Global Site

Breadcrumb navigation

Our Researchers

March 27, 2025

Prakash Chaki

Senior Researcher
Ph.D. in Information and Communication Engineering

Bio

Prakash Chaki received his master's degree in electrical engineering from the Indian Institute of Technology (IIT) Bombay, India, and the Ph.D. degree in information and communication engineering from The University of Tokyo, Japan. Since 2013, he is with the R&D division of NEC Corporation where he is currently involved in research of Beyond 5G (B5G) and 6G wireless communications. His research interests include wireless communications, networks, and channel coding. Dr. Chaki was a recipient of the NEC Young Researcher Award 2019, the NEC Patent Award for contribution in terms of large number of issued patents in 2021, the IEICE Young Researcher Award 2016, and a two-time recipient of the NEC Excellence in Invention Award in 2015 and 2018. In 2023, he was recognized for Notable Services and Contributions towards the advancement of IEEE and the Engineering Professions. Dr. Chaki has served as a 3GPP RAN1 delegate for the standardization of 5G new radio (NR), and has also served in various capacities in IEEE including being the Executive Committee (EXCOM) member of IEEE Japan Council, EXCOM member of IEEE Tokyo Section, Chair of IEEE Tokyo Section Young Professionals, and the Chair of IEEE Tokyo Section Educational Activities. He serves as an Editor for IEEE Comunications Society Technology News, and as a reviewer for several top international journals including the IEEE Transactions on Communications, IEEE Journal on Selected Topics in Signal Processing, IEEE Transactions on Vehicular Technology, IET, ETRI, and Wiley journals. Dr. Chaki held a Guinness World Record.

Research Area

  • Wireless Communications
  • Signal Processing
  • Wireless Networks

Selected Publications

Peer-Reviewed International Journals (Impact Factor higher than 6.0 only)

  1. P. Chaki and S. Sugiura, "Capacity and Outage Probability Analysis of Faster-Than-Nyquist Cooperative NOMA," in IEEE Wireless Communications Letters, vol. 12, no. 9, pp. 1632-1636, Sept. 2023, doi: 10.1109/LWC.2023.3285754. (Impact Factor: 6.3, as of 2023).
  2. P. Chaki, T. Ishihara, and S. Sugiura, "Precoded Filterbank Multicarrier Index Modulation With Non-Orthogonal Subcarrier Spacing," in IEEE Transactions on Communications, vol. 71, no. 2, pp. 700-713, Feb. 2023, doi: 10.1109/TCOMM.2022.3228307. (Impact factor: 8.3, as of 2023).
  3. P. Chaki, T. Ishihara, and S. Sugiura, "Eigendecomposition-Precoded Faster-Than-Nyquist Signaling With Index Modulation," in IEEE Transactions on Communications, vol. 70, no. 7, pp. 4822-4836, July 2022, doi: 10.1109/TCOMM.2022.3173302. (Impact factor: 8.3, as of 2023).
  4. S. Kadam, D. Prabhu, N. Rathi, P. Chaki and G. S. Kasbekar, "Exploiting Group Structure in MAC Protocol Design for Multichannel Ad Hoc Cognitive Radio Networks," in IEEE Transactions on Vehicular Technology, vol. 68, no. 1, pp. 893-907, Jan. 2019, doi: 10.1109/TVT.2018.2883392. (Impact factor: 6.8, as of 2023).

