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Our mission is to explore state-of-the-art wireless communication technologies and to establish basic concepts that would inspire researchers for many years to go on. In particular, we have specialized in high-speed millimeter-wave communications, power-saving algorithms, highly-parallel wireless signal processing, and nonsquare differential coding. It is worth noting that our representative paper on index modulation has been recognized as the top one percent of papers in the WoS database.

Research areas: mobile communications, post-quantum physical layer security, quantum speedup for wireless communications.

Opening(s)

Our laboratory was launched in April 2020. Since it is a fresh laboratory, we welcome fresh and highly motivated students to explore the edge of wireless technologies. Currently, we are accepting up to one MEXT-funded master's course student from abroad. Please check our official website for application deadlines. If you are interested in joining our laboratory as a Ph.D. candidate, please send your detailed CV and a list of research publications to the email address provided at the bottom of this web page. Dr. Naoki Ishikawa, who is the PI of this laboratory, has worked on both communication engineering and information science, resulting in a wide range of research topics. The current topics are given as follows.

• 2024/10/16 A new preprint on quantum polar ML decoding is available for download.
• Shintaro Fujiwara and Naoki Ishikawa, “Quantum speedup for polar maximum likelihood decoding,” arXiv:2411.04727 [quant-ph].
• 2024/11/03 The 3rd Quantum Programming Contest Qcoder, developed by Mr. Yukiyoshi and his collaborators, was held. (Qcoder)
• 2024/10/27 Mr. Rou, a PhD candidate at Prof. Abreu's group, will give a presentation at Asilomar Conference on Signals, Systems, and Computers.
• Hyeon Seok Rou, Kein Yukiyoshi, Taku Mikuriya, Giuseppe Thadeu Freitas de Abreu, and Naoki Ishikawa, “AFDM chirp-permutation-index modulation with quantum-accelerated codebook design,” Asilomar Conference on Signals, Systems, and Computers, California, US, October 2024.
• 2024/10/17 A new preprint on quadratic assignment problem is available for download.
• Taku Mikuriya, Kein Yukiyoshi, Shintaro Fujiwara, Giuseppe Thadeu Freitas de Abreu, and Naoki Ishikawa, “Quantum speedup for the quadratic assignment problem,” arXiv:2410.12181 [quant-ph].
• 2024/10/16 A new preprint on Grover adaptive search with spin variables is available for download.
• Shintaro Fujiwara and Naoki Ishikawa, “Grover adaptive search with spin variables,” arXiv:2410.11633 [quant-ph].
• 2024/10/10 Our paper on the quantum algorithm for binary constant weight codes has been accepted for publication in Quantum Information Processing.
• Kein Yukiyoshi and Naoki Ishikawa, “Quantum search algorithm for binary constant weight codes,” Quantum Information Processing, in press. (arXiv)
• 2024/10/10 Mr. Yukiyoshi, a second-year master's course student, gave a presentation on GAS at IEEE VTC2024-Fall, and received the IEEE VTS Tokyo/Japan Chapter 2024 Young Researcher's Encouragement Award. (Program p. 45 / IEEE VTS Tokyo/Japan Chapter / YNU)
• Kein Yukiyoshi, Taku Mikuriya, Hyeon Seok Rou, Giuseppe Abreu, Naoki Ishikawa, “Grover adaptive search for maximum likelihood detection of generalized spatial modulation,” IEEE Vehicular Technology Conference (VTC2024-Fall), Washington DC, US, October 2024.
• 2024/10/08 Mr. Baba, a first-year master's course student, gave a presentation on DNN-based detector for Grassmann constellation at IEEE VTC2024-Fall, and received the IEEE VTS Tokyo/Japan Chapter 2024 Young Researcher's Encouragement Award. (Program p. 37 / IEEE VTS Tokyo/Japan Chapter / YNU)
• Ryusei Baba, Hiroki Iimori, Chandan Pradhan, Szabolcs Malomsoky, and Naoki Ishikawa, “Deep neural network based reduced-complexity detector for Grassmann constellation,” IEEE Vehicular Technology Conference (VTC2024-Fall), Washington DC, US, October 2024.

List of past announcements

The fundamental limit of semiconductor miniaturization is approaching. The day may come when wireless technology will no longer be able to meet the increasing demand for communications. Our goal is to revolutionize wireless communications by breaking the limit of classical computation through quantum computation. Specifically, we try to solve NP-hard problems specific to the wireless field using the Grover search, which is an algorithm that can provide a quantum speedup.

In Wi-Fi networks, it is easy for third parties to observe raw digital information. Since this information is encrypted in the transport layer, we can feel safe to use, but this security is not guaranteed for eternity. For example, the widely used public-key encryption method, RSA, has been threatened by the invention of Shor’s algorithm, which performs integer factoring in polynomial time using a quantum computer. In order to enhance security, we try to encrypt radio waves themselves using true random numbers extracted from wireless physical layer.

When a wireless device moves fast, the surrounding radio environment changes rapidly, resulting in poor communication quality. To address this challenging problem, we have worked on a unique technique called non-square differential coding, which is expected to improve the performance of 5G millimeter-wave communications. By contrast, this new scheme suffers from the error propagation problem. It is not going to be easy!

In general, when considering a new scheme for the physical layer, we inevitably encounter a tradeoff between the computational complexity and the achievable performance. Between two stools, you fall to the ground. Since 2008, a new technique called index modulation has attracted attention because it may be capable of striking the tradeoff. We try to investigate its fundamental property by invoking recent technologies that have been developed for machine learning.

Clarivate Analytics Japan surveyed the top 20 most cited papers of the Heisei era. In this survey, seven papers on software and databases were nominated. Our laboratory publishes source codes and databases online that are necessary to reproduce out research outcomes, and we believe it can further accelerate research development. Our GitHub account can be found here.

IEEE Journal & Magazine Papers Published by Researchers in Japan

This web page provides a list of IEEE journal/magazine papers published by researchers in Japan, covering the period from 1954 to the present. It is useful for understanding the transition of research conducted in Japan, the bias of researcher population, distinguished researchers in each field, and the international research presence. The list is automatically aggregated using the open data DBLP, but it is updated about once a year because it is checked as carefully as possible before publication.

WiPhy

This Python package enables one to easily investigate the performance of state-of-the-art technologies that have gained attention in the field of wireless communications. Different from GNU Radio and other relevant packages, it adopted tensor operations for time-consuming algorithms. Thus, it succeeded in achieving incredibly fast simulations, even though it relied on high-overhead Python.

IMToolkit

This Python package is dedicated to the index modulation (IM) scheme, which has attracted tremendous attention since 2008. The performance of IM heavily depends on the index patterns that activate K out of M elements. This package contains 560MB of optimal patterns that are obtained through our proposed combinatorial optimization algorithm. Currently, it supports 100% of IM parameters for M <= 20 and 75.5% for M <= 32.