研究者詳細 - 上原　一浩

論文 - 上原　一浩

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Study of signal separation and demodulation techniques considering IQ imbalance by stored data batch signal processing 査読

Yudai Mita, Yuta Hiraoka, Tomofumi Hikasa, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 14 ( 1 ) 30 - 33 2025年1月

A study on the effect of water on the received power characteristics of water level gauge antennas installed in underpass 査読

Koichi Yamaguchi, Shuhei Yamamoto, Ryota Ogata, Shigeru Tomisato, Kazuhiro Uehara

IEICE Communications Express 12 ( 12 ) 640 - 642 2023年12月

A study on continuous phase signal separation and demodulation method using stored data batch signal processing 査読

Tomofumi Hikasa, Takuyuki Hirakawa, Syo Nakaie, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 11 ( 12 ) 734 - 740 2022年12月

Evaluation of sensor terminal signal separation performance based on modulation systems in storage-based batch signal processing using STFT 査読

Takuyuki Hirakawa, Toru Nishiyama, Syo Nakaie, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 11 ( 6 ) 319 - 323 2022年6月

Receivable signal sequence number increase in LED visible light wireless communications by spatially parallel signal transmission 査読

Ryosuke Okamoto, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 11 ( 6 ) 296 - 301 2022年6月

A new scheme of automatic modulation classification using Convolutional Neural Network with constellation diagram 査読国際誌

Yutao Liu, Toru Nishiyama, Shigeru Tomisato, Kazuhiro Uehara

IEICE Communications Express 10 ( 8 ) 492 - 497 2021年8月

Examination of signal separation/demodulation method of multi-value modulation sensor terminal signal using STFT in storage batch signal processing 査読国際誌

Toru Nishiyama, Takuyuki Hirakawa, Syo Nakaie, Shigeru Tomisato, Satoshi Denno, Kazuhiro Uehara

IEICE Communications Express 10 ( 8 ) 458 - 462 2021年8月

Inter-system interference reduction of adaptive bandwidth control for multi-band wireless transmission 査読国際誌

Naoto Takamatsu, Shigeru Tomisato, Kazuhiro Uehara, Satoru Shimizu, Yoshinori Suzuki

IEICE Communications Express 10 ( 6 ) 337 - 342 2021年6月

Adaptive bandwidth control for multi-band OFDM transmission with spectrum sharing 査読国際誌

Yoshiki Inuzuka, Shigeru Tomisato, Kazuhiro Uehara, Satoru Shimizu, Yoshinori Suzuki

IEICE Communications Express 9 ( 5 ) 131 - 135 2020年5月

Transmission performance improvement by non-linear distortion noise power control in multi-band systems 査読

Shigeru Tomisato, Jumpei Onji, Kazuhiro Uehara

International Journal of Computer and Software Engineering (IJCSE) 4 ( 143 ) 2019年3月

[招待論文] ソフトウェア無線・コグニティブ無線技術の研究開発招待査読

上原一浩

電子情報通信学会論文誌(B) J100-B ( 9 ) 693 - 704 2017年9月

High-Capacity Wireless Access Networks Using 920 MHz Band for Wide-Area IoT/M2M Services 招待査読

Kazunori Akabane, Nobuaki Mochizuki, Shigeru Teruhi, Mamoru Kobayashi, Shuichi Yoshino, Masashi Shimizu, Kazuhiro Uehara

IEICE TRANSACTIONS ON COMMUNICATIONS E99B ( 9 ) 1920 - 1929 2016年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

In the near future, many sensors and terminals will be connected to the public network to provide various convenient IoT/M2M services. In order to connect many sensors to the network efficiently, wireless communication systems in the 920MHz band are seen as attractive solutions. We are focusing on the 920MHz band to research and develop high-capacity protocols that can accommodate many terminals, and low power consumption technologies for battery-driven terminals. In this paper, we describe the following three concrete wireless systems that use our proposals. (1) A physical distribution pallet management system that can handle thousands of pallet-embedded sensors and a wireless module with a battery lifetime of about ten years. (2) Water leakage monitoring system for underground pipes by using sensors and a wireless module in each valve box. (3) A wide-area and high-capacity radio relay system for smart metering services like the reading of gas meters. The radio relay system can accommodate various sensors and terminals and has large potential for providing various IoT/M2M services in conjunction with smart metering services.

