S
Shuji Kobayakawa
Researcher at Fujitsu
Publications - 23
Citations - 597
Shuji Kobayakawa is an academic researcher from Fujitsu. The author has contributed to research in topics: Signal & Antenna (radio). The author has an hindex of 12, co-authored 22 publications receiving 597 citations.
Papers
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Patent
Array antenna system of wireless base station
TL;DR: In this article, an adaptive weight calculating unit calculates adaptive weights for obtaining in-phase correlation signals from the respective antenna outputs, and a beamformer multiplies, by the adaptive weights, output signals from corresponding antenna elements and combines the resulting products to output a combined signal.
Patent
High frequency power amplifier with high efficiency and low distortion
Naofumi Okubo,Yoshihiko Asano,Hiroshi Kurihara,Yoshimasa Daido,Kazuhiko Kobayashi,Shuji Kobayakawa,Toru Maniwa +6 more
TL;DR: In this paper, a high frequency amplifier containing a constant envelope signal generation circuit for transforming an input signal to form two constant envelope signals where phases of the constants envelope signals correspond to an amplitude of an envelope of the input signal, two amplifying circuits for separately amplifying two constant envelopes, and a power synthesizing circuit for synthesizing the first and second amplified signals to generate an amplified signal of an input electric signal.
Patent
Constant-amplitude wave combination type amplifier
Naofumi Okubo,Yoshihiko Asano,Hiroshi Kurihara,Yoshimasa Daido,Kazuhiko Kobayashi,Shuji Kobayakawa,Toru Maniwa +6 more
TL;DR: In this paper, a wave combining circuit for combining the first and second constant-amplitude waves and for generating an output wave was proposed for a wave combination type amplifier with a first amplifier outputting a first amplified output and a second amplifier producing a second amplified output.
Patent
Multiple-beam antenna system of wireless base station
TL;DR: In this article, a transmission beam former for subjecting a transmission signal to beam forming is provided, based upon whether an uplink reception signal is present or not, a controller performs control so as to carry out downlink beam forming, thereby forming a downlink transmission beam in a direction identical with that of the optimum uplink receiving beam.
Patent
Interference canceller equipment and interference cancelling method for use in a multibeam-antenna communication system
TL;DR: In this article, a multistage interference cancellation system for CDMA (Code Division Multiple Access) multibeam-antenna communication system is presented. But the system is not suitable for wireless networks.