Peer-Reviewed International Conference Papers

  1. P. Chaki, J. Shikida and K. Muraoka, "Eigenvector Prediction: A Low-Complexity Approach to Channel Prediction in 5G Sub-6 GHz Multiuser Massive MIMO," 2025 IEEE International Conference on Communications (ICC) Workshops, Montreal, Canada, 2025, pp. 1-6. (Annual Flagship Conference of IEEE Communications Society).
  2. P. Chaki, J. Shikida, and K. Muraoka, “Resource allocation for sounding reference signal in 5G massive MIMO under channel aging,” IEEE Global Communications Conference (GLOBECOM) Workshops, Cape Town, South Africa, 2024, pp. 1172-1177. (Annual Flagship Conference of IEEE Communications Society).
  3. P. Chaki, J. Shikida and K. Muraoka, "Exploiting Sparse Matrix Solution to Mitigate Channel Aging in Sub-6 GHz 5G MU-MIMO Using Beamspace-Delay-Doppler Domain," 2024 IEEE International Conference on Communications (ICC) Workshops, Denver, CO, USA, 2024, pp. 475-480, doi: 10.1109/ICCWorkshops59551.2024.10615510. (Annual Flagship Conference of IEEE Communications Society).
  4. P. Chaki and S. Sugiura, "Power-Domain-Multiplexed Precoded Faster-Than-Nyquist Signaling for NOMA Downlink," IEEE Global Communications Conference (GLOBECOM), Rio de Janeiro, Brazil, 2022, pp. 3977-3982, doi: 10.1109/GLOBECOM48099.2022.10001617. (Annual Flagship Conference of IEEE Communications Society).
  5. P. Chaki, T. Ishihara and S. Sugiura, "Precoded Non-Orthogonal Frequency Division Multiplexing with Subcarrier Index Modulation," 2022 IEEE 95th Vehicular Technology Conference: (VTC-Spring), Helsinki, Finland, 2022, pp. 1-5, doi: 10.1109/VTC2022-Spring54318.2022.9860537. (Flagship Conference of IEEE Veh. Tech. Society).
  6. P. Chaki, T. Ishihara and S. Sugiura, "Eigenvalue Decomposition Precoded Faster-Than-Nyquist Transmission of Index Modulated Symbols," 2021 IEEE International Symposium on Information Theory (ISIT), Melbourne, Australia, 2021, pp. 3279-3284, doi: 10.1109/ISIT45174.2021.9518263. (Annual Flagship Conference of IEEE Information Theory Society).
  7. P. Chaki and N. Kamiya, "A Novel Design of CRC-Concatenated Polar Codes," IEEE International Conference on Communications (ICC), Shanghai, China, 2019, pp. 1-6, doi: 10.1109/ICC.2019.8761833. (Annual Flagship Conference of IEEE Communications Society).
  8. P. Chaki and N. Kamiya, "On the Properties of Bit-Reversal Shortening in Polar Codes," 2018 International Symposium on Information Theory and Its Applications (ISITA), Singapore, 2018, pp. 437-441, doi: 10.23919/ISITA.2018.8664298.
  9. P. Chaki, T. Kanazawa and K. Miyoshi, "Strategic Mobility and Cooperative Caching in DTN: A Social Dilemma Perspective," 2016 IEEE 84th Vehicular Technology Conference (VTC-Fall), Montreal, QC, Canada, 2016, pp. 1-6, doi: 10.1109/VTCFall.2016.7881238. (Flagship Conference of IEEE Veh. Tech. Society).
  10. S. Kadam, D. Prabhu, N. Rathi, P. Chaki and G. S. Kasbekar, "Exploiting group structure in MAC protocol design for multichannel ad hoc Cognitive Radio Networks," 2016 IEEE Wireless Communications and Networking Conference (WCNC), Doha, Qatar, 2016, pp. 1-7, doi: 10.1109/WCNC.2016.7564797. (Annual Core Conference of IEEE Communications Society).
  11. M. Yasuda, P. Chaki and G. Motoyoshi, "A Wi-Fi P2P communication platform between wireless LAN memory cards: Prototype implementation and performance evaluation," 2016 13th IEEE Annual Consumer Communications & Networking Conference (CCNC), Las Vegas, NV, USA, 2016, pp. 1101-1106, doi: 10.1109/CCNC.2016.7444943. (Annual Core Conference of IEEE Communications Society).
  12. P. Chaki, M. Yasuda and N. Fujita, "Seamless Group Reformation in WiFi Peer to Peer network using dormant backend links," 2015 12th Annual IEEE Consumer Communications and Networking Conference (CCNC), Las Vegas, NV, USA, 2015, pp. 773-778, doi: 10.1109/CCNC.2015.7158075. (Annual Core Conference of IEEE Communications Society).

