16 results about "Radio relay" patented technology

There is provided techniques for controlling an RIS. The RIS comprises a controller entity and a reflector entity. The reflector entity is associated with configurable reflection properties defining how radio waves that impinge the reflector entity are reflected. The reflection properties are controlled by the controller entity. A method is performed by a network node. The method comprises determining that the RIS to refrain from reflecting signals communicated in radio waves between the network node and a user equipment. The method comprises, in response thereto, providing an indication to the controller entity for the RIS to enter a non-relay mode according to which the reflector entity is to apply a default configuration of the reflection properties.

This invention provides a communication system capable of maintaining FDD communication in a base station device and a terminal device, and reducing the impact of phase noise in a relay radio section between a radio relay device and a gateway device. The radio relay device includes a means for converting an FDD signal transmitted and received in a radio section of a service link between the radio relay device and the terminal device, and a TDD signal transmitted and received in a relay radio section between the radio relay device and the gateway device. The gateway device includes a means for converting an FDD signal transmitted / received to / from the base station device, and a TDD signal transmitted / received in the relay radio section between the gateway device and the radio relay device. The radio relay device and the gateway device transmit / receive radio signals in the TDD scheme in the relay radio section.

A radio relay system according to one embodiment of the present invention relays a radio wave radiated by a radio communication device to a moving radio terminal, and includes: a plurality of radio wave direction change units that each change the direction of travel of a radio wave incident from the radio communication device so that the radio wave is emitted in another direction; and a control unit that controls the direction of the radio wave emitted by each of the radio wave direction change units. The control unit includes: an estimation unit that estimates a position to which the radio terminal is to move after elapse of a predetermined period of time; and a sequential allocation unit that uses the position of the radio terminal estimated by the estimation unit to determine an allocation in which each of the radio wave direction change units sequentially emits a radio wave toward the radio terminal each time the predetermined period of time elapses.

The present invention relates to the field of communications, and more particularly to methods and a system for providing high-speed communications on a high-speed railway. The technical result is a better quality communication channel provided by train-to-ground radio relay links. The claimed system for providing high-speed communications on a high-speed railway comprises an internal and an external data exchange network. The internal network unites tail-end radio frequency modules mounted in the rear part of a train and equipped with narrow-band antennae, head-end radio frequency modules mounted in the front part of the train and equipped with narrow-band antennae, and switching equipment capable of processing signals from said modules and of providing network devices connected to said equipment with access to the external data exchange network. The external data exchange network unites base stations equipped with narrow-band antennae, said base stations being capable of establishing communication with the tail-end and head-end radio frequency modules in the train and being arranged in proximity to the railway clearance along the path of travel of the train. The antennae of the base stations and of the radio frequency modules in the train are configured to radiate radio waves in a short millimeter wave band.

To continue continuous communication with only a small interruption without being subject to a restriction in a wireless relay system that cannot resume relay communication unless a predetermined transmission pause time is set when the relay of continuous communication exceeds a predetermined time limit. [Solution] The repeater 100 switches between two pairs of opposite waves. When relaying continuous communication on one pair of waves begins, a timer is started to measure the time limit of 3 minutes and 30 seconds before that (S217 → S222). When continuous communication exceeds 2 minutes 30 seconds, carrier sense for the other pair of waves is repeated. If a transmission stop or dead state occurs and the result of the most recent carrier sense at that time is an idle state, relaying on the currently used pair of waves is terminated and a beacon signal to switch to the other pair of waves is transmitted, causing communication terminals 201 and 202 to also set the other pair of waves to a use state (S223 to S230 → FIG. 5A). The pair of waves used is changed before the time limit, so the above restriction is not imposed.

To easily determine the antenna beam of a wireless relay device.SOLUTION: A wireless relay device receives notification of terminal beam information from a wireless terminal indicating the directional direction of the wireless terminal's antenna beam to be directed toward a base station, which has been determined between the wireless terminal and the base station, and determines the wireless relay device's antenna beam to be directed toward the base station on the basis of the directional direction indicated in the terminal beam information notified from the wireless terminal.SELECTED DRAWING: Figure 3

The wireless communication system includes a wireless relay station staying in the air, a ground station for transmitting and receiving radio waves to and from the wireless relay station, and a wireless relay station monitoring control device. The wireless relay station monitoring control device calculates a prediction value of a rainfall attenuation amount of the feeder link at a movement candidate position in a radio relay area of the wireless relay station and a current position on the basis of weather prediction information. Further, the communication quality of the feeder link at the movement candidate position and the current position is predicted based on the prediction value. Further, a position at which attenuation of the feeder link is predicted to be less than that at which the wireless relay station stays at the current position is selected from the movement candidate positions on the basis of the communication quality.

