Tomoaki OHTSUKI


A Smart City Based on Ambient Intelligence
Tomoaki OHTSUKI 
Publication:   
Publication Date: 2017/09/01
Vol. E100-B  No. 9  pp. 1547-1553
Type of Manuscript:  INVITED PAPER (Special Issue the Past, Present, and Future of Communications Technologies in the IEICE)
Category: Network
Keyword: 
a smart cityambient intelligenceinformation and communication technology (ICT)Internet of things (IoT)
 Summary | Full Text:PDF(1.4MB)

Low Computational Complexity Direction-of-Arrival Estimation of Wideband Signal Sources Based on Squared TOPS
Hirotaka HAYASHI Tomoaki OHTSUKI 
Publication:   
Publication Date: 2017/01/01
Vol. E100-A  No. 1  pp. 219-226
Type of Manuscript:  Special Section PAPER (Special Section on Wideband Systems)
Category: 
Keyword: 
array signal processingDOA estimationwideband signals
 Summary | Full Text:PDF(793.5KB)

DOA Estimation Using Temporal Spatial Virtual Array Based on Doppler Shift with Adaptive PRI Control
Hirotaka HAYASHI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2016/09/01
Vol. E99-B  No. 9  pp. 2009-2018
Type of Manuscript:  Special Section PAPER (Special Section on Integration Technologies of Ambient Intelligence and Sensor Networks)
Category: 
Keyword: 
array signal processingDOA estimationDoppler radarMIMO radar
 Summary | Full Text:PDF(1012.5KB)

Algorithm Design of Relative Magnitude Coefficients Using Brent's Method on the K-User MIMO-IFC
Kunitaka MATSUMURA Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2016/08/01
Vol. E99-B  No. 8  pp. 1902-1909
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMOinterference alignmentBrent's method
 Summary | Full Text:PDF(611.6KB)

Power-Absorption-Based Model for Power Compensation in WLAN Positioning Using Smartphone
Masaaki YAMAMOTO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2015/06/01
Vol. E98-B  No. 6  pp. 1125-1132
Type of Manuscript:  PAPER
Category: Sensing
Keyword: 
indoorpositioningWLANsmartphone
 Summary | Full Text:PDF(1.4MB)

FOREWORD
Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2014/09/01
Vol. E97-B  No. 9  pp. 1750-1751
Type of Manuscript:  FOREWORD
Category: 
Keyword: 
 Summary | Full Text:PDF(227.2KB)

Adaptive Q-Learning Cell Selection Method for Open-Access Femtocell Networks: Multi-User Case
Chaima DHAHRI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2014/08/01
Vol. E97-B  No. 8  pp. 1679-1688
Type of Manuscript:  PAPER
Category: Network Management/Operation
Keyword: 
open access femtocell networkshandoverreinforcement learningQ-learningfuzzy logic
 Summary | Full Text:PDF(3.1MB)

Optimal Channel-Sensing Scheme for Cognitive Radio Systems Based on Fuzzy Q-Learning
Fereidoun H. PANAHI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2014/02/01
Vol. E97-B  No. 2  pp. 283-294
Type of Manuscript:  Special Section PAPER (Special Section on Technologies for Effective Utilization of Spectrum White Space)
Category: 
Keyword: 
cognitive radio (CR)partially observable Markov decision process (POMDP)Fuzzy Q-Learning (FQL)Baum-Welch Algorithm (BWA)
 Summary | Full Text:PDF(2.2MB)

MIMO Receiver with Antenna Subset Selection: Algorithm and Hardware Implementation
Kazuhiko MITSUYAMA Tetsuomi IKEDA Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/04/01
Vol. E96-B  No. 4  pp. 1039-1050
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMOantenna subset selectioncondition numberhardware implementationfield experiment
 Summary | Full Text:PDF(3.2MB)

FOREWORD
Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2012/12/01
Vol. E95-B  No. 12  pp. 3653-3653
Type of Manuscript:  FOREWORD
Category: 
Keyword: 
 Summary | Full Text:PDF(227.1KB)

State Classification with Array Sensor Using Support Vector Machine for Wireless Monitoring Systems
Jihoon HONG Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2012/10/01
Vol. E95-B  No. 10  pp. 3088-3095
Type of Manuscript:  Special Section PAPER (Special Section on Medical Information Communication Technology for Disaster Recovery and Human Health Care Support)
Category: 
Keyword: 
wireless monitoringarray antennasupport vector machine
 Summary | Full Text:PDF(1.1MB)

PAPR Reduction of TDD-CDMA Using Joint Transmission Technique
Norharyati BINTI HARUM Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2012/03/01
Vol. E95-B  No. 3  pp. 933-942
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
TD-SCDMATDDjoint transmissionprecodingPAPR
 Summary | Full Text:PDF(1.1MB)

