Hitachi, Ltd.

Tsukasa Sasayama

Mikio Kuwahara

Hajime Kanzaki

Koichiro Furueda

Tatsunori Ohara

Necessary transmission power of terminals is secured while suppressing total transmission power in base station, so that FFR technology is realized with high frequency utilization efficiency to thereby realize both of compactness of base station and increase of communication capacity. Frequency resource is divided into frequency for boundary area of cell and frequency for central area of cell. Transmission power per unit frequency is fixed in the frequency for boundary area of cell and is set to be variable in the frequency for central area of cell. Transmission power per unit frequency is adjusted so as to satisfy necessary power of terminals connected to frequency for central area of cell. When it is judged that total transmission power of base station exceeds prescribed value, terminal is moved from central area to boundary area of cell, so that total transmission power is suppressed to be equal to or smaller than standard.

Transmission power adjustment method in wireless communication system and base station

A radio communication system is provided in which, based on a measurement condition and neighbor information specified by a base station to which a mobile terminal is connected, the mobile terminal measures the reception quality of the neighboring base stations included in the neighbor information and, when a transmission request is received from the connected base station, transmits the measurement result to the connected base station. In this radio communication system, the base station transmits neighbor information, which specifies the base stations for which interference measurement is to be performed, and a measurement result transmission request to the mobile terminal at a predetermined time for measuring the interference of neighboring base stations and, in response to it, the mobile terminal transmits the measurement result of the base stations, specified by the base station for measuring the interference, to the base station.

Radio base station, radio communication system and interference notifying method in radio communication system

When DFFR is performed in a heterogeneous environment in which a pico base station coexists in the area of a macro base station and when the pico base station judges that, based on the received-signal quality report result from a mobile terminal, the macro base station causes interference to the pico base station, the pico base station reports an interference power threshold to be notified to the macro base station based on the transmission power setting value of the macro base station, the transmission power setting value of the pico base station, and the estimated interference amount calculated from the scan report result. The macro base station transmits a result of comparison between the transmission powers of multiple frequency resources and the interference power threshold, to the pico base station and the pico base station selects a frequency resource, unlikely to be affected by interference.

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Yokohama, Japan

Tsukasa Sasayama