1. Home
  2.  > Programs & Courses
  3.  > Graduate School of Science and Engineering : Information and Computer Science (Laboratories : Laboratory for Information Theory and its Applications)

Graduate School of Science and Engineering
Information and Computer Science

Laboratory for Information Theory and its Applications

Website of the Laboratory (In Japanese)

We invite you to join us to do research and development on high-speed, reliable, and secure communications.



Telephone : +81-774-65-6295
Office : YE-215
Database of Researchers

Masakazu YOSHIDA
[Assistant Professor]
Telephone : +81-774-65-6294
Office : YE-214
Database of Researchers

Research Topics

1.Coding for multiple-access channel
2.Coding for MIMO systems
3.Adaptive signal processing for wireless communications
4.Channel coding and wireless communications
5.Relationship between quantum error-correction and state discrimination
6.Quantum uncertainty relation with classical information
7.Security analysis of quantum key distributions

Research Contents

Information theory, coding theory, communications theory, and cryptography are fundamentals in constructing modern information network. Based on these basic theories, we do research and development on information transmission, with particular attention to reliable communications with channel coding and secure communications with quantum cryptography. We expect this focus to bring new and important scientific and applied knowledge to information transmission.

[high-speed and reliable communication]: channel coding and decoding algorithm for wireless communication systems

In wireless communication systems, channel noise and interference would result in the unreliable information transmission. The interference, for example, in the multiuser communication systems, is due to that multiple users share a common channel. In the multiple-input multiple-output (MIMO) communication system, the interference occurs due to simultaneous transmission from multiple antennas. Shannon’s coding theorem shows that the reliable information transmission is possible if the transmission rate is less than the channel capacity. We focus on the channel coding to realize the reliable information transmission in multiuser communication systems and MIMO systems. We aims high-reliable coding scheme and low-complexity decoding algorithms with the transmission rate approaches the theoretic limit. We will publish the results in leading international journals and conferences, and will transfer results from recent research in these areas to industry in mobile communications, wireless LAN, and satellite communications.

Much attention is being paid to applied technologies of quantum information theory, the discipline of information science based on quantum mechanics. Particularly advantageous over traditional techniques are quantum cryptography and quantum communication. Quantum cryptography is a next-generation encryption technique offering higher security than the existing techniques. Quantum communication uses quantum correlations to enable quantum teleportation and communication with super-dense coding, which are considered impossible with the existing techniques. Our research team focuses on analyzing security of quantum cryptography and improving its encryption capabilities, and analyzing and enhancing transmission efficiency of quantum communication. We also study the fundamentals of quantum information theory with a view to developing novel applied technologies.


  • Error-correcting code
  • Signal processing
  • Wireless communications
  • Quantum error-correction

  • State discrimination
  • Uncertainty relation
  • Quantum key distribution