Some Selected Publications in Domestic Conferences

  1. P. Chaki, J. Shikida, and K. Muraoka, "Impact of channel aging on 5G NR multiuser massive MIMO: Performance analysis with system level simulation," IEICE Society Conference 2023.
  2. P. Chaki and N. Kamiya, "Rate matching in polar codes," IEICE Society Conference 2018.
  3. P. Chaki, M. Yasuda, and G. Motoyoshi, "Experimental evaluation of a virtual overlay network on top of dynamic topology reformation in Wi-Fi peer-to-peer networks," IEICE General Conference 2016.
  4. P. Chaki, M. Yasuda, and N. Fujita, "Seamless Group Reformation in Wi-Fi Peer-to-Peer Networks," IEICE General Conference 2014.

Google Scholar link: new windowhttps://scholar.google.com/citations?user=KCZKzz8AAAAJ&hl=en
Dblp link: new windowhttps://dblp.org/pid/123/4601.html
IEEE Xplore AuthorPage: new windowhttps://ieeexplore.ieee.org/author/37085583011

Patent Applications

Find published list in Google Patents: new windowhttps://patents.google.com/?inventor=prakash+chaki&oq=prakash+chaki&sort=new

  • P. Chaki, “Link-adaptive sounding reference signal allocation with implicit signaling,” JP2025/043069.
  • P. Chaki, K. Muraoka, and Y. Maruta, “Communication apparatus and method therefor,” JP2024/176902.
  • P. Chaki, “Base station system, and radio unit and method therefor,” JP2024/150560.
  • P. Chaki and K. Muraoka, “Communication method and apparatus for channel sounding,” JP2024/004343.
  • P. Chaki, J. Shikida, and K. Muraoka, “Channel prediction to combat channel-aging with low complexity,” JP2023/014775.
  • P. Chaki, J. Shikida, and K. Muraoka, and T. Doi, “Method and device for channel prediction in wireless communication systems,” US20240146581A1.
  • P. Chaki, "Communication method and device using recurrent decoding iterations for polar codes," US20230155606A1.
  • P. Chaki and N. Kamiya, "Method and apparatus for construction of polar codes," US11418285B2.
  • P. Chaki and N. Kamiya, "Rate matching in polar codes," WO2019030908A1.
  • N. Kamiya and P. Chaki, "Method and apparatus for generating redundant bits for error detection," US20200201712A1.
  • P. Chaki and N. Kamiya, "Communication method and apparatus using polar codes," US11177834B2.
  • P. Chaki and N. Kamiya, "Design of puncturing pattern for polar codes," WO2018073850A1.
  • P. Chaki, M. Yasuda, and K. Nakajima, "Method and system for inter-group communication in a wireless P2P network," US10834542B2.
  • P. Chaki, M. Yasuda, and G. Motoyoshi, "Method system and device for fast initial link setup in wireless peer to peer network," WO2017115397A1.
  • P. Chaki, M. Yasuda, K. Nakajima, "Group formation control in multi-group peer-to-peer network," US10425476B2.
  • P. Chaki, M. Yasuda, and K. Nakajima, "Traffic-aware group reformation in a multi-group P2P network", US10652730B2.
  • P. Chaki, M. Yasuda, and K. Nakajima, "Inter-group communication control in wireless peer-to-peer networks," WO2017037766A1.
  • N. Fujita, P. Chaki, and M. Yasuda, "Communication method, communication system, wireless terminal, and communication control method in wireless communication network," US10412774B2.
  • M. Yasuda, P. Chaki, and N. Fujita, "Method and system for communication between groups in wireless communication network," US10499442B2.
  • M. Yasuda, P. Chaki, and N. Fujita, "Communication system, communication method, and wireless terminal for wireless communication network," WO2016024400A1.
  • P. Chaki, M. Yasuda, K. Nakajima, "A device within a wireless peer-to-peer network, wireless communication system and control method," US20180376400A1.
  • P. Chaki, M. Yasuda, K. Nakajima, "Scheduled group reformation among multiple P2P groups following switching schedule," US10244379B2.
  • P. Chaki, M. Yasuda, K. Nakajima, "Mechanism for quick connection in wireless peer to peer networks," US20180343547A1.
  • P. Chaki, M. Yasuda, and N. Fujita, "Group reformation mechanism for reducing disruption time in wireless peer to peer networks," US10270850B2.

