Abstract: There is provided a wireless communication system which can improve throughputs in wireless communication by effectively using frequency resources. In the wireless communication system including a plurality of wireless communication stations which may operate as wireless communication terminals or wireless base stations, the wireless communication station includes an access right acquisition means of acquiring an access right upon generating transmitting data; a determination means of determining whether or not different data destined to a plurality of wireless communication stations can be transmitted on different channels according to OFDMA; and a data transmitting means of transmitting data to the receivable wireless communication stations using OFDMA when the determination means determines that different data destined to a plurality of wireless communication stations can be transmitted on different channels.

Abstract: In a wireless communication system in which an AP and a plurality of STAs are connected to each other and the AP simultaneously transmits a wireless frame destined for each STA with FDMA, in which the AP includes a control frame transmission unit that generates a control frame having information on a frequency resource allocated to the each STA and transmits the control frame on a primary channel being used in a shared manner by the each STA and a wireless frame transmission unit that simultaneously transmits the wireless frame destined for the each STA on the frequency resource allocated to the each STA, and in which the STA includes a frequency resource selection reception unit that receives the control frame on the primary channel and receives a wireless frame destined for the STA itself on a frequency resource notified by the control frame.

Abstract: A ball bearing unit for a turbocharger according to an embodiment includes: an outer ring, a first inner ring, a second inner ring, a first machined retainer and a second machined retainer. The outer ring has an inner peripheral surface provided with an outer ring raceway surface at one end side and an outer ring raceway surface at another end side. At least one of the first machined retainer and the second machined retainer includes a plurality of pockets that hold the plurality of balls in a rollable manner in a circumferential direction. Each of the pockets has a diameter of equal to or more than 1.03 times and equal to or less than 1.07 times of a diameter of the balls.

Abstract: Interference in preamble signals and pilot signals in cooperative transmission using interference suppressing technology is avoided. A wireless apparatus for transmitting a wireless signal on which directivity control has been performed to stations in a wireless system including at least one wireless apparatus is provided with a known signal generating unit which generates a known signal to be added to the wireless signal, a weighting processing unit which performs weighting on the known signal generated by the known signal generating unit, and a wireless processing unit which transmits the known signal on which the weighting has been performed by the weighting processing unit.

Abstract: An instrument panel reinforcement in a tubular shape according to one aspect comprises a large-diameter portion that supports a steering column, a small-diameter portion that has an outer diameter smaller than an outer diameter of the large-diameter portion and has a thickness smaller than a thickness of the large-diameter portion, and an intermediate portion that is arranged between the large-diameter portion and the small-diameter portion. The intermediate portion is formed integrally with the large-diameter portion and has an outer diameter smaller than the outer diameter of the large-diameter portion.

Abstract: A rolling bearing is filled with a grease composition that contains a fluorine-based grease including a fluorine-based base oil and a fluorine-based thickener, a non-fluorine-based grease including a non-fluorine-based base oil and a non-fluorine-based thickener, and an additive serving as a dispersant. The non-fluorine-based thickener includes at least one of aliphatic-aromatic urea, alicyclic-aliphatic urea and aliphatic urea. The dispersant includes at least one of polycarboxylic acid metal salt, fluorine-containing group/lipophilic group-containing oligomer, fluorinated ether diamide, and organic acid metal salt.

Abstract: A wireless communication system includes a plurality of terminal apparatuses that perform communication using a first frequency band in which communication based on a random access scheme is performed and a second frequency band which is different from the first frequency band, a first base station apparatus that performs communication using the first frequency band, a second base station apparatus that performs communication using the second frequency band, and a cooperation control apparatus that selects a terminal apparatus that transmits user data via the first base station apparatus from among the plurality of terminal apparatuses based on information acquired by the first base station apparatus and the second base station apparatus.

Abstract: A grease composition according to an embodiment includes a base oil, a thickener and 0.5% by weight or more of a dispersing agent, the dispersing agent including at least one of a carboxylic acid metal salt, a metal salt of a polycarboxylic acid and a copolymer of a carboxylic acid metal salt and a hydrocarbon compound.

Abstract: An actuator includes a stepping motor; a multi-stage gear device including a first stage gear attached to a rotation shaft of the motor, wherein a gear of each stage engages with a gear of a next stage; and a base member on which the multi-stage gear device and the stepping motor are mounted, wherein in the multi-stage gear device, a grease composition for resin is applied to a bearing part of the gear, and to an engaging part between the gears, and the grease composition for resin includes: (a) a base oil including a poly-alpha-olefin oil with a kinematic viscosity at 100° C. of 4 to 6 mm2/s; (b) a thickening agent which is lithium soap; (c) a viscosity increasing agent; (d) a solid lubricant; and (e) an anti-wear agent, and wherein the NLGI consistency number of the composition is 00, 0, 1, or 2.

