Abstract: An allocation method for allocating individual downlink data signals to positions on a time axis when a base station transmits the individual downlink data signals to a plurality of terminal stations. The allocation method includes provisionally allocating individual downlink data signals of the individual downlink data signals for terminal stations having long propagation delay times to positions of relatively early timings and provisionally allocating individual downlink data signals of the individual downlink data signal for terminal stations having short propagation delay times to positions of relatively late timings, changing the positions such that, when it is estimated that a collision will occur when receiving response signals transmitted from the terminal stations, it is estimated that a collision will not occur, in the provisionally allocating, and fixing, as the positions of the individual downlink data signals on the time axis, the positions changed in the changing of the positions.

Abstract: A station placement design method includes: extracting candidates for an installation location of a wireless base station from point group data in accordance with designated conditions for an installation location of a wireless base station; determining presence/absence of visibility between a plurality of designated wireless terminal stations and the candidates for an installation location of a wireless base station based on the point group data and generating a first list including information in which the candidates for an installation location of a wireless base station and wireless terminal stations determined to have presence of visibility for the candidates for an installation location of a wireless base station are associated with each other; generating a second list including information representing combinations of the candidates for an installation location of a wireless base station that enable all of the plurality of designated wireless terminal stations to be accommodated based on the first list

Abstract: An accommodation station transmission unit modulates light based on an RF signal to generate an optical signal and outputs the generated optical signal, a base station transmission unit demultiplexes the output optical signal for each of wavelengths, outputs the demultiplexed optical signals, converts the demultiplexed optical signals into electrical signals to demodulate the RF signal, outputs the demodulated RF signal, and each of first ports of a matrix operation unit including the plurality of first ports and a plurality of second ports and configured to use each of the first ports as a reference port and perform, on signals obtained by the reference ports, a BFN matrix operation of performing phase changes that are different for each of positions of the reference ports and cause each of phases of signals output from the plurality of second ports to have a linear inclination receives the demodulated RF signal and forms transmission beams in different directions for each of wavelengths by a plurality of tr

Abstract: A wireless communication system includes: a communication control device; and a plurality of wireless base station devices capable of forming a plurality of beams and transmitting signals, the communication control device including: an estimation unit configured to estimate whether or not a range of a first beam emitted by a first wireless base station device among the plurality of wireless base station devices is correlated with a range of a second beam emitted by a second wireless base station device different from the first wireless base station device; and a use prohibition unit configured to prohibit the first wireless base station device from using the first beam or prohibit the second wireless base station device from using the second beam in a case where the estimation unit estimates that the range of the first beam is correlated with the range of the second beam.

Abstract: An interference evaluation method for evaluating, over an area, radio-wave interference that occurs between a first radio station and a second radio station includes: a distinguishing step of acquiring information indicating topographic cross-sections of respective azimuths centered about the first radio station, and distinguishing the topographic cross-section into a segment in which there is visibility from the position of the first radio station and a segment in which there is no visibility from the position of the first radio station; and a specification step of specifying a position at which a desired interference amount is reached based on a distance between the first radio station and the second radio station in a segment distinguished as having visibility from the position of the first radio station, and specifying a position at which the desired interference amount is reached by evaluating the radio-wave interference for each square of an evaluation target region segmented into squares in a segment d

Abstract: A radio communication method performed by a radio communication device includes an inverse fast Fourier transform step of performing inverse fast Fourier transform on a digital electric signal associated with a downlink radio signal, a digital-to-analogue conversion step of converting the digital electric signal subjected to the inverse fast Fourier transform into a first analogue electric signal, an electro-optic conversion step of converting the first analogue electric signal into an optical signal, a step of transmitting the optical signal, a photoelectric conversion step of converting the transmitted optical signal into a second analogue electric signal, and a step of transmitting the downlink radio signal corresponding to the second analogue electric signal.

