Abstract: A satellite communication earth station includes a detection unit that detects a longitude, a latitude, an altitude, an azimuth, and an inclination of the antenna, a drive unit that drives the antenna to adjust the azimuth angle, the elevation angle, and the polarization angle of the antenna to the communication satellite, a determination unit that determines whether the longitude, the latitude, the altitude, the azimuth, or the inclination detected by the detection unit or the azimuth angle, the elevation angle, or the polarization angle driven by the drive unit makes a change from an initial setting value to a predetermined threshold value or more, and a stop processing unit that stops transmission of the radio wave from the antenna when the determination unit determines that the change from the initial setting value to the predetermined threshold value or more is made.

Abstract: Determination information necessary to determine accuracy of detection of a longitude, a latitude, and an altitude of an antenna is acquired, whether the accuracy of detection of the longitude, the latitude, and the altitude is in a necessary and sufficient level is determined in accordance with the acquired determination information, the longitude, the latitude, the altitude, the azimuth, and the inclination of the antenna are detected also after elapse of a predetermined time after the transmission of the radio wave from the antenna is stopped, and the antenna is driven to adjust the azimuth angle, the elevation angle, and the polarization angle of the antenna to the communication satellite in accordance with the longitude, the latitude, the altitude, the azimuth, and the inclination of the antenna detected after elapse of the predetermined time after the transmission of the radio wave from the antenna is stopped.

Abstract: A portable station stores satellite information related to the longitude and the beacon signal of a plurality of communications satellites, executes a rough adjustment process of computing an antenna direction with respect to a target communications satellite on the basis of the longitude of the target communications satellite acquired from the satellite information and an installation location of the portable station itself, and roughly adjusting the antenna direction of the portable station itself in the computed antenna direction, and executes a fine adjustment process of, in a case where the frequency of a beacon signal is a predetermined frequency of the target communications satellite, measuring the beacon signal while increasing or decreasing the azimuth by treating the azimuth of the roughly adjusted antenna as a reference direction, and in a case where a measurement result of a beacon signal matches the information related to the beacon signal from another communications satellite at the longitude th

Abstract: A plurality of control signals transmitted in individual frequency bands by a moving transmission station via a plurality of transmission antennas and a plurality of data signals transmitted in a common frequency band by the transmission station via the plurality of transmission antennas in synchronization with the control signals are received by each of a plurality of antennas disposed at different positions. Based on symbol timings of the control signals received by the antenna, a sampling rate error between the plurality of control signals transmitted by the plurality of transmission antennas, respectively, is compensated for. Based on the control signals subjected to the sampling rate error compensation, frame timings of the plurality of data signals transmitted by the transmission station via the plurality of transmission antennas are synchronized.

Abstract: A satellite communication system includes a plurality of earth station apparatuses and a control earth station apparatus, the plurality of earth station apparatuses each accommodating a terminal apparatus that establishes a session by using a control message being dedicated to perform communication, the control earth station apparatus transmitting and/or receiving a control signal on a controlling line to an earth station apparatus of the plurality of earth station apparatuses via a relay satellite, and the satellite communication system performing circuit-switching of a communicating line between the plurality of earth station apparatuses that are connected by single-hop connection to allow a plurality of the terminal apparatuses to perform communication with each other.

Abstract: In a radio system including: a plurality of transmitting station devices; a receiving relay station device for relaying radio signals transmitted by the transmitting station devices; and a receiving station device for receiving the radio signals relayed by the receiving relay station device, with a first transmission capacity between the receiving relay station device and the receiving station device varying, the receiving relay station device performs control to cause the transmitting station devices to transmit the radio signals if the first transmission capacity is greater than or equal to a predetermined value. With this configuration, a lack of information can be prevented even if the transmission capacity between the receiving relay station device and the receiving station device varies.

Abstract: A satellite communication system communicates via a communication satellite using one of a plurality of portable station devices as a master station device and another portable station device as a slave station device. The master station device transmits a first control signal for the slave station device to establish synchronization. The master station device determines that the slave station device is in a communicable state by a second control signal received from the slave station device that has received the first control signal and established synchronization. The master station device selects one of at least one slave station devices in a communicable state and transmits a third control signal for instructing start of transmission of a communication signal to the selected slave station device and the subject device. Due to this, it is possible to connect a channel between portable station devices without the intervention of a control station device or a regulation station device.

