Sanyo Electric Co., Ltd.

Kyocera Corporation

Hokkaido University

Sanyo Telecommunications Co., Ltd.

Masashi Iwami

Yoshiharu Doi

Takeo Miyata

Jun Kitakado

Tadayoshi Ito

Yasutaka Ogawa

Takeo Ohgane

Toshihiko Nishimura

Seigo Nakao

Toshinori Iinuma

Tetsuo Okamoto

Katsutoshi Kawai

Maimi Monzen

Tadayoshi Itou

Takeshi Tokairin

Takashi Ozeki

Hirotaka Koike

In a base station, a downlink radio resource and an uplink radio resource to be used for transmission of a known signal from a communication terminal are associated for null steering to be performed based on the known signal. A correction value calculating unit calculates a first correction value used to correct a downlink quality value obtained by a communication terminal. The correction value calculating unit calculates a second correction value used to correct a downlink quality value obtained by a communication terminal.

Base station and method of calculating correction value

A communication section controls the transmission directivity of a plurality of antennas, based on a known signal transmitted from a communication terminal. A radio resource allocating section allocates a downlink radio resource and allocates an uplink radio resource. A grouping processing section for classifying classifies a plurality of communication terminals with which the communication section communicates into a first terminal group executing an application with high communication quality of transfer data and a second terminal group executing an application with low communication quality of transfer data. A unit period is determined in which an uplink radio resource for a known signal usable for the transmission of the known signal by a communication terminal and a downlink radio resource appear. A correspondence between the downlink radio resource and the uplink radio resource for the known signal is defined for null steering based on the known signal in the unit period.

Base station and communication control method

An FFT processing unit performs an FFT process on an OFDM signal received by a reception unit. Based on an output signal of the FFT processing unit, an interference wave level acquisition unit obtains a signal level of an interference wave in a unit radio resource not used by the base station with respect to each of a plurality of candidate timings for the reference timing in the base station. A reference timing adjustment unit determines a new timing of the reference timing from the plurality of candidate timings based on the signal level of the interference wave obtained by the interference wave level acquisition unit.

Base station and method of adjusting reference timing on base station

A base station apparatus switches between a communication mode for performing communication with a communication party and a calibration mode for performing a calibration process. In the calibration mode, a weight vector in accordance with a first algorithm for performing a null steering directivity control for orienting an area of drastically-lowered antenna gain in the direction of arrival of a reception signal. Furthermore, multiple transmission signals weighted by the acquired weight vector are output, and a correction value for readjusting the result of the null steering directivity control is acquired from a control PC. In the communication mode, multiple transmission signals are corrected by using the correction value acquired in a calibration mode, and the corrected signals are output.

Wireless apparatus for measuring a received wireless signal and measurement system using the wireless apparatus

An RSSI detection unit detects a level of a received signal. An error detection unit performs error detection of the received signal. An error correction control unit causes an error correction unit to perform error correction of the received signal only when the error detection unit detects an error and the level of the received signal detected by the RSSI detection unit is not lower than a predetermined value.

Radio communication apparatus suppressing correction error while maintaining communication quality, and method and program for error correction

An AA communication method using an AA communication device including a plurality of AA communication units includes: receiving a signal transmitted from a receiving terminal in each AA communication unit of UN-A and UN-BF, and measuring a receive level of the signal transmitted from the receiving terminal for each communication unit; calculating a transmit weight vector based on received signals corresponding to the signal transmitted from the receiving terminal for each AA communication unit; calculating a received power based on a measured value of the receive level and the transmit weight vector for each AA communication unit; comparing the received powers of the AA communication units, and, to match the received powers to the received power of the unit having a lowest received power, making a downward correction of an amplitude of the transmit weight vector for each of the other communication units; and transmitting a signal using the transmit weight vector after the correction by each communication unit.

Wireless communication method and wireless communication device

A measuring unit inputs a detection received signal and measures a received RSSI value as the detection received signal. A first comparator inputs a plurality of received RSSI values measured by the measuring unit and compares them with a predetermined threshold value. A signal difference deriving unit derives a relative relationship among the plurality of RSSI values. A second comparator compares the relative relationship with a predetermined value. If the first comparator and the second comparator detect any malfunction, a decision unit receives notification accordingly from the first comparator and the second comparator and finally judges the malfunction of communication functions associated therewith.

