IEICE Trans

Takefumi HIRAGURI

Fast-Converging Constant Modulus Algorithm with Variable Step Size for Multibeam Massive MIMO Kentaro NISHIMORI Kazuki MARUTA Takefumi HIRAGURI Hidehisa SHIOMI
Publication: Publication Date: 2022/10/01 Vol. E105-B No. 10 pp. 1154-1161 Type of Manuscript: Special Section PAPER (Special Section on Multidisciplinary and Innovative Key technologies in Advanced communication systems (MIKA)) Category: Keyword: constant modulus, blind algorithm, variable step size, multibeam, massive MIMO, QAM,
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Traffic Reduction Technologies and Data Aggregation Control to Minimize Latency in IoT Systems Hideaki YOSHINO Kenko OTA Takefumi HIRAGURI
Publication: Publication Date: 2021/07/01 Vol. E104-B No. 7 pp. 706-715 Type of Manuscript: INVITED PAPER (Special Section on Future Directions of Research and Development on Communication Quality) Category: Keyword: IoT, fog, edge, data aggregation, QoS, latency, control, communication quality, communication traffic,
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Queueing Delay Analysis and Optimization of Statistical Data Aggregation and Transmission Systems Hideaki YOSHINO Kenko OTA Takefumi HIRAGURI
Publication: Publication Date: 2018/10/01 Vol. E101-B No. 10 pp. 2186-2195 Type of Manuscript: PAPER Category: Network Keyword: sensor data, optimal aggregation, IoT, queueing analysis, communication traffic,
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Multi-Beam Massive MIMO with Beam-Selection Using Only Amplitude Information in Uplink Channel Fumiya MURAMATSU Kentaro NISHIMORI Ryotaro TANIGUCHI Takefumi HIRAGURI
Publication: Publication Date: 2018/07/01 Vol. E101-B No. 7 pp. 1544-1551 Type of Manuscript: Special Section PAPER (Special Section on Communication Quality in Wireless Networks) Category: Keyword: massive MIMO, hybrid analog-digital beamforming, constant modulus algorithm, beam-selection method,
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Novel Access Control Scheme with Collision Detection Utilizing MIMO Transmission Procedure in WLAN Systems Takefumi HIRAGURI Kentaro NISHIMORI Yoshiaki MORINO Mamoru UGAJIN Hideaki YOSHINO
Publication: Publication Date: 2018/07/01 Vol. E101-B No. 7 pp. 1561-1574 Type of Manuscript: Special Section PAPER (Special Section on Communication Quality in Wireless Networks) Category: Keyword: MIMO, access control, WLAN, collision detection, orthogonally polarized antenna,
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Effect of User Antenna Selection on Block Beamforming Algorithms for Suppressing Inter-User Interference in Multiuser MIMO System Nobuyoshi KIKUMA Kentaro NISHIMORI Takefumi HIRAGURI
Publication: Publication Date: 2018/07/01 Vol. E101-B No. 7 pp. 1523-1535 Type of Manuscript: INVITED PAPER (Special Section on Communication Quality in Wireless Networks) Category: Keyword: multiuser MIMO, block beamforming, user antenna selection, achievable bit rate, throughput,
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An (N+N²)-Mixer Architecture for a High-Image-Rejection Wireless Receiver with an N-Phase Active Complex Filter Mamoru UGAJIN Takuya SHINDO Tsuneo TSUKAHARA Takefumi HIRAGURI
Publication: Publication Date: 2017/04/01 Vol. E100-A No. 4 pp. 1008-1014 Type of Manuscript: PAPER Category: Circuit Theory Keyword: integrated circuit, wireless receiver, image rejection, mismatch correction, 3-phase analog circuit, complex filter,
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A Novel Collision Avoidance Scheme Using Optimized Contention Window in Dense Wireless LAN Environments Yoshiaki MORINO Takefumi HIRAGURI Hideaki YOSHINO Kentaro NISHIMORI Takahiro MATSUDA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2016/11/01 Vol. E99-B No. 11 pp. 2426-2434 Type of Manuscript: PAPER Category: Wireless Communication Technologies Keyword: IEEE802.11 MAC, contention window, transmission efficiency,
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FFT-Based Block Diagonalization at User Terminal for Implicit Beamforming in Multiuser MIMO System Hayate KIMOTO Kentaro NISHIMORI Takefumi HIRAGURI Hideo MAKINO
