Ntt Docomo, Inc.

Ntt Mobile Communications Network, Inc.

Fujifilm Corporation

Nit Docomo, Inc.

Ntt Decomo, Inc.

Yoshihiro Ishikawa

Seizo Onoe

Mikio Iwamura

Takahiro Hayashi

Takehiro Nakamura

Masafumi Usuda

Yoshiaki Ofuji

Yasunori Ohta

Hideki Suzuki

Hidehiro Ando

Masakazu Nakajo

Yuzuru Ohtsuka

Osamu Kuroda

Yukihiko Okumura

Takaaki Sato

Tetsuro Imai

Rie Nagato

Mamoru Sawahashi

Minami Ishii

Narumi Umeda

Kazunori Obata

Kazufumi Yunoki

Akihiro Higashi

Shinichi Mori

Etsuhiro Nakano

Masafumi Hata

Mototsugu Suzuki

Yoshitaka Hiramoto

Tetsurou Imai

Koushirou Kitao

Yasuyuki Watanabe

Sung Uk Moon

Akihiro Maebara

Takaaki Satoh

Yoshiaki Oofuji

Mikio c/o Ntt Docomo Inc Iwamura

A femto base station according to the present invention includes: a downlink perch channel signal transmission power controller unit configured to change a transmission power of a downlink perch channel signal when a first condition is satisfied; and an uplink reception sensitivity controller unit configured to change an uplink reception sensitivity when a second condition is satisfied after the first condition is satisfied.

Base station and mobile communication method to change a transmission power of communication channel

A receiving apparatus for receiving a downlink signal in which pilot symbols are mapped discontinuously, includes: a unit configured to extract reference signals from the downlink signal that is Fourier transformed by a Fourier transform unit; a unit configured to generate a first signal having a first window size by arranging the extracted reference signals on the frequency axis and by performing inverse Fourier transform on the reference signals; a unit configured to divide the first signal into a plurality of signals to extract a signal included in a second window; a unit configured to generate a second signal that includes the signal included in the second window and that has a window size similar to the first window size; a Fourier transform unit configured to generate a third signal from the second signal; and a unit configured to calculate received power based on the third signal.

Receiving apparatus and receiving method

A reception device calculates a radio quality in a downlink by using a plurality of pilot symbols transmitted from a base station. The reception device includes a correlation calculation unit and a radio quality calculation unit. The correlation calculation unit calculates a correlation value between a first pilot symbol and a second pilot symbol on a time axis or a correlation value there between on a frequency axis. If the correlation value obtained by the correlation calculation unit exceeds a predetermined threshold value, the radio quality calculation unit calculates a radio quality in the downlink by using a reception quality of the first pilot symbol and a reception quality of the second pilot symbol.

Receiving device and radio quality calculation method

In this invention, a channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data. The output data with the highest quality is selected by judging reliability of these plurality of demodulated data. It is also possible to select some weighting sequences based on the result of the reliability judgment of the demodulated data for predetermined period of time. In this case, after the selection, demodulation is performed by using these selected weighting sequences only.

Channel estimation device and method, demodulation device and method, and fading frequency decision device and method

A measuring apparatus for measuring service quality in an area in a communication system, in which a plurality of base stations use one frequency band for transmitting downlink signals, includes: a receiver configured to receive constant power signals that are the downlink signals transmitted by the base stations through constant power channels in which transmission powers are constant; a reception power measuring unit configured to measure reception powers of the constant power signals transmitted by the respective base stations; a reception power selector configured to select a reception power which is a base for measurement of the quality in the area, out of the reception powers measured by the reception power measuring unit; and an area quality measuring unit configured to measure the quality in the area on the basis of the reception power selected by the reception power selector, and a total of the reception powers not selected by the reception power selector.

Measuring apparatus and area quality measuring method

A channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data.

There is provided a handover control method that does not produce quality deterioration or other similar problems during handover in a mobile communication system in which a first channel shared by a plurality of mobile stations and second channels exclusively used by respective mobile are used in combination. A handover control method according to the present invention comprises: a step in which a data signal is transmitted from one base stationA to a mobile stationby using a first channel; a step in which a control signal is transmitted from a plurality of base stationsA,B including the base stationA to the mobile stationby using a second channel; a step in which the mobile stationreceives a plurality of control signals; a step in which, of the plurality of control signals received, information regarding reception quality of the control signal from the base stationA that transmitted the data signal is transmitted from the mobile stationto the base stationA; and a step in which information relating to reception quality is received by the base stationA and transmission control is performed of the data signal transmitted by the base stationA, in accordance with the received information relating to reception quality.

Mobile station, mobile communication system, handover control method, handover control program and recording medium

A base station captures phase difference information between a long period spreading code of a common control channel of the base station and a long period spreading code of a common control channel of a neighboring base station of the base station from a mobile station. The base station transmits the phase difference information to a mobile station. The mobile station carries out cell search in accordance with the received phase difference information.

