Abstract: The present invention provides a wireless communication system capable of performing communication between wireless communication apparatuses respectively mounted on vehicles performing platooning is characterized in that a frequency channel used in data transmission and reception between an own vehicle and a preceding vehicle adjacent to the own vehicle, and a frequency channel used in data transmission and reception between the own vehicle and a succeeding vehicle adjacent to the own vehicle are different from each other.

Abstract: In a wireless communication device, which is mounted on a vehicle and performs wireless communication with a wireless communication device as a communication target using a plurality of frequency channels, the plurality of frequency channels includes a first channel and a second channel, and the first channel uses at least a radio signal of a polarization plane orthogonal to a polarization plane of a radio signal in the second channel.

Abstract: Communication quality such as a delay time is stabilized when a plurality of communication devices on the same mobile object simultaneously perform communication. A wireless communication system that is mounted on a mobile object is a wireless communication system including a first communication device and a second communication device that are mounted on a first mobile object. When information is shared by mobile objects by transmitting packets based on information acquired from a network within the first mobile object to a communication device mounted on a second mobile object, the first communication device and the second communication device transmit packets having the same content by adopting the same communication method and using different channels, and a signal transmission timing from the second communication device is set to be later than a transmission timing from a communication device from the first communication device.

Abstract: Communication quality such as a delay time is stabilized when a plurality of communication devices on the same mobile object simultaneously perform communication. A wireless communication system that is mounted on a mobile object is a wireless communication system including a first communication device and a second communication device that are mounted on a first mobile object. When information is shared by mobile objects by transmitting packets based on information acquired from a network within the first mobile object to a communication device mounted on a second mobile object, the first communication device and the second communication device transmit packets having the same content by adopting the same communication method and using different channels, and a signal transmission timing from the second communication device is set to be later than a transmission timing from a communication device from the first communication device.

Abstract: The invention is intended to, even in a situation where there are many candidate wireless base stations (WBSs) to which a mobile terminal (MT) may connect, get information of communication conditions between the MT and each of those WBSs and determine an WBS to which the MT should connect in a shorter time. A coverage area of the first WBS is overlapped partially at least by a coverage area of the second WBS. The MT transmits a signal for connection using a predetermined frequency. Upon receiving the signal for connection, the second WBSs each notify the WBS communication manager of their reception results of the signal for connection. The WBS communication manager selects a second WBS to communicate with the MT based on the reception results and notifies the selected second WBS to transmit a response signal to the signal for connection to the MT.

Abstract: When a carrier aggregation using a macro cell of a legacy carrier as a primary cell and using a small cell of a new carrier type as a secondary cell is performed, transmission of a control channel (PUCCH) of an uplink is concentrated on an uplink of the macro cell and frequency efficiency is degraded. For this reason, in a state in which the macro cell is configured as the primary cell, a serving cell transmitting the PUCCH is configured to a terminal and the terminal transmits the PUCCH using the configured serving cell.

Abstract: Interference applied to neighbor cells during terminal handovers can be reduced in wireless communication systems containing base stations having different cell sizes. A serving cell makes handover judgment criteria easier based on pre-acquired cell size information on its own cell and cell size information of neighbor cells in order to facilitate terminal handovers from a base station with a large cell size to a base station with a small cell size. The serving cell finds evaluation function values based on the propagation state (e.g. reference signal received power) between the terminal and target cell, and the interference and load information exchanged between the base stations, and selects the terminal for handover by comparing the evaluation function value with the handover criteria value. The system selects a target cell having a good effect in lowering interference such as a cell with large reference signal received power acquired from a terminal, to serve as the handover destination.

Abstract: A radio communication system using an orthogonal frequency division multiplexing system, including: a baseband unit; and one or plural remote radio units coupled with the baseband unit through an interface; wherein the baseband unit includes a first sample frequency conversion part that performs a first sample frequency conversion processing that down-samples a transmitting signal transmitted through the interface, wherein the remote radio unit includes a second sample frequency conversion part that performs a second sample frequency conversion processing that up-samples a signal received through the interface, and wherein the baseband unit further includes an inverse fast fourier transform part that generates the transmitting signal by an inverse fast fourier transform, and a transmitter characteristic compensation part that conducts frequency characteristic compensation of the first sample frequency conversion processing and the second sample frequency conversion processing for a signal that has not been su

Abstract: Even when a downlink radio traffic volume is larger than an uplink radio traffic volume in a radio communication system, but uplink resources are redundant in a related art radio communication system, free uplink resources could not be sufficiently utilized. In a base station having a cellular unit that performs cellular communication with a terminal, and a D2D unit that performs communication with the terminal through a device-to-device communication system, when the downlink radio resources get tight, and the uplink radio resources are redundant, the D2D unit of the base station conducts transmission and reception with the terminal with the use of the uplink radio resources.

Abstract: The present invention provides a method of controlling the selection of a cell in a radio communication system for increasing the capacity of the system by effectively utilizing a small cell base station and a base station apparatus for realizing it. At least one base station of a macrocell base station and a small cell base station is provided with plural antennas, and the base station selects a cell and adjusts a criterion for reselection by generating processing gain using the plural antennas by signal processing and performing a cell selection bias correcting process using the processing gain using the plural antennas.