Japanese Patent Applications

  • チャキ プラカシュ, "Polar符号の回帰的復号反復法を用いた通信方法および装置," JP2023521074A.
  • チャキ プラカシュ, 神谷 典史, Polar符号の構築のための方法および装置," JP7279779B2.
  • チャキ プラカシュ, 神谷 典史, "Polar符号におけるレートマッチング," JP2020530972A.
  • 神谷 典史, チャキ プラカシュ, "誤り検出用冗長ビットの生成方法及び装置," JP6875661B2.
  • チャキ プラカシュ, 神谷 典史, "Polar符号を用いた通信方法及び装置,”JP6817552B2.
  • チャキ プラカシュ, 神谷 典史, "ポーラ符号のためのパンクチャリングパターンの設計,”JP6734577B2.
  • チャキ プラカシュ, 安田真人, 中島一彰, "ワイヤレスP2Pネットワークにおけるグループ間通信の方法およびシステム," JP6558500B2.
  • チャキ プラカシュ, 安田真人, 中島一彰, "マルチグループピアツーピアネットワークにおけるグループ形成制御," JP6597802B2.
  • チャキ プラカシュ, 安田真人, 中島一彰, "マルチグループP2Pネットワークにおけるトラフィック認識型グループ再構成," JP6551547B2.
  • 藤田範人,チャキ プラカシュ,安田真人, "無線通信ネットワークにおける通信方法、通信システム、無線端末および通信制御方法," JPWO2016024401A1.
  • 安田真人,チャキプラカシュ,藤田範人, "無線通信ネットワークにおけるグループ間通信方法およびシステム," JP6669066B2.
  • 安田真人,チャキプラカシュ,藤田範人, "無線通信ネットワークにおける無線端末、通信方法および通信システム,"JP6583274B2.
  • チャキプラカシュ,安田真人,中島一彰,"無線ピアツーピアネットワーク内のデバイス、無線通信システム及び制御方法," JP6540892B2.
  • チャキプラカシュ,安田真人,中島一彰,"複数のp2pグループ間での切替えスケジュールに従ったグループ再構成," JP6493563B2.
  • チャキプラカシュ,安田真人,中島一彰,"無線ピアツーピアネットワークにおける高速接続メカニズム," JP6443549B2.
  • チャキプラカシュ,安田真人,中島一彰, "無線ピアツーピアネットワークにおいて停止時間を短縮するためのグループ再形成メカニズム," JP6238037B2.

European Patent Applications

  • P. Chaki and N. Kamiya, "Prüfbit-verkettete polare codes," EP3602794A1.
  • N. Fujita, P. Chaki, and M. Yasuda, "Kommunikationsverfahren in drahtloskommunikationsnetzwerk, kommunikationssystem, drahtloses endgerät und kommunikationssteuerungsverfahren," EP3182743A1.
  • M. Yasuda, P. Chaki, and N. Fujita, "Verfahren und system zur kommunikation zwischen gruppen in einem drahtloskommunikationsnetzwerk," EP3182740A4.
  • M. Yasuda, P. Chaki, and N. Fujita, "Kommunikationssystem, kommunikationsverfahren und drahtloses endgerät für ein drahtloskommunikationsnetzwerk," EP3182744A4.
  • P. Chaki, M. Yasuda, and N. Fujita, "Gruppenneubildungs-Mechanismus zum Reduzieren von Disruptionszeit in drahtlosen Peer-to-Peer-Netzwerken," DE112014006431T5.

