Ntt Docomo, Inc.

Nippon Telegraph and Telephone Corporation

Hidetoshi Kayama

Narumi Umeda

Lan Chen

Masayuki Motegi

Daisuke Kitazawa

Hiroki Harada

Yasuhiro Oda

Jiyun Shen

Tamami Maruyama

Ngoc Hao Tran

Heng Qiu

Xiaolin Hou

Zhan Zhang

Lei Du

Hiromasa Fujii

Anxin Li

Yong Bai

Shunji Miura

Hideki Tobe

Xiangming Li

Hiroto Yasuda

Zhongshan Zhang

Yuan Yan

Takeshi Yamashita

Jyunichirou Hagiwara

Kazuaki Takeda

Liu Liu

Qin Mu

Hiroshi Yoshida

Hiroyuki Yamamoto

Chongning Na

Atsushi Harada

Takeo Ichikawa

Ismail Guvenc

Moo Ryong Jeong

Masahiro Morikura

Xinying Gao

Hitoshi Takanashi

Hideo Matsuki

Masataka Iizuka

Hiromasa Fuji

A determination apparatus for determining communication availability in an Orthogonal Frequency Division Multiplexing (OFDM) scheme communication system, the determination apparatus includes a reception unit configured to receive a wireless signal including an OFDM symbol in which a pilot signal is inserted at a constant interval in a frequency axis direction, an obtaining unit configured to obtain a discrete sample signal by sampling the wireless signal, a correlation value calculation unit configured to calculate a correlation value of the discrete sample signal for a time shift amount that is defined in advance according to the constant interval, and a determination unit configured to determine the communication availability in the communication system based on at least a result of determination whether the correlation value for the time shift amount has a peak or not.

Determination apparatus for determining communication availability and determination method

The present disclosure provides a base station, a communication system and a method thereof. The communication system includes three base stations adjacent to each other, and each base station serves at least one UE. The method includes: acquiring, by each base station, a channel matrix of a channel from the base station to an adjacent base station; calculating an interference alignment-based transmission precoding matrix for each base station based on the channel matrices of the channels between the base stations; and precoding, by each base station, data to be transmitted with the interference alignment-based transmission precoding matrix.

Base station, communication system and method thereof

A method of designing a reflectarray including a substrate having a surface perpendicular to a predetermined axis, wherein elements are disposed on the substrate. The method obtains a reflection phase of the elements as a function of a design parameter such as element spacing, when a radio wave enters the arranged elements, and stores a relationship between the reflection phase and the design parameter in a memory. Here, the design parameter is equally set for the elements. The method repeatedly determines, for each of the elements, the design parameter of a specific element in accordance with the relationship. The function of the design parameter has a range of almost 360 degrees with respect to a range of the design parameter. The reflection phase is the continuous function of the element spacing such that two resonant points occur at which the reflection phase becomes zero.

Reflectarray and design method

A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis; and at least first and second element groups, wherein the first and second element groups are disposed on the substrate, and include elements that reflect a radio wave. The first element group and the second element group reflect the radio wave with corresponding reflection phases which are different from each other. The radio wave enters while forming an angle other than 0 degrees with respect to the predetermined axis. The elements included in the first element group reflect the radio wave with a first reflection phase, and the elements included in the second element group reflect the radio wave with a second reflection phase, wherein the second reflection phase is different from the first reflection phase.

The present application provides an information transmission method, an information transmission apparatus, and a base station. The information transmission method comprises: an allocation step of, according to a search space allocation mode, performing search space allocation in a target resource consisting of at least two resource subsets and allocating, for the first user, a first search space capable of transmitting the first user control information, the search space allocation mode being associated with the at least two resource subsets; and a first transmission step of transmitting the first user control information via the first search space so that the first user can acquire the first user control information from the first search space according to the search space allocation mode. According to the present invention, the resource utilization efficiency will be improved.

Information transmission method, information transmission apparatus, and base station

A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis, and elements disposed on the substrate. A specific element among the elements reflects the incident wave with a specific reflection phase among a plurality of reflection phases. Each of the elements has an element structure including, at least, a patch and a ground plate. Element spacing of first neighboring elements is different from element spacing of second neighboring elements, and a length of a gap between patches of the first neighboring elements is equal to a length of a gap between patches of the second neighboring elements.

