Nippon Telegraph and Telephone Corporation

Naoki Kita

Yushi Shirato

Kota Ito

Kazuto Goto

Hideyuki Tsuboi

Mizuki Suga

Hideki Toshinaga

Yutaka Imaizumi

Chunhsiang Huang

Atsushi Ota

Nobuaki Otsuki

Takeshi Onizawa

Shuki Wai

Daisei Uchida

Tatsuhiko Iwakuni

Hiroyuki Nakamura

Tatsuya Fukui

Go Yazawa

Satoshi Kurosaki

The present invention performs: generating base station positional relationship specification data indicating a positional relationship between travel trajectory and a base station candidate position, and terminal station positional relationship specification data indicating a positional relationship between the travel trajectory and a terminal station candidate position, based on travel trajectory data indicating the travel trajectory of a moving body for measuring an object present in a three-dimensional space within a measurable distance predetermined and acquiring point cloud data indicating a position of the object measured in the three-dimensional space, the measurable distance, base station candidate position data indicating a candidate position for installing a base station apparatus, and terminal station candidate position data indicating a candidate position for installing a terminal station apparatus; and specifying a reliability coefficient indicating a degree of reliability of a processing result of a prescribed evaluation processing performed based on the point cloud data, based on the base station positional relationship specification data and the terminal station positional relationship specification data generated.

Station placement assistance method, station placement assistance apparatus and station placement assistance program

An installation candidate presentation device extracts, for each of one or more installation candidates that are candidates for an installation place of a first wireless device, by using planar map data indicating a planar map of a region including the installation candidates, and a target building at which second wireless devices are to be installed, respectively, an outline range of the building, which is visible from the installation candidate. The installation candidate presentation device calculates, for each installation candidate, by using three-dimensional map data indicating a three-dimensional map obtained by measuring the same region as the planar map data, area of part of a wall surface corresponding to the extracted outline range, the part being visible from the installation candidate, and calculates a total of the area calculated for the building in the region. The installation candidate presentation device presents an installation candidate selected based on the calculated total.

Installation candidate presentation method, installation candidate presentation apparatus and program

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.

Communication system, communication method, accommodation station device and base station device

On two-dimensional map data indicating buildings serving as candidates for installing terminal station devices, locations of base station installation structures serving as candidates for installing base station devices are set as base station candidate locations, and for each of the base station candidate locations, buildings that have other buildings between themselves and the base station candidate location are selected as visibility detection subject buildings. The heights of the buildings are set at an identical length, a higher position than the buildings is set as an installation altitude of the base station devices, and for each selected visibility detection subject building, a visibility range of the visibility detection subject building from the installation altitude of the base station device in the base station candidate location is detected. Three-dimensional point cloud data acquired by photographing a region including the base station installation structures and the buildings are narrowed down on the basis of the detected visibility ranges, and using the narrowed-down point cloud data, the visibility of the buildings from the base station candidate locations is determined.

Station placement designing method and station placement designing apparatus

A base station apparatus includes a centralized station apparatus and a plurality of access points connected to the centralized station apparatus via optical fibers. Based on propagation delay times in the optical fibers, the centralized station apparatus performs grouping such that access points, among a plurality of access points, with a difference in propagation delay time within a threshold value, belong to the same group. The plurality of access points perform connection processing for each of the groups, to communicate with wireless terminals subordinate to the plurality of access points.

Base station apparatus, communication method, and aggregate station apparatus

An APand STAsacquire time information from an external device, and synchronize time. The APsets, in a first signal, a transmission start time of the first signal, and transmits the first signal to the STA. The STAstransmit, to the AP, a second signal in which a delay time is set, the delay time being calculated from a difference between the transmission start time acquired from the first signal and a reception start time of the first signal at the own station. The APacquires delay time from the second signal of each STA, decides a timing for permitting transmission by each of the STAsby time division, on the basis of the acquired delay time, and notifies the STAsthereof. The STAseach effect control to start transmission of signals to the APat the timing notified from the AP

Wireless communication system, access point apparatus, wireless station apparatus and wireless communication method

A wireless communication device is presented. The wireless communication device includes: a high-frequency circuit; and an analog signal processing circuit that performs gain adjustment such that a gain for each of the plurality of antenna elements, in case of a signal transmission or in case of a signal reception, is a predetermined value being dependent on a position of the antenna element. The analog signal processing circuit includes a first splitter/combiner between the high-frequency circuit and the plurality of antenna elements. For each antenna element in the plurality of antenna elements, a second splitter/combiner is coupled to a particular antenna element in the plurality of antenna elements and, for each antenna element in the plurality of antenna elements, two or more phase shifters of a given M system are connected in parallel with each other and coupled between the first splitter/combiner and a corresponding second splitter/combiner.

Wireless communication device and wireless communication method

One aspect of the present invention is a shielding rate calculation device including a voxel division unit for dividing a Fresnel zone into a plurality of voxels each having a size corresponding to acquisition conditions at the time of acquiring point group data indicating a shielding object in an inter-wireless-station space between a transmission station and a reception station, and a calculation unit for calculating a shielding rate against a radio wave traveling from the transmission station toward the reception station on the basis of a position, a shape, and a size of a shielding voxel, which is a voxel at a position indicated by the point group data, among the plurality of voxels.

Shielding rate calculating apparatus, shielding rate calculating method and program

An accommodation station transmission unit modulates light to generate an optical signal based on an RF signal and outputs the generated optical signal, a base station transmission unit obtains the optical signal from an input port, demultiplexes the obtained optical signal for each wavelength, outputs the demultiplexed optical signals from output ports of corresponding wavelengths from among a plurality of output ports allocated to each of the wavelengths of the light, and demodulates the RF signal by converting the optical signals output by the output ports into electrical signals, a plurality of transmission antennas emit the demodulated RF signal, and a reflect array or a transmit array receives the RF signal emitted by each of the transmission antennas and forms a transmission beam in a different direction for each position of the transmission antenna that is a transmission source of the RF signal for each RF signal.

Wireless transmitting system, wireless receiving system, base station apparatus, wireless communication system, wireless transmitting method, and wireless receiving method

A line-of-sight determination method includes: a point cloud data acquisition step of acquiring point cloud data including a first position indicating a position of a first wireless station and a plurality of second positions indicating positions on a structure serving as a candidate in which a second wireless station opposing the first wireless station is to be installed; and a line-of-sight determination step of determining whether or not there is a line of sight between the first position and at least one of the second positions, and determining whether or not there is a line of sight between the first wireless station and the structure based on the determination result. In the line-of-sight determination step, if it has been determined that there is no line of sight between the first position and a first second position of the second positions, it is not determined whether or not there is a line of sight between the first position and a second second position among the second positions, the second second position being located in the vicinity of the first second position.

Perspective determination method, perspective determination apparatus and program

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.

Allocation method and signal processing apparatus

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; and sorting the second list in order from the smallest number of the candidates for an installation location of a wireless base station to the largest.

Station placement designing method, station placement designing apparatus and program

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 transmission antennas emitting the RF signal output by each of the second ports of the matrix operation unit.

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 distinguished as having no visibility from the position of the first radio station.

Interference evaluation method, interference evaluation apparatus and interference evaluation program

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 connections aside from the reference wire connection in accordance with the calculated phase adjustment amount.

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Musashino, Japan

Naoki Kita