Subcarrier Mapping for Single-User SC-FDMA Relay Communications
Yu HEMMI Koichi ADACHI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2011/12/01
Vol. E94-A  No. 12  pp. 2776-2779
Type of Manuscript:  Special Section LETTER (Special Section on Wideband Systems)
Category: 
Keyword: 
relay communicationSC-FDMAsubcarrier mapping
 Summary | Full Text:PDF(831.7KB)

Robust DOA Estimation for Uncorrelated and Coherent Signals
Hui CHEN Qun WAN Hongyang CHEN Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2011/10/01
Vol. E94-A  No. 10  pp. 2035-2038
Type of Manuscript:  LETTER
Category: Digital Signal Processing
Keyword: 
coherent signalsdirection of arrival(DOA)sparse reconstruction
 Summary | Full Text:PDF(218.5KB)

Performance Evaluation of Iterative LDPC-Coded MIMO OFDM System with Time Interleaving
Kazuhiko MITSUYAMA Kohei KAMBARA Takayuki NAKAGAWA Tetsuomi IKEDA Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2010/12/01
Vol. E93-A  No. 12  pp. 2654-2662
Type of Manuscript:  Special Section PAPER (Special Section on Wideband Systems)
Category: 
Keyword: 
MIMOMMSELDPCtime Interleaving
 Summary | Full Text:PDF(1.3MB)

6-Axis Sensor Assisted Low Complexity High Accuracy-Visible Light Communication Based Indoor Positioning System
Chinnapat SERTTHIN Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2010/11/01
Vol. E93-B  No. 11  pp. 2879-2891
Type of Manuscript:  Special Section PAPER (Special Section on Fundamental Issues on Deployment of Ubiquitous Sensor Networks)
Category: 
Keyword: 
visible light communication (VLC)visible light communication identification (VLID)field-of-view (FOV)6-axis sensorroot means square of error distance (RMSED)switching estimated receiver position (SwERP)
 Summary | Full Text:PDF(3.5MB)

Multi-Band Received Signal Strength Fingerprinting Based Indoor Location System
Chinnapat SERTTHIN Takeo FUJII Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2010/08/01
Vol. E93-B  No. 8  pp. 1993-2003
Type of Manuscript:  Special Section PAPER (Special Section on Implementation, Experiments, and Practice for Ad Hoc and Mesh Networks)
Category: 
Keyword: 
fingerprintingmulti-band signalfrequency diversityindoor positioning systemreceived signal strength (RSS)multi-frequency band (multi-band) capability terminal
 Summary | Full Text:PDF(2.7MB)

An Improved User Selection Algorithm in Multiuser MIMO Broadcast with Channel Prediction
Zhi MIN Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2009/08/01
Vol. E92-B  No. 8  pp. 2667-2674
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
multiuser MIMOuser selectionmultiuser diversity
 Summary | Full Text:PDF(327KB)

Indoor Event Detection with Eigenvector Spanning Signal Subspace for Home or Office Security
Shohei IKEDA Hiroyuki TSUJI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2009/07/01
Vol. E92-B  No. 7  pp. 2406-2412
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
home or office securityintruder detectioneigenvector spanning signal subspaceantenna array
 Summary | Full Text:PDF(865.6KB)

Random Beamforming Using Iterative Power Allocation with Small Feedback Information and Low Latency
Yuki TSUCHIYA Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2009/05/01
Vol. E92-B  No. 5  pp. 1908-1911
Type of Manuscript:  LETTER
Category: Wireless Communication Technologies
Keyword: 
random beamformingmultiuser diversitypower allocationAMC
 Summary | Full Text:PDF(400KB)

Turbo Equalized Double Window Cancellation and Combining Robust to Large Delay Spread Channel
JunHwan LEE Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2009/02/01
Vol. E92-B  No. 2  pp. 517-526
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
OFDMISIICITEDWCCHDFSDF
 Summary | Full Text:PDF(1.3MB)

Convergence Acceleration of Iterative Signal Detection for MIMO System with Belief Propagation
Satoshi GOUNAI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/08/01
Vol. E91-B  No. 8  pp. 2640-2647
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMO systemsbelief propagationiterative signal detectionconvergence acceleration
 Summary | Full Text:PDF(721.2KB)

Mapping for Iterative MMSE-SIC with Belief Propagation
Satoshi GOUNAI Tomoaki OHTSUKI Toshinobu KANEKO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/07/01
Vol. E91-B  No. 7  pp. 2187-2197
Type of Manuscript:  PAPER
Category: Fundamental Theories for Communications
Keyword: 
MIMOMMSE-SICBelief PropagationMapping
 Summary | Full Text:PDF(996.9KB)

