Koichi ICHIGE


Improving Elevation Estimation Accuracy in DOA Estimation: How Planar Arrays Can Be Modified into 3-D Configuration
Hiroki MORIYA  Koichi ICHIGE  Hiroyuki ARAI  Takahiro HAYASHI  Hiromi MATSUNO  Masayuki NAKANO 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2012/10/01
Vol. E95-A  No. 10  pp. 1667-1675
Type of Manuscript: Special Section PAPER (Special Section on Advances in Adaptive Signal Processing and Applications)
Category: DOA
Keyword: 
direction of arrival estimationarray signal processingsensor arraysantenna arrays
  Summary |  Full Text:PDF (1.5MB)

Automated Microwave Filter Tuning Based on Successive Optimization of Phase and Amplitude Characteristics
Yosuke TAKEUCHI  Koichi ICHIGE  Koichi MIYAMOTO  Yoshio EBINE 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2011/02/01
Vol. E94-A  No. 2  pp. 617-624
Type of Manuscript: Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
microwave filterbandpass filtertuningoptimization
  Summary |  Full Text:PDF (1.2MB)

Efficient Heterodyne Digital Receiver with Direct RF-to-Digital Conversion for Software Defined Radio
Minseok KIM  Takayuki MOTEKI  Koichi ICHIGE  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/04/01
Vol. E92-A  No. 4  pp. 1056-1062
Type of Manuscript: Special Section PAPER (Special Section on Advanced Technologies Emerging Mainly from the 21st Workshop on Circuits and Systems in Karuizawa)
Category: 
Keyword: 
multimodeRF to digital conversionsamplingsoftware defined radiocognitive radio
  Summary |  Full Text:PDF (866.7KB)

High Resolution DOA Estimation Using Unwrapped Phase Information of MUSIC-Based Noise Subspace
Koichi ICHIGE  Kazuhiko SAITO  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2008/08/01
Vol. E91-A  No. 8  pp. 1990-1999
Type of Manuscript: Special Section PAPER (Special Section on Signal Processing)
Category: 
Keyword: 
direction of arrival estimationarray antennaMUSIC methodphase characteristics
  Summary |  Full Text:PDF (579KB)

High Resolution DOA Estimation Using Second-Order Differential of MUSIC Spectrum
Koichi ICHIGE  Yoshihisa ISHIKAWA  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2007/03/01
Vol. E90-A  No. 3  pp. 546-552
Type of Manuscript: Special Section PAPER (Special Section on Multimedia and Mobile Signal Processing)
Category: Communications
Keyword: 
direction of arrival estimationarray antennaMUSIC methodRoot-MUSIC method
  Summary |  Full Text:PDF (573.5KB)

Filter Effect on Low-IF Multichannel Receiver: How a Simple Filter Improves Digital Communication Quality
Nozomi ZAMA  Koichi ICHIGE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/12/01
Vol. E89-B  No. 12  pp. 3471-3474
Type of Manuscript: LETTER
Category: Wireless Communication Technologies
Keyword: 
low-IF receivercosine rolloff filterdigital modulationsoftware defined radio
  Summary |  Full Text:PDF (273KB)

Accurate Source Number Detection Using Pre-Estimated Signal Subspace
Yoshihisa ISHIKAWA  Koichi ICHIGE  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/12/01
Vol. E89-B  No. 12  pp. 3257-3265
Type of Manuscript: Special Section PAPER (Special Section on Software Defined Radio Technology and Its Applications)
Category: 
Keyword: 
source number detectionarray antennaAICMDLMUSIC methodbeamformer method
  Summary |  Full Text:PDF (515.2KB)

An Efficient Signed-Power-of-Two Term Allocation for Filter Coefficients in Digital Communication System
Koichi ICHIGE  Hideaki MUNEMASA  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/12/01
Vol. E89-B  No. 12  pp. 3266-3268
Type of Manuscript: Special Section LETTER (Special Section on Software Defined Radio Technology and Its Applications)
Category: 
Keyword: 
digital modulationBER characteristicscosine rolloff filterSPT term
  Summary |  Full Text:PDF (196KB)

Experimental Study of Jitter Effect on Digital Downconversion Receiver with Undersampling Scheme
Minseok KIM  Aiko KIYONO  Koichi ICHIGE  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Information and Systems
Publication Date: 2005/07/01
Vol. E88-D  No. 7  pp. 1430-1436
Type of Manuscript: Special Section PAPER (Special Section on Recent Advances in Circuits and Systems--Part 1)
Category: Communications and Wireless Systems
Keyword: 
clock jitterundersamplingdownconversionDDCEVM
  Summary |  Full Text:PDF (505.3KB)

