Abstract: The performance of a power supply module is to be improved. The occurrence of discharge in the power supply module is to be prevented, and the size of the power supply module is to be reduced. In a power supply module, substrates are provided being stacked in a planar view. A low voltage circuit and a high voltage circuit are formed on a first substrate such that a distance is kept for preventing surface discharge, and a low voltage circuit is formed on a second substrate. A distance between a component of a high voltage alternating current circuit on the high voltage circuit and a component of the low voltage circuit is three times a shortest distance, at which space discharge does not occurs, between a component that constitutes a high voltage direct current circuit on the high voltage circuit and a component that constitutes the low voltage circuit.

Abstract: A radio communication device that receives signals by using a plurality of reception antennas in a radio communication system employing multi-station simultaneous transmission includes: processing circuitry that estimates channel information on the basis of training symbol sequences, which are different depending on the base-station antennas, included in received signals, and outputs a channel information estimation result; performs a channel matrix extending process of extending dimension of a channel matrix on the basis of the channel information estimation result and a coding rule of the received signals, and extending array's degree of freedom; generates an interference suppression weight by using the channel matrix resulting from the channel matrix extending process; and extends dimension of a received signal vector by using a result of observation over symbol duration time for a plurality of symbols, and multiplies the received signal vector resulting from the extension of dimension by the interference

Abstract: A radio communication apparatus includes an estimator that estimates virtual cell identification information, channel responses for each antenna, and arrival delay amounts for each antenna, a selector that calculates the channel power level of each ground base station from the channel responses, calculates the arrival delay amount of each ground base station from the arrival delay amounts, and selects one or more desired ground base stations and interference ground base stations from the virtual cell identification information, the channel power levels, and the arrival delay amounts, a combiner that, based on the number of the antennas, combines the channel responses of the desired ground base stations into one effective desired channel matrix, and combines the channel responses of the interference ground base stations into one effective interference channel matrix, and a controller that controls directivity using the effective desired channel matrix and the effective interference channel matrix.

Abstract: A wireless relay station to be included in a ladder-type wireless relay network along a moving route of a moving object includes a relay control unit that includes station identification information in the wireless relay network assigned sequentially along the moving route to each of the wireless relay stations included in the wireless relay network and deployed along the moving route, configures and updates, using a first routing table that provides an address of a destination wireless relay station, a second routing table including the address, the station identification information, and an information update time, being associated with one another, of the destination wireless relay station, and provides control to share, among the wireless relay stations included in the wireless relay network, the second routing table configured and updated by each wireless relay station; and a relay communication unit that performs wireless relay communication with other wireless relay stations.

Abstract: A transmission apparatus that transmits a block signal including a plurality of data symbols, includes: a data-symbol generation unit that generates a data symbol; a symbol arrangement unit that arranges the data symbol and a same-quadrant symbol such that one same-quadrant symbol that becomes a signal point in a same quadrant in a complex plane is inserted per block at a predetermined position in each block signal to generate a block symbol; a CP insertion unit that inserts a Cyclic Prefix into the block symbol; and an interpolation unit that performs interpolation processing on the block symbol on which CP insertion has been performed.

Abstract: A lower base station according to the present invention includes: a CSI acquisition unit that acquires channel information indicating a channel state between the lower base station and one or more mobile terminals; a lower scheduler unit that transmits the channel information to a higher base station, and determines the number of signal streams and a modulation and coding scheme for a destination terminal that is a mobile terminal selected from among the one or more mobile terminals, based on the destination terminal and a data transmission rate for the destination terminal, sent for notification by the higher base station; and an MU-MIMO signal processing unit that performs Multi User-Multiple Input Multiple Output precoding for the mobile terminal.

Abstract: In a communication system that performs multihop wireless transmission between radio stations arranged at intervals, allocation of a same channel is repeated every odd-number of hops among a plurality of consecutive hops, and reception antennas and transmission antennas for radio signals relayed by the radio stations are installed at such positions that transmission paths of the radio signals have zigzag shapes.

Abstract: A management server includes a processor and a storage that stores correlation information in which a category into which content is classified, location information, and an access frequency are correlated with one another. The processor acquires access information on an access from a wireless terminal to a content server via an access point and a network, a content requested by the wireless terminal, and location information corresponding to the accessed access point, updates the correlation information by rewriting the access frequency corresponding to a category to which the requested content belongs and the acquired location information, according to the access information, specifies a category and location information such that an access frequency related to the category and location information in the updated correlation information satisfies a criterion, and stores a content belonging to the category in a cache area of an access point corresponding to the location information.

Abstract: A base station as a transmitter includes: a plurality of antenna units each capable of forming a plurality of beams; a candidate beam grouping unit that performs grouping of each beam formable by the plurality of antenna units, the grouping being performed based on the antenna unit that forms each beam; and a transmission signal generation unit that generates a transmission signal including beam identification information of a beam formed by the plurality of antenna units and group information indicating a group to which the beam belongs, and outputs the transmission signal generated to the antenna unit that forms a beam corresponding to the beam identification information included in the transmission signal.

Abstract: A lower base station according to the present invention includes: a CSI acquisition unit that acquires channel information indicating a channel state between the lower base station and one or more mobile terminals; a lower scheduler unit that transmits the channel information to a higher base station, and determines the number of signal streams and a modulation and coding scheme for a destination terminal that is a mobile terminal selected from among the one or more mobile terminals, based on the destination terminal and a data transmission rate for the destination terminal, sent for notification by the higher base station; and an MU-MIMO signal processing unit that performs Multi User-Multiple Input Multiple Output precoding for the mobile terminal.