Abstract: In a band sharing communication system in which there are a primary system and a secondary system in descending order of priority of communication, the systems share frequency bands, and a base station or a line control device performs allocation of a requested band of a terminal station of each system, the base station or the line control device including: occupied band setting means for setting a primary occupied band and a secondary occupied band adjacent to the primary occupied band; band allocation means for allocating a vacant band of the primary occupied band with respect to a requested band of a primary terminal station and allocating a vacant band of the secondary occupied band with respect to a requested band of a secondary terminal station; and band transferring means for, when there is no vacant band in the primary occupied band with respect to a requested band of the primary terminal station, transferring a band of the secondary occupied band from the secondary occupied band to the primary occupi

Abstract: In a wireless communication system that performs a wireless communication by performing band division into a plurality of sub-spectra, a transmission device includes a band division unit and a transmission gain control unit configured to control a transmission gain of each of transmission signals of a plurality of sub-spectra for each sub-spectrum in accordance with information that is related to a power density of each sub-spectrum and fed back from a reception device so that the power density of each of reception signals of the plurality of sub-spectra on the reception device is uniform, and the reception device includes a reception power density detection unit configured to detect the power density of each of the plurality of sub-spectra to be received, a feedback unit configured to feed back information regarding the power density to the transmission device, and a band synthesis unit. Thus, it is possible to avoid deterioration of signal quality in hand division and synthesis transmission.

Abstract: An object is to provide a method and a system of adjusting a power amplifier which makes it possible to adjust a linearizer using signals of two carriers by the same power, to reduce the influence of the non-linearity on a multicarrier signal compared with the conventional. A method of adjusting a power amplifier, the power amplifier including a linearizer to reduce an intermodulation caused by non-linearity of the power amplifier, includes: inputting two signals generated by a signal generator into the power amplifier; measuring power of each order of first intermodulations of the two signals output from the power amplifier; calculating a power sum of second intermodulations by the plurality of signals using the measured power of each order of the first intermodulations; and adjusting the linearizer so that the power sum of the second intermodulations by the plurality of signals takes a minimum value or at most a predetermined value.

Abstract: In a band sharing communication system in which there are a primary system and a secondary system in descending order of priority of communication, the systems share frequency bands, and a base station or a line control device performs allocation of a requested band of a terminal station of each system, the base station or the line control device includes: occupied band setting means for setting a primary occupied band and a secondary occupied band adjacent to the primary occupied band; band allocation means for allocating a vacant band of the primary occupied band with respect to a requested band of a primary terminal station and allocating a vacant band of the secondary occupied band with respect to a requested band of a secondary terminal station; and band transferring means for, when there is no vacant band in the primary occupied band with respect to the requested band of the primary terminal station, if a vacant band equivalent to the requested band is present in the secondary occupied band such that th

Abstract: A band sharing communication system in which there are an N-ary system and an N+1-ary system in descending order of priority of communication, the systems share frequency bands and allocation of a requested band of a terminal station of each system is performed, includes: occupied band setting means for setting an N-ary occupied band and an N+1-ary occupied band adjacent to the N-ary occupied band; band allocation means for allocating a vacant band of the N-ary occupied band with respect to a requested band of an N-ary terminal station and allocating a vacant band of the N+1-ary occupied band with respect to a requested band of an N+1-ary terminal station; and band transferring means for, when there is no vacant band in the N-ary occupied band with respect to the requested band of the N-ary terminal station, if a vacant band equivalent to the requested band is present in the N+1-ary occupied band such that the vacant band is adjacent to the N-ary occupied band, transferring the vacant band from the N+1-ary oc

Abstract: A reception apparatus includes: an interference estimation unit configured to estimate a frequency band of an interference signal in a reception signal on which the interference signal having a narrower frequency band than that of a transmission signal transmitted by a transmission apparatus is superimposed; a feedback unit configured to feed back the frequency band of the interference signal estimated by the interference estimation unit to the transmission apparatus; and a band synthesis unit configured to synthesize a plurality of sub-spectra in a frequency band corresponding to a plurality of sub-spectra decomposed by the transmission apparatus, and a transmission apparatus includes: a band division control unit configured to perform control for determining a band in which a transmission signal is divided based on the frequency band of the interference signal fed back from the reception apparatus; and a band division unit configured to band-divide the transmission signal into a plurality of sub-spectra so

