Abstract: There is provided a propagation environment reproduction device including: an anechoic chamber that blocks an electromagnetic wave from the outside; reconfigurable intelligent surfaces (RISs) that are installed in the anechoic chamber; a RIS control device that provides a control signal to the RISs; a transmission antenna that is installed in the anechoic chamber; a channel emulator that controls a characteristic of an electromagnetic wave transmitted from the transmission antenna; a reception antenna that is installed in the anechoic chamber as an evaluation target; and a control server that controls the RIS control device and the channel emulator. The RIS includes a first RIS that has a characteristic of changing transmittance of the electromagnetic wave according to the control signal and is disposed between the transmission antenna and the reception antenna.

Abstract: A radio wave propagation environment reproduction system according to an embodiment includes: a transmitter to transmit radio waves in a predetermined direction in a reverberation chamber; a reflection angle change RIS to reflect the radio waves transmitted; an installation angle controller to control an installation angle of the reflection angle change RIS; a reflection angle controller to control a reflection angle of the radio waves; a direction-of-arrival estimator to estimate a direction of arrival of the radio waves reflected; and a control server to control the installation angle controller and the reflection angle controller on the basis of the direction of arrival of the radio waves estimated.

Abstract: A base station according to an embodiment is a base station that performs wireless communication with a terminal using a directional antenna within a predetermined area, the base station including: acquisition circuitry configured to acquire data from a database that holds data indicating an antenna directivity suitable for each state of a terminal or each arrival direction of a radio wave from the terminal measured in a scale model in which a structure within a predetermined area is reduced at a predetermined scale factor; collection circuitry configured to collect a state of a terminal or an arrival direction of a radio wave from the terminal in practice within a predetermined area; and controller configured to control directivity of the directional antenna with respect to the terminal in practice within a predetermined area based on the state of the terminal or the arrival direction and data.

Abstract: A radio base station and a radio terminal perform radio communication based on a TDD scheme. A slot configuration includes allocation of a downlink period and an uplink period to the radio terminal. The relay reflects a signal transmitted from the radio base station or the radio terminal or receives and reradiates the signal to form a transmission path between the radio base station and the radio terminal. A relay characteristic includes a parameter determining a coverage area in which the transmission path is formed. A downlink relay characteristic during the downlink period and an uplink relay characteristic during the uplink period are not common but determined separately. Then, the relay characteristic during the downlink period is set to the downlink relay characteristic, and the relay characteristic during the uplink period is set to the uplink relay characteristic. In other words, the relay characteristic is switched between downlink communication and uplink communication.

Abstract: Provided is a wireless communication system that detects an object inside a communication area including: a base station device; and a terminal device, in which the base station device controls a timing for transmitting a reference signal for measuring a state of a propagation path on the basis of a pilot signal included in a wireless signal received from the terminal device during wireless communication and detects an object inside the communication area on the basis of propagation state information indicating a state of the propagation path received from the terminal device during wireless sensing, and the terminal device transmits, to the base station device, propagation state information measured on the basis of a reference signal received from the base station device. It is thus possible to transmit the reference signal for measuring a state of the propagation path without degrading a throughput of wireless communication.

Abstract: The reflection direction control system includes a plurality of reflection units each including a plurality of reflection elements, a position estimation unit for estimating a position of each of the wireless terminals on the basis of radio waves transmitted to the plurality of reflection parts wireless terminals, a direction estimation unit for estimating an incident direction of the radio waves transmitted by each of the wireless terminals to the reflection units, a phase calculation unit for calculating a phase of the radio waves to be reflected so that the reflection unit reflects the radio waves made incident in the direction estimated by the direction estimation unit in a predetermined direction, and a phase control unit for controlling the phase of the radio waves reflected by each of the plurality of reflection elements on the basis of the phase calculated by the phase calculation unit.

