Hitachi-kokusai Electric Inc.

Kokusai Electric Co., Ltd.

Koji Yotsumoto

Yoichi Kushioka

Mitsuhiro Takashima

Shunji Abe

Tetsuhiko Miyatani

Satoru Yasui

Takahito Ishii

Keiju Ito

Teppei Shoji

An antenna control device includes a weight unit in which weight values to be superimposed on transmission/reception signals are set for forming radiation patterns using a plurality of antennas and a weight synthesis unit that superposes the weight values on the transmission/reception signals. The antenna control device further includes an arrival direction detector that detects arrival directions of the reception signals, a distribution information calculator that calculates distribution information of the detected arrival directions, a signal quality calculator that calculates signal quality information of each of the radiation patterns, and a radiation pattern selector that selects a radiation pattern on the basis of the distribution information and signal quality information for the radiation patterns, and sets the weight values corresponding to the selected radiation pattern in the weight unit.

Autonomous radiation pattern generation antenna control device, control method therefor, and wireless communication system

A synchronization signal conversion device comprises a first communication device and a second communication device. The first communication device acquires, from the received GPS signals, time synchronization information synchronized to a GPS reference time, and wirelessly transmits the time synchronization information at a frequency different from that of the GPS signals. The second communication device receives the radio signals from the first communication device and acquires the time synchronization information, synchronizes internal time information to the GPS reference signal on the basis of the time synchronization information, and generates pseudo-GPS reception signals including satellite information and outputs the signal to a reception-side base station device such that the synchronized internal time information and pre-stored position information are acquired at the base station device.

Synchronization signal conversion device

To provide a device for radio communication using a plurality of antennas, in which: an amplitude/phase adjuster () and an amplitude/phase controller () control the amplitude and the phase of signals input from at least two antennas such that a directivity, allowing a desired signal to be obtained; an amplitude/phase adjuster () and an amplitude/phase controller () control the amplitude and the phase of the signals input from the antennas such that an arrival direction of the desired signal becomes a null point and that a directivity, allowing a signal other than the desired signal to be obtained; a signal synthesizer () combines the signals; a signal synthesizer () combines the signals; and a desired signal generator removes a signal from the signal synthesizer () from a signal from the signal synthesizer ().

Device for radio communication using a plurality of antennas

In a noise canceller device, interference signal adjustment units adjust delay, phase and amplitude of a signal received by a sub antenna under different conditions to obtain adjustment signals, and subtract the adjustment signals from a signal received by a main antenna to obtain differential signals. An average power calculation unit calculates an average power for each of the differential signals. An optimal condition search unit determines the values of delay, phase and amplitude that result in the minimum average power, and sets the values in an optimal interference signal adjustment unit. The optimal interference signal adjustment unit adjusts the signal received by the sub antenna using optimal values for delay, phase and amplitude to obtain an optimal adjustment signal. A cancellation unit subtracts the optimal adjustment signal from the signal received by the main antenna to remove interference signals, and outputs a desired signal to a host device.

Noise canceller device

A noise canceller device for removing interference signals from other systems and improving communication quality of a desired signal is provided. The noise canceller device comprises a first calculation unit performing cross-correlation processing on interference signals received by sub-antennas, a first peak detection unit detecting peaks of the interference signals, a first information acquisition unit acquiring first interference signal information, a composition unit composing the interference signals, a second calculation unit performing correlation processing between a signal received by a main antenna and the composed interference signal, a second peak detection unit detecting a peak of the composed interference signal, a second information acquisition unit acquiring second interference signal information, an interference signal replica generation unit generating an interference signal replica, and a removal unit subtracting the interference signal replica from the received signal by the main-antenna.

In a receiver to process a received signal including one or more carrier signals, an FFT processing section executes FFT processing on the received signal to obtain FFT processing results at, for example, four points. On the basis of the FFT processing results from the FFT processing section, a selecting section selects one point from a plurality of, e.g., four points. An FFT processing result corresponding to the point selected by the selecting section is used for demodulation processing.

Receiver

A transmitter capable of suppressing a peak of a transmission signal includes a frequency domain acquisition unit for obtaining a frequency domain signal from the signal for transmission; and a level control unit for controlling a level of the frequency domain signal obtained by the frequency domain acquisition unit to suppress a peak in a time domain transmission signal. Further, the transmitter includes a time domain conversion unit for converting the frequency domain signal into the time domain transmission signal whose level has been controlled by the level control unit; and a transmission unit for transmitting the time domain transmission signal.