Abstract: A reception device includes: a reception unit receiving transmission signals; a splitting unit splitting received signals into real component and imaginary component; a narrowing unit narrowing down possible signal point candidates of real component of the signal and imaginary component of the signal to signal point candidates based on the real component and the imaginary component of the split received signal; a signal point candidate hypothesizing unit hypothesizing one signal point candidate of real component from the signal point candidates of real component obtained by narrowing-down and hypothesizing one signal point candidate of imaginary component from the signal point candidates of imaginary component obtained by narrowing-down; and a signal estimation value calculating unit estimating real component of the signal based on the one hypothesized real component signal point candidate and estimating imaginary component of the signal based on the one hypothesized imaginary component signal point candidate

Abstract: A base station serving as a transmission apparatus includes a plurality of transmission antennas capable of forming beams directed to a plurality of terminals, which are reception apparatus, and a precoder configured to perform outer precoding on transmission signals transmitted from the plurality of transmission antennas. The plurality of terminals include at least one first reception apparatus, which are transmission destinations of the transmission signals, and second reception apparatus, which are reception apparatus other than the first reception apparatus. The precoder performs outer precoding on the transmission signals transmitted from the plurality of transmission antennas so that received power in the second reception apparatus among the plurality of reception apparatus is equal to or less than a threshold.

Abstract: A reception device according to the present invention includes: a signal division unit; a maximum-likelihood point search unit; a maximum-likelihood point search unit; a replica-vector calculation unit; a replica-vector calculation unit; and a likelihood calculation unit. Wherein, the signal division unit divides a reception signal including a plurality of multiplexed signals respectively into a real component and an imaginary component; the maximum-likelihood point search unit narrows down candidate signal points; the maximum-likelihood point search unit to narrows down candidate signal points; the a replica-vector calculation unit calculates a first replica vector by using the first candidate signal point; the replica-vector calculation unit calculates a second replica vector by using the second candidate signal point; and the likelihood calculation unit calculates a likelihood of the modulation signal by using the first replica vector and the second replica vector.

Abstract: A base station apparatus includes a ground station device and a plurality of ground antenna devices coupled to the ground station device via an optical transmission path. The ground station device performs electrical-optical conversion on an analog electrical signal to be transmitted to a mobile station and a reference clock signal to generate optical signals, performs wavelength division multiplexing on the obtained optical signals to generate a multiplexed optical signal, and outputs the multiplexed optical signal to the optical transmission path.

Abstract: A reception device includes: a reception unit receiving transmission signals; a splitting unit splitting received signals into real component and imaginary component; a narrowing unit narrowing down possible signal point candidates of real component of the signal and imaginary component of the signal to signal point candidates based on the real component and the imaginary component of the split received signal; a signal point candidate hypothesizing unit hypothesizing one signal point candidate of real component from the signal point candidates of real component obtained by narrowing-down and hypothesizing one signal point candidate of imaginary component from the signal point candidates of imaginary component obtained by narrowing-down; and a signal estimation value calculating unit estimating real component of the signal based on the one hypothesized real component signal point candidate and estimating imaginary component of the signal based on the one hypothesized imaginary component signal point candidate

Abstract: A distributed antenna system includes a plurality of antenna groups which includes first antennas and second antennas. The first antennas form beams in a first direction along a mobile station track and transmit identical signals at identical frequencies. The second antennas form beams in a second direction opposite to the first direction and transmit identical signals at identical frequencies. The antenna groups are installed on one side of the mobile station track.

Abstract: A transmission apparatus that transmits a block signal including a plurality of data symbols, includes: a data-symbol generation unit that generates a data symbol; a symbol arrangement unit that arranges the data symbol and a same-quadrant symbol such that one same-quadrant symbol that becomes a signal point in a same quadrant in a complex plane is inserted per block at a predetermined position in each block signal to generate a block symbol; a CP insertion unit that inserts a Cyclic Prefix into the block symbol; and an interpolation unit that performs interpolation processing on the block symbol on which CP insertion has been performed.

Abstract: A transmission apparatus that transmits a block signal including a plurality of data symbols, includes: a data-symbol generation unit that generates a data symbol; a symbol arrangement unit that arranges the data symbol and a same-quadrant symbol such that one same-quadrant symbol that becomes a signal point in a same quadrant in a complex plane is inserted per block at a predetermined position in each block signal to generate a block symbol; a CP insertion unit that inserts a Cyclic Prefix into the block symbol; and an interpolation unit that performs interpolation processing on the block symbol on which CP insertion has been performed.

Abstract: A transmission device to be applied to a communication system configured to carry out multi-user MIMO downlink communication, includes a precoder configured to apply transmission precoding processing, a nonlinear processor configured to carry out successive interference cancellation, a beam forming controller configured to form a plurality of beams and to control a beam radiation direction, and a user ordering processor configured to estimate a positional relationship among the plurality of user terminals from radiation direction information on each of the beams, order users in ascending order of a distance from a specific user, and determine a pairing of a transmission target user and an interference permissible user. The precoder determines two users of the transmission target user and the interference permissible user for each user based on the pairing result, and carries out null steering for users other than the two users, to thereby carry out the transmission precoding processing.

Abstract: A base station apparatus includes a ground station device and a plurality of ground antenna devices coupled to the ground station device via an optical transmission path. The ground station device performs electrical-optical conversion on an analog electrical signal to be transmitted to a mobile station and a reference clock signal to generate optical signals, performs wavelength division multiplexing on the obtained optical signals to generate a multiplexed optical signal, and outputs the multiplexed optical signal to the optical transmission path.