Information Network Laboratory

T. Imai

Takamasa Imai

Office: 23-417 Ext.: 3725


09/1992, D.Eng., Osaka University

03/1982, M.Eng, Osaka University

Y. Ide

Yusuke Ide
(Assistant Professor)

Laboratory: 23-418 Ext.: 3726


03/2009, Ph.D. (Engineering), Yokohama National University

03/2005, M.Eng., Yokohama National University

Research Field

Communications Engineering.

Research Overview

Studying broadband networks and green communication.

Research Subjects

  • 1.Optical wireless communication.
  • 2. Localization systems.
  • 3. Energy efficient networks.


The demand for higher data rates has increased rapidly owing to the widespread use of mobile devices such as smartphones and tablets. To satisfy this demand, technologies for broadband access/core networks and mobile networks are vital. The localization of information terminals is required because of the limited power budget.

Modern sustainable societies also require energy efficient networks. Therefore, our research is focused on the following four main themes.

  • (1) Indoor/outdoor optical wireless systems for broadband mobile communication.
  • (2) Broadband optical access and core networks,including metro/access network integration.
  • (3) Localization system for broadband mobile communication.
  • (4) Green wireless and wireline communication protocols.


    T. Imai:

  • 1) T. Taniguchi, N. Sakurai, K. Kumozaki and T.Imai, “Full-duplex 1.0 Gbit/s data transmission over 60 GHz radio-on-fiber access system based on the loop-back optical heterodyne technique”, IEEE Journal of Lightwave Technology, vol. 26(13), pp. 1765–1776 (2008).
  • 2) M. Yoshino, S. Kaneko, T. Taniguchi, N. Miki, K. Kumozaki, T. Imai, N. Yoshimoto, and M. Tsubokawa, “Beat noise mitigation of spectral amplitude coding OCDMA using heterodyne detection,” Journal of Lightwave Technology, vol. 26(8), pp. 962–970 (2008).
  • 3) S. Nishihara, S. Kimura, T. Toshida, M. Nakamura, J. Terada, K. Nishimura, K. Kishine, K. Kato, Y. Ohtomo, N. Yoshimoto, T. Imai and M. Tsubokawa, “Burst-mode 3R receiver for 10-Gbit/s PON system with high sensitivity, wide dynamic range, and fast response,” Journal of Lightwave Technology, vol. 26(1), pp. 99–107 (2008).
  • 4) T. Taniguchi, N. Sakurai, K. Kumozaki and T. Imai, “Loop-back optical heterodyne technique for 1.0 Gbit/s data transmission over 60 GHz radio-on-fiber uplink,” Journal of Lightwave Technology, vol. 25(6), pp. 1484–1494 (2007).
  • 5) H. Suzuki, M. Fujiwara, T. Suzuki, N. Yoshimoto, K. Iwatsuki, and T. Imai, “Colorless and plug-and-play technologies for WDM access over existing power-splitter-based infrastructure,” Journal of Optical Networking, vol. 6(7), pp. 830–839 (2007).
  • Y. Ide:

  • 1) Y. Ide, “Local subgraph structure can cause localization in continuous-time quantum walk,” Yokohama Mathematical Journal, vol. 60, pp. 113–123 (2014).
  • 2) Y. Ide, N. Konno, E. Segawa, and X.-P. Xu, “Localization of discrete time quantum walks on the glued trees,” Entropy, vol. 16(3), pp. 1501–1514 (2014).
  • 3) Y. Ide, N. Konno, and M. Takei, “Some basic properties of a rotor-router model with i.i.d. initial rotor-routers on the line,” Proceedings of the 45th International Symposium on Stochastic Systems Theory and its Applications, pp. 303–306 (2014).
Affiliated Academic Organizations

T. Imai:
The Institute of Electrical and Electronics Engineers (IEEE), The Optical Society of America (OSA), The Institute of Electronics, Information and Communication Engineers (IEICE), The Japan Society of Applied Physics (JSAP).

Y. Ide:
Mathematical Society of Japan, Physical Society of Japan, Institute of Electronics, Information and Communication Engineers.

Current members
◯ Professors: 1 ◯ Assistant Professors: 1
◯ Undergraduates: 13