Contributions to 5G new radio (NR) Release 15 standardization as 3GPP RAN1 delegate

Authored Tdocs

  • R1-1701884, "Polar code design for control channel", in 3GPP RAN1 standardization meeting R1-88 for 5G, Feb 13-17, 2017, Athens, Greece.
  • R1-1705561, "Design of shortened polar codes for control channel", in 3GPP RAN1 standardization meeting R1-88bis for 5G, Apr 3-7, 2017, Spokane, Washington, USA.
  • R1-1709497, "Design of assistance bit aided polar codes for NR control channel", in 3GPP RAN1 standardization meeting R1-89 for 5G, May 15-19, 2017, Hongqiao, China.
  • R1-1707058, "Evaluation of rate-matching schemes for polar codes", in 3GPP RAN1 standardization meeting R1-89 for 5G, May 15-19, 2017, Hongqiao, China.
  • R1-1707059, "Evaluation of sequence design for polar codes", in 3GPP RAN1 standardization meeting R1-89 for 5G, May 15-19, 2017, Hongqiao, China.
  • R1-1710587, "Polar code construction for NR control channel", in 3GPP RAN1 standardization meeting R1-ah-18512 for 5G, June 27-30, 2017, Qingdao, China.
  • R1-1710591, "Sequence design evaluation for rate-matched polar codes", in 3GPP RAN1 standardization meeting R1-ah-18512 for 5G, June 27-30, 2017, Qingdao, China.
  • R1-1712334, "Polar code construction with single CRC polynomial and interleaver", in 3GPP RAN1 standardization meeting no. R1-90 for 5G, August 21-25, 2017, Prague, Czech Republic.
  • R1-1712335, "Rate-matching in polar codes", in 3GPP RAN1 standardization meeting no. R1-90 for 5G, August 21-25, 2017, Prague, Czech Republic.
  • R1-1716729, "On DL polar code construction using distributed CRC and interleaver", in 3GPP RAN1 standardization meeting R1-ah-18959 for 5G, August 3-7, 2017, Nagoya, Japan.

Awards/Prizes

Some selected honors/awards

  1. Notable Services and Contributions towards the advancement of IEEE and the Engineering Professions, Oct. 2023, issued by Institute of Electrical and Electronics Engineers (IEEE), Piscataway, New Jersey, USA.
  2. NEC Patent Award for Contribution in terms of Large Number of Issued Patents, June 2021, issued by NEC Corporation.
  3. IEEE YESIST12 2021 Special Mention, issued by IEEE YESIST12 2021.
  4. NEC Young Researcher Award 2019, August 2019, issued by NEC Corporation.
  5. NEC Excellent Invention Award 2018, June 2018, issued by NEC Corporation.
  6. IEICE Young Researcher Award 2016, March 2017, issued by Institute of Electronics, Information, and Communication Engineers (IEICE).
  7. NEC Excellent Invention Award 2015, June 2015, issued by NEC Corporation.
  8. Torch Bearer 2012-13, April 2013, issued by H14, Indian Institute of Technology (IIT) Bombay.
  9. Guinness World Record: Most people solving Rubik's cubes simultaneously, March 2012, issued by Guiness World Records.
  10. Limca Book of World Record: Most people solving Rubik's cubes simultaneously, March 2012, issued by Limca Book of Records - India.
  11. Project Research Assistantship for graduate studies, issued by IIT Bombay.
  12. Scholarship for undergraduate studies (selected based on performance in higher secondary examination), issued by Steel Authority of India Limited (SAIL).

Academic society, community, etc.

