Abstract: In an upper-airspace staying type communication relay apparatus that performs an MU-MIMO radio communication with plural terminal apparatuses located in a cell, it is intended to improve the communication quality of the entire cell and enhance the system capacity, while suppressing an increase in overhead in the terminal apparatus and the communication relay apparatus even if the number of terminal apparatuses located in the cell increases.

Abstract: Provided is a two-dimensional phased array antenna having a simple configuration capable of reducing the number of control systems and the number of control input ports for phase control of antenna elements.

Abstract: A system and a method for suppressing a deterioration of communication quality due to frequent occurrence of handovers at cell boundaries of a plurality of cells formed by a plurality of radio relay apparatuses that can move in an upper airspace, are provided. In the system, each of the plurality of radio relay apparatuses for performing a radio communication with a terminal apparatus comprises a radio relay station which is movably provided by flying in an upper airspace, forms a cell toward the ground or the sea, and performs a radio communication with a terminal apparatus located in the cell. Each of the plurality of radio relay apparatuses flies in cooperation with each other so as to maintain a positional relationship between the radio relay apparatuses by an autonomous control or external control.

Abstract: A radio relay apparatus, which can monitor a status of a radio relay apparatus for realizing a three-dimensional network, without providing a dedicated line, is provided. The radio relay apparatus can fly and move in an upper airspace, and comprises a first antenna for transmitting and receiving a radio signal of a feeder link to and from a gateway station on a communication network side provided on the ground or on the sea, a second antenna for transmitting and receiving a radio signal of a service link to and from a terminal apparatus, a relay processing section for relaying the radio signal of the feeder link and the radio signal of the service link, which is provided between the first antenna and the second antenna, an information acquisition section for acquiring monitoring information on the status of the radio relay apparatus, and an information communication section for transmitting the monitoring information to the gateway station via the feeder link.

Abstract: Provided is an aerial-floating type communication relay apparatus capable of reducing a size and suppressing a movement of a cell footprint. The communication relay apparatus comprises an array antenna that has plural antenna elements forming a cell for performing a radio communication of a service link with a terminal apparatus, an information acquisition section that acquires information on at least one of a position and an attitude of the communication relay apparatus, and a control section that controls phases and amplitudes of plural transmission/reception signals transmitted/received via each of the plural antenna elements of the array antenna so as to fix the position of the cell footprint, based on the information on at least one of the position and the attitude of the communication relay apparatus.

Abstract: In a mobile communication system using a mobile-type radio relay apparatus that forms a plurality of cells toward the ground or the sea while moving in an upper airspace, a deterioration in communication quality, which is caused by a Doppler shift of a reception signal due to a relative movement of a radio relay apparatus with respect to a terminal apparatus of each of a plurality of cells or a feeder station on the ground or on the sea, is suppressed. The communication system comprises a mobile-type radio relay apparatus that is disposed movably by flying in an upper airspace, forms a plurality of cells from an antenna at a predetermined altitude toward the ground or the sea, and performs a radio communication with a terminal apparatus located in each of the plurality of cells.

Abstract: In a mobile communication system using a mobile-type radio relay apparatus that forms a plurality of cells toward the ground or the sea while moving in an upper airspace, a deterioration in communication quality, which is caused by a Doppler shift of a reception signal due to a relative movement of a radio relay apparatus with respect to a terminal apparatus of each of a plurality of cells or a feeder station on the ground or on the sea, is suppressed. The communication system comprises a mobile-type radio relay apparatus that is disposed movably by flying in an upper airspace, forms a plurality of cells from an antenna at a predetermined altitude toward the ground or the sea, and performs a radio communication with a terminal apparatus located in each of the plurality of cells.

Abstract: A radio relay apparatus, which can monitor a status of a radio relay apparatus for realizing a three-dimensional network, without providing a dedicated line, is provided. The radio relay apparatus can fly and move in an upper airspace, and comprises a first antenna for transmitting and receiving a radio signal of a feeder link to and from a gateway station on a communication network side provided on the ground or on the sea, a second antenna for transmitting and receiving a radio signal of a service link to and from a terminal apparatus, a relay processing section for relaying the radio signal of the feeder link and the radio signal of the service link, which is provided between the first antenna and the second antenna, an information acquisition section for acquiring monitoring information on the status of the radio relay apparatus, and an information communication section for transmitting the monitoring information to the gateway station via the feeder link.

Abstract: A system and a method for suppressing a deterioration of communication quality due to frequent occurrence of handovers at cell boundaries of a plurality of cells formed by a plurality of radio relay apparatuses that can move in an upper airspace, are provided. In the system, each of the plurality of radio relay apparatuses for performing a radio communication with a terminal apparatus comprises a radio relay station which is movably provided by flying in an upper airspace, forms a cell toward the ground or the sea, and performs a radio communication with a terminal apparatus located in the cell. Each of the plurality of radio relay apparatuses flies in cooperation with each other so as to maintain a positional relationship between the radio relay apparatuses by an autonomous control or external control.