Abstract: Communication is performed between a radio base station and a radio terminal via a reflector. The radio base station transmits a measurement signal including a beam ID of a transmission beam for measuring communication quality between the radio base station and the radio terminal. The reflector reflects the measurement signal incident on the reflector in multiple reflection directions to generate multiple reflected measurement signals. Moreover, the reflector modulates the incident measurement signal during reflection to add information about a reflection direction ID being different for each of the multiple reflection directions to each of the multiple reflected measurement signals. The radio terminal demodulates a reflected measurement signal received from the reflector to acquire the reflection direction ID and the beam ID.

Abstract: A passive relay device (100) relays radio communication between the inside of a radio wave shielding structure (200) and the outside of the radio wave shielding the structure (200), and the device includes an internal antenna (10) which connects with the inside, an external antenna (20) which connects with the outside, and a connection part (30) which connects the internal antenna (10) and the external antenna (20).

Abstract: A wireless communication system including, a primary transmitting station and a primary receiving station which are being in communication, a secondary transmitting station and one or more secondary receiving stations which use the identical frequency that are used in the above wireless environment, the one or more secondary receiving stations including a secondary receiving station serving as a destination, the secondary receiving station serving as the destination receiving a transmitted signal from the secondary transmitting station, the wireless communication system including a plurality of relay stations located between the secondary transmitting station and the one or more secondary receiving stations, wherein the secondary transmitting station includes a relay station selection unit configured to select at least one relay station that relays the transmitted signal from among the plurality of relay stations, add information for turning on the at least one selected relay station to the transmitted signal

Abstract: A wireless transmission device transmits a radio signal with a plurality of beam patterns and outputs transmission beam identifiers corresponding to the beam patterns to an object detection device, a wireless reception device receives the radio signal transmitted by the wireless transmission device with a plurality of beam patterns, measures received signal strength for each of the beam patterns and outputs reception beam identifiers and the received signal strength to the object detection device, and the object detection device detects an object within a detection area on the basis of the transmission beam identifiers, the reception beam identifiers and the received signal strength. This enables device-free object detection by utilizing a beamforming function, so that it is possible to achieve high detection accuracy while preventing increase in cost.

Abstract: A relay system includes: one or more radiation units configured to form a beam in a predetermined direction by radiating radio waves from each of a plurality of elements; a detection unit configured to detect a physical environment on a radio wave propagation path that affects the beam formed by the radiation unit; a direction determination unit configured to determine a direction in which the radiation unit should form the beam based on the physical environment detected by the detection unit; a phase calculation unit configured to calculate a phase of radio wave to be radiated by each of the plurality of elements such that the radiation unit forms a beam in the direction determined by the direction determination unit; and a phase control unit configured to control the phase of the radio wave radiated by each of the plurality of elements based on the phase calculated.

Abstract: Interference in preamble signals and pilot signals in cooperative transmission using interference suppressing technology is avoided. A wireless apparatus for transmitting a wireless signal on which directivity control has been performed to stations in a wireless system including at least one wireless apparatus is provided with a known signal generating unit which generates a known signal to be added to the wireless signal, a weighting processing unit which performs weighting on the known signal generated by the known signal generating unit, and a wireless processing unit which transmits the known signal on which the weighting has been performed by the weighting processing unit.

Abstract: A reflection direction control method includes an arrival direction estimation step of estimating an arrival direction of radio waves transmitted by a wireless terminal to one or more reflection units each including a plurality of reflection elements capable of dynamically changing phase characteristics when the radio wave is reflected, a phase control step of controlling a phase of a radio wave reflected by each of the plurality of reflection elements so that the reflection unit reflects, in a predetermined direction, the radio wave transmitted from the estimated arrival direction, and a switching step of switching between an antenna mode in which the reflection unit is caused to receive the radio wave of which the arrival direction is estimated and a reflection mode in which the reflection unit is caused to reflect the radio wave.