Implementation of FPGA Based Fast Unitary MUSIC DOA Estimator
Minseok KIM  Koichi ICHIGE  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2004/09/01
Vol. E87-C  No. 9  pp. 1485-1494
Type of Manuscript: Special Section PAPER (Special Section on Wave Technologies for Wireless and Optical Communications)
Category: Wireless Network System Performances
Keyword: 
adaptive antennasmart antennaFPGA implementationDOA estimationMUSICEVD
  Summary |  Full Text:PDF (989.8KB)

A Fast Algebraic Approach to the Eigenproblems of Correlation Matrices in DOA Estimation
Koichi ICHIGE  Masashi SHINAGAWA  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2003/02/01
Vol. E86-B  No. 2  pp. 865-869
Type of Manuscript: LETTER
Category: Antenna and Propagation
Keyword: 
adaptive array antennaDOA estimationeigenproblemsMUSIC method
  Summary |  Full Text:PDF (399.5KB)

Design of Jacobi EVD Processor Based on CORDIC for DOA Estimation with MUSIC Algorithm
Minseok KIM  Koichi ICHIGE  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2002/12/01
Vol. E85-B  No. 12  pp. 2648-2655
Type of Manuscript: Special Section PAPER (Special Issue on Software Defined Radio Technology and Its Applications)
Category: 
Keyword: 
adaptive antennaFPGA implementationDOA estimationMUSICEVD
  Summary |  Full Text:PDF (604.7KB)

A Computationally Efficient Algorithm for Exponential B-Splines Based on Difference/IIR Filter Approach
Takeshi ASAHI  Koichi ICHIGE  Rokuya ISHII 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2002/06/01
Vol. E85-A  No. 6  pp. 1265-1273
Type of Manuscript: Special Section PAPER (Special Section on Papers Selected from 2001 International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2001))
Category: 
Keyword: 
B-splineexponential splinedecompositionreconstruction
  Summary |  Full Text:PDF (895.6KB)

An Efficient Algorithm for Decomposition and Reconstruction of Images by Box Splines
Takeshi ASAHI  Koichi ICHIGE  Rokuya ISHII 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/08/01
Vol. E84-A  No. 8  pp. 1883-1891
Type of Manuscript: Special Section PAPER (Special Section on Digital Signal Processing)
Category: Image/Visual Signal Processing
Keyword: 
box splineB-splinedecompositionreconstruction
  Summary |  Full Text:PDF (1.6MB)

Experiments of DOA Estimation by DBF Array Antenna at 2.6 GHz
Kohei MORI  Yuki INOUE  Koichi ICHIGE  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/07/01
Vol. E84-B  No. 7  pp. 1871-1875
Type of Manuscript: Special Section LETTER (Special Issue on Adaptive Array Antenna Techniques for Advanced Wireless Communications)
Category: 
Keyword: 
DBF array antennaDOA estimationMUSIC algorithmestimation error
  Summary |  Full Text:PDF (533.7KB)

Concept and Evaluation of a 2-D FDTD Formulation Based on Expanded Wave Equation Approach
Koichi ICHIGE  Hiroyuki ARAI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2001/07/01
Vol. E84-C  No. 7  pp. 981-993
Type of Manuscript: PAPER
Category: Electromagnetic Theory
Keyword: 
computational electromagneticsFDTD formulationwave equationMaxwell's equations
  Summary |  Full Text:PDF (1.5MB)

A New Formulation for Discrete Box Splines Reducing Computational Cost and Its Evaluation
Takeshi ASAHI  Koichi ICHIGE  Rokuya ISHII 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/03/01
Vol. E84-A  No. 3  pp. 884-892
Type of Manuscript: PAPER
Category: Image
Keyword: 
box splineB-splineinterpolationtruncated power
  Summary |  Full Text:PDF (757KB)

A Simple Scheme of Decomposing and Reconstructing Continuous-Time Signals by B-Splines
Koichi ICHIGE  Masaru KAMADA  Rokuya ISHII 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1998/11/20
Vol. E81-A  No. 11  pp. 2391-2399
Type of Manuscript: PAPER
Category: Digital Signal Processing
Keyword: 
waveletsB-splinesmultifold RRS functions
  Summary |  Full Text:PDF (626.3KB)