MIMO Systems in the Presence of Feedback Delay
Kenichi KOBAYASHI Tomoaki OHTSUKI Toshinobu KANEKO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/03/01
Vol. E91-B  No. 3  pp. 829-836
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMOCSIE-SDMSVDZFMMSE
 Summary | Full Text:PDF(765.2KB)

MIMO System with Relative Phase Difference Time-Shift Modulation for Rician Fading Environment
Kenichi KOBAYASHI Takao SOMEYA Tomoaki OHTSUKI Sigit P.W. JAROT Tsuyoshi KASHIMA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/02/01
Vol. E91-B  No. 2  pp. 459-465
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMORician fadingdirect pathphase differenceTurbo code
 Summary | Full Text:PDF(682.1KB)

Scheduling Algorithm with Power Allocation for Random Unitary Beamforming
Yuki TSUCHIYA Tomoaki OHTSUKI Toshinobu KANEKO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/01/01
Vol. E91-B  No. 1  pp. 232-238
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
random beamformingMIMOpower allocationAMC
 Summary | Full Text:PDF(417.8KB)

Double Window Cancellation and Combining for OFDM in Time-Invariant Large Delay Spread Channel
JunHwan LEE Yoshihisa KISHIYAMA Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2007/10/01
Vol. E90-A  No. 10  pp. 2066-2078
Type of Manuscript:  Special Section PAPER (Special Section on Nonlinear Theory and its Applications)
Category: Communications and Sequences
Keyword: 
CP-OFDMDWCCISIICIQPSK16QAM64QAM
 Summary | Full Text:PDF(2.2MB)

Performance Evaluation of SAGE Algorithm for Channel Estimation and Data Detection Using Superimposed Training in MIMO System
Fumiaki TSUZUKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/06/01
Vol. E90-B  No. 6  pp. 1460-1466
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
SAGE algorithmsuperimposed pilotMIMO
 Summary | Full Text:PDF(410.7KB)

LDPC Codes in Communications and Broadcasting
Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/03/01
Vol. E90-B  No. 3  pp. 440-453
Type of Manuscript:  INVITED SURVEY PAPER
Category: 
Keyword: 
LDPC codesBP algorithmsLLRcooperation
 Summary | Full Text:PDF(339.1KB)

Lowering the Error Floors of Irregular LDPC Code on Fast Fading Environment with Perfect and Imperfect CSIs
Satoshi GOUNAI Tomoaki OHTSUKI Toshinobu KANEKO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2007/03/01
Vol. E90-B  No. 3  pp. 569-577
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
irregular Low-Density Parity-Check codeordered statistic decodingCRCerror floorChannel State Information
 Summary | Full Text:PDF(477.8KB)

Chip-Level Detection in Optical Frequency Hopping Code Division Multiple Access
Shoji ICHIKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2006/07/01
Vol. E89-A  No. 7  pp. 2056-2062
Type of Manuscript:  PAPER
Category: Communication Theory and Signals
Keyword: 
CDMAfrequency hoppingchip-level detectionFBG
 Summary | Full Text:PDF(364.2KB)

Companding System Based on Time Clustering for Reducing Peak Power of OFDM Symbol in Wireless Communications
Osamu TAKYU Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2006/07/01
Vol. E89-A  No. 7  pp. 1884-1891
Type of Manuscript:  Special Section PAPER (Special Section on Multi-dimensional Mobile Information Networks)
Category: 
Keyword: 
peak power problemOFDM symbolcompressing and expanding (companding) system
 Summary | Full Text:PDF(467.7KB)

Bootstrapped Modified Weighted Bit Flipping Decoding of Low Density Parity Check Codes
Yoichi INABA Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2006/04/01
Vol. E89-A  No. 4  pp. 1145-1149
Type of Manuscript:  LETTER
Category: Coding Theory
Keyword: 
low density parity check codesWBF algorithmmodified WBF algorithmbootstrap decoding
 Summary | Full Text:PDF(257KB)

A Sign Selection Method of Orthogonal Variable Spreading Factor Code for Peak Power Reduction in Multi-Rate OFCDM Systems
Osamu TAKYU Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/04/01
Vol. E89-B  No. 4  pp. 1333-1345
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
OFCDMmulti-rate communicationOVSF codepeak power problem
 Summary | Full Text:PDF(1.3MB)

Reliability-Based Hybrid ARQ (RB-HARQ) Schemes Using Low-Density Parity-Check (LDPC) Codes
Yoichi INABA Tomonori SAITO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/04/01
Vol. E89-B  No. 4  pp. 1170-1177
Type of Manuscript:  PAPER
Category: Fundamental Theories for Communications
Keyword: 
Reliability-Based Hybrid ARQ (RB-HARQ) schemeLow-Density Parity-Check (LDPC) Codes
 Summary | Full Text:PDF(587.1KB)

