Softbank Corporation

Koji Tashiro

Kenji Hoshino

Atsushi Nagate

Yoshichika Ota

Mitsukuni Konishi

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. The communication relay apparatus receives an uplink signal from each of plural terminal apparatuses via an array antenna, estimates angle information indicating a direction of the terminal apparatus for each of the plural terminal apparatuses, selects a terminal apparatus to be assigned to each of plural radio resources used for a downlink based on the estimation result of the angle information, calculates a downlink beamforming weight based on the estimation result of the angle information, and transmits a downlink signal to the terminal apparatus via the array antenna based on the beamforming weight corresponding to the terminal apparatus and the radio resources assigned to the terminal apparatus.

Massive MIMO for HAPS based on angle information on user apparatus

When there is a movement or attitude change of an upper-airspace staying type communication relay apparatus, it is suppressed of an increase in control signals and disconnection of communication with a terminal apparatus in a cell configuring a service area, and it is reduced of a circuit scale and power consumption of a base-station processing section. The base-station processing section of the communication relay apparatus performs, with respect to a radio resource part for control communication by which a communication is performed with plural terminal apparatuses located in a cell via a single or plural beams for control among downlink and uplink radio resources used for service links, a footprint fixation control for performing a precoding and a postcoding so as to fix a position of a footprint corresponding to the beam for control, based on information on at least one of a position and attitude of the communication relay apparatus, and does not perform the footprint fixation control on the basis of the information on the at least one of the position and attitude, with respect to downlink and uplink radio resource parts other than the radio resource part for control communication.

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Tokyo, Japan

Koji Tashiro