Abstract: Using an array antenna in which a spacing between adjacent antenna elements is constant, each of combinations of two antenna elements in positions symmetrical relative to a center of an array is connected by wire connections in two paths, and a path length between the antenna elements in the combination of two antenna elements is the same in all of the combinations: a phase adjustment amount is calculated for each wire connection aside from a reference wire connection on the basis of an arrival direction of a wireless signal received by one antenna element in the combination of two antenna elements and a re-radiation direction of a wireless signal transmitted as a re-radiated wave by the other antenna element corresponding to the one antenna element, taking into account a phase difference between a signal transmitted by the wire connections connected to the one antenna element and a signal transmitted by the reference wire connection; and phase rotation is applied to the signal transmitted by the wire connect

Abstract: Point cloud data between a base station device and a terminal station device is acquired as a point cloud data group. A radius of a first Fresnel zone defined by the base station device and the terminal station device at each position where the point cloud data group is acquired is calculated. A region specified by the radius at each position where the point cloud data group is acquired is scanned to detect the point cloud data, and a non-line-of-sight region is extracted. A ratio of a total area of all the extracted non-line-of-sight regions to an area of a region constructed by the first Fresnel zone is calculated. A received power is estimated based on the calculated ratio between the areas. Whether or not there is a line of sight between the base station device and the terminal station device is determined based on the received power.

Abstract: A projection unit (12) of an interference power estimation device (1) projects an orbit of a satellite onto a map representing a ground surface. A range acquisition unit (13) determines a plurality of ranges on the map so that the projected orbit is included in the ranges. An altitude calculation unit (14) calculates an altitude of the orbit of the satellite in each of the ranges. A range interference calculation unit (16) calculates, for each of the ranges, an interference power between the satellite at a position determined by a latitude and a longitude of the range and the altitude calculated for the range and a radio station installed on the ground surface. An estimation result calculation unit (17) selects, as an estimation result, a maximum value among the interference powers calculated for each of the ranges.

Abstract: A derivation method includes: a transmission step of transmitting, to a wireless terminal, a first radio-wave signal according to an optical signal with a first wavelength and a second radio-wave signal according to an optical signal with a second wavelength; a communication start time information acquisition step of acquiring information on a first communication start time and information on a second communication start time; a reception time information acquisition step of acquiring information on a first reception time and information on a second reception time; a transmission time period derivation step of deriving a first round trip time and deriving a second round trip time; and an optical fiber length derivation step of deriving an optical fiber length, based on the first round trip time, the second round trip time, a group velocity or a group delay time of the optical signal with the first wavelength, and a group velocity or a group delay time of the optical signal with the second wavelength.

Abstract: A wireless communication method includes a reception step of receiving a signal transmitted from a first wireless station, a transmission step of transmitting the signal received in the reception step to a second wireless station, a control signal transmission/reception step of transmitting/receiving a control signal related to switching of a reception beam used in the reception step or a transmission beam used in the transmission step, and a beam control step of controlling switching of the reception beam or the transmission beam on the basis of the control signal.

Abstract: A method of estimating inter-user orthogonality in a distributed antenna system in which a base station includes a plurality of distributed antennas installed at a plurality of locations and which performs simultaneous radio transmissions with a plurality of user stations, the method of estimating inter-user orthogonality including the steps of: estimating a position of each of the user stations on the basis of installation positions of the plurality of distributed antennas, beam directions of the plurality of distributed antennas to each user station being a radio transmission partner, and an antenna height of each of the user stations; estimating an interference radio wave direction on the basis of the position of each of the user stations estimated in the step of estimating a position and installation positions of the plurality of distributed antennas; and calculating an angle difference between the beam direction and the interference radio wave direction to estimate orthogonality between the user stations

Abstract: In two-dimensional map information showing communication equipment installation structures on which communication equipment is installed, roads, and buildings, a narrow region between the buildings is detected based on a distance of an interval of the buildings adjacent to each other and a predetermined length and a connection line connecting the buildings is imparted to an opened portion of the detected narrow region, a line-of-sight detection line is extended with any one of the communication equipment installation structures set as a start point and the line-of-sight detection line is rotated around the start point, intersections of the line-of-sight detection line and a contour line of the building or the connection line is detected and the intersection at a shortest distance from the start point among the detected intersections is detected as a line-of-sight intersection, and, when the line-of-sight intersection and another line-of-sight intersection belong to the same building, a line-of-sight range lin