Abstract: Provided are a wireless communication method, a base station, a wireless communication system and a communication apparatus whereby an interference power is calculated from an estimated propagation channel estimation result and the transmission power is controlled based on the interference power or the interference is suppressed by controlling the directivity, thereby increasing the transmission capacity. A propagation channel estimation circuit performs propagation channel estimation from a response signal transmitted from a terminal station and estimates a propagation channel estimation result. An interference power calculation circuit measures each interference power from a signal of each sub-carrier received by each of wireless units, and calculates an interference power for each sub-carrier from the propagation channel estimation result estimated by the propagation channel estimation circuit.

Abstract: A transmitter that has a plurality of antenna elements and executes spatially multiplexed transmission of data to a receiver via the antenna elements, where the data is weighted utilizing a transmission weight. Channel state information, which indicates propagation characteristics between the antenna elements and an antenna element of the receiver, is obtained or estimated. When the channel state information has been updated, an updated transmission weight is computed based on the previous channel state information before the updating thereof and/or the updated channel state information, and the previous transmission weight before the updating thereof, which was computed for the previous channel state information.

Abstract: The number of OFDM symbols for channel estimation is reduced, overhead due to a pilot signal and a feedback signal is reduced, and the throughput is improved.

Abstract: A wireless communication system includes a first wireless station including antenna elements, transmission units corresponding to the antenna elements, and a transmission directivity control unit that controls transmission directivity of the antenna elements, and second wireless stations each including a reception power measurement unit that measures a reception power. The transmission directivity control unit determines the transmission directivity of each of the antenna elements so that a signal does not reach a particular second wireless station among the second wireless stations. The transmission units generate wireless signals using the transmission directivity. The antenna elements transmit the generated wireless signals.

Abstract: In a system which performs wireless communication from an access point to stations using group identification information, the frequency of uses of group identification information that overlaps with that of another access point is reduced. An association between a station apparatus included in a group that is a target for simultaneous transmission and group identification information is stored, each station apparatus included in the group is notified of the group identification information, group identification information that is being used in the other access point apparatus is acquired, and if group identification information that is being used by the access point apparatus itself overlaps with the group identification information used by the other access point apparatus, the group identification information is changed so as to reduce the number of pieces of overlapping group identification information.

Abstract: The number of training signals for channel estimation is reduced.

Abstract: A wireless communication apparatus is provided that is capable of performing setting of a wireless LAN access point so that frequency utilization efficiency of an entire wireless communication system that includes wireless LAN access points of different manufacturers and different model numbers is improved.

Abstract: A transmitter that has a plurality of antenna elements and executes spatially multiplexed transmission of data to a receiver via the antenna elements, where the data is weighted utilizing a transmission weight. Channel state information, which indicates propagation characteristics between the antenna elements and an antenna element of the receiver, is obtained or estimated. When the channel state information has been updated, an updated transmission weight is computed based on the previous channel state information before the updating thereof and/or the updated channel state information, and the previous transmission weight before the updating thereof, which was computed for the previous channel state information.

Abstract: There is provided a wireless communication system which can improve throughputs in wireless communication by effectively using frequency resources. In the wireless communication system including a plurality of wireless communication stations which may operate as wireless communication terminals or wireless base stations, the wireless communication station includes an access right acquisition means of acquiring an access right upon generating transmitting data; a determination means of determining whether or not different data destined to a plurality of wireless communication stations can be transmitted on different channels according to OFDMA; and a data transmitting means of transmitting data to the receivable wireless communication stations using OFDMA when the determination means determines that different data destined to a plurality of wireless communication stations can be transmitted on different channels.

Abstract: In order to provide a wireless communication system capable of improving the throughput of wireless communication by effectively using frequency resources, in a wireless communication system in which a first wireless access point which communicates with one or more wireless stations within a first cell by orthogonal frequency-division multiple access and a second wireless access point which is capable of performing carrier sensing with the first wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other, the first wireless access point includes a transmission opportunity acquiring unit which acquires a transmission opportunity when data to be transmitted is generated; and a transmitting unit of permission for use which transmits permission for use of channels which are not scheduled to use within the first cell, to the second wireless access point in a period in which the transmissio

Abstract: Provided are a wireless communication method, a base station, a wireless communication system and a communication apparatus whereby an interference power is calculated from an estimated propagation channel estimation result and the transmission power is controlled based on the interference power or the interference is suppressed by controlling the directivity, thereby increasing the transmission capacity. A propagation channel estimation circuit performs propagation channel estimation from a response signal transmitted from a terminal station and estimates a propagation channel estimation result. An interference power calculation circuit measures each interference power from a signal of each sub-carrier received by each of wireless units, and calculates an interference power for each sub-carrier from the propagation channel estimation result estimated by the propagation channel estimation circuit.