Fujitsu Corporation

Ryo Koizumi

Kazuo Nagatani

Hiroyoshi Ishikawa

Shinichiro Kobayashi

Yasuharu Amezawa

Hikaru Ishikawa

Akihiko Komatsuzaki

Takeshi Sugiyama

Takuro Nishikawa

Toshiyuki Takada

Yumihiko Annaka

Hiroshi Yasui

A radio communication apparatus configured to perform frequency conversion on a first transmission signal modulated at a frequency in a specific frequency band into a second transmission signal having a frequency in a transmission frequency band, in which the apparatus includes: a circuit configured to generate a first calibration signal having a frequency higher than a highest frequency in the specific frequency band, and a second calibration signal having a frequency lower than a lowest frequency of the specific frequency band; a circuit configured to add the first and second calibration signals to the first transmission signal; a circuit configured to estimate a phase at a center frequency in the specific frequency band of the first transmission signal, and output a phase correction coefficient corresponding to the estimated phase; and a circuit configured to correct the phase of the first transmission signal, based on the phase correction coefficient.

Radio communication apparatus and antenna calibration method

A peak suppression device includes a suppression-signal generating unit and a band pass filter (BPF). The suppression-signal generating unit generates a suppression signal that is obtained by adding, to a transmission signal, a frequency component in which components of frequencies from a boundary of a band of the transmission signal to a frequency that is away therefrom toward an out-band of the transmission signal by predetermined frequencies are attenuated, out of frequency components of a signal to suppress a peak of the transmission signal. The BPF attenuates, after the suppression signal is amplified by the amplifier, a frequency component outside the band of the transmission signal in the amplified suppression signal.

Peak suppression device and peak suppression method

Growing community of inventors

Yokohama, Japan

Ryo Koizumi