Nec Corporation

Katsumi Tanoue

Ichiro Kaneko

Genichiro Sekine

A base station system includes a base station device (), a wireless transmission device () and a data transfer device (), each of which can be installed outdoors. Enclosures (and) of the devices (-) each provide a degree of protection from water and dust ingress necessary for being installed outdoors. The enclosure () of the base station device () accommodates electronic equipment () functioning as a base station. The enclosure () of the wireless transmission device () accommodates electronic equipment () functioning as a radio station to perform wireless transmission with the other device for connecting the base station device () to a mobile backhaul network. The enclosure () of the data transfer device () accommodates electronic equipment () functioning as a router or a switch to transfer data packets or data flames between the base station device () and the wireless transmission device (). This eliminates the need for construction of a building/shelter to install the base station system.

Base station system

A propagation delay-propagation loss table is stored in advance in a radio base station, a first area and a second area being set in advance in the propagation delay-propagation loss table, the first area being predicted to contain the relation between the propagation delay and propagation loss when a mobile station is not within the service area of a repeater, while in the second area the effect of the control delay and power gain caused by the repeater upon this first area is taken into consideration. In the radio base station, it is then determined that a mobile station is within the service area of the radio base station when the relation between the propagation loss value that has been reported from the mobile station and the propagation delay that has been calculated is contained within the first area, and it is determined that the mobile station is within the service area of the repeater when the relation is contained within the second area.

Service area determination method for determining whether a mobile terminal is in the service area of a repeater or in the service area of a radio base station

A controller in a wireless communication system for a mobile station simultaneously communicating with a plurality of base stations comprises a receiver receiving a plurality of signals, relating to a fist communication type, from a plurality of base stations, and receiving a signal, relating to a second communication type different from the first communication type, from a specific base station; and a transmitter, coupled to the receiver, transmitting a control signal generated on the basis of the signal relating to the second communication type received by the receiver from the specific base station, to the plurality of base stations and the specific base station.

Controller and control method for mobile communication system

A CDMA mobile communication system is disclosed in which a reference value, an uplink signal SIR value, which is used in a closed-loop transmission power control is updated in base transceiver stations. The uplink signal target SIR value is updated independently at base transceiver stations and not at the base station controller. At the base transceiver station, when a decoder detects a loss of synchronization of a user signal from a mobile station, a demodulator adds a step value &#x394;SIR that has been set in advance to the uplink signal SIR value that has been reported from the base station controller to obtain an uplink signal target SIR provisional value. When this uplink signal target SIR provisional value is smaller than an uplink signal target SIR maximum value that has been set in advance, the uplink signal target SIR value is updated to the uplink signal target SIR provisional value.

CDMA mobile communication system in which updating of a reference value for controlling closed-loop transmission power is realized in a base transceiver station

In a CDMA receiver which receives, as a reception signal ( ), a signal given by subjecting a data signal comprising predetermined pattern data (PS) to spread modulation by the use of a spread code, a correlation value calculating unit ( ) produces correlation value data obtained by multiplying the reception signal by the spread code and the predetermined pattern data. A signal-to-interference ratio calculating portion ( ) calculates a signal-to-interference ratio of the reception signal. A reception timing determining portion ( ) determines a reception timing of the predetermined pattern data in response to the correlation value data and the signal-to-interference ratio. Preferably, the reception timing determining portion determines the reception timing such that the maximum value of said correlation value data exceeds a predetermined first threshold value and that said signal-to-interference ratio exceeds a predetermined second threshold value when said correlation value data have the maximum value.

CDMA receiver

A receiving device comprises a demodulating section for demodulating transmission signal into a demodulated signal having a digital speech signal and a error detecting code. The demodulating section divides the digital speech signal into first through N-th subframe speech signals and detects a received field intensities of the first through the N-th subframe speech signals to produce first through N-th field detection signals representative of the received field intensities of the first through the N-th subframe speech signals, respectively, where N represents a positive integer which is greater than one. An error detecting section detects whether or not the digital speech signals has an error in accordance with the error detecting code to produce an n-th error detection signal when the digital speech signal has an error and when an n-th field detection signal has a received field intensity that is not greater than a predetermined received field intensity, where n is a variable between one and N, both inclusive. An interpolating section carries out interpolation of the digital speech signal in response to the n-th error detection signal to produce a speech signal.

Detecting and replacing bad speech subframes wherein the output level of

A communication channel is dynamically assigned to a mobile station in autonomous decentralized channel assignment in TDMA/TDD communications system. An interference detection criterion is determined depending on a signal strength of a call request signal. It is determined whether interference occurs in a transmitting time slot relative to the interference detection criterion in a selected channel, and further determined whether interference occurs in a receiving time slot relative to a predetermined interference detection criterion in the selected channel. When it is determined that no interference occurs in the selected transmitting and receiving time slots, the selected channel is assigned to the mobile station.

Channel assignment method in mobile communications system

A handover method for a mobile radio communications system, which reduces the disconnection time when the radio channel is switched from one radio base station to another radio base station. When the electric field received from a first radio base station weakens beyond a preset level during communication, the mobile station receives TDMA frames intermittently from other radio base stations without disconnecting communication with the first radio base station, and selects a second radio base station based on the strength of the received electric fields. In a similar manner, the mobile station then intermittently prepares for connection with the second radio base station while continuing the communication with the first radio base station.

Method of radio channel switching over in a mobile radio communications

A radio frame synchronization system performs synchronization control of radio frames to be transmitted from a plurality of radio base stations respectively connected to wire lines to a mobile station. Each of the radio base stations includes a receiver, a sync signal detecting section, and a phase correcting section. The receiver receives a time-division radio signal to be transmitted from a distant radio base station in operation to the mobile station when a home radio base station is activated. The sync signal detecting section detects a sync signal from a reception output from the receiver. The phase correcting section generates a radio frame reference signal, indicating a timing at which a radio frame is transmitted to the mobile station, on the basis of a phase difference between the radio frame synchronization reference signal supplied from the wire line and the sync signal from the sync signal detecting section.

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Tokyo, Japan

Katsumi Tanoue