In a wireless repeating system that performs group communication using paired waves in a semi-duplex system, communication becomes impossible if there is jamming radio waves at the repeater or communication terminal. [Solution] The repeater 50 has a modulation / transmission unit TX01 for communication and a reception / demodulation unit RX01, as well as a reception / demodulation unit RX02 that cyclically scans a group of channels that are always available to search for an available pair of waves, and each communication terminal 60 has a modulation / transmission unit TX11 and a reception / demodulation unit RX11 that has the cyclic scanning function in standby mode. When jamming radio waves are detected in RX01 of the repeater 50, the RX01 changes the setting to the pair of waves that is the farthest away from a non-available pair of waves among the available pairs of waves searched for by RX02, and transmits a channel change request (CCR) from TX01. Each communication terminal 60 receives the CCR during the cyclic scanning process of RX11, and changes the setting of TX11 and RX11 to the transmission / reception pair of waves that corresponds to the receiving channel of the CCR.

It is provided of a communication system capable of suppressing a fluctuation in a reception power of a known signal from a base station due to an attitude change of a radio relay apparatus, and performing an appropriate gain control of a power amplifier of the radio relay apparatus based on the reception power of the known signal, in case that the base station uses a plurality of linear polarization antennas for wireless communication with the radio relay apparatus. The base station comprises an antenna apparatus that has a plurality of linear polarization antennas capable of transmitting and receiving radio waves with different angles of linear polarization planes from each other when performing a feeder-link communication with the radio relay apparatus, and a base-station processing section or an externally-attached phase control apparatus for controlling a phase difference between plural transmission signals supplied to the plurality of the linear polarization antennas, so that a combined polarization of radio waves of the known signal transmitted from the antenna apparatus to the radio relay apparatus becomes a circular polarization or an elliptical polarization, with respect to a predetermined time slot for transmitting to the radio relay apparatus a specific known signal usable for gain control of a power amplifier of the radio relay apparatus.

To provide a ground system, an unmanned aircraft, and a radio relay system capable of appropriately replacing the unmanned aircraft under the assumption that the radio relay system is mounted on the unmanned aircraft.SOLUTION: The ground system includes a transmission unit configured to transmit, to an unmanned aerial vehicle, a frame to be relayed by the unmanned aerial vehicle, a reception unit configured to receive, from the unmanned aerial vehicle, a signal indicating that synchronization of the frame is established in the unmanned aerial vehicle, and a control unit configured to control transmission of switching information for notifying a timing for starting or stopping relay of the frame in the unmanned aerial vehicle in accordance with the signal indicating that synchronization of the frame is established.SELECTED DRAWING: Figure 3

This radio base station executes setting in a radio resource control layer with a radio relay device provided with a reflection plate, and receives a setup completion message from the radio relay device. The radio base station receives the setup completion message including identification information for identifying the radio relay device.

The invention belongs to the technical field of high-speed rail communication security, and discloses a high-speed rail communication secure transmission method based on active RIS assistance. Comprising the following steps: constructing a high-speed rail communication system comprising a base station, an active RIS, a mobile relay and an eavesdropper; establishing a channel model; defining a reflection coefficient matrix of the active RIS; deriving received signal expressions of the mobile relay and the eavesdropper; calculating the signal-to-noise ratio of the mobile relay and the eavesdropper, and solving the channel capacity of the mobile relay and the eavesdropper according to the Shannon theorem; establishing an optimization problem taking the minimum transmitting power of the base station as a target, and setting a constraint condition; the beamforming vector of the base station and the phase shift matrix of the active RIS are jointly optimized, and an optimization problem is solved through an alternating optimization algorithm so as to realize the minimization of the transmitting power of the base station; seamless coverage and stable connection in the high-speed running process of the train are ensured, and the high-reliability requirement of high-speed rail communication is met.

A wireless base station according to the present invention controls transmission of system information broadcast within a cell, and transmits, within the cell, system information including an information element indicating whether a wireless relay device comprising a reflector plate can be supported.

1. The name of the design product: unmanned aerial vehicle (H-shaped). 2. The use of the design product: as a remote control unmanned aerial vehicle, adopting H-shaped design, used for material delivery, equipment mounting and radio relay, etc. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

1. The name of the design product: unmanned aerial vehicle (I type). 2. The use of the design product: as a remote control unmanned aerial vehicle, adopting I type design, used for material delivery, equipment mounting and radio relay, etc. 3. The design points of the design product: in shape. 4. The picture or photo that can best show the design points: perspective view.

1. The name of the design product: unmanned aerial vehicle (H type). 2. The use of the design product: as a remote control unmanned aerial vehicle, with H-shaped design, for material delivery, equipment mounting and radio relay, etc. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.