Atsushi OHTA


Spectral Efficiency Improvement of Fractional Frequency Reuse by Inter-Cell Interference Cancellation on Cooperative Base Station
Kazuki MARUTA  Atsushi OHTA  Masataka IIZUKA  Takatoshi SUGIYAMA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2012/06/01
Vol. E95-B  No. 6  pp. 2164-2168
Type of Manuscript: LETTER
Category: Wireless Communication Technologies
Keyword: 
inter-cell interference cancellationbase station cooperationfractional frequency reuse
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Verifying Structurally Weakly Persistent Net Is Co-NP Complete
Atsushi OHTA  Kohkichi TSUJI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2011/12/01
Vol. E94-A  No. 12  pp. 2832-2835
Type of Manuscript: Special Section LETTER (Special Section on Mathematical Systems Science and its Applications)
Category: 
Keyword: 
concurrent systemPetri netsubclasscomputational complexity
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Computational Complexity of Liveness Problem of Normal Petri Net
Atsushi OHTA  Kohkichi TSUJI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/11/01
Vol. E92-A  No. 11  pp. 2717-2722
Type of Manuscript: Special Section PAPER (Special Section on Theory of Concurrent Systems and its Applications)
Category: 
Keyword: 
concurrent systemPetri netlivenesscomputational complexity
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A New User Selection Measure in Block Diagonalization Algorithm for Multiuser MIMO Systems
Riichi KUDO  Yasushi TAKATORI  Kentaro NISHIMORI  Atsushi OHTA  Shuji KUBOTA  Masato MIZOGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2009/10/01
Vol. E92-B  No. 10  pp. 3206-3218
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
Keyword: 
multiuser MIMOuser selectionblock diagonalizationchannel capacity
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Antenna Selection Method for Terminal Antennas Employing Orthogonal Polarizations and Patterns in Outdoor Multiuser MIMO System
Naoki HONMA  Riichi KUDO  Kentaro NISHIMORI  Yasushi TAKATORI  Atsushi OHTA  Shuji KUBOTA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/06/01
Vol. E91-B  No. 6  pp. 1752-1759
Type of Manuscript: Special Section PAPER (Special Section on 2007 International Symposium on Antennas and Propagation)
Category: Smart Antennas & MIMO
Keyword: 
MIMOmultiuserurban environmentpolarizationpatternantenna selection
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New Downlink Beamforming Method for Cooperative Multiple Access Point Systems
Riichi KUDO  Yasushi TAKATORI  Kentaro NISHIMORI  Atsushi OHTA  Shuji KUBOTA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/09/01
Vol. E90-B  No. 9  pp. 2303-2311
Type of Manuscript: Special Section PAPER (Special Section on 2006 International Symposium on Antennas and Propagation)
Category: Smart Antennas
Keyword: 
MIMOdownlinkbeamformingmultiple access point system
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New Robust Beamforming Method for Frequency Offsets in Uplink Multiuser OFDM-MIMO
Yasushi TAKATORI  Riichi KUDO  Atsushi OHTA  Koichi ISHIHARA  Kentaro NISHIMORI  Shuji KUBOTA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/09/01
Vol. E90-B  No. 9  pp. 2312-2320
Type of Manuscript: Special Section PAPER (Special Section on 2006 International Symposium on Antennas and Propagation)
Category: Smart Antennas
Keyword: 
multiuser MIMOuplinkbeamformingfrequency offset
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A Simple and Feasible Decision-Feedback Channel Tracking Scheme for MIMO-OFDM Systems
Yusuke ASAI  Wenjie JIANG  Takeshi ONIZAWA  Atsushi OHTA  Satoru AIKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/05/01
Vol. E90-B  No. 5  pp. 1052-1060
Type of Manuscript: Special Section PAPER (Special Section on Advanced Transfer Technologies for the Next Generation Network)
Category: 
Keyword: 
MIMOOFDMchannel trackingchannel estimationDoppler frequencyIEEE 802.11nwireless LANframe aggregation
  Summary |  Full Text:PDF (1.4MB)

A Synchronization Scheme for Packet Mode MIMO-OFDM Signals in Wireless LAN
Takeshi ONIZAWA  Takafumi FUJITA  Yusuke ASAI  Daisei UCHIDA  Atsushi OHTA  Satoru AIKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/01/01
Vol. E90-B  No. 1  pp. 92-104
Type of Manuscript: PAPER
Category: Terrestrial Radio Communications
Keyword: 
wireless LANMIMOOFDMpacket modesynchronization
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FPGA Implementation of Eigenbeam MIMO-OFDM for Wireless LAN and Its Experimental Performance
Takeshi ONIZAWA  Atsushi OHTA  Yusuke ASAI  Satoru AIKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/12/01
Vol. E89-B  No. 12  pp. 3233-3241
Type of Manuscript: Special Section PAPER (Special Section on Software Defined Radio Technology and Its Applications)
Category: 
Keyword: 
software-defined radiofield programmable gate arrayMIMO-OFDMeigenbeamwireless LAN
  Summary |  Full Text:PDF (3.5MB)

FOREWORD
Atsushi OHTA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2006/11/01
Vol. E89-A  No. 11  pp. 3165-3165
Type of Manuscript: FOREWORD
Category: 
Keyword: 
  Summary |  Full Text:PDF (54.2KB)

A Simplified Maximum Likelihood Detector for OFDM-SDM Systems in Wireless LAN
Wenjie JIANG  Takeshi ONIZAWA  Atsushi OHTA  Satoru AIKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/06/01
Vol. E88-B  No. 6  pp. 2427-2437
Type of Manuscript: Special Section PAPER (Special Section on 2004 International Symposium on Antennas and Propagation)
Category: 
Keyword: 
OFDM-SDMMLDZFcomplexity reductionWLAN
  Summary |  Full Text:PDF (1.6MB)