Spatial Multiplexing in Optical Wireless MIMO Communications Over Indoor Environment
Daisuke TAKASE Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/04/01
Vol. E89-B  No. 4  pp. 1364-1371
Type of Manuscript:  PAPER
Category: Optical Wireless Communications
Keyword: 
optical wireless multiple-input multiple-output (OMIMO)subcarrier multiplexing (SCM)nonlinearity of LDzero forcing (ZF)intermodulation distortion (IMD)optical modulation index (OMI)
 Summary | Full Text:PDF(454.8KB)

Performance Analysis of Statistical STBC Cooperative Diversity Using Binary Sensors with Observation Noise
Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/03/01
Vol. E89-B  No. 3  pp. 970-973
Type of Manuscript:  LETTER
Category: Network
Keyword: 
cooperative diversitySTBCsensor networkobservation noise
 Summary | Full Text:PDF(194.3KB)

Computational Complexity Reduction of MLD Based on SINR in MIMO Spatial Multiplexing Systems
Katsunari HONJO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/03/01
Vol. E89-B  No. 3  pp. 914-921
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
MIMOMLDSINR
 Summary | Full Text:PDF(629.5KB)

Channel Estimation with Selective Superimposed Pilot Sequences under Fast Fading Environments
Fumiaki TSUZUKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/02/01
Vol. E89-B  No. 2  pp. 556-563
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
channel estimationselective superimposed pilot
 Summary | Full Text:PDF(782.8KB)

Lowering Error Floor of Irregular LDPC Codes by CRC and OSD Algorithm
Satoshi GOUNAI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/01/01
Vol. E89-B  No. 1  pp. 1-10
Type of Manuscript:  PAPER
Category: Fundamental Theories for Communications
Keyword: 
irregular low-density parity-check codelog-likelihood ratio belief propagationordered statistic decodingCRCerror floormaximum likelihood decoding
 Summary | Full Text:PDF(564.2KB)

Throughput Maximization Transmission Control Scheme for MIMO Systems
Kenji SUTO Yoshitaka HARA Tomoaki OHTSUKI Yoshikazu TAKEI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/10/01
Vol. E88-B  No. 10  pp. 4040-4046
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMOthroughputtransmission control
 Summary | Full Text:PDF(476.2KB)

Rake Performance for UWB-IR System with SISO and MISO
Takahiro EZAKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/10/01
Vol. E88-B  No. 10  pp. 4112-4116
Type of Manuscript:  LETTER
Category: Wireless Communication Technologies
Keyword: 
UWB-IRSISO-UWB-IRMISO-UWB-IRMMSE-RAKE
 Summary | Full Text:PDF(304.8KB)

Computational Complexity and Performance of RAKE Receivers with Channel Estimation for DS-UWB
Hiroyuki SATO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2005/09/01
Vol. E88-A  No. 9  pp. 2318-2326
Type of Manuscript:  Special Section PAPER (Special Section on Ultra Wideband Systems)
Category: RAKE Receiver
Keyword: 
DS-UWBMRC-RAKEMMSE-RAKEMRC-RAKE-Equalizerthe computational complexitythe accuracy of channel estimation
 Summary | Full Text:PDF(417.9KB)

Decoding Algorithms Based on Oscillation for Low-Density Parity Check Codes
Satoshi GOUNAI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2005/08/01
Vol. E88-A  No. 8  pp. 2216-2226
Type of Manuscript:  PAPER
Category: Coding Theory
Keyword: 
low-density parity-check codelog likelihood ratio belief propagationordered statistic decodingoscillation
 Summary | Full Text:PDF(667.4KB)

Criterion for Reducing Error Rate Degradation by Nonlinear Amplifier for Multicarrier Transmission
Osamu TAKYU Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/07/01
Vol. E88-B  No. 7  pp. 3057-3061
Type of Manuscript:  LETTER
Category: Wireless Communication Technologies
Keyword: 
multi-carrier transmissionnonlinear distortionpeak power problem
 Summary | Full Text:PDF(289.8KB)

Pre-Rake Diversity Combining for UWB Systems in IEEE 802.15 UWB Multipath Channel
Shunsuke IMADA Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/05/01
Vol. E88-B  No. 5  pp. 2193-2199
Type of Manuscript:  LETTER
Category: Wireless Communication Technologies
Keyword: 
UWBRake diversity combiningPre-Rake diversity combining
 Summary | Full Text:PDF(741.4KB)