Abstract: A radio communication method of connecting a base station with a plurality of terminal stations, the base station including a plurality of radio communication units compatible with a plurality of communication standards or communication schemes, the method including collecting, from each of the plurality of terminal stations, communication quality information representing a communication quality of the terminal station, collecting, from each of the plurality of terminal stations, communication performance information representing a communication performance of the terminal station, collecting, from each of the plurality of terminal stations, identifier information that identifies the terminal station, calculating, based on the communication quality information, the communication performance information and the identifier information that are collected, a setting policy including a setting for each of the plurality of radio communication units, and a switching policy of setting a condition for switching the pl

Abstract: Estimating a propagation environment of a radio wave using a scale model. The method includes the following steps. The scale model is created. In the scale model, a light source capable of emitting directional light and scanning an irradiation direction is installed, regarding the light source as a transmission station of a radio wave. The light source scans an inside of the scale model, and a center light generation state in which center light directed to a measurement point set in the scale model is generated is detected in a process of scanning. A light receiving sphere is installed such that a center coincides with the measurement point. A direction connecting a position of an irradiated point appearing on the light receiving sphere and a position of the center under the center light generation state is estimated as an arrival direction of the light reaching the measurement point.

Abstract: The present disclosure relates to a propagation environment estimation method suitable for environment estimation of a wireless signal using a scale model. The method includes the following steps. The scale model is created. A light source regarded as a transmission station of the radio wave is installed in the scale model, and a measurement range in the scale model is irradiated by the light source. The measurement range irradiated by the light source is captured, and gradation of light obtained by the capture is converted into a reception level of the radio wave.

Abstract: The present disclosure relates to a propagation environment estimation method suitable for environment estimation of a wireless signal using a scale model. The scale model is created. In the scale model, a light source regarded as a transmission station of a radio wave is installed. In the scale model, a light receiving element regarded as a receiver of the radio wave is installed. The light source irradiates a measurement range set in the scale model, and the light receiving element measures a light reception level. Data of the light reception level acquired in the previous step is converted into a reception level of the radio wave.

Abstract: A wireless communication system includes a sensing unit that detects an obstacle currently present between a transmitting station and a receiving station. There is an environment memory that stores information on a detection result of the sensing unit, an environment prediction unit that predicts a variation in a radio wave propagation environment between the transmitting station and the receiving station from the information stored in the environment memory. There is further a simulation calculation unit that simulates an environment in which a communication path between the receiving station and a reflector and a communication path between the transmitting station and the reflector are a line-of-sight environment on the basis of a prediction result of the environment prediction unit and calculates a control parameter of the reflector that achieves the environment. Further, a reflector control unit controls the reflector in accordance with the control parameter calculated by the simulation calculation unit.

Abstract: A base station according to an embodiment is a base station that performs wireless communication with a terminal using a directional antenna within a predetermined area, the base station including: acquisition circuitry configured to acquire data from a database that holds data indicating an antenna directivity suitable for each state of a terminal or each arrival direction of a radio wave from the terminal measured in a scale model in which a structure within a predetermined area is reduced at a predetermined scale factor; collection circuitry configured to collect a state of a terminal or an arrival direction of a radio wave from the terminal in practice within a predetermined area; and controller configured to control directivity of the directional antenna with respect to the terminal in practice within a predetermined area based on the state of the terminal or the arrival direction and data.

Abstract: A propagation model estimation system according to an embodiment includes a selection unit that selects an area for which a radio wave propagation model is to be estimated, a modeling unit that models a radio wave reflection characteristic in the selected area, a determination unit that determines a scale ratio of the selected area, a frequency scale model based on the scale ratio, and at least one material based on the modeled radio wave reflection characteristic and the frequency scale model, a creation unit that creates an area scale model in which a structure in the selected area is reduced at the scale ratio using the material by means of a 3D printer, an arrangement unit that arranges, in the area scale model, at least one transmitting station that transmits a radio wave based on the frequency scale model and at least one receiving station that receives the radio wave transmitted by the transmitting station while moving, a measurement unit that measures a propagation characteristic of the radio wave rec