Abstract: In a power grid stabilization system, a second energy storage system has a larger energy storage capacity than a first energy storage system. A bidirectional AC/DC converter is connected between an AC power grid and a pair of input and output terminals of the first energy storage system. A first bidirectional DC/DC converter is connected between the pair of input and output terminals of the first energy storage system and a pair of input and output terminals of the second energy storage system.

Abstract: A radio wave arrival angle detection device of the present invention extracts symbols and resolves the same into sub-carriers having various frequency components, for OFDM carrier waves received by a first antenna and a second antenna, respectively. The arrival angle of the carrier waves is calculated on the basis of the geometric relationship between a phase shift of the respective sub-carriers of the OFDM carrier waves received by the first antenna and the second antenna, and the arrangement of the first antenna and the second antenna.

Abstract: A radio wave arrival angle detection device of the present invention extracts symbols and resolves the same into sub-carriers having various frequency components, for OFDM carrier waves received by a first antenna and a second antenna, respectively. The arrival angle of the carrier waves is calculated on the basis of the geometric relationship between a phase shift of the respective sub-carriers of the OFDM carrier waves received by the first antenna and the second antenna, and the arrangement of the first antenna and the second antenna.

Abstract: A mobile communication system includes a mobile station provided in a moving object moving along a predetermined route, and a plurality of base stations provided along the route. The mobile station includes an interruption time determining unit that determines whether an interruption time, in which the base station communicating with the mobile station which is currently connected is interrupted communication with the mobile station, is within a predetermined permissible time range for a travel direction side of the route more forward than a current position of the moving object, and a handover processing unit that performs handover processing when the interruption time determining unit determines that the interruption time is not within the permissible time range.

Abstract: A mobile communication system includes a mobile station and base stations, and the mobile station includes a base station selection unit, a first selected base station determination unit, a second selected base station determination unit, an inhibition command data transmission unit that transmits data for commanding inhibition of a downlink to a base station when the first selected base station determination unit determines that the base station is selected at the previous time and is not selected at this time, and a permission command data transmission unit that transmits data for commanding permission of a downlink to a base station when the second selected base station determination unit determines that the base station is not selected at the previous time and is selected at this time.

Abstract: A mobile communication system includes a mobile station and base stations, and the mobile station includes a base station selection unit, a first selected base station determination unit, a second selected base station determination unit, an inhibition command data transmission unit that transmits data for commanding inhibition of a downlink to a base station when the first selected base station determination unit determines that the base station is selected at the previous time and is not selected at this time, and a permission command data transmission unit that transmits data for commanding permission of a downlink to a base station when the second selected base station determination unit determines that the base station is not selected at the previous time and is selected at this time.

Abstract: A mobile communication system includes a mobile station provided in a moving object moving along a predetermined route, and a plurality of base stations provided along the route. The mobile station includes an interruption time determining unit that determines whether an interruption time, in which the base station communicating with the mobile station which is currently connected is interrupted communication with the mobile station, is within a predetermined permissible time range for a travel direction side of the route more forward than a current position of the moving object, and a handover processing unit that performs handover processing when the interruption time determining unit determines that the interruption time is not within the permissible time range.