Lecturer: Dr. Tadashi Matsumoto, NTT DoCoMo
Date: May 11, 2001
Time: 9:30 - 11:30
Room: TL 201, Telecommunication Laboratory & Centre for Wireless Communications, Tutkijantie 2E
This lecture is intended to provide an overview of the fundamental theory, concepts, and performances of adaptive signal processing required in post-IMT 2000 broadband mobile communication systems. The assumption made during this lecture is that multiple users aim to transmit their signals using the same time- and frequency-slots without spreading their signals in the frequency domain.
The lecture will be started by briefly summarizing adaptive signal processing for narrowband signal transmission over mobile radio channels such as adaptive equalizers and adaptive arrays. The lecture then focuses on joint spatial and temporal equalization algorithms by explaining how the adaptive signal processing schemes for narrowband signals can be extended to broadband systems. Results of link-level and system-level simulations using field measurement data collected through a series of two-dimensional channel sounding measurement campaigns are presented to verify the effectiveness of the joint spatial and temporal equalizer. The lecture will also introduce the Turbo-equalizer concept together with algorithms and their performances in broadband mobile communication channels. Finally, a reasonable extension of the Turbo-equalizer to broadband MIMO channels is addressed briefly.
Tadashi Matsumoto received his B.S., M.S., and Ph.D. degrees in electrical engineering from Keio University, Yokohama-shi, Japan in 1978, 1980 and 1991, respectively.
He joined Nippon Telegraph and Telephone Corporation (NTT) in April 1980. From April 1980 to May 1987, he researched signal transmission technologies, such as modulation/demodulation schemes, as well as radio link design for mobile communications systems. He participated in the R&D project of NTT's high-capacity mobile communications system, where he was responsible for the development of the base-station transmitter/receiver equipment for the system. From May 1987 to February 1991, he researched error control strategies, such as Forward Error Correction (FEC), Trellis Coded Modulation (TCM), and Automatic Repeat Request (ARQ) in digital mobile radio channels. He developed an efficient new ARQ scheme suitable to the error occurrence in TDMA mobile signal transmission environments. He was involved in the development of a Japanese TDMA Digital Cellular Mobile Communications System. He led the development project for facsimile and data communications service units for the system. In July 1992, he transferred to NTT Mobile Communications Network Inc. (NTT DoCoMo) Kanagawa, Japan. From February 1991 to April 1994, he was responsible for research on Code Division Multiple Access (CDMA) mobile communications systems. He intensively researched multiuser detection schemes in multipath mobile communications environments. He was also responsible for research on error control schemes for CDMA Mobile communications systems. He concentrated on research of Maximum Aposteriori Probability (MAP) algorithm and its reduced complexity version for decoding of concatenated codes. From 1992 to 1994, he served as a part-time lecturer at Keio University. In April 1994, he was with NTT America, where he served as a Senior Technical Advisor of a joint project with NTT and NEXTEL Communications. In March 1996, he returned to NTT and since then he has been researching time-space signal processing and Turbo equalization techniques for broadband mobile signal transmission. Presently, he is an Executive Research Engineer at NTT DoCoMo.
Dr. Matsumoto served as a Secretary of the IEEE Vehicular Technology Society Tokyo Chapter from 1998 to 2001. For the 2000-Spring IEEE Vehicular Technology Conference that took place in Tokyo, May, 2000, he served as a conference secretary. For his contribution to the VTS society, he received an outstanding service award from the society in 2001. He is a member of the Institute of Electronics, Information and Communication Engineers (IEICE) of Japan.
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