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2016/01/01 Vol. E99-B No. 1 pp. 115-123 Type of Manuscript: Special Section PAPER (Special Section on Recent Progress in Antennas, Propagation and Wireless Systems Related to Topics in ISAP2014) Category: Antennas and Propagation Keyword: multiuser MIMO, block diagonalization, FFT, implicit beamforming, IEEE802.11ac, eigenvalue,
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Survey of Transmission Methods and Efficiency Using MIMO Technologies for Wireless LAN Systems Takefumi HIRAGURI Kentaro NISHIMORI
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2015/07/01 Vol. E98-B No. 7 pp. 1250-1267 Type of Manuscript: INVITED SURVEY PAPER Category: Keyword: MIMO, MU-MIMO, transmission efficiency, overhead, access control, MAC protocol, CSI feedback, implicit beamforming, PHY,
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Multicast Transmission Access Control Methods for Various Wireless LAN Applications Toshiyuki OGAWA Takefumi HIRAGURI Kentaro NISHIMORI Hideaki YOSHINO Kenya JIN'NO
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2014/11/01 Vol. E97-B No. 11 pp. 2534-2542 Type of Manuscript: PAPER Category: Terrestrial Wireless Communication/Broadcasting Technologies Keyword: Interference wave, multicast transmission, packet collision, packet loss, WLAN,
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Transmission Rate by User Antenna Selection for Block Diagonalization Based Multiuser MIMO System Kentaro NISHIMORI Takefumi HIRAGURI Hideo MAKINO
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2014/10/01 Vol. E97-B No. 10 pp. 2118-2126 Type of Manuscript: Special Section PAPER (Special Section on Recent Progress in Measurement and Design Techniques on Antennas, Propagation and Wireless Systems) Category: Keyword: multiuser MIMO, block diagonalization, user antenna selection, IEEE802.11ac, eigenvalue,
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Analog Decoding Method for Simplified Short-Range MIMO Transmission Ryochi KATAOKA Kentaro NISHIMORI Takefumi HIRAGURI Naoki HONMA Tomohiro SEKI Ken HIRAGA Hideo MAKINO
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2014/03/01 Vol. E97-B No. 3 pp. 620-630 Type of Manuscript: PAPER Category: Antennas and Propagation Keyword: short-range MIMO transmission, zero forcing, unitary matrix, 90-degree phase shifter, optimal element spacing,
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Non-iterative Algorithm of MIMO Adaptive Array Based on Correlation Matrix Including Parasitic Antennas Naoki HONMA Kentaro NISHIMORI Takefumi HIRAGURI Yoshitaka TSUNEKAWA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2013/07/01 Vol. E96-B No. 7 pp. 1945-1952 Type of Manuscript: PAPER Category: Antennas and Propagation Keyword: adaptive array, tunable reactance device, MIMO, correlation matrix,
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User-Oriented QoS Control Method Based on CSMA/CA for IEEE802.11 Wireless LAN System Akira KISHIDA Masashi IWABUCHI Toshiyuki SHINTAKU Tetsu SAKATA Takefumi HIRAGURI Kentaro NISHIMORI
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2013/02/01 Vol. E96-B No. 2 pp. 419-429 Type of Manuscript: Special Section PAPER (Special Section on Quality of Communication Services Improving Quality of Life) Category: Keyword: user-oriented, QoS, fixed backoff, CSMA/CA, IEEE802.11,
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Power Saving Control Method for Battery-Powered Portable Wireless LAN Access Points in an Overlapping BSS Environment Masakatsu OGAWA Takefumi HIRAGURI Kentaro NISHIMORI Naoki HONMA Kazuhiro TAKAYA Kazuo MURAKAWA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2011/03/01 Vol. E94-B No. 3 pp. 658-666 Type of Manuscript: Special Section PAPER (Special Section on Information and Communication Technologies for Next-generation Mobile Multimedia Life) Category: Keyword: IEEE802.11, power saving, portable access point, overlapping BSS,
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Development of Multi Channel Ad-Hoc Network System Kentaro NISHIMORI Takefumi HIRAGURI Masakatsu OGAWA Naoki HONMA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2011/03/01 Vol. E94-B No. 3 pp. 667-675 Type of Manuscript: Special Section PAPER (Special Section on Information and Communication Technologies for Next-generation Mobile Multimedia Life) Category: Keyword: ad-hoc networks, vertical antenna arrangement, distributed channel allocation, multi channels,
