Nec Corporation

Oval Corporation

Kenichi Takai

Naoki Matsubara

Kohji Takahashi

Jun Tanimoto

Shuuzou Yanagi

Kyouji Watanabe

Shinji Oda

Shinsuke Imai

A mobile communication system in which a number of common channels are added due to the offering of a new service includes: the assumption that a plurality of common channels can be arranged to transmit the same data, a monitor means that uses the reception path search results of either dedicated channels or random access channels of mobile stations to monitor the communication state of mobile stations within the cell and a control means that, when it is determined that distribution within the cell of mobile stations that receive the new service is unbalanced, effects control to divide and use the communication range permitted by a plurality of common channels.

Mobile communication system, common channel transmission control device, and common channel transmission control method used in the system and device

A mobile communication system including base stations, wherein each base station includes: a report unit which exchanges a current target value of communication quality for a mobile station with other base stations; a comparison unit which compares a current target value of a current station with target values of the other base stations; and a management unit which changes the current target value based on the comparison result of the comparison unit.

Mobile communication system, base station, transmission power control method, and program

A multi-vortex flowmeter includes a vortex type detection device including a measurement tube provided in a flow channel to allow a fluid to be measured to pass, a vortex generator provided in the measurement tube to face a flow of the fluid to be measured, and a vortex detector for detecting a change based on a Karman vortex generated by the vortex generator. The flowmeter also includes a thermal type detection device including a temperature sensor and a heating temperature sensor, each protruding into the flow channel, and a flow rate converter, in which a pressure gauge for measuring a pressure in a pipe wired together with the vortex detector and the thermal detection device is provided integrally with the flow rate converter.

Multi-vortex flowmeter integrating pressure gauge

A communication bit rate computing unit () computes the cumulative bit rate of downlink communication data, at which a base station communicates with a terminal, and totalizes the bit rates for each sector area. A amplitude/phase control unit () checks whether the cumulative bit rate for each sector area, reported from the communication bit rate computing unit (), is higher than a first threshold or lower than a second threshold. If the cumulative bit rate is higher than the first threshold, the amplitude/phase control unit () performs directing characteristic control so as to narrow the area range of the corresponding sector area to a range smaller than a standard area range. If the cumulative bit rate is lower than the second threshold, the amplitude/phase control unit () performs directing characteristic control so as to widen the area range of the corresponding sector area to a range larger than the standard area range.

Radio communication system, base station apparatus, and downlink transmission directing characteristic method used therefor

An adaptive antenna directivity control method and a system therefor is capable of reducing interference in an up-link and/or a down-link upon initiation of handoff to improve communication quality upon initiation of handoff to speed-up directivity control resulting in increasing of channel capacity. In the adaptive antenna directivity control method, a mobile station and base station to be connected with the mobile station in radio through an up-link and a down-link are governed by a supervisory station. Respective transmission signal or reception signal of a plurality of antenna elements of the base station are varied in amplitude and phase for combining in a particular orientation for establishing a directivity by a radiation pattern by combining. The method includes step of initiating soft handoff in the mobile station, step of obtaining an installation position information from a first base station which is connected before handoff and directivity information of an up-link of the first base station relative to the mobile station, step of predicting an orientation of the mobile station from own station by a second base station to be connected by handoff on the basis of the directivity information of the up-link, and step of determining an initial directivity control parameter of the up-link corresponding to obtained orientation of the mobile station.

Adaptive antenna directivity control method and system therefor

In an adaptive antenna device having directivity pattern generators operable in accordance with different algorithms, respectively, in a baseband modem, beam steering processing, null steering processing, and estimating processing of an arrival direction are executed in parallel to one another. Parameters resulting from the beam and the null steering processing are controlled by processing results of the estimating processing and are weighted and combined to individually generate directivity patterns based on the different algorithms.

Adaptive antenna device operable in accordance with different algorithms

Circuitry for controlling the directivity of an adaptive antenna including a plurality of antenna elements and forming the directivity by varying signals fed to the antenna elements such that a gain in a preselected direction increases is disclosed. The circuitry includes a transmitting section for transmitting a scanning pilot channel for scanning on a downlink while causing the pilot channel to move in a propagation range covered by the adaptive antenna. A receiving section receives a signal representative of the intensity of the scanning pilot channel received by a mobile station. A controller detects a transmission direction in which the mobile station receives the scanning pilot channel with the highest quality, and applies the directivity parameter of the detected direction to the directivity of a downlink. The circuitry improves the directivity of the downlink in mobile communication.