Malfunction detection method and base station apparatus utilizing the same

A slot of a low multiplicity is processed to narrow transmission timing intervals for already-connected users and thereby to make preparation for a new user, and a slot of a high multiplicity is processed to keep the maximum transmission timing intervals for the already-connected users so that the preparation for the new user is not performed. As a result, it is possible to provide the slot prepared for the new user while maximizing the transmission timing intervals. Further, the transmission timing intervals for the already-connected users are kept as large as possible during the traffic channel for preventing the deterioration of characteristics, and the shifting of the transmission timing is performed for the new user during the control channel so that the optimum transmission timing intervals can be achieved when the traffic channel is established. A DSP () executes the processing.

Radio base system and transmission timing control method

When once determined to be free of any demodulation error by an interference removing unit provided user by user, a replica signal calculated by the interference removing unit is subtracted from an input signal vector, and a calculated user signal is output as it is as a final user signal. When it is determined by the interference removing unit that there is a demodulation error, the user signal is again calculated by the interference removing unit of an interference canceller of a next stage. As subtraction of the replica signal corresponding to the user signal having a demodulation error from the input signal vector is inhibited, precision of the interference wave removal can be improved.

Radio reception system

An adaptive array apparatus () that has a weight converge on an optimal value is provided. The adaptive array apparatus repeatedly adjusts the weight using predetermined calculations so as to minimize a difference between a desired signal and a combined signal which has been weighted with the weight. A parameter control unit () judges whether an adjusted weight is located closer to an optimal value than a reference value, and according to the judgment result, changes a step size which is used in the predetermined calculations performed by a reception weight calculating unit (), to determine the extent to which the weight should be adjusted. With this construction, the adaptive array apparatus can increase convergence stability and speed in calculating a weight, and the weight converges on an optimal value.

Adaptive array device, adaptive array method and program

In an adaptive array (), fading rate of a user is measured by a fading rate measuring circuit (), and the transmit weight vector is weighted in accordance with the fading rate by a transmitting circuit (). Thus, transmission power is increased for a user of which fading rate is large, and thus transmission directivity control for such a user becomes possible.

Radio device with transmission directivity, and control method and control program for the radio device

A spatial multiplex base station () estimates an optimal array parameter appropriate to a propagation environment of a received signal and changes the array parameter in an adaptive manner. The optimal value is estimated by referring to a table prepared in advance, by searching for the optimal value while executing an array process multiple times using different parameters, or by searching for the optimal value from the results of the previous frames. Consequently, a weight estimation sequential algorithm is executed based on the estimated array parameter. This enables realization of optimal signal reception in a radio receiving device, regardless of the propagation environment.

Radio receiving device, array parameter optimal value estimation method, and array parameter optimal value estimation program

Radio receiving system

For each of a plurality of users having multiple connection to a specific time slot a synchronization window of a predetermined temporal length having a center corresponding to a synchronization position is set to disallow a subsequent signal reception outside the widow. Furthermore timings of transmission for users are controlled to prevent synchronization windows from overlapping or being too distant from each other in the time slot. Thus, synchronization positions can be prevented from approaching each other or having an inverted time relationship therebetween. This process is provided by a DSP in software.

Radio base station system permitting path division multiple connection, and synchronization window control method and synchronization window control program therefor

A first reception circuit (SR) separates a signal from a desired terminal among signals from an adaptive array antenna (#to #), based on a reception weight vector calculated in a reception weight vector calculator (). A remodulation circuit () generates a first replica signal from a signal of a demodulated desired wave. A replica generating circuit () multiplies signals from a plurality of antennas by a weight vector for an interfering wave from a second reception circuit (SR), and generates a second replica signal corresponding to a signal from an interfering wave terminal. A reception response vector calculator () derives an impulse response of a propagation path of the signal from the desired terminal, based on the first and second replica signals.

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Gifu, Japan

Masashi Iwami