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A Stochastic Approach to Design MIMO Antenna with Parasitic Elements Based on Propagation Characteristics Naoki HONMA Kentaro NISHIMORI Riichi KUDO Yasushi TAKATORI Takefumi HIRAGURI Masato MIZOGUCHI
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2010/10/01 Vol. E93-B No. 10 pp. 2578-2585 Type of Manuscript: Special Section PAPER (Special Section on Advanced Technologies in Antennas and Propagation in Conjunction with Main Topics of ISAP2009) Category: Antennas Keyword: MIMO, parasitic antennas, mobile antennas, Yagi-Uda arrays,
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A Novel Interference Avoidance Technique on Mobile Wireless Routers Using IEEE802.11n PSMP Akira KISHIDA Takefumi HIRAGURI Masakatsu OGAWA Kentaro NISHIMORI Naoki HONMA Tetsu SAKATA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2010/08/01 Vol. E93-B No. 8 pp. 2053-2062 Type of Manuscript: Special Section PAPER (Special Section on Implementation, Experiments, and Practice for Ad Hoc and Mesh Networks) Category: Keyword: IEEE802.11n, IEEE802.16e, mutual system interference, PSMP, wireless relay,
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Transmission History Based Distributed Adaptive Contention Window Adjustment Algorithm Cooperating with Automatic Rate Fallback for Wireless LANs Masakatsu OGAWA Takefumi HIRAGURI Kentaro NISHIMORI Kazuhiro TAKAYA Kazuo MURAKAWA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2010/08/01 Vol. E93-B No. 8 pp. 2063-2072 Type of Manuscript: Special Section PAPER (Special Section on Implementation, Experiments, and Practice for Ad Hoc and Mesh Networks) Category: Keyword: IEEE 802.11, CSMA/CA, contention window adjustment, automatic rate fallback,
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Frame Resource Allocation Schemes that Improve System Capacity and Latency Performance of Time-Division Duplex Multihop Relay Systems Youhei OHNO Tatsuya SHIMIZU Takefumi HIRAGURI Masashi NAKATSUGAWA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2010/08/01 Vol. E93-B No. 8 pp. 2035-2042 Type of Manuscript: Special Section PAPER (Special Section on Implementation, Experiments, and Practice for Ad Hoc and Mesh Networks) Category: Keyword: multihop relay, frame resource allocation, system capacity, latency,
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Power Saving Control for Battery-Powered Portable WLAN APs Masakatsu OGAWA Takefumi HIRAGURI
Publication: IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences Publication Date: 2009/09/01 Vol. E92-A No. 9 pp. 2253-2256 Type of Manuscript: Special Section LETTER (Special Section on Multi-dimensional Mobile Information Networks) Category: Keyword: IEEE802.11, power saving, portable access point,
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Power Saving Scheme Suitable for Wireless LAN in Multimedia Communications Takefumi HIRAGURI Masakatsu OGAWA Makoto UMEUCHI Tetsu SAKATA
Publication: IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences Publication Date: 2009/09/01 Vol. E92-A No. 9 pp. 2184-2190 Type of Manuscript: Special Section PAPER (Special Section on Multi-dimensional Mobile Information Networks) Category: Wireless LAN System Keyword: wireless LAN, power saving, quality of service, multicasting, broadcasting,
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Proposal of Wireless Traffic Control Schemes for Wireless LANs Takefumi HIRAGURI Takeo ICHIKAWA Masataka IIZUKA Shuji KUBOTA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2008/05/01 Vol. E91-B No. 5 pp. 1340-1348 Type of Manuscript: Special Section PAPER (Special Section on Communication Quality) Category: QoS Control Mechanism and System Keyword: wireless LAN, IEEE802.11, traffic control, load barancing, QoS,
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Novel Multiple Access Protocol for Voice over IP in Wireless LAN Takefumi HIRAGURI Takeo ICHIKAWA Masataka IIZUKA Masahiro MORIKURA
Publication: IEICE TRANSACTIONS on Communications Publication Date: 2002/10/01 Vol. E85-B No. 10 pp. 2145-2152 Type of Manuscript: Special Section PAPER (Special Issue on Mobile Multimedia Communications) Category: Keyword: wireless LAN, CSMA/CA, VoIP, H.323,
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