Multiple-Subcarrier Optical Communication System with Peak Reduction Carriers
Shota TERAMOTO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/11/01
Vol. E87-B  No. 11  pp. 3385-3388
Type of Manuscript:  LETTER
Category: Optical Wireless Communications
Keyword: 
multiple-subcarrierinfraredoptical systempower reductionpeak reduction carrier
 Summary | Full Text:PDF(318.5KB)

Information and Signal Processing for Sensor Networks
Akira OGAWA Takaya YAMAZATO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2004/10/01
Vol. E87-A  No. 10  pp. 2599-2606
Type of Manuscript:  INVITED PAPER (Special Section on Wide Band Systems)
Category: 
Keyword: 
sensor networkscollaborative information and signal processingjoint source and channel codingdeterministic and statistic collaborationcooperative diversity
 Summary | Full Text:PDF(316.8KB)

OFDM Packet Transmission System with Added Pilot Semi-Blind Iterative Channel Estimation for Tracking Fast Time-Varying Channel
Naoto OHKUBO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/09/01
Vol. E87-B  No. 9  pp. 2729-2737
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
OFDMadded pilot semi-blind channel estimation
 Summary | Full Text:PDF(859.1KB)

Diversity Gain in Ultra Wideband Impulse Radio (UWB-IR)
Takahiro EZAKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/08/01
Vol. E87-B  No. 8  pp. 2385-2390
Type of Manuscript:  LETTER
Category: Wireless Communication Technology
Keyword: 
UWB-IRST-UWB-IRTI-UWB-IRdiversity
 Summary | Full Text:PDF(511.6KB)

Space-Time/Space-Frequency Block Coded OFDM with Diagonalized Maximum Likelihood Decoder (ST/SF-OFDM with DMLD)
Hiroshi KANEMARU Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/07/01
Vol. E87-B  No. 7  pp. 2034-2039
Type of Manuscript:  LETTER
Category: Wireless Communication Technology
Keyword: 
STBCST-OFDMSF-OFDMDMLD
 Summary | Full Text:PDF(419.2KB)

Space-Time-Frequency Block Codes over Frequency Selective Fading Channels
Kenji SUTO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/07/01
Vol. E87-B  No. 7  pp. 1939-1945
Type of Manuscript:  PAPER
Category: Wireless Communication Technology
Keyword: 
STBCST-OFDMSF-OFDMSTF-OFDM
 Summary | Full Text:PDF(387.3KB)

Frequency Offset Compensation with MMSE-MUD for Multi-Carrier CDMA in Quasi-Synchronous Uplink
Osamu TAKYU Tomoaki OHTSUKI Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/06/01
Vol. E87-B  No. 6  pp. 1495-1504
Type of Manuscript:  PAPER
Category: Wireless Communication Technology
Keyword: 
MC-CDMAMMSE-MUDfrequency offset compensationquasi-synchronousuplink
 Summary | Full Text:PDF(758.8KB)

Decoding Algorithms for Low-Density Parity-Check Codes with Multilevel Modulations
Hisashi FUTAKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2004/05/01
Vol. E87-B  No. 5  pp. 1282-1289
Type of Manuscript:  PAPER
Category: Fundamental Theories
Keyword: 
low-density parity-check (LDPC) codebelief propagation (BP) algorithmuniformly most powerful (UMP) BP-based algorithmnormalized BP-based algorithmmultilevel modulation
 Summary | Full Text:PDF(453.9KB)

Low-Density Parity-Check (LDPC) Coded OFDM Systems: Bit Error Rate and the Number of Decoding Iterations
Hisashi FUTAKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2003/11/01
Vol. E86-B  No. 11  pp. 3310-3316
Type of Manuscript:  LETTER
Category: Wireless Communication Technology
Keyword: 
OFDMturbo codeslow-density parity-check codesbelief propagation algorithm
 Summary | Full Text:PDF(535.5KB)

Space-Time Transmit Diversity Schemes with Low-Density Parity-Check (LDPC) Codes
Hisashi FUTAKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2003/10/01
Vol. E86-B  No. 10  pp. 3131-3136
Type of Manuscript:  LETTER
Category: Wireless Communication Technology
Keyword: 
space-time block codingturbo codeslow-density parity-check codes
 Summary | Full Text:PDF(421.3KB)

Multibits/Sequence-Period Optical CDMA Receiver with Double Optical Hardlimiters
Kenji WAKAFUJI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2003/10/01
Vol. E86-A  No. 10  pp. 2670-2677
Type of Manuscript:  PAPER
Category: Spread Spectrum Technologies and Applications
Keyword: 
optical CDMADHLOOKmultibits/sequence-periodReed-Solomon codes
 Summary | Full Text:PDF(536.2KB)

