Yohtaro UMEDA

Resource Block Assignment to Reduce Peak to Average Power Ratio in Multi-User OFDM
Osamu TAKYU Yohtaro UMEDA Fumihito SASAMORI Shiro HANDA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2014/08/01
Vol. E97-B  No. 8  pp. 1689-1700
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
multiuser OFDM, PAPR, resource block assignment, 
 Summary | Full Text:PDF
Phase Rotation for Constructing Uniform Frequency Spectrum in IFDMA Communication
Takeo YAMASAKI Osamu TAKYU Koichi ADACHI Yohtaro UMEDA Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2010/12/01
Vol. E93-A  No. 12  pp. 2672-2681
Type of Manuscript:  Special Section PAPER (Special Section on Wideband Systems)
Category: 
Keyword: 
SC-FDMA, IFDMA, decision directed channel estimation (DDCE), phase rotation, 
 Summary | Full Text:PDF
Frequency Rotation for Suppressing Multipath Interference and Achieving Large Frequency Diversity in Uplink IFDMA
Osamu TAKYU Yohtaro UMEDA Masao NAKAGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2010/05/01
Vol. E93-B  No. 5  pp. 1284-1288
Type of Manuscript:  LETTER
Category: Wireless Communication Technologies
Keyword: 
IFDMA, frequency rotation, suppressing, multipath interference, 
 Summary | Full Text:PDF
Scattered Pilot Assisted Channel Estimation for IFDMA Uplink
Takeo YAMASAKI Osamu TAKYU Yohtaro UMEDA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2009/12/01
Vol. E92-B  No. 12  pp. 3803-3814
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
SC-FDMA, IFDMA, Scattered Pilot Assisted Channel Estimation, PAPR, 
 Summary | Full Text:PDF
49-GHz Operation of an SCFL Static Frequency Divider Using High-Speed Interconnections and InP-Based HEMTs
Yohtaro UMEDA Kazuo OSAFUNE Takatomo ENOKI Haruki YOKOYAMA Yasunobu ISHII 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1999/07/25
Vol. E82-C  No. 7  pp. 1080-1085
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter Wave Technology)
Category: Active Devices and Circuits
Keyword: 
InP, HEMT, IC, interconnection, delay, static frequency divider, 
 Summary | Full Text:PDF
Exclusive OR/NOR IC for 40-Gbit/s Clock Recovery Circuit
Koichi MURATA Taiichi OTSUJI Takatomo ENOKI Yohtaro UMEDA Mikio YONEYAMA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1999/03/25
Vol. E82-C  No. 3  pp. 456-464
Type of Manuscript:  Special Section PAPER (Special Issue on Ultra-High-Speed IC and LSI Technology)
Category: Compound Semiconductor Devices
Keyword: 
exclusive OR/NOR, clock recovery circuit, InP HEMT, 
 Summary | Full Text:PDF
Ultrahigh-Speed IC Technologies Using InP-Based HEMTs for Future Optical Communication Systems
Yohtaro UMEDA Takatomo ENOKI Taiichi OTSUJI Tetsuya SUEMITSU Haruki YOKOYAMA Yasunobu ISHII 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1999/03/25
Vol. E82-C  No. 3  pp. 409-418
Type of Manuscript:  INVITED PAPER (Special Issue on Ultra-High-Speed IC and LSI Technology)
Category: 
Keyword: 
InP, HEMT, IC, optical communication, delay, 
 Summary | Full Text:PDF
Silicon Nitride Passivated Ultra Low Noise InAlAs/InGaAs HEMT's with n+-InGaAs/n+-InAlAs Cap Layer
Yohtaro UMEDA Takatomo ENOKI Kunihiro ARAI Yasunobu ISHII 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1992/06/25
Vol. E75-C  No. 6  pp. 649-655
Type of Manuscript:  Special Section PAPER (Special Issue on MMIC Technology)
Category: 
Keyword: 
InGaAs, HEMT, low noise, equivalent circuit, InP, 
 Summary | Full Text:PDF