Hitachi, Ltd.

Hitachi Communication Technologies, Ltd.

Hitachi Advanced Systems Corporation

Koji Meguro

Mikio Kuwahara

Kenzaburo Fujishima

Masanori Taira

Toru Okamoto

To provide a wireless base station comprising an array antenna which transmits packets to terminals, a packet scheduler which determines transmission sequence of the packets, a modulator which generates modulated signals based on the packets, and a beam former for transmission signal which multiplies the packets with array weights for transmission signal and outputs the transmission signal to the array antenna the beam former for transmission signal comprises a memory which stores the array weights for transmission signal associated with the terminals' IDs. The beam former for transmission signal receives the IDs of selected terminals from the packet scheduler, refers to the memory, and selects the array weights for transmission signal by the IDs of the terminals.

Wireless base station using weighting elements of an array antenna

A radio communication apparatus enhances cell throughput by adaptive selection of spatially multiplexed channels in consideration of interferences in a local cell and reducing load for calculation of array weights by storing them in advance as fixed values and outputting fixed beams. To reduce the calculation load for the adaptive selection of spatially multiplexed channels that takes interferences within the local cell into consideration, the radio communication apparatus adopts a packet scheduling method that selects a combination of fixed beams and determines the number of spatially multiplexed channels, based on the fixed beams for mobile apparatuses with packets waiting to be transmitted and pre-calculated correlative quantities of inter-beam interferences between these fixed beams.

Radio communication apparatus and packet scheduling method

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Yokohama, Japan

Koji Meguro