Kddi Corporation

Kddi Research, Inc.

University of Southern California

Issei Kanno

Takeo Ohseki

Kosuke Yamazaki

Yasuhiro Suegara

Masahito Umehara

Masaaki Ito

Andreas F Molisch

Yutaro Kurita

Ryochi Kataoka

Shunsuke Kamiwatari

Naoto Tsumachi

Yoshiaki Amano

The method includes: executing, when first APs that are changed from a cluster AP to a non-cluster AP due to a change of a cluster occurs, first processing on processing target APs including the first APs and a second AP that is the non-cluster AP satisfying a predetermined condition in relation to the first APs, and thereby determining, as an operation mode of the processing target APs. The first processing includes: selecting one first processing target AP from the processing target APs, and determining a downstream-only mode as the operation mode of the one first processing target AP, and determining a upstream-only mode or a sleep mode as the operation mode of a second processing target AP that is different from the one first processing target AP and is among the processing target APs.

Processing apparatus of cell-free communication system

A communication device capable of connecting to and communicating with another device using a first function operating as a terminal device and a second function operating as a base station device, the communication device acquires a first reception power density of a signal of a downlink received from an upstream device connected by the first function, acquires a second reception power density of a signal of an uplink received from a downstream device connected by the second function, and transmits a transmission power control command for controlling transmission power of the signal of the downlink to the upstream device, based on the first reception power density and the second reception power density.

Communication device, control method and computer-readable storage medium for executing transmission power control in relay transmission

A terminal device that comprises a plurality of antennas notifies a network to which the terminal device belongs of information according to which it is possible to specify at least one of, among the plurality of antennas, a second antenna having a predetermined characteristic in common with a first antenna included in the plurality of antennas, and a third antenna not having the predetermined characteristic in common with the first antenna.

Terminal device, network node, and control method for communication control with consideration given to antenna arrangement

A terminal comprises a function capable of operating in a plurality of states that include a first state in which a connection with a base station has been established, and a second state in which a connection with a base station has not been established, but the base station holds information regarding the terminal device. After starting operation in the second state from a state in which the terminal operates with a first base station in the first state, if predetermined information that enables communication with the first base station in the second state and that has been acquired from the first base station in the first state is held, the terminal determines whether a signal transmission target has changed from the first base station to a second base station device, and performs communication according to a result of the determination.

Enabling a terminal device to perform efficient communication in a stand-by state

A control apparatus that is connected to a plurality of antennas and performs communication of user data with a terminal apparatus using at least one of the plurality of antennas, specifies a reception state of a random access preamble transmitted from the terminal apparatus for establishing connection with the control apparatus, at each of the plurality of antennas, selects an antenna to be used when performing communication of user data with the terminal apparatus, from the plurality of antennas based on the respective reception states at the plurality of antennas, and performs control such that communication of user data is performed with the terminal apparatus using the selected antenna.

Control apparatus selectively using plurality of antennas, control method, and computer-readable storage medium

A control apparatus may wirelessly communicate with a terminal apparatus. When a random access preamble is received from the terminal apparatus, if the random access preamble is not based on a setting notified by the control apparatus, the control apparatus may scramble communication with the terminal apparatus after the random access preamble is received, using a scrambling sequence that is based on second identification information different from first identification information corresponding to the control apparatus.

Control apparatus selectively using plurality of antennas, terminal apparatus communicating with control apparatus, and communication method

A terminal apparatus transmits a predetermined message to a base station apparatus based on a two-step random access procedure, upon receiving one signal that is transmitted from the base station apparatus in response to the predetermined message, and includes pieces of upper layer control information for the terminal apparatus and another terminal apparatus in a multiplexed manner, specifies a first radio resource for transmitting a first response signal indicating whether or not succeeded in receiving control information that is for the terminal apparatus and is included in the one signal, and is different from a second radio resource for transmitting a second response signal for the other terminal apparatus, based on at least one of a control signal that is used for transmitting the one signal and the one signal, and transmits the first response signal using the first radio resource.

Terminal apparatus for executing two-step random access procedure, base station apparatus, and control method

A terminal apparatus, which executes a two-step random access procedure or a four-step random access procedure to establish a connection with a base station apparatus, executes control such that, in a case where a first message of the two-step random access procedure including a preamble and predetermined information for connection establishment is transmitted and a number of unsuccessful attempts to receive the first message by the base station apparatus exceeds a predetermined number, the terminal apparatus transmits a second message to be transmitted from the terminal apparatus to the base station apparatus in the four-step random access procedure.

Terminal apparatus, base station apparatus, control method, and computer-readable storage medium for executing random access procedure

A terminal apparatus notifies, when transmitting an uplink second signal to a base station apparatus using a wireless resource that is used when receiving a downlink first signal transmitted from the base station apparatus, the base station apparatus of information indicating whether or not the terminal apparatus has a capability of suppressing influence of interference of the second signal on the first signal.

Terminal apparatus, base station apparatus, control method, and storage medium in system that can execute full-duplex communication

Terminal device that performs communication in stand-by state, method for controlling the same, and computer-readable storage medium

A terminal apparatus, which is able to establish a connection with a base station apparatus via a two-step random access procedure by transmitting a first signal including a random access preamble and predetermined information to the base station apparatus and receiving a second signal as a reply to the first signal from the base station apparatus, acquires a random access-radio network temporary identifier (RA-RNTI) on the basis of a radio resource having been used to transmit the predetermined information with the first signal, and executes reception processing of the second signal using the RA-RNTI.

A base station device transmits a control signal for causing a transition from an RRC_CONNECTED state to an RRC_INACTIVE state and including connection parameter information to a terminal device. The terminal device performs uplink transmission to the base station device using the connection parameter information included in the control signal in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned. The base station device performs uplink reception from the terminal device that is in the RRC_INACTIVE state to which the RRC_CONNECTED state has transitioned using the connection parameter information included in the control signal.

Mobile communication system, terminal device, base station device, communication method, and computer program

The present embodiments relate to multi user detection in distributed antenna systems. A communication system may include a central processing circuitry and a plurality of access points connected to the central processing circuitry via a fronthaul interface. Each access point of the plurality of access points may include a plurality of antennas configured to receive signals from a plurality of UEs, and a local processing circuitry connected to the plurality of antennas. The local processing circuitry may be configured to estimate channel properties of a MIMO channel between the UEs and the antennas of the access point, and determine a subset of the UEs using the channel properties. The local processing circuitry may transmit data associated with the subset of wireless communication devices to the central processing circuitry for use to perform multiuser detection at the central processing circuitry.

Systems and methods for multiuser detection in distributed antenna systems

A wireless communication terminal and a communication system selection method are capable of selecting a communication system having high battery usage efficiency by keeping battery remaining time long and satisfying throughput required by the application depending on scenes. The wireless communication terminalcapable of selecting plural communication systems comprises an application information acquisition unitfor acquiring a type of used application; an evaluation amount calculation unitfor changing a communication system selection criterion in response to the type of application thus acquired and calculating an evaluation amount with respect to time adding predetermined time to communication system switching time; and a system selection unitfor comparing the evaluation amounts thus calculated and selecting any one of communication systems. Therefore, it is possible to select/switch to the communication system having high battery usage efficiency among plural systems in response to a real-time requirement of the application.

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Fujimino, Japan

Issei Kanno