Riichi KUDO


User Equipment Centric Downlink Access in Unlicensed Spectrum for Heterogeneous Mobile Network
Riichi KUDO B. A. Hirantha Sithira ABEYSEKERA Yusuke ASAI Takeo ICHIKAWA Yasushi TAKATORI Masato MIZOGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2015/10/01
Vol. E98-B  No. 10  pp. 1969-1977
Type of Manuscript:  Special Section PAPER (Special Section on 5G Radio Access Networks―Part II: Multi-RAT Heterogeneous Networks and Smart Radio Technologies)
Category: 
Keyword: 
heterogeneous networkCSMA/CAunlicensed spectrumwireless LANRXOPhidden terminal problem
 Summary | Full Text:PDF(3.4MB)

Weighted-Combining Calibration on Multiuser MIMO Systems with Implicit Feedback
Hayato FUKUZONO Tomoki MURAKAMI Riichi KUDO Yasushi TAKATORI Masato MIZOGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2015/04/01
Vol. E98-B  No. 4  pp. 701-713
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
multiple-input multiple-output (MIMO)channel reciprocityimplicit feedbackcalibrationminimum mean square error (MMSE)
 Summary | Full Text:PDF(2.6MB)

Maximum Likelihood Demodulators and Their Evaluations on Amplify-and-Forward Cooperative OFDM-Based Wireless LAN Systems
Hayato FUKUZONO Yusuke ASAI Riichi KUDO Koichi ISHIHARA Masato MIZOGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2014/11/01
Vol. E97-B  No. 11  pp. 2435-2448
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
cooperative communicationorthogonal frequency division multiplexing (OFDM)wireless local area network (LAN)amplify-and-forward (AF) modeGolden codeAlamouti codelog likelihood ratio
 Summary | Full Text:PDF(2.7MB)

Implementation and Evaluation of Real-Time Distributed Zero-Forcing Beamforming for Downlink Multi-User MIMO Systems
Tomoki MURAKAMI Koichi ISHIHARA Riichi KUDO Yusuke ASAI Takeo ICHIKAWA Masato MIZOGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/10/01
Vol. E96-B  No. 10  pp. 2521-2529
Type of Manuscript:  Special Section PAPER (Special Section on Recent Progress in Antennas and Propagation in Conjunction with Main Topics of ISAP2012)
Category: Wireless Communication Technologies
Keyword: 
multiuser MIMOinter-cell interferencedistributed systemwireless LAN system
 Summary | Full Text:PDF(4.7MB)

Game-Theoretic Analysis of Multibandwidth Channel Selection by Coordinated APs in WLANs
Kohei HANADA Koji YAMAMOTO Masahiro MORIKURA Koichi ISHIHARA Riichi KUDO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/06/01
Vol. E96-B  No. 6  pp. 1277-1287
Type of Manuscript:  Special Section PAPER (Special Section on Heterogeneous Networks for Future Cellular Systems)
Category: 
Keyword: 
wireless LANmultibandwidthchannel selectionIEEE 802.11acoverlapping BSSgame theory
 Summary | Full Text:PDF(1.6MB)

Performance Evaluation of Interference-Aware Multi-Cell Beamforming for an Overlapping Cells Environment
Tomoki MURAKAMI Riichi KUDO Takeo ICHIKAWA Naoki HONMA Masato MIZOGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/06/01
Vol. E96-B  No. 6  pp. 1492-1501
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
MIMOmulti-cell beamforminginter-cell interference (ICI)WLANdecentralized control scheme
 Summary | Full Text:PDF(4.2MB)

A Band-Divided Receiver Prototype for Wideband Optical Signals
Munehiro MATSUI Riichi KUDO Yasushi TAKATORI Tadao NAKAGAWA Koichi ISHIHARA Masato MIZOGUCHI Takayuki KOBAYASHI Yutaka MIYAMOTO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2011/07/01
Vol. E94-B  No. 7  pp. 1801-1808
Type of Manuscript:  Special Section PAPER (Joint Special Section on Opto-electronics and Communications for Future Optical Network)
Category: 
Keyword: 
coherent receiveranalog to digital converterOFDMreal-timeheterodyne receiver
 Summary | Full Text:PDF(1.4MB)

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: 
MIMOparasitic antennasmobile antennasYagi-Uda arrays
 Summary | Full Text:PDF(1.9MB)

1616 MIMO Testbed for MU-MIMO Downlink Transmission
Kentaro NISHIMORI Riichi KUDO Naoki HONMA Yasushi TAKATORI Masato MIZOGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2010/02/01
Vol. E93-B  No. 2  pp. 345-352
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
multiuser MIMOadaptive modulation schemeOFDMeigenvaluebit interleaver
 Summary | Full Text:PDF(697.5KB)

Frequency-Domain Equalization for Coherent Optical Single-Carrier Transmission Systems
Koichi ISHIHARA Takayuki KOBAYASHI Riichi KUDO Yasushi TAKATORI Akihide SANO Yutaka MIYAMOTO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2009/12/01
Vol. E92-B  No. 12  pp. 3736-3743
Type of Manuscript:  PAPER
Category: Fiber-Optic Transmission for Communications
Keyword: 
frequency-domain equalization (FDE)coherent optical transmissionchromatic dispersion (CD)polarization mode dispersion (PMD)digital signal processing (DSP)
 Summary | Full Text:PDF(2.6MB)

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
 Summary | Full Text:PDF(2.1MB)

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
 Summary | Full Text:PDF(1.2MB)

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
 Summary | Full Text:PDF(1.7MB)

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
 Summary | Full Text:PDF(782.4KB)

Novel Downlink Beamforming Method Using Selective STBC with Common Eigenvectors for MIMO-OFDM Systems
Riichi KUDO Yasushi TAKATORI Kentaro NISHIMORI Koichi TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/08/01
Vol. E89-B  No. 8  pp. 2170-2179
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMOeigenvectorOFDMachievable spectrum efficiencySTBCbeamformingmaximum Doppler frequencyfeedback overhead
 Summary | Full Text:PDF(1.4MB)

Frequency Correlation Characteristics Due to Antenna Configurations in Broadband MIMO Transmission
Kentaro NISHIMORI Nobuhiko TACHIKAWA Yasushi TAKATORI Riichi KUDO Koichi TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/06/01
Vol. E88-B  No. 6  pp. 2438-2445
Type of Manuscript:  Special Section PAPER (Special Section on 2004 International Symposium on Antennas and Propagation)
Category: 
Keyword: 
MIMOfrequency correlationantenna arrangementOFDMdelay signalsangular spread
 Summary | Full Text:PDF(2.1MB)