Design Criteria for Phase Sequences in Selected Mapping
Naoto OHKUBO Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2003/09/01
Vol. E86-B  No. 9  pp. 2628-2636
Type of Manuscript:  PAPER
Category: Wireless Communication Technology
Keyword: 
SLMPAPRMC-CDMAPTS
 Summary | Full Text:PDF(666.6KB)

Multiple Subcarrier Modulation for Infrared Wireless Systems Using Punctured Convolutional Codes and Variable Amplitude Block Codes
Hiroe YAMAGUCHI Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2003/08/01
Vol. E86-B  No. 8  pp. 2433-2439
Type of Manuscript:  PAPER
Category: Optical Wireless Communications
Keyword: 
indoor infrared wireless systemMSMRCPCblock code
 Summary | Full Text:PDF(523.7KB)

Improved Design Criteria and New Trellis Codes for Space-Time Trellis Coded Modulation in Fast Fading Channels
Yukihiro SASAZAKI Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2003/03/01
Vol. E86-B  No. 3  pp. 1057-1062
Type of Manuscript:  PAPER
Category: Wireless Communication Technology
Keyword: 
space-time trellis codetransmit diversity (TD)fast fading channels
 Summary | Full Text:PDF(347.3KB)

Equalization for Infrared Wireless Systems Using OOK-CDMA
Hiroe YAMAGUCHI Ryoko MATSUO Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2002/10/01
Vol. E85-B  No. 10  pp. 2292-2299
Type of Manuscript:  PAPER
Category: Optical Wireless Communications
Keyword: 
indoor infrared wireless systemOOK-CDMAequalizer
 Summary | Full Text:PDF(499.7KB)

Indoor Infrared Wireless Systems Using OOK-CDMA with Decision-Feedback Equalizer on Diffuse Channels
Hiroe YAMAGUCHI Ryoko MATSUO Michihito MATSUO Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/04/01
Vol. E84-B  No. 4  pp. 960-966
Type of Manuscript:  PAPER
Category: Wireless Communication Technology
Keyword: 
infraredOOKCDMADFEchannel estimation
 Summary | Full Text:PDF(516.7KB)

Direct-Detection Optical Synchronous CDMA Systems with Interference Canceller Using Group Information Codes
Hiroshi SAWAGASHIRA Katsuhiro KAMAKURA Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2000/11/25
Vol. E83-A  No. 11  pp. 2138-2142
Type of Manuscript:  Special Section LETTER (Special Section on Spread Spectrum Techniques and Applications)
Category: 
Keyword: 
CDMAmultiple access interferenceinterference cancellergroup information codes
 Summary | Full Text:PDF(453.9KB)

Optical Spread Time CDMA Communication Systems with PPM Signaling
Katsuhiro KAMAKURA Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1999/07/25
Vol. E82-B  No. 7  pp. 1038-1047
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
optical ST-CDMAPPMMAIphase maskspectral resolutionrepetition rate
 Summary | Full Text:PDF(1.1MB)

Performance Analysis of ADSL with Punctured Convolutional Code
Weizu YANG Tomoaki OHTSUKI Masami UEDA Kazuya MATSUMOTO Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1999/07/25
Vol. E82-B  No. 7  pp. 1030-1037
Type of Manuscript:  PAPER
Category: Communication Theory
Keyword: 
ADSLDMTpunctured convolutional code
 Summary | Full Text:PDF(971.4KB)

Performance Analysis of Direct-Detection Optical CDMA Systems with Optical Hard-Limiter Using Equal-Weight Orthogonal Signaling
Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1999/03/25
Vol. E82-B  No. 3  pp. 512-520
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
CDMAchannel interferencecancellerequal-weight orthogonal signalingoptical hard-limiter
 Summary | Full Text:PDF(294.9KB)

Performance Analysis of Optical Frequency-Domain Encoding CDMA Enhancement of Frequency Division Multiplexing
Katsuhiro KAMAKURA Yoshinobu GAMACHI Hideyuki UEHARA Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1998/09/25
Vol. E81-B  No. 9  pp. 1749-1757
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
FE-CDMAFDMspatial filterphase maskultrashort light pulsemulti-access interference (MAI)
 Summary | Full Text:PDF(841.8KB)

Direct-Detection Optical Asynchronous CDMA Systems with Double Optical Hard-Limiters: APD Noise and Thermal Noise
Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1998/07/25
Vol. E81-B  No. 7  pp. 1491-1499
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
CDMAchannel interferencedouble optical hard-limitersAPD noisethermal noise
 Summary | Full Text:PDF(662.2KB)

