Ntt Docomo, Inc.

Katsutoshi Kusume

Hidekazu Taoka

Satoshi Nagata

Yuichi Kakishima

Mikio Iwamura

Liang Hu

Patrick Agyapong

Emmanuel Ternon

Guido Dietl

Petra Weitkemper

Karim Ibrahim Khashaba

Kazuki Takeda

Yoshihisa Kishiyama

Kazuaki Takeda

Nobuhiko Miki

Qun Zhao

Yongsheng Zhang

Gerhard Bauch

Christian Hartmann

Christian Bettstetter

Jamal Bazzi

Robert Vilzmann

A user apparatus, for use in a radio communication system including a base station forming a cell, configured to receive a discovery signal of device-to-device communication, including: an information reception unit configured to receive, from a base station of a residing cell, a resource range in which a discovery signal can be transmitted in a neighbor cell; and a discovery signal reception unit configured to receive a discovery signal at a time position that is synchronized with the neighbor cell in response to receiving a synchronization signal that is synchronized with the neighbor cell within the resource range received by the information reception unit.

User apparatus, base station, discovery signal reception method and discovery signal transmission method

To suitably perform communication using a new control unit, even in the case of using the new control unit comprised of the number of subcarriers different from that of the existing resource block, a user terminal according to one aspect of the present invention is characterized by having a receiving section that receives information on a first resource unit comprised of subcarriers lower in number than a predetermined number, and a control section which identifies a frequency region of a second resource unit comprised of the same number of subcarriers as the predetermined number based on the information, and controls communication using the first resource unit inside the frequency region.

User terminal and radio communication method

How to apply an Alamouti like space-time coding (or transmit diversity) to a Filter Bank Multicarrier (FBMC) transmission using Offset QAM (OQAM). In FBMC, due to the orthogonality in the real domain only, an intrinsic interference results thereof for the imaginary component. Simply adapting the Alamouti scheme to FBMC OQAM is not obvious since the intrinsic interference terms are not equivalent at each antenna since it depends on the surrounding symbols. The application proposes to use a precoding symbol chosen to cancel out (zero) the intrinsic interference individually for each antenna, ie a code rate of 1/2 (sending one data symbol requires two time units). A more elaborated embodiment proposes to choose the contiguous precoding symbols such that a virtual QAM Alamouti scheme is achieved, without rate loss.

Transmit diversity from orthogonal design for FBMC/OQAM

A method is described for controlling a small cell base station in a wireless communication system having a plurality of small cell base stations controlled by a macro base station. The method includes taking, by a small cell base station, a measurement for obtaining information describing a vicinity around the small cell base station and reporting the information from the small cell base station to the macro base station.

Macro-cell assisted small cell discovery and resource activation

A method is described for controlling a user equipment to be served by a small cell base station in a wireless communication system including a plurality of small cell base stations controlled by a macro base station. The method includes signaling, by the small cell base station, the small cell base station capabilities to the macro base station; signaling, by the user equipment, the user equipment capabilities to the macro base station; and signaling, by the macro base station, a small cell base station configuration to the user equipment.

A method is described for controlling a small cell base station and a user equipment to be served by the small base station in a wireless communication system having a plurality of small cell base stations controlled by a macro base station. The method has, in response to a request from the macro base station to the small cell base station, performing, by the small cell base station, a beacon transmission on one or more resources, in response to a request from the macro base station to the user equipment, performing, by the user equipment, a channel quality measurement on the one or more resources, and reporting the measured channel quality from the user equipment to the macro base station.

Macro cell assisted small cell discovery and resource activation

A user apparatus configured to perform transmission of a discovery signal by radio, including: means that determines a resource group pattern to be used by the user apparatus based on information transmitted from a base station, and determines a resource group including one discovery resource or a plurality of discovery resources that can be used for transmitting the discovery signal from among one resource group or a plurality of resource groups included in the resource group pattern; and means that selects a discovery resource to be used for transmitting the discovery signal from among the determined resource group.

User apparatus, base station, discovery resource selection method, and control signal transmission method

Disclosed is a mobile terminal device and a radio base station apparatus capable of effectively feeding back PMIs by selecting a precoder using double codebooks Wand Win downlink MIMO transmission. The mobile terminal device includes a feedback control signal generating section that individually performs channel coding for the first PMI selected from the first codebook for wideband/long-period and the second PMI selected from the second codebook for subband/short-period and a transmit section that transmits the individually channel-coded first and second PMIs to the radio base station apparatus on a physical uplink shared channel (PUSCH).