  • new windowEditor, IEEE Communications Society Technology News (CTN), Jun 2024 - present
  • Chair, IEEE Tokyo Section Educational Activities, Jan 2021 to Dec 2022.
  • Chair, IEEE Tokyo Section Young Professionals, Jan 2021 to Dec 2022.
  • Executive Committee Member, IEEE Japan Council, Jan 2021 to Dec 2022.
  • Executive Committee Member, IEEE Tokyo Section, Jan 2021 to Dec 2022.
  • Committee Member, IEEE Tokyo Section Young Professionals, Jan 2019 to Dec 2020.
  • Member, Institute of Electrical and Electronics Engineers (IEEE), 2018-present.
  • 3GPP RAN1 Delegate for Release 15 of 5G new radio (NR).
  • Executive Committee Member, IIT Bombay Alumni Association Japan Chapter (2015-2018, 2024-)
  • Session Chair, International Symposium on Information Theory and its Applications (ISITA) 2018, Singapore.

Featuring in media, newspapers, magazine articles

Few selected interviews and media appearances

Journal Review Activities

  • Reviewer, IEEE Transactions on Communications
  • Reviewer, IEEE Transactions on Vehicular Technology
  • Reviewer, IEEE Journal on Selected Topics in Signal Processing
  • Reviewer, Electronics Letters (IET)
  • Reviewer, ETRI Journal (Wiley)
  • Reviewer, Transactions on Emerging Telecommunication Technologies (Wiley)

Selected Seminars/Workshops Organized

  • Industrial R&D lab. visit and discussion (online) at Sumitomo Electric Industries, in IEEE Tokyo Section, Nov. 2021.
  • Seminar on "5G and beyond: An insider story" by Dr. A. Nimbalker and Dr. Y. Blankenship, Senior Standardization Experts from Ericsson USA, in IEEE Tokyo Section, Dec. 2021.
  • Career seminar on "My Journey with IEEE" by Ms. S. Land, IEEE CEO/President 2021, in IEEE Tokyo Section, Mar. 2022.
  • Career seminar on "IEEE Region 10 and you" by Mr. D. Mathur, IEEE Region 10 Director 2021-22, in IEEE Tokyo Section, Jun. 2022.
  • Seminar on "Find Your Major: Information Theory and Coding" by Prof. M. Medard, Massachusetts Institute of Technology (MIT) Professor of Electrical Engineering and Computer Science, in IEEE Tokyo Section, Jul. 2022.
  • Seminar on "Find Your Major: Speech Signal Processing" by Dr. K. Lee, Senior Scientist of Agency of Science, Technology, and Research (A*STAR) Singapore, in IEEE Tokyo Section, Aug. 2022.
  • Workshop on "Secrets to High-Quality Technical Writing" by Dr. A. Sugiyama of Yahoo! JAPAN Research, at IEEE Tokyo Section, Sep. 2022.
  • Industrial R&D lab. visit and discussion (online) at Yahoo! JAPAN Research, with Dr. A. Tajima, Head of Yahoo! JAPAN Research, in IEEE Tokyo Section, Nov. 2022.
  • Idea contest towards SDGs, in IEEE Tokyo Section, 2020.
  • Idea contest towards SDGs, in IEEE Tokyo Section, 2021.

Other Activities

  • Member, Japanese Red Cross Society Blood Donation Service
  • NEC RISE culture transform program 2024, at NEC Corporation
  • Union Representative, NEC Workers' Union (NWU), Mar 2017 - Apr 2020
  • NEC RISE culture transform program (1st generation, 2018-2019) at NEC Corporation
  • Volunteer at student mentoring program, GE Japan
  • Press Operations, Tokyo 2020
  • Official Volunteer at Tokyo Marathon, Yokohama Marathon, Tamagawa Marathon, The Asia-Pacific Corporate Games
  • Volunteer at Group for Rural Activities (teaching school students), IIT Bombay

Languages

English, Japanese, Hindi, Bengali

Contact

new windowLinkedIn

Academic/professional career summary

Academic

Ph.D. in Information and Communication Engineering, The University of Tokyo, Japan.
Master in Electrical Engineering, Indian Institute of Technology (IIT) Bombay, India.

Professional

Oct. 2013-present:
R&D Division, NEC Corporation, Japan.

Go back to Researchers at NEC