AccessJP

Search

Menu

Study at TCU

Reseacher

Name SAWAHASHI Mamoru
Official Title Professor
Affiliation Department of Electrical, Electronic, and Communication Engineering
E-mail sawahasi@tcu.ac.jp
Web
  1. https://www.gyosekisys.gl.tcu.ac.jp/Main.php?action=Top
Profile In 1985, he joined the NTT Electrical Communications Laboratories, and in 1992 he transferred to NTT DOCOMO, INC. In NTT, he was engaged in the research of modulation/demodulation techniques for mobile radio. He was also engaged in the research and development of radio access technologies for W-CDMA and 4G LTE systems in NTT DOCOMO. From April 2006, he assumed the position of Professor of Musashi Institute of Technology (now Tokyo City University). From 2006, he is engaged in the research of radio access technologies for LTE, LTE-Advanced, and 5G NR systems including waveform, cell search, channel estimation, modulation scheme, channel coding, MIMO signal detection. The current his major interests are radio access technologies and mobile radio backhaul technologies aiming at the Beyond 5G systems.
Research Field(Keyword & Summary)
  1. (1)Physical-layer cell ID detection for single-carrier transmission

    We investigate the multiplexing scheme and the sequence of synchronization signals for detecting the physical-layer cell identity (PCID) detection and the performance on the PCID detection probability for broadband single-carrier transmission for Beyond 5G systems.

  2. (2) Efficient modulation scheme for Beyond 5G systems

    We investigate the efficient modulation schemes with low peak-to-average power ratio (PAPR) and robustness for phase noise including circular QAM and triangular QAM schemes for Beyond 5G systems.

  3. (3) Waveform for Beyond 5G systems

    We investigate waveform that achieves high spectral efficiency, low PAPR, and mitigates phase noise including faster-than Nyquist (FTN) signaling for Beyond 5G systems.

  4. (4)Compensation techniques of phase noise and frequency offset

    We investigate the estimation and compensation techniques of phase noise and frequency offset in access links and backhaul links for 5G and Beyond 5G systems.

  5. (5) LOS-MIMO for mobile radio backhaul

    We investigate LOS-MIMO techniques including equalization of multipath interference for mobile radio backhaul for Beyond 5G systems.
Representative Papers
  1. K. Ota, M. Sawahashi, and S. Nagata, “Physical Cell ID Detection Probability Using NR Synchronization Signals in 28-GHz Band,” To be published at IEICE Trans. on Commun., vol.E104-B, no.4, pp.436-445, Apr. 2021.
  2. A. Shimura, M. Sawahashi, S. Nagata, and Y. Kishiyama, “Physical Cell ID Detection Probabilities Using Frequency Domain PVS Transmit Diversity for NB-IoT Radio Interface,” Accepted and to be appreared at IEICE Trans. on Commun., vol. E102-B, no. 8, pp. 1477-1489, Aug. 2019.
  3. T. Ohtomo, H. Yamada, M. Sawahashi, and K. Saito, “Performance of Iterative Digital Self-Interference Canceler with Alternating Estimate Subtraction for OFDM Using Full Duplex,” Accepted and to be appreared at IEICE Trans. on Commun., vol. E102-B, no. 8, pp. 1490-1502, Aug. 2019.
  4. T. Ebihara, Y. Kuge, H. Taoka, N. Miki, and M. Sawahashi, “ Performance of Outer-Loop Control for Adaptive Modulation and Coding Based on Mutual Information in OFDM MIMO SDM,” IEICE Trans. on Communications, vol.E98-B, no.8, pp. 1506-1517, Aug. 2015.
  5. L. Deng, T. Kawamura, H. Taoka, and M. Sawahashi, " Comparative Study of Open