Mobile terminal device and radio base station apparatus

In a radio relay station, the channel quality of relay links is measured with the use of sounding reference signals from mobile terminals. Feedback information including the measurement results of the channel quality of the relay links is transmitted to a radio base station via a backhaul link. In the radio base station, the channel quality of the direct links is measured with the use of sounding reference signals from the mobile terminals. A correction value from the measurement results of the channel quality from the radio relay station is subtracted. Radio resources are allocated to a mobile terminal based on the measurement results of the channel quality of the direct links and the subtraction results.

Radio relay station, radio base station and radio communication method with channel quality measurement

The present invention is designed to implement radio communication to maintain good communication quality even when the number of antennas provided in a radio base station apparatus is greater than the number of transmission layers of a downlink control channel, a broadcast channel, and cell-specific reference signals. When, from a radio base station apparatus () having a plurality of transmitting antennas, at least one of a downlink control channel, a broadcast channel and a cell-specific reference signal is transmitted with fewer transmission layers than the number of all transmitting antennas, a smaller number of antennas than the number of all transmitting antennas are made virtual in a precoding weight multiplication section (), and also transmission weights that make the average transmission power of the transmitting antennas or transmission streams the same are multiplied, and the signals multiplied by the transmission weights are transmitted from the transmitting antennas on the downlink.

Radio base station apparatus, radio communication system and radio communication method

The present invention is directed to preventing the load to be required for blind detection in a mobile station apparatus (UE) from increasing and switching between SU-MIMO and MU-MIMO dynamically, even in the event the system bandwidth is expanded. The present invention has a DCI format selection section () that selects identification information which identifies between a DCI format for SU-MIMO and a DCI format for MU-MIMO, a control signal generation section () that generates control signals including the identification information and including the DCI format for SU-MIMO or MU-MIMO, having the same number of bits, and a transmission section that transmits the control signals to a mobile station apparatus.

Base station apparatus, mobile station apparatus and control information transmission method

The present invention makes it possible to feed back PMIs that are required to generate precoding weights, while securing improvement of throughput performance, in downlink MIMO transmission using a plurality of transmitting antennas. With the present invention, in a mode to include a PTI (Precoder Type Indicator) in a PUCCH and feedback the PTI to a radio base station apparatus for downlink MIMO transmission using a plurality of transmitting antennas, the transmission cycle of feedback information corresponding to report 2 and report 3 when the value of the PTI is 0 are made different from the transmission cycle of feedback information corresponding to report 2 and report 3 when PTI=1 and the former feedback information and the latter feedback information are multiplexed, and the multiplexed signal is transmitted to the radio base station apparatus by the PUCCH.

Feedback method and mobile terminal apparatus

The present invention makes it possible to generate precoding weights reliably, even in downlink MIMO transmission using a plurality of transmitting antennas. The present invention includes: a first feedback information selection section () that, in a mode to include a PTI in a PUCCH and feed back the PTI to a radio base station apparatus for downlink MIMO transmission using a plurality of transmitting antennas, selects the same RI as the last RI that was fed back, when the value of the PTI is changed from 0 to 1; a multiplexer () that multiplexes the RI and the PTI after the change on a subframe; and a transmission section that transmits the multiplex signal to the radio base station apparatus by the PUCCH.

Feedback method, mobile terminal apparatus and radio base station apparatus

To perform feedback of channel information suitable for MU-MIMO transmission while exploiting a codebook that defines precoding matrixes and PMIs suitable for SU-MIMO transmission, it is a feature that a channel matrix corresponding to a channel transmission path is defined using a plurality of precoding matrixes defined in a codebook suitable for SU-MIMO transmission and a plurality of adjustment coefficients to respectively adjust the plurality of precoding matrixes, a channel information selecting section () selects a plurality of precoding matrixes and/or a plurality of adjustment coefficients, and that the selected plurality of precoding matrixes and/or the plurality of adjustment coefficients are transmitted to a base station apparatus as channel information in uplink.

Mobile station apparatus and channel information feedback method

The present invention reduces the increase of the amount of feedback information, and, regardless of whether the correlation between antennas is high or low, increases the data rate upon MIMO transmission. A feedback information transmission method to assume a Hermitian transpose of a precoding matrix corresponding to a PMI that is selected in accordance with the amount of channel variation as a channel matrix (effective channel: h) and transmit feedback information to use in MIMO transmission to a base station apparatus, includes selecting a PMI and an RI in accordance with the amount of channel variation and measuring a CQI for single-user MIMO transmission, calculating complementary information (for example, CQI difference information &#x394;CQI) to complement the difference between the CQI for single-user MIMO transmission and a CQI for multi-user MIMO transmission, and transmitting the PMI, RI, CQI for single-user MIMO transmission and complementary information to the base station apparatus as feedback information.

Growing community of inventors

Tokyo, Japan

Katsutoshi Kusume