carrier, N quadrature detectors which receive outputs sent from the N A/D converters therein and digitally quadrature-detect the outputs, respectively, 2N LPFs which allow only desire bands of outputs of the N quadrature detectors to pass therethrough, and N delay time correcting means each of which corrects a processing delay time deviation for each carrier inside the multicarrier receiver in a time unit of less than 1/fs using a fractional delay filter. The delay time correcting means has, for example, an M-stage shift register which operates at fs and generates a delay of M/fs, and a fractional delay filter which operates at fs and includes an even number of tap coefficients and which generates a delay different from M/fs by 0.5/fs.

Abstract: Provided are a multiple antenna receiver and a method of receiving a signal. A multiple antenna receiver includes a plurality of antennas to receive a plurality of received symbols, a QR decomposition unit to perform QR decomposition for a channel matrix, a Q-received symbol generator to generate Q-received symbols corresponding to the plurality of antennas, a subtractor to remove a component corresponding to at least one neighbor symbol from a target received symbol corresponding to one of the Q-received symbols, an adder to add a signal component to the target received symbol, a first FDE to perform frequency domain equalization for an output of the subtractor, and a second FDE to perform frequency domain equalization for an output of the adder.

Abstract: A transmitter, that effectively suppresses a peak level of transmit signals, equipped with a peak reduction signal generating means that generates a peak reduction signal. A level of the peak reduction signal is based on a transmit signal level threshold for determining a peak of the transmit signal, and is based on a transmit signal peak level. Further, a phase of the peak reduction signal is based on the phase of the transmit signal. The transmitter is also equipped with a peak reduction signal processing means that subjects the peak reduction signal to band restriction and orthogonal modulation, and is equipped with a transmit signal level suppressing means that subtracts the peak reduction signal subjected to band restriction and orthogonal modulation from the transmit signal.

Abstract: A transmitter for averagedly suppressing the variation in input level of an amplifier according to variation in carrier level. The transmitter includes an input power calculation section for calculating mean input power of each carrier, an output power calculating section for calculating mean output power of each carrier after the carrier band is limited, a monitoring section for identifying a carrier having the maximum mean input power, acquiring the maximum value, acquiring the mean output power of the identified carrier, determining the ratio of the mean input power to the mean output power, and calculating level control information which is the ratio of the ratio determined above to a predetermined expected value, and a signal level adjusting section for adjusting the level of a multicarrier signal by multiplying the level control information outputted from the monitoring section.

Abstract: The present invention provides a transmitting apparatus equipped with a modulator, a frequency converter that up-converts a modulated signal (or digital IF signal) of a baseband, and an amplifier that amplifies a transmit signal lying in a radio frequency band to a desired signal level. In the transmitting apparatus, a controller including a level determinater and a bias setter is provided with a limiter setter. The level determinater and bias setter of the controller setter perform dynamic bias control of the amplifier. Further, the limiter setter changes the setting of a threshold value of the limiter according to an average level of an input signal.

Abstract: The invention provides a spectrum analyzing method, a distortion detector and a distortion compensation amplifying device for performing time/frequency conversion processing at high speed, and reducing a convergent time of a compensation coefficient. The distortion detector for detecting distortion in a frequency area with respect to an input signal includes a time window processing section for multiplying the input signal by a time window; an averaging processing section for averaging an output of the time window processing section; an FFT processing section 52 for converting an output of the averaging processing section from a time area to a frequency area; and a distortion extracting section 53 for extracting a distortion component from an output of the FFT processing section 52.

Abstract: A memory effect distortion component compensating unit compensates for a distortion component caused by a memory effect of an amplifier by using a time difference of results from raising an input signal to even power.

Abstract: A transmitter for averagedly suppressing the variation in input level of an amplifier according to variation in carrier level. The transmitter comprises an input power calculation section (16) for calculating mean input power of each carrier, an output power calculating section (17) for calculating mean output power of each carrier after the carrier band is limited, a monitoring section (18) for identifying a carrier having the maximum mean input power, acquiring the maximum value, acquiring the mean output power of the identified carrier, determining the ratio of the mean input power to the mean output power, and calculating level control information which is the ratio of the ratio determined above to a predetermined expected value, and a signal level adjusting section (15) for adjusting the level of a multicarrier signal by multiplying the level control information outputted from the monitoring section (18).