Performance Analysis of Direct-Detection Optical Synchronous CDMA Systems with Co-channel Interference Canceller
Tomoaki OHTSUKI Masanori TAKEOKA Eiji IWAHASHI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1997/11/25
Vol. E80-A  No. 11  pp. 2260-2263
Type of Manuscript:  Special Section LETTER (Special Section on Information Theory and Its Applications)
Category: Coding Theory/Communication
Keyword: 
CDMAco-channel interferencecanceller
 Summary | Full Text:PDF(269.9KB)

Direct-Detection Optical Synchronous CDMA Systems with Channel Interference Canceller Using Time Division Reference Signal
Tomoaki OHTSUKI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1996/12/25
Vol. E79-A  No. 12  pp. 1948-1956
Type of Manuscript:  Special Section PAPER (Special Secton on Spread Spectrum Techniques and Applications)
Category: 
Keyword: 
CDMAchannel interference,canceller,time division reference signal
 Summary | Full Text:PDF(730.5KB)

Cutoff Rate Analysis of Overlapping Multi-Pulse Pulse Position Modulation (OMPPM) in Optical Direct-Detection Channel
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1996/09/25
Vol. E79-A  No. 9  pp. 1471-1474
Type of Manuscript:  Special Section LETTER (Special Section on Information Theory and Its Applications)
Category: Communication
Keyword: 
OMPPMcutoff ratedistance
 Summary | Full Text:PDF(298.4KB)

Access Timing Controlled Direct-Detection Optical CDMA Systems with PPM Signaling
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1996/09/25
Vol. E79-A  No. 9  pp. 1392-1400
Type of Manuscript:  Special Section PAPER (Special Section on Information Theory and Its Applications)
Category: Communication/Spread Spectrum
Keyword: 
CDMAATC-CDMAprime sequence codesPPM
 Summary | Full Text:PDF(711.9KB)

Performance Analysis of Optical Synchronous PPM/CDMA Systems with Interference Canceller Under Number-State Light Field
Yoshinobu GAMACHI Tomoaki OHTSUKI Hideyuki UEHARA Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1996/07/25
Vol. E79-B  No. 7  pp. 915-922
Type of Manuscript:  Special Section PAPER (Special Issue on Optical Access Networks toward Life Enhancement)
Category: 
Keyword: 
interferenceinterference cancellerPPMsynchronous CDMA
 Summary | Full Text:PDF(712KB)

Performance Analysis of Multi-Pulse Pulse Position Modulation Using Avalanche Photodiode in Optical Intersatellite Links
Norihito AOKI Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1996/01/25
Vol. E79-B  No. 1  pp. 52-56
Type of Manuscript:  PAPER
Category: Satellite Communication
Keyword: 
APDISLMPPM
 Summary | Full Text:PDF(416.3KB)

Effects of Hard-Limiter and Error Correction Coding on Performance of Direct-Detection Optical CDMA Systems with PPM Signaling
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1995/09/25
Vol. E78-A  No. 9  pp. 1092-1101
Type of Manuscript:  Special Section PAPER (Special Section on Information Theory and Its Applications)
Category: 
Keyword: 
hard-limitererror correction codingCDMAPPM
 Summary | Full Text:PDF(805.5KB)

Coding for Multi-Pulse PPM with Imperfect Slot Synchronization in Optical Direct-Detection Channels
Kazumi SATO Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1995/06/25
Vol. E78-B  No. 6  pp. 916-922
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
multi-pulse pulse position modulationslot synchronizationtiming offsetpunctured convolutional codesReed-Solomon codes
 Summary | Full Text:PDF(607.4KB)

Performance Analysis of Coherent Optical POLSK Receives with Local Oscillator Intensity Noise and Unmatched Quantum Efficiencies
Hideyuki UEHARA Tomoaki OHTSUKI Iwao SASASE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1994/12/25
Vol. E77-B  No. 12  pp. 1590-1599
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
coherentPOLSKphase noiseintensity noisequantum efficiencies
 Summary | Full Text:PDF(704.1KB)

Lower Bounds on Capacity and Cutoff Rate of Differential Overlapping Pulse Position Modulation in Optical Direct-Detection Channel
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1994/10/25
Vol. E77-B  No. 10  pp. 1230-1237
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
DOPPMcapacitycutoff ratewindow
 Summary | Full Text:PDF(671.3KB)

Error Performance of Overlapping Multi-Pulse Pulse Position Modulation (OMPPM) and Trellis Coded OMPPM in Optical Direct-Detection Channel
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1994/09/25
Vol. E77-B  No. 9  pp. 1133-1143
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
MPPMOMPPMtrellis codesdistance
 Summary | Full Text:PDF(863.9KB)

Performance Analysis of Multi-Pulse PPM with Imperfect Slot Synchronization in Optical Direct-Detection Channel
Kazumi SATO Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1994/08/25
Vol. E77-B  No. 8  pp. 1032-1039
Type of Manuscript:  PAPER
Category: Optical Communication
Keyword: 
multi-pulse pulse position modulationtiming offsettiming jitterslot synchronization
 Summary | Full Text:PDF(629.8KB)