Transmitter capable of suppressing peak of transmission signal

The uplink signal circuitry of the base station device includes an authenticating unit, an access right setup unit, and a changeover switch for changeover between the setup of the access right and the authentication process. When a user performs the operation of setting up the right to access to the base station device, the changeover switch is flipped to select the access right setup unit. The access right setup unit executes authentication process on the basis of the IMSI (code unique to user terminal) sent from the user terminal. If the result of authentication is successful, the IMSI of the user terminal is registered in the authentication memory. Thereafter, the changeover switch is flipped to select the authenticating unit to authenticate the user terminal on the basis of the IMSI of the user terminal registered in the authentication memory. The authenticated user terminal is then connected with an upper device.

Base station device for setting up the access rights for user terminals in response to user actuation of switches or buttons

In a communication device for receiving signals from devices that become communication partners, received signals from the respective devices are identified. Each of the devices that become communication partners is provided with a frequency spectrum of a pattern specific to each of the devices. The communication device stores correspondence between information identifying the devices that become communication partners and the frequency spectrums provided to the respective devices, acquires a frequency spectrum contained in a received signal, compares the frequency spectrum acquired with the frequency spectrums stored to identify a device corresponding to the frequency spectrum that coincides with the frequency spectrum acquired and which is stored.

Communication device

A correlation detection apparatus which realizes software CDMA inverse-spread processing. A reception circuit receives an RACH preamble from a mobile station, and an A/D converts the preamble into digital received data. An FFT unit FFT-processes the received data to obtain an FFT result. An RACH code storage unit holds an RACH preamble code, and another FFT unit FFT-processes the RACH preamble code to obtain another FFT result. A multiplication unit multiples the FFT result by the other FFT result. An IFFT unit IFFT-processes a result of multiplication input from the multiplication unit to obtain a delay profile. A data decoding unit decodes the received data by using the delay profile, and obtains decoded data.

Correlation detection apparatus and fourier transform apparatus

Disclosed is a W-CDMA wireless base station adapted to meet various specifications over a wide range to dynamically change the allocated numbers of RACH's and DPCH's depending on a cell radius and the number of Signatures. The W-CDMA wireless base station that performs an optimal channel allocation based on parameters received from an external network, comprises: a preamble detection and path search section adapted to perform an RACH preamble detection in a reception base band signal or perform a path search of the reception base band signal; demodulation section adapted to demodulate the reception base band signal by including therein a plurality of fingers and combining outputs of the fingers; a control section adapted to control said preamble detection and path search section to switch itself either to a preamble detection section or to a path search section so as to change the allocated numbers of RACH's and DPCH's based on the parameters.

CDMA wireless base station

A method and system are provided for recognizing a path having low level signals, which is conventionally treated as useless, as a valid receiving path. Recognition is made from a plurality of receiving paths in a CDMA wireless telecommunication system by receiving at least one set of signals through a transmission path, generating at least two spread codes each with its own delay time, and calculating at least two correlation values of the set of signals with the spread codes. A CDMA wireless telecommunication mobile station is also provided for receiving a set of telecommunication signals through a telecommunication path from a base station. At least two spread codes are generated, each with its own delay time and a predetermined number of spread code bits. At least two correlation values of the set of signals are calculated with the spread codes.

Method and apparatus for recognizing a receiving path in a CDMA system

A receiver detects a highly precise approximate value of the power of a reception signal with a high speed. A first comparator outputs a larger of a component I and component Q of a reception signal as a first output value and a smaller as a second output value. A 3-bit shift register multiplies the first output value by &#x215b;, a subtractor subtracts the by-&#x215b;-multiplied value from the first output value, and a 1-bit shift register multiplies the second output value by &#xbd;. A 2-bit shift register multiplies the by-&#xbd;-multiplied value by &#xbc;, a first adder adds the first output value and the by-&#xbc;-multiplied value, and a second adder adds an output value from the subtractor and an output value from the 1-bit shift register. A second comparator outputs the value of a larger result of the two additions as an approximate power of the reception signal.

A CDMA mobile station apparatus receives a spread control signal including a non-orthogonal spread signal generated using a non-orthogonal spreading code which is non-orthogonal with a data signal spreading code and a spread data signal produced by spreading a data signal with a data signal spreading code from a base station apparatus via a radio link. The mobile station apparatus has a non-orthogonal spread signal generating unit for generating a non-orthogonal spread signal whose phase rotation caused by a radio transmission path is compensated for using a non-orthogonal spreading code, a subtracting unit for subtracting the generated non-orthogonal spread signal from the received signal to generate a difference signal, and a data signal demodulating unit for demodulating the difference signal into a data signal. The mobile station apparatus is capable of canceling an entire spread broadcasting signal, processing a band-limited signal, or processing a spreading code with a suppression coefficient.

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Tokyo, Japan

Koji Yotsumoto