DOI： 10.1587/transcom.2016SNI0001

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非対称縦積み線路を用いた準ミリ波帯バランスミキサ査読

山口陽, 加保貴奈, 豊田一彦, 上原一浩, 中川匡夫, 荒木純道

電子情報通信学会論文誌(C) J98-C ( 5 ) 266 - 275 2016年5月

[招待論文] ユーザセントリックな無線通信システム実現に向けたマルチバンド一括送受信フロントエンド招待査読

加保貴奈, 山口陽, 芝宏礼, 大島心平, 中川匡夫, 上原一浩

電子情報通信学会論文誌(C) J99-C ( 5 ) 258 - 265 2016年5月

Concurrent Multi-Band Mixer with Independent and Linear Gain Control 査読

Takana Kaho, Yo Yamaguchi, Hiroyuki Shiba, Tadao Nakagawa, Kazuhiro Uehara, Kiyomichi Araki

IEICE TRANSACTIONS ON ELECTRONICS E98C ( 7 ) 659 - 668 2015年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

Novel multi-band mixers that can receive multiple band signals concurrently are proposed and evaluated. The mixers achieve independent gain control through novel relative power control method of the multiple local oscillator (LO) signals. Linear control is also achieved through multiple LO signal input with total LO power control. Theoretical analysis shows that odd-order nonlinearity components of the multiple LO signals support linear conversion gain control. Dual-and triple-band tests are conducted using typical three MOSFET mixers fabricated by a 0.25 mu m SiGe BiCMOS process. Measurements confirm over 40 dB independent control of conversion gain, linear control achieved through LO input power control. The proposed mixers have high input linearity with a 5 dBm output third intercept point. A method is also proposed to reduce interference caused by mixing between multiple LO signals.

DOI： 10.1587/transele.E98.C.659

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Dependency on Beamwidth in an SD Method Utilizing Two-Ray Fading Characteristics 査読

Ken Hiraga, Kazumitsu Sakamoto, Maki Arai, Tomohiro Seki, Hideki Toshinaga, Tadao Nakagawa, Kazuhiro Uehara

IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS 14 56 - 59 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Using ray-tracing propagation calculation, we clarify the dependency on antenna element beamwidth of the channel capacity of a spatial division (SD) transmission method utilizing the characteristics of two-ray fading. It was clarified that the SD transmission method can be effectively applied to microstrip antennas or horn antennas with beamwidth of more than 10, but that it is not effective when applied to narrow-beam antennas with less than 10 beamwidth. In such cases, simple parallel transmission is a better way to utilize the narrow beam to increase channel capacity.

DOI： 10.1109/LAWP.2014.2355258

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ホワイトスペース利用実現に向けた広帯域周波数センシングシステムの提案と性能評価査読

芝宏礼, 山口陽, 山田貴之, 加保貴奈, 中川匡夫, 上原一浩

電子情報通信学会論文誌(B) J97-B ( 12 ) 1224 - 1233 2014年12月

Spatial Division Transmission without Signal Processing for MIMO Detection Utilizing Two-Ray Fading 査読

Ken Hiraga, Kazumitsu Sakamoto, Maki Arai, Tomohiro Seki, Tadao Nakagawa, Kazuhiro Uehara

IEICE TRANSACTIONS ON COMMUNICATIONS E97B ( 11 ) 2491 - 2501 2014年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

This paper presents a spatial division (SD) transmission method based on two-ray fading that dispenses with the high signal processing cost of multiple-input and multiple-output (MIMO) detection and antennas with narrow beamwidth. We show the optimum array geometries as functions of the transmission distance for providing a concrete array design method. Moreover, we clarify achievable channel capacity considering reflection coefficients that depend on the polarization, incident angle, and dielectric constant. When the ground surface is conductive, for two-and three-element arrays, channel capacity is doubled and tripled, respectively, over that of free space propagation. We also clarify the application limit of this method for a dielectric ground by analyzing the channel capacity's dependency on the dielectric constant. With this method, increased channel capacity by SD transmission can be obtained merely by placing antennas of wireless transceiver sets that have only SISO (single-input and single-output) capability in a two-ray propagation environment. By using formulations presented in this paper for the first time and adding discussions on the adoption of polarization multiplexing, we clarify antenna geometries of SD transmission systems using polarization multiplexing for up to six streams.

DOI： 10.1587/transcom.E97.B.2491

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Performance evaluation of a simple decoding method for millimeter-wave short-range MIMO transmission through a wall 査読

Kazumitsu Sakamoto, Ken Hiraga, Tomohiro Seki, Tadao Nakagawa, Kazuhiro Uehara

IEICE Communications Express 3 ( 4 ) 131 - 137 2014年4月

Study on MIMO transmission using orthogonal directivities obtained from higher order microstrip antenna modes 査読

M. Arai, T. Seki, K. Hiraga, K. Sakamoto, H. Toshinaga, T. Nakagawa, K. Uehara

ELECTRONICS LETTERS 50 ( 7 ) 562 - 564 2014年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：INST ENGINEERING TECHNOLOGY-IET

A simpler MIMO transmission method using orthogonal directivities is proposed. In future wireless communication systems, higher data rates will be required since large amounts of data will be transmitted and received. MIMO technology is useful for achieving higher data rates. However, since MIMO detection becomes complicated when the number of antennas becomes large, a simpler method should be considered. To solve this problem, the present authors proposed a spatial division method using orthogonal directivities. This previously proposed method to N streams is expanded transmission for application to much higher data rate systems. Furthermore, using higher order antenna modes at the same frequency to more easily obtain orthogonal directivities is proposed. To evaluate the proposed method, it is confirmed by numerical analysis that the capacity of the proposed method increases without MIMO detection when the number of antennas becomes large.

DOI： 10.1049/el.2014.0120

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