Performance Analysis of Multi-Pulse Pulse Position Modulation (MPPM) in Noisy Photon Counting Channel
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1994/08/25
Vol. E77-A  No. 8  pp. 1381-1386
Type of Manuscript:  Special Section LETTER (Special Section on Information Theory and Its Applications)
Category: 
Keyword: 
MPPMnoisy photon counting channeldistanceconvolutional codesRS codes
 Summary | Full Text:PDF(462.2KB)

Capacity and Cutoff Rate of Overlapping Multi-Pulse Pulse Position Modulation (OMPPM) in Optical Direct-Detection Channel: Quantum-Limited Case
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1994/08/25
Vol. E77-A  No. 8  pp. 1298-1308
Type of Manuscript:  Special Section PAPER (Special Section on Information Theory and Its Applications)
Category: 
Keyword: 
capacitycutoff rateOMPPMquantum limited
 Summary | Full Text:PDF(890.4KB)

The Effects of Laser Phase Noise on Optical Coherent Coded Subcarrier Multiplexing System with Distributing Local Oscillator in Local Loop
Tomoaki OHTSUKI Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1993/02/25
Vol. E76-C  No. 2  pp. 293-300
Type of Manuscript:  Special Section PAPER (Special Issue on Optical/Microwave Interaction Devices, Circuits and Systems)
Category: Fiber Optic Radio Links
Keyword: 
subcarrier multiplexingphase noisecrosstalkIMD
 Summary | Full Text:PDF(594.5KB)

Coherent Subcarrier Multiplexed System with Distributing Local Oscillator in Local Loop
Tomoaki OHTSUKI Hiroyuki YASHIMA Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1992/06/25
Vol. E75-B  No. 6  pp. 499-505
Type of Manuscript:  Special Section PAPER (Special Issue on Communication Theory)
Category: 
Keyword: 
subcarrier multiplexeddistributing local oscillator local loopcoherent SCM
 Summary | Full Text:PDF(607.4KB)

Parallel Rate-Variable Punctured Convolutional Coded PPM in Photon Communication
Tomoaki OHTSUKI Hiroyuki YASHIMA Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1992/01/25
Vol. E75-C  No. 1  pp. 44-49
Type of Manuscript:  Special Section PAPER (Joint Special Section on Fundamentals of Next Generation Opto-Technologies)
Category: 
Keyword: 
photon communicationpunctured covolutional coded PPM
 Summary | Full Text:PDF(468.2KB)

Coherent Optical Polarization-Shift-Keying (POLSK) Homodyne System Using Phase-Diversity Receivers
Ichiro SETO Tomoaki OHTSUKI Hiroyuki YASHIMA Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1992/01/25
Vol. E75-C  No. 1  pp. 50-57
Type of Manuscript:  Special Section PAPER (Joint Special Section on Fundamentals of Next Generation Opto-Technologies)
Category: 
Keyword: 
coherent optical communicationsphase-diversity homodyne receiverspolarization-shift-keying (POLSK)
 Summary | Full Text:PDF(563.1KB)

Parallel Rate-Variable Punctured Convolutional Coded PPM in Photon Communication
Tomoaki OHTSUKI Hiroyuki YASHIMA Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1992/01/25
Vol. E75-A  No. 1  pp. 46-51
Type of Manuscript:  Special Section PAPER (Joint Special Section on Fundamentals of Next Generation Opto-Technologies)
Category: 
Keyword: 
photon communicationpunctured covolutional coded PPM
 Summary | Full Text:PDF(414.1KB)

Coherent Optical Polarization-Shift-Keying (POLSK) Homodyne System Using Phase-Diversity Receivers
Ichiro SETO Tomoaki OHTSUKI Hiroyuki YASHIMA Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1992/01/25
Vol. E75-A  No. 1  pp. 52-59
Type of Manuscript:  Special Section PAPER (Joint Special Section on Fundamentals of Next Generation Opto-Technologies)
Category: 
Keyword: 
coherent optical communicationsphase-diversity homodyne receiverspolarization-shift-keying (POLSK)
 Summary | Full Text:PDF(494.6KB)

Cutoff Rate and Capacity of MPPM in Noiseless Photon Counting Channel
Tomoaki OHTSUKI Hiroyuki YASHIMA Iwao SASASE Shinsaku MORI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1991/12/25
Vol. E74-B  No. 12  pp. 4080-4084
Type of Manuscript:  PAPER
Category: Communication Systems and Transmission Equipment
Keyword: 
 Summary | Full Text:PDF(378KB)