Abstract: In a wireless communication system that includes a base station, a plurality of relay stations that are moving, and a plurality of terminal stations in a service area, and performs downlink multiple access from the base station to each of the plurality of terminal stations via one or more relay stations of the plurality of relay stations, the base station includes a downlink multiple access unit configured to identify a relay station of the plurality of relay stations transmitting a signal receivable in the service area based on positions of the plurality of relay stations, frequency multiplex-transmit a data signal in a different frequency band to each of the plurality of terminal stations via the relay station, and spatial multiplex-transmit a data signal to a terminal station of the plurality of terminal stations supporting spatial multiplex transmission in a particular frequency band and via the plurality of relay stations.

Abstract: [Problem] A comprehensive line control in which a first wireless communication system preferentially uses a frequency band and a second wireless communication system secondarily uses an unused band is realized.

Abstract: An object is to provide a method and a system of adjusting a power amplifier which makes it possible to adjust a linearizer using signals of two carriers by the same power, to reduce the influence of the non-linearity on a multicarrier signal compared with the conventional. A method of adjusting a power amplifier, the power amplifier including a linearizer to reduce an intermodulation caused by non-linearity of the power amplifier, includes: inputting two signals generated by a signal generator into the power amplifier; measuring power of each order of first intermodulations of the two signals output from the power amplifier; calculating a power sum of second intermodulations by the plurality of signals using the measured power of each order of the first intermodulations; and adjusting the linearizer so that the power sum of the second intermodulations by the plurality of signals takes a minimum value or at most a predetermined value.

Abstract: In a wireless transmission system that transmits and receives a modulated signal between a transmitter and a receiver that are coupled through a wireless transmission path, the transmitter includes a spectrum division filter bank dividing the modulated signal and generating a plurality of sub-spectrum signals each of which is arranged at a predetermined frequency position, and subjects the plurality of sub-spectrum signals arranged in spectra to a direct spectrum division transmission, and the receiver includes a spectrum combination filter bank extracting the plurality of sub-spectrum signals from the received signals arranged in spectra and subjected to the direct spectrum division transmission to combine the sub-spectrum signals into an original modulated signal.

Abstract: In a wireless transmission system that transmits and receives a modulated signal between a transmitter and a receiver that are coupled through a wireless transmission path, the transmitter includes a spectrum division filter bank dividing the modulated signal and generating a plurality of sub-spectrum signals each of which is arranged at a predetermined frequency position, and subjects the plurality of sub-spectrum signals arranged in spectra to a direct spectrum division transmission, and the receiver includes a spectrum combination filter bank extracting the plurality of sub-spectrum signals from the received signals arranged in spectra and subjected to the direct spectrum division transmission to combine the sub-spectrum signals into an original modulated signal.

Abstract: The present invention provides a reflow apparatus capable of precisely adjusting the heating temperature and heating time when heating a work for reflow. A work transfer conveyor for transferring a work into a furnace body is disposed, wherein a plurality of preheating zones through for preheating the work, a plurality of reflow zones for heating the work for reflow, and a plurality of cooling zones for cooling the work are successively arranged along the work transfer conveyor in the furnace body. The individual reflow zones are formed shorter than the individual preheating zones in the work transfer direction. It is preferable that the sizes of the individual reflow zones in the transfer direction are shortened to approximately 65% to 85% with respect to the individual preheating zones or the conventional individual reflow zones.

Abstract: A reflow system in which a reflow furnace is sequentially divided into a plurality of zones along a conveying path of a heat target which is conveyed and by controlling temperatures of the plurality of zones, the heat target which is conveyed is reflowed has: a cooling and flux collecting apparatus circulating and cooling atmosphere gases in furnace bodies of a part or all of the plurality of zones and collecting a flux; and a flow rate control unit which is inserted into a circulating path of the atmosphere gas of each of the zones and can control a flow rate. When the temperature of the zone is reduced, by controlling the flow rate control unit, the flow rate is set to be higher than that upon collecting the flux.