Abstract: A position measurement method includes a point group data generation step of generating point group data indicating a position of an object around a predetermined route measured by a measurement unit moving along the route, an acquisition step of acquiring a plurality of pieces of point group data generated by being measured at different timings with respect to the same route, and a position identification step of identifying a detection target position indicating a position of a predetermined object present around the route on the basis of a difference in the position for each of the plurality of pieces of point group data.

Abstract: A radio communication method performed by a terminal station device includes: a first radio communication step of establishing connection to a first base station device among a plurality of surrounding base station devices; a control step of recording information regarding the first base station device on a storage unit as first connection destination information; and a second radio communication step of establishing connection to a second base station device different from the first base station device with regard to the first connection destination information among the plurality of base station devices.

Abstract: Provided is a wireless relay system including multiple terminal station apparatuses and a base station apparatus. The base station apparatus includes: a base station reception unit that respectively receives pieces of upstream data traffic from the multiple terminal station apparatuses; an encoding unit that, if pieces of upstream data traffic that require mutual forwarding in opposite directions are present in the respective pieces of upstream data traffic, performs network encoding on the respective pieces of upstream data traffic such that the pieces of upstream data traffic are pieces of data traffic of mutually identical content; and a base station transmission unit that simultaneously transmits encoded data traffic as downstream data traffic to the multiple terminal station apparatuses.

Abstract: A shielding object identifying unit identifies a partial point cloud representing a shielding object existing in a Fresnel zone on a basis of point cloud data indicating a position of the shielding object in the Fresnel zone between two wireless stations. A criterion decision unit decides an evaluation criterion of propagation loss by the shielding object on a basis of distribution of the partial point cloud. A determination unit makes determination related to communication between the two wireless stations on a basis of the evaluation criterion.

Abstract: A derivation method is a derivation method performed by a communication system, including: a transmission step of transmitting a first radio-wave signal according to an optical signal with a first wavelength and a second radio-wave signal according to an optical signal with a second wavelength; a communication start time information acquisition step of acquiring information on a first communication start time and information on a second communication start time; a reception time information acquisition step of acquiring information on a first reception time that is a reception time related to the first radio-wave signal, and information on a second reception time that is a reception time related to the second radio-wave signal; and an optical fiber length derivation step of deriving a length of the optical fiber, based on the first communication start time, the first reception time, the second communication start time, the second reception time, a group velocity or a group delay time of the optical signal wit

Abstract: n wavelengths set such that delay differences between optical signals due to wavelength dispersion in an optical fiber between accommodation and base stations are at equal intervals are assigned to n antenna elements of the base station which are at predetermined intervals. The accommodation station adjusts the phases of optical signals of the wavelengths or modulated signals that modulate the optical signals such that the amounts of phase shift of their RF signals are at predetermined intervals. The accommodation station transmits beacon signals multiple times while varying a transmission phase shift interval ?1 and the terminal transmits beacon number information of a beacon signal selected based on received power multiple times.

Abstract: A communication system includes a central station device and a base station device. The central station device includes: a plurality of signal processing units, each generating an electrical signal of a wireless signal by performing signal processing corresponding to a wireless system; a conversion unit that generates an optical signal by performing intensity modulation on the electrical signal; and a signal processing control unit that controls the conversion unit to generate an optical signal in which a plurality of the electrical signals are multiplexed. The base station device includes: an electrical signal generation unit that receives the optical signal generated in the central station device via an optical transmission path and converts the received optical signal into a plurality of electrical signals; and a plurality of antenna devices, each wirelessly transmitting the wireless signal according to the electrical signal generated by the electrical signal generation unit.