A multi-beam reflectarray includes two or more element arrays including plural elements aligned along a predetermined direction. The multi-beam reflectarray is such that, in each of a first element group and a second element group included in at least one of the element arrays, a difference between phases of radio waves reflected by corresponding two elements is in proportion to a first product of a distance between the two elements and a value of a trigonometric function with respect to an angle of reflection by the two elements, and a distance between neighboring elements in the first element group is equal to a product of a rational number and a distance between neighboring elements in the second element group.

Multi-beam reflectarray

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 method for adaptive coordinated transmission in wireless communications includes: determining more than one transmitter for performing coordinated transmission, configuring one of the more than one transmitter to be a serving transmitter with others of the more than one transmitter being cooperating transmitters, and determining more than one receiver; determining, by a cooperating transmitter, a cooperation mode according to measured signal parameters of the more than one receiver after receiving a cooperation request from the serving transmitter, and providing the cooperation mode to the serving transmitter; generating, by each of the more than one transmitter, a transmit signal corresponding to the more than one receiver according to the cooperation mode determined, and transmitting the transmit signal to each of the more than one receiver.

Method, system and transmitter for adaptive coordinated transmission in wireless communications

A method for accessing a hybrid network and a gateway communication system are disclosed. The method comprises: sensing by a gateway apparatus a relay request slot on a downlink common control channel of the wide area network; transmitting by a wireless terminal a relay request signal requesting to relay a data packet to be transmitted, in the relay request slot on the downlink common control channel; and if the relay request signal from the wireless terminal is sensed in the relay request slot, establishing by the gateway apparatus a connection with the wireless terminal in a distributed network environment. As such, the gateway apparatus accesses the wireless distributed network only when the surrounding wireless terminals require data relay, without sensing signals on both networks simultaneously.

Method for accessing hybrid network, and gateway apparatus, wireless terminal and communication system thereof

The present invention discloses a method for determining an uplink demodulation reference signal (DMRS), which includes: taking one of multiple transmit antennas in the uplink as a base transmit antenna, taking other transmit antennas as subordinating transmit antennas and setting a DMRS for the base transmit antenna; establishing DMRS subordinating relationships between the base transmit antenna and each of the subordinating transmit antennas; and setting a DMRS for each of the subordinating transmit antennas according to the DMRS of the base transmit antenna and the DMRS subordinating relationship between the base transmit antenna and each of the subordinating transmit antennas. The present invention also provides a user equipment (UE) and an uplink system for providing DMRSs for multiple transmit antennas. The method, UE and system are applicable in both SU-MIMO transmission and MU-MIMO transmission.

Method for determining demodulation reference signal in the uplink, UE and uplink system

A data processing method and a base station for downlink transmit diversity are disclosed. One embodiment of the method comprises: obtaining data symbol groups formed by arranging a first type data symbol and a second type data symbol in an interval, wherein the first type data symbol is more important; determining a first antenna port pairing mode corresponding to a current slot; performing, for OFDM symbols including the reference signal in the current slot, an antenna port and subcarrier mapping on symbols in a transmit diversity matrix corresponding to the data symbol groups according to the first antenna port pairing mode, wherein a subcarrier in which a symbol related to the first type data symbol is located is nearer to a subcarrier in which a reference signal at the same antenna port is located; and performing an inverse fast fourier transform and a cyclic prefix insertion processing on symbols mapped to subcarriers and then mapping the time domain symbols to a physical antenna for transmission. According to embodiments of the invention, comparatively important symbols may obtain better protection.

Data processing method and base station for downlink transmit diversity

A method for accessing a hybrid network including a wide area network and a distributed network, a gateway apparatus, a wireless terminal and a gateway communication system are disclosed for reducing the power consumption of the wireless terminal which is an access gateway. The method comprises: sensing by a gateway apparatus a relay request slot on a downlink common control channel of the wide area network; transmitting by a wireless terminal a relay request signal requesting to relay a data packet to be transmitted, in the relay request slot on the downlink common control channel; and if the relay request signal from the wireless terminal is sensed in the relay request slot, establishing by the gateway apparatus a connection with the wireless terminal in a distributed network environment. As such, the gateway apparatus accesses the wireless distributed network only when the surrounding wireless terminals require data relay, without sensing signals on both networks simultaneously, in order to reduce the power consumption.

Growing community of inventors

Yokohama, Japan

Hidetoshi Kayama