Sharp Kabushiki Kaisha Corporation

Huawei Technologies Co., Limited

Mitsuru Sakamoto

Yuhsuke Takagi

Tadashi Shimonabe

Akira Ohshima

Shigeto Suzuki

Shinichi Sawada

Akio Yoshihara

Keiji Hikoso

Shumpei Fuse

Takashi Naito

Kouki Suzuki

A wireless communication system allows a handover operation to a base station communicating through a plurality of frequency bands. The mobile terminal includes a communication unit adapted to perform communication with any of the base stations through a plurality of frequency bands. The communication unit of the base station notifies, when communication through a plurality of frequency bands is possible, a mobile terminal about information directed to identifying a main frequency band from relevant frequency bands in a manner allowing discrimination from one or more frequency bands other than the main frequency band. The communication unit of the mobile terminal determines that, upon receiving information directed to identifying a main frequency band from the second base station during having communication connection with the first base station, that the frequency band identified by the relevant information is a subject of handover towards the second base station.

Wireless communication system, communication method, base station, and mobile terminal

During a period of parallel-like radio communication with two or more first base stations, the first base station designates a second base station correlated with one of the two or more first base stations, and temporarily suspends the radio communication in accordance with a first communications standard to issue, to a mobile station, a request of measurement for the designated second base station. The first base station receives a result of the measurement for the designated second base station. The first base station notifies the mobile station of a handover from the first communications standard to a second communications standard, and also notifies the mobile station of a request for starting a coordination mode in which the two or more second base stations including the designated second base station establish communication with the mobile station in coordination with each other.

Communication system and communication method

A radio communication system includes transmission/reception devices which perform communication by dynamically switching a first transmission mode and a second transmission mode having a lower quality than the first transmission mode, wherein the transmission/reception devices have a transmission mode decision means which fixes a transmission mode upon communication to the first transmission mode for a given period of time.

Radio communication system and method using spatial diversity and spatial multiplexing modes

A communication system includes: a determination unit, provided in any one of a first base station, a second base station, and a mobile station, which determines a transmission timing change amount on the basis of reception timing of a signal transmitted between the first or second base station and the mobile station. The mobile station includes a handover execution unit which performs a handover from the first base station to the second base station on the basis of the transmission timing change amount calculated by the determination unit.

Communication system, mobile station, base station, and communication method

It is possible to complete a re-connection in a short time and prevent instantaneous interruption of communication by including a plurality of base station apparatuses and a mobile station apparatus; the mobile station apparatus includes: a delay difference detecting unit that detects a difference in reception timing between a signal from the base station apparatus with which the mobile station apparatus currently communicates and a signal from the base station apparatus that is a re-connection destination candidate; a transmission timing calculating unit that calculates, based on the difference in reception timing, a transmission timing to the base station apparatus that is the re-connection destination candidate; and a re-connection processing unit that, having detected a disconnection of the communication with the base station apparatus with which the mobile station apparatus currently communicates, uses the transmission timing to start a communication with the base station apparatus that is the re-connection destination candidate.

Mobile communication system, mobile station apparatus and re-connection method

A mobile communication device includes antennas, transmitting units, and receiving units. A baseband processing unit of the mobile communication device transmits data signals to a base station device through a receiving unit and an antenna that are selected based on an instruction received from the base station device. The baseband processing unit transmits reference signals to the base station device through the transmitting units and the antennas while preventing transmission frequencies of the reference signals from overlapping one another. A baseband processing unit of the base station device transmits, to the mobile communication device based on qualities of the received reference signals, a signal indicating information concerning which of the antennas and the transmitting units of the mobile communication device are used for transmitting the data signals, the signal also indicating information concerning whether or not to make the transmitting units and the antennas share transmission of the reference signals. Thus, interferences due to degradation of communication quality and to an increase in the number of reference signals can be prevented.

Mobile communication system, mobile communication device, and method for employing antenna and transmitting unit selection for transmission of reference and data signals

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Osaka, Japan

Mitsuru Sakamoto