Nippon Telegraph and Telephone Corporation

Kazuto Goto

Naoki Kita

Yushi Shirato

Hideyuki Tsuboi

Hideki Toshinaga

Kota Ito

Atsushi Ota

Yutaka Imaizumi

Shuki Wai

Daisei Uchida

Chunhsiang Huang

Takeshi Onizawa

Tatsuhiko Iwakuni

Hiroyuki Nakamura

Mizuki Suga

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

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 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

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 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

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.

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

A projection unit () of an interference power estimation device () projects an orbit of a satellite onto a map representing a ground surface. A range acquisition unit () determines a plurality of ranges on the map so that the projected orbit is included in the ranges. An altitude calculation unit () calculates an altitude of the orbit of the satellite in each of the ranges. A range interference calculation unit () 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 () selects, as an estimation result, a maximum value among the interference powers calculated for each of the ranges.

Interference power estimation method, interference power estimation apparatus and program

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 line along the contour line of the building is imparted to between the two line-of-sight intersections.

Perspective detection method, perspective detection apparatus and perspective detection program

A first wireless communication apparatus assigns a pilot signal without an effective signal component at least in an adjacent frequency component to a generated transmit signal, and transmits the transmit signal including the pilot signal. A second wireless communication apparatus converts the received signal or a frequency-converted signal obtained by frequency conversion of the signal into a signal in a frequency domain, sets an approximate value of the distance between the second wireless communication apparatus and the first wireless communication apparatus, calculates a coefficient &#x3b3;k, based on the approximate value of the distance, the effective bandwidth, the speed of light, the number of FFT points, and the frequency component number, extracts a signal in the frequency domain, generates a phase noise compensated sampling signal, and reproduces data transmitted by the first wireless communication apparatus.

Wireless communication apparatus and wireless communication method

A receiving station performs first signal detection processing on a received radio signal, performs a retransmission request to a transmitting station in a case in which a code error is detected in a detected radio packet for user data, and enqueues the radio packet in a reception buffer in a case in which no code error is detected. In parallel with the first signal detection processing, the receiving station performs second signal detection processing on the received signal with a longer processing delay than that of the first signal detection processing, and in a case in which no code error is detected in the detected radio packet for user data, the receiving station enqueues the radio packet in the reception buffer. The receiving station outputs, at a predetermined timing, the radio packet for user data with no code error detected, the radio packet being enqueued in the reception buffer.

Retransmission control method

A wireless communication system which includes first and second wireless station apparatuses having a plurality of antenna elements and performs directivity forming. For Tand Tsuch that T=N&#xd7;Tand T=N&#xd7;Twith a predetermined period T, the wireless communication system performs the steps of sequentially switching Ntypes of directional beams at intervals of period Tand transmitting signals while performing switching with an identical directional beam switching pattern maintained over period T, sequentially switching Ntypes of directional beams at intervals of period Tand receiving signals over the period Tor more while performing switching with an identical directional beam switching pattern maintained over the period T, searching for a directional beam having a highest reception level among those acquired over a predetermined period, and setting the searched directional beam as a directional beam to be used.

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Musashino, Japan

Kazuto Goto