A Reduced-Complexity Signal Detection Scheme Employing ZF and K-Best Algorithms for OFDM/SDM
Takafumi FUJITA  Atsushi OHTA  Takeshi ONIZAWA  Takatoshi SUGIYAMA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/01/01
Vol. E88-B  No. 1  pp. 66-75
Type of Manuscript: Special Section PAPER (Special Section on Multi-carrier Signal Processing Techniques for Next Generation Mobile Communications--Part 1)
Category: Space Division Multiplexing
Keyword: 
OFDMSDMMIMOMLDZero-ForcingK-bestM-algorithmIEEE 802.11a
  Summary |  Full Text:PDF (806KB)

FOREWORD
Atsushi OHTA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2004/04/01
Vol. E87-A  No. 4  pp. 773-773
Type of Manuscript: FOREWORD
Category: 
Keyword: 
  Summary |  Full Text:PDF (40.6KB)

A Scheme to Evaluate Cell Throughput of Multi-Rate Wireless LAN Systems with CSMA/CA
Takafumi FUJITA  Takeshi ONIZAWA  Satoru HORI  Atsushi OHTA  Satoru AIKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/04/01
Vol. E87-B  No. 4  pp. 880-890
Type of Manuscript: PAPER
Category: Wireless Communication Technology
Keyword: 
wireless LANsOFDMCSMA/CAcell throughputsystem capacity
  Summary |  Full Text:PDF (1.3MB)

NP-Hardness of Liveness Problem of Bounded Asymmetric Choice Net
Atsushi OHTA  Kohkichi TSUJI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2002/05/01
Vol. E85-A  No. 5  pp. 1071-1074
Type of Manuscript: Special Section LETTER (Special Section on Discrete Mathematics and Its Applications)
Category: 
Keyword: 
concurrent systemPetri netlivenesscomputational complexity
  Summary |  Full Text:PDF (265.1KB)

Polynomial Time Decidability of Monotone Liveness of Time Bounded AC/DC Nets
Atsushi OHTA  Kohkichi TSUJI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/11/01
Vol. E84-A  No. 11  pp. 2865-2870
Type of Manuscript: Special Section PAPER (Special Section on Concurrent Systems Technology)
Category: 
Keyword: 
concurrent systemPetri netlivenesscomputational complexity
  Summary |  Full Text:PDF (225.5KB)

PRIME ARQ: A Novel ARQ Scheme for High-Speed Wireless ATM
Atsushi OHTA  Masafumi YOSHIOKA  Masahiro UMEHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/03/01
Vol. E84-B  No. 3  pp. 474-483
Type of Manuscript: Special Section PAPER (Special Issue on Innovative Mobile Communication Technologies at the Dawn of the 21st Century)
Category: 
Keyword: 
ARQwireless ATMquality of service (QoS)selective repeat ARQerror compensation
  Summary |  Full Text:PDF (9.1MB)

Turing Machine Equivalence of Time Asymmetric Choice Nets
Atsushi OHTA  Kohkichi TSUJI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2000/11/20
Vol. E83-A  No. 11  pp. 2278-2281
Type of Manuscript: Special Section LETTER (Special Section on Concurrent Systems Technology)
Category: 
Keyword: 
time Petri netTuring machinesdecidability
  Summary |  Full Text:PDF (183.1KB)

On Liveness of Extended Partially Ordered Condition Nets
Atsushi OHTA  Kohkichi TSUJI  Tomiji HISAMURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1999/11/20
Vol. E82-A  No. 11  pp. 2576-2578
Type of Manuscript: Special Section LETTER (Special Section on Concurrent Systems Technology)
Category: 
Keyword: 
Petri netlivenesssiphontrap
  Summary |  Full Text:PDF (128.6KB)

On Liveness of Time POC Nets with the Static Fair Condition
Atsushi OHTA  Tomiji HISAMURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1999/08/20
Vol. E82-A  No. 8  pp. 1648-1655
Type of Manuscript: PAPER
Category: Concurrent Systems
Keyword: 
concurrent systemtime Petri netsubclassliveness
  Summary |  Full Text:PDF (351.9KB)

An Algebraic Criterion for State Machine Allocatable Nets
Atsushi OHTA  Tomiji HISAMURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1998/04/20
Vol. E81-A  No. 4  pp. 626-627
Type of Manuscript: Special Section LETTER (Special Section on Concurrent Systems Technology)
Category: 
Keyword: 
Petri netstate machine allocatable netfree choice net
  Summary |  Full Text:PDF (153.2KB)

Dynamic Time-Slot Assignment Schemes for TDMA-Based Wireless ATM
Makoto UMEUCHI  Atsushi OHTA  Masahiro UMEHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1997/08/20
Vol. E80-B  No. 8  pp. 1182-1191
Type of Manuscript: Special Section PAPER (Special Issue on Mobile Computing)
Category: 
Keyword: 
ATMwireless accessTDMAtime-slot assignment
  Summary |  Full Text:PDF (742.5KB)

On Some Analysis Properties of Petri Net Systems under the Earliest Firing Rule
Atsushi OHTA  Tomiji HISAMURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1996/11/20
Vol. E79-A  No. 11  pp. 1791-1796
Type of Manuscript: Special Section PAPER (Special Section on Description Models for Concurrent Systems and Their Applications)
Category: 
Keyword: 
Petri netsthe earliest furing rulelivenessreachability
  Summary |  Full Text:PDF (521.7KB)