Directivity control circuitry for an adaptive antenna

A cellular mobile communication network in a code division multiple access system includes plural base stations covering cells, respectively, a host base station communicable with the plural base stations and plural mobile stations moved in the cells; when a mobile station becomes uncontrollable, the base station communicating the failure mobile station requests the host base station to register the identity code of the failure mobile station in a list of failure stations, and changes the control channel from an original radio frequency to a new radio frequency without informing the failure mobile station of the new radio frequency so as to disconnect the failure mobile station from the cellular mobile communication network; when another mobile station transmits a request for communication to a base station, the base station inquires the host base station whether the request is acceptable or not, and the host base station checks the list to see whether the identity code of the mobile station has been already registered; thus, the failure mobile station never communicates with the base stations, and does not serve as a serious interference power source.

Method for forcibly disconnecting failure mobile station from cellular

A cellular mobile communication network in a code division multiple access system includes plural mobile stations and at least one base station, and the at least one base station periodically supplies a transmission power control instruction representative of decrease or increase of the transmission power of a transmit signal from each mobile station to the at least one base station; when the base station receives the transmit signal from a mobile station, the base station measures the electric power to see whether or not the mobile station is faithful to the transmission power control instruction; if the mobile station repeats the disobedience, the mobile station is diagnosed to be a failure station serving as a serious interference power source.

Method for detecting failure mobile station in cellular mobile

In a spread spectrum communication system, as base station transmission channels are used a synchronizing channel for continuously transmitting a predetermined PN code from a base station (generated by a synchronizing pilot channel generating block), a identifying channel for continuously transmitting a predetermined multivalued PN code every base station (generated by an identifying pilot channel generating block), and a communication channel for enabling the identification of a base station transmitting data by multiplying the multivalued PN code used in the identifying channel by communication data after spectrum spreading (generated by a communication channel generating block).

Spread spectrum communication system

A method and apparatus of transmission power control to minimize a downward interference caused by the soft hand-off operation for a mobile station existing in the cell border in a cellular mobile communication system which uses a code division multiple access (CDMA) system for radio communication system are provided. The mobile station detects the signal power of pilot channels of the respective base stations A and B, and reports them to the respective base stations. Each base station calculates the propagation characteristic between the mobile station and the base station to determine a transmission power of the traffic channel, which is the most suitable level for the mobile station which is executing the soft hand-off operation, based on the relation among the reported information, the current transmission power of the pilot channel and the traffic channel. The respective base station controls the transmission power of the traffic channel in such the manner that all the received signal power of the traffic channels at the mobile station should be the same, and that the resultant received signal power of the downward traffic channels at the mobile station is made constant.

Method of transmission power control in a cellular mobile communication

A vortex flowmeter detector is attached to or detachable from a vortex generation body for measurement of flow rate. The vortex flowmeter detector comprises a cylindrical oscillation tube having a bottom and a vortex detection part which is fixed by a fixing flange of the oscillation tube, wherein the oscillation tube is detachably inserted into a hole which is open to the vortex generation body at one end thereof, and the oscillation tube is fixed by a flange. An alternate pressure caused by a Karman vortex is introduced from both sides of the vortex generation body into the hole so as to oscillate the oscillation tube. This oscillation is received by a spring plate by way of an element cover, and it is transmitted to piezoelectric elements which are stuck to two chamfers of an elastic base material.

Vortex flow meter detector and vortex flow meter

A feedforward-type distortion compensation circuit which can compensate for a non-linear distortion component generated by a main amplifier. The circuit has a main amplifier path in which the main amplifier, a first variable attenuator and a first variable phase shifter are interposed, first and second delay line paths, a first power distributor for distributing an input signal to the main amplifier path and the first delay line path, an auxiliary amplifier path in which an auxiliary amplifier, a second variable attenuator and a second variable phase shifter are interposed, a second power distributor interconnecting the main amplifier path and the second delay line path, a first power combiner interconnecting the first delay line path and the auxiliary amplifier path, a second power combiner combining the signals from the second delay line path ant the auxiliary amplifier path to output, and a signal transmission path connecting between the branch ends of the second power distributor and the first power combiner. First and second pilot signals are coupled with the input signal and the signal transmitting the main amplifier path, respectively. The first variable attenuator and the first variable phase shifter are controlled in response to level and phase differences of the first pilot signal components at the first power combiner, respectively. Similarly, the second variable attenuator and the second variable phase shifter are controlled in response to level and phase differences of the second pilot signal components at the second power combiner, respectively.

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Tokyo, Japan

Kenichi Takai