Abstract: This invention provides a mobile communication system which expanded the operation limitation of the heretofore adopted mobile communication systems and improved the spectrum efficiency greatly. A data transmission method for use in the mobile communication system of the present invention includes means for channel pluralizing by which to expand the Shannon limit and means for interference reduction by which to expand the interference limit. More specifically, a transmitting module comprises M units of modulators and L units of transmitting antennas, generates L units of signals by multiplying M units of modulated signals by a complex matrix consisting of M×L units of elements, and transmits the L units of signals from the L units of transmitting antennas.

Abstract: A base station is provided with a plurality of radio units that communicate with a terminal, and a control device connected to the plurality of radio units. When there is a large number of terminals positioned at a boundary of the communication areas of a first radio unit and a second radio unit among the plurality of radio units, the control device makes a first cell ID of the first radio unit and a second cell ID of the second radio unit being identical.

Abstract: Transmission power relative to a propagation path having a variation in gain is controlled to increase communication channel capacity, and a data rate is controlled in accordance with the variation of the increased communication channel capacity. In order to increase the communication channel capacity, the transmission power is determined so that the sum of noise power (=received noise power/propagation path gain) converted into one at a transmitter and the transmission power becomes constant. As a result, contrary to the background art, the transmission power is controlled to be reduced when the propagation path gain decreases and to be increased when the propagation path gain increases.

Abstract: A discontinuous change in a transmission timing in a time domain, which is caused by a transmission timing adjustment processing of an OFDMA uplink or the like, brings about a discontinuous rotation of a signal phase in a frequency domain, resulting in reduced communication quality. A wireless communication system of the present invention allows the signal phase of the frequency domain in a receiving station to be continuous before and after the timing adjustment processings by controlling a signal sequence in a transmission signal after conversion in the time domain in synchronization with the timing adjustment processing.

Abstract: A cellular radio communication system includes a first mobile terminal, a base station that performs radio communication with first mobile terminals, a second mobile terminal, and a second base station that performs radio communication with second mobile terminals. In the downlink communication, the base station selects a high data rate mode when the radio interference from the base station to the second mobile terminals that are located close to an edge of a communication area of the second base station is small. The base station selects an interference mitigation mode in the downlink communication when the radio interference from the base station to the second mobile terminals that are located close to the edge of the communication area of the second base station is large. Thus, inter-cell interference control can be performed in collaboration with base stations in the radio communication system without having communication interface between the base stations.

Abstract: This invention provides a mobile communication system which expanded the operation limitation of the heretofore adopted mobile communication systems and improved the spectrum efficiency greatly. A data transmission method for use in the mobile communication system of the present invention includes means for channel pluralizing by which to expand the Shannon limit and means for interference reduction by which to expand the interference limit. More specifically, a transmitting module comprises M units of modulators and L units of transmitting antennas, generates L units of signals by multiplying M units of modulated signals by a complex matrix consisting of M×L units of elements, and transmits the L units of signals from the L units of transmitting antennas.

Abstract: In a time slot in which a first base station for performing a multicast transmission executes the multicast transmission, a second base station which does not perform the multicast transmission does not perform a unicast data transmission. The time slot in which the first base station performs the multicast transmission is notified to the second base station from a multicast control apparatus for performing scheduling of the multicast transmission to the first base station. Information to receive the multicast transmission is notified from the second base station to a terminal connected to the second base station.

Abstract: An information transmission method in a multi-carrier wireless communication system in which a transmitter and a receiver conduct communication by using one or plural resource blocks containing plural modulation symbols. One or plural resource blocks correspond to one or plural frequency carriers and one or plural time symbols, including: an operation in which a pilot signal is transmitted by using a part of plural modulation symbols in resource blocks, an operation in which transmission information is encoded by using an error correction code, and an operation in which encoded information is mapped and allocated to modulation symbols, wherein a number of modulation symbols in each resource block in which encoded information is mapped is independent to a number of modulation symbols in resource blocks used to transmit pilot signals, and encoded information mapped and allocated to modulation symbols at the same position as pilot signal is transmitted, are punctured.

Abstract: Ameliorate deterioration in quality of communication caused by intercell interference with respect to a multicarrier communications protocol, such as OFDM. A method of positioning an error correction-coded signal is changed with a data symbol that is transmitted simultaneously with a pilot signal and a data symbol that is not simultaneous with the pilot symbol. Else, a modulation protocol is changed with a data symbol that is transmitted simultaneously with a pilot signal and a data symbol that is not simultaneous with the pilot symbol. It would further be permissible to lower either a signal amplitude or a power level of a data symbol that is transmitted simultaneously with a pilot signal.

Abstract: This invention provides a mobile communication system which expanded the operation limitation of the heretofore adopted mobile communication systems and improved the spectrum efficiency greatly. A data transmission method for use in the mobile communication system of the present invention includes means for channel pluralizing by which to expand the Shannon limit and means for interference reduction by which to expand the interference limit. More specifically, a transmitting module comprises M units of modulators and L units of transmitting antennas, generates L units of signals by multiplying M units of modulated signals by a complex matrix consisting of M×L units of elements, and transmits the L units of signals from the L units of transmitting antennas.