Neighboring base station information update method, information management method for cell search in mobile communications system, cell search method of mobile station, mobile communications system, mobile station, base station and control station

A CDMA apparatus including a propagation path variation estimator for estimating propagation path variations between respective prior transmit power control sections and a current transmit power control section to obtain propagation path variation estimation values, wherein each of the propagation path variation estimation values is obtained by estimating a propagation path variation between a different corresponding prior transmit power control section and the current transmit power control section; propagation path variation correction part for generating a plurality of corrected products, each corrected product obtained by multiplying at least one of vector, amplitude and/or power of a received signal of the different corresponding prior transmit power control section by said propagation path variation estimation value obtained by estimating the propagation path variation between the different corresponding prior transmit power control section and the current transmit power control section; and averaging part for averaging the plurality of corrected products.

Channel identifier assigning method and mobile communications system

In mobile communication systems employing the CDMA method, the communication quality is acquired from the CDMA pilot channel. A communication quality acquisition apparatus comprises a delay profile acquisition unit comprising a control unit, synchronization unit and measurement unit, in addition to a data storage unit. The communication quality is measured by the synchronization unit and the measurement unit which are alternatively controlled by the control unit. When the communication quality is acquired through the CDMA pilot channel, the data acquisition efficiency can be significantly raised.

Apparatus and method for acquisition of communication quality

When cassettes are placed on a conveyor disposed in a cassette loader and detectors disposed on a support plate on the conveyor detect information of identification strips on side walls of the cassettes, the cassettes are judged as being loaded properly in the cassette loader. When the detectors fail to detect the identification strips, the cassettes are judged as not being loaded in a desired state in the cassette loader.

Radiation image information reading apparatus

Resource measurement deviceacquires a measured value x of the resource use condition in transmitting/receiving sectionin respect of the wireless resource that is the subject of monitoring. Also, correction value calculation devicecalculates a correction value in accordance with the number of packet users at transmitting/receiving sectionand adjustment deviceadjusts the call acceptance threshold value xusing the correction value, so as to obtain a corrected threshold value x'. Comparatorthen compares the measured value of the resource use condition x and the corrected threshold value x&#x2032; and outputs the comparison result to call acceptance control device. If x&#x2267;x&#x2032;, call acceptance control devicerestricts acceptance of new calls. Thus, the call acceptance control method, mobile communication system and base station device whereby deterioration of communication quality is suppressed irrespective of the switching system are provided in mobile communication in which multiple access is performed with shared wireless resources.

Call acceptance control method, mobile communication system and base station device

A traffic measurement device comprises a noise power setting unit configured to set a reference noise power, which is a reference value used to measure a traffic volume at a base station, a noise power measurement unit configured to measure a noise power at the base station, and a calculation unit configured to calculate the traffic volume based on the reference noise power and the measured noise power. Another traffic measurement device comprises a transmission power setting unit configured to set a reference transmission power, which is a reference value used to measure the traffic volume at a base station, a transmission power measurement unit configured to measure a transmission power at the base station, and a calculation unit configured to calculate the traffic volume based on the reference transmission power and the measured transmission power.

Traffic measurement device and traffic measurement method

A cassette is delivered from a cassette loader through a stock unit to a releasing unit. After a stimulable phosphor panel is supplied from the cassette to a reading unit by an unlocking mechanism and a panel ejecting mechanism, the cassette is fed to a position below an erasing unit so as to wait for the stimulable phosphor panel. After recorded radiation image information is read from the stimulable phosphor panel by the reading unit, the stimulable phosphor panel is fed to the erasing unit, which erases remaining radiation image information from the stimulable phosphor panel. Thereafter, the stimulable phosphor panel is stored back into the waiting cassette, which is delivered to a cassette discharger.

Apparatus for and method of reading and erasing radiation image information

A control method of searching for a neighboring cell of a mobile station communicating with a base-station is provided in a direct sequence CDMA mobile communication system which transmits information by carrying out double modulation using a first spreading code group and a second spreading code. The first spreading code group includes spreading codes that have a same repetition period as an information symbol period and are used in common by the base stations, and the second spreading code has a repetition period longer than the information symbol period. The base stations are assigned different second spreading codes. The control method stores at least one second spreading code and its phase into a first table, which second spreading code corresponds to a perch channel whose second spreading code and phase are known; stores a second spreading code used by a neighboring base station into a second table; searches for a perch channel whose second spreading code and phase are unknown; and searches for a perch channel whose second spreading code and phase are known. The neighboring cell search method can save the power consumption and time required for the mobile station to carry out the cell search with preventing an increase in the total cost of the system.

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Yokosuka, Japan

Yoshihiro Ishikawa