Hitachi-kokusai Electric Inc.

Kokusai Electric Co., Ltd.

Nec Corporation

Kokusai Electric Corporation

Yozan Corporation

Tetsuhiko Miyatani

Naoki Hongo

Yoichi Okubo

Kenzo Urabe

Masaki Suto

Shunji Abe

Ichiro Imaizumi

Norio Hasegawa

Jun Watanabe

Toshio Takada

Hisashi Kawai

Yoshihiko Akaiwa

Masato Horaguchi

Hitoshi Kato

Osamu Sato

Guoliang Shou

Toshifumi Sato

Takashi Okazaki

Takashi Okada

Changming Zhou

Masashi Naito

Koji Yotsumoto

Kazuyoshi Sato

Kiyoshi Funada

Yasuo Sera

Kouya Hoshina

Teppei Shoji

Masami Yoshida

Takahiro Todate

Zhou Changming

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 nodeaccording to the present disclosure includes a schedulerconfigured 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, and a communication unitconfigured to perform radio communication with a communication terminalby 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

Remote node, center node, communication system, communication terminal, and communication method

Transmission channel estimation is performed for NT&#xd7;NR reception signals and estimated transmission channel values are thereby output. The estimated transmission channel values are divided into N groups of NT&#xd7;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.

Information processing apparatus and information processing method, and non-transitory computer readable medium storing information processing program

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.

Spectrum analyzing method, distortion detector and distortion compensation amplifying device

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.

Multicarrier receiver and transmitter with delay correcting function

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.

Transmitter

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.

Transmitter for suppressing a variation in input level of a multicarrier signal

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.

Transmitting apparatus

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. For example, the amplifier may include a memory effect distortion component compensating unit having an even power raising unit for raising an input signal to even power, an even power raising result delaying unit for delaying a signal of a result of even power raising, an even power raising result time difference detecting unit for detecting a difference between a signal of an even power raising result and a delayed signal, an input signal multiplying unit for multiplying a signal of a detection result by an input signal, a distortion compensation coefficient multiplying unit for multiplying a signal of a multiplication result by a distortion compensation coefficient, and a distortion compensation coefficient multiplication result adding unit for adding an input signal and a signal of a multiplication result.

Distortion-compensated amplifier using predistortion technique

A cell search determination circuit is provided which is capable of reducing misdetections in the identification of a scramble code number. A mobile station in W-CDMA cellular communications confirms a scramble code identified by cell search. The cell search determination circuit includes a first fingerfor performing correlation operation of the scramble code and a receiving signal, a second fingerfor performing correlation operation of a first synchronous channel code and the receiving signal, an averagerfor generating a phase vector in which noise components of an output from the first fingerare suppressed, a first power adder for determining and integrating a power of the first finger, a second power adder for determining and integrating a power of the second finger, a first threshold determinerfor outputting a threshold value corresponding to an output from the first power adder, and a comparatorfor performing a threshold determination of an output from the second power addition means using the threshold value.

Cell search determination circuit

A telecommunications device is provided that enables monitoring of the directivity of a wireless communications system that wirelessly transmits signals using multiple communications antennas while controlling the overall directivity of the multiple antennas. At least one monitor antenna, installed separately from multiple communications antennas controlled to achieve a prescribed overall directivity, wirelessly receives signals from the multiple communications antennas. A directivity information acquisition mechanism uses the signals received by the monitor antenna to acquire information regarding the overall directivity of the multiple communications antennas. The directivity information acquired by the directivity information output mechanism is output to an external achieved directivity accuracy monitoring mechanism, and the achieved directivity accuracy monitoring mechanism monitors the accuracy of achieved overall directivity of the multiple communications antennas based on a difference between the directivity information and directivity information predicted to be acquired when a prescribed directivity is achieved.

Telecommunications device

A receiver that uses multiple antennas to receive signals arriving over multiple paths and is configured for enhanced received signal path detection accuracy and improved reception quality includes a receive weight generating circuit that generates receive weights for every antenna based on signals received from the antennas, a summing circuit that calculates sums of results obtained by multiplying the signals from the antennas and the receive weights of the individual antennas generated by the receive weight generating circuit and path detection circuit that detects the paths of the received signals based on the sums calculated by the summing circuit.

Receiver

To provide an amplifying device which is reduced in size, weight and cost and which can improve the distortion compensation performance. In the amplifying device, input signals are each subjected to digital orthogonal modulation using an IF and further to offset rotation processing in digital orthogonal modulators, then bifurcated into a main signal system and a control system, and detection of a power value is performed at an IF band in a power detecting section of the control system. Therefore, offset rotation processing of the input signals in the power detection is not required, so that a structure for matching phases of a multi-carrier signal and a power value signal is not required, resulting in improving the distortion compensation performance without using an analog delay line.

Amplifying device

A communication device for transmitting and/or receiving signals by using a communication antenna includes signal characteristic information detection means for detecting information regarding signal characteristics of a calibration signal which are contained in a signal received by the communication antenna, calibration means for calibrating a communication antenna chain based on the detected signal characteristic information, and cancellation signal generating means for generating a cancellation signal corresponding to a calibration signal contained in the signal received by the communication antenna based on the calibration signal. The device also includes signal cancellation-by-subtraction means for subtracting the generated cancellation signal from the signal received by the communication antenna, and receive signal processing means for processing the received signal that is diminished by the cancellation signal.

Communication device

A peak limiter for use in a system for amplifying a multi-carrier signal receives a baseband signal of each carrier of the multi-carrier signal. The multi-carrier signal is computationally estimated to have carriers combined in an RF band, and obtains power information of the multi-carrier signal to limit an amplitude of the baseband signal based on the power information of the estimated multi-carrier signal to thereby provide peak-limited baseband signals. Thus, the distortion generated by performing the unnecessary peak limitation can be effectively prevented to thereby improve the reliability of the entire system.

Peak limiter and multi-carrier amplification apparatus

To provide an amplifying device with reduced size, weight and cost. The amplifying device delays input signals using digital delay sections in a main signal system, performs offset rotation processing of digital input signals in carrier offset sections and power detection in a power detecting section in a control system, matches phases of a multi-carrier signal of the main signal system and a power value signal of the control system in a phase control section, and gives distortion compensation in a predistorter for canceling a nonlinear characteristic generated in an amplifier.

Growing community of inventors

Tokyo, Japan

Tetsuhiko Miyatani