Ntt Docomo, Inc.

Shunji Miura

Hideaki Takahashi

Hiromasa Fujii

Hiroki Harada

Hidetoshi Kayama

Tomoyuki Ohya

Hiroto Yasuda

Noriyuki Maeda

Hiromitsu Asakura

Hiromasa Fuji

Ohya Tomoyuki

A CRS base station () includes a transmitting section configured to transmit a synchronization establishment signal, a receiving section configured to receive a random access signal corresponding to the synchronization establishment signal, a determining section configured to determine whether or not the random access signal received by the receiving section has been transmitted from an MCS terminal () and an interference reduction processing section configured to perform interference reduction processing on the MCS terminal () when the determining section determines that the random access signal has been transmitted from the MCS terminal ().

User terminal

A wireless station in a second communication system, with at least a portion of a first frequency band used in a first communication system and a portion of a second frequency band used in the second communication system being shared or neighboring, the wireless station including a waveform characteristic quantity extracting unit that extracts a waveform characteristic quantity which shows a statistical characteristic of a signal received from the first communication system; a communication parameter determining unit that determines communication parameters to be used for the wireless station in the second communication system depending on a determination result of whether the extracted waveform characteristic quantity is of a predetermined waveform characteristic quantity for reducing an interference; and a transmission and reception unit that transmits and receives a wireless communication signal in the second communication system in accordance with the determined communication parameters.

Wireless station, interference avoidance method, and system for interference avoidance

Radio base station and frequency band sharing method

A signal detection apparatus includes: a unit configured to select a particular detection target signal from among plural candidates of detection target signals; a unit configured to calculate a cyclic autocorrelation value at a center coordinate point specified by at least a cyclic parameter and a shift parameter of the particular detection target signal; a unit configured to calculate a cyclic autocorrelation value of each of (L&#x2212;1) coordinate points belonging to a common area that is used commonly for different detection target signals; a unit configured to calculate a test statistic of the particular detection target signal; and a unit configured to determine presence or absence of the particular detection target signal according to a comparison result between the test statistic and a threshold, wherein the test statistic is calculated by using the cyclic autocorrelation value in each of the (L&#x2212;1) coordinate points belonging to the common area.

Signal detection apparatus and signal detection method

Disclosed is a signal generation device that employs a transmission method using inverse Fourier transform. The signal generation device includes: a modulation unit which modulates transmission data to obtain modulation data; a serial-parallel conversion unit which converts the modulation data input in series to parallel data of a predetermined size smaller than the size of inverse Fourier transform; a duplication unit which selects and duplicates all or a portion of the parallel data to obtain duplication data; a first time-axis shift unit which shifts the duplication data along the time axis to obtain time-axis shift data; and an inverse Fourier transform unit which carries out inverse Fourier transform on the parallel data obtained by the serial-parallel conversion unit and the time-axis shift data obtained by the first time-axis shift unit.

Signal generation device and signal generation method

When a frequency band is shared between a large cell system having a large cell base station and a small cell system having a small cell base station, the large cell base station dynamically controls dedicated resources for the large cell base station and shared resources for both the large cell base station and the small cell base station based on predetermined information, broadcasts allocation information of dedicated resources for the large cell base station and shared resources for both the large cell base station and the small cell base station, to the small cell base station belonging to the own cell, and the small cell base station belongs to at least one large cell base station and determines resource assignment in the own cell based on the resource allocation information broadcast from the large cell base station.

Radio communication method and radio base station

A signal detection apparatusfor determining whether a detection target signal is included in a received radio signal, includes: a waveform feature amount calculation unitconfigured to calculate a waveform feature amount Rrepresenting a waveform feature; a test statistic calculation unitconfigured to calculate test statistic Zof each detection target signal by using the waveform feature amount; and a signal decision unitconfigured to determine presence or absence of each detection target signal by comparing the test statistic Zof each detection target signal with a threshold &#x393;, wherein, under a condition where a specific detection target signal is removed, the test statistic calculation unit calculates a test statistic for a detection target signal which is not removed, and the signal decision unit determines presence or absence of the detection target signal by comparing the calculated test statistic with the threshold.

Signal detection apparatus and signal detection method for use in radio station of radio communication system

A transmission apparatus including: a layer multiplexing unit configured to assign, to a radio resource which is divided based on a time, a frequency and a layer, a bit sequence which constitutes at least one information source to be transmitted, in accordance with a communication state and a priority level of the information source; and a layer coding unit configured to perform a layer coding processing for the bit sequence assigned to the radio resource. The layer multiplexing unit performs the assignment so that a length of each bit sequence assigned to each radio resource becomes equivalent.

Transmission apparatus and transmission method

The object of the present invention is to achieve reduction of interference between cells and improvement of maximum throughput so as to improve spectrum efficiency. A wireless base station which transmits a radio signal between itself and a plurality of mobile stations by means of OFDMA includes: a multiplexing part for generating user data; a channel assignment control part for selecting a plurality sets of sub-carriers among a plurality of sub-carriers so as to constitute a radio frame containing sub-channels assigned to each of the plurality sets of sub-carriers and for setting in the radio frame the user data and control data by means of orthogonal frequency division multiplexing; and a transmission part for transmitting a radio signal containing the radio frame; where, the channel assignment control part is constituted so that the radio frame is divided into 2 zones for the control and user data and all the sub-channels in the zone for control data are divided into groups for each of sectors; the control data is allocated on the corresponding divided groups; and the user data is allocated on all the sub-channels in the zone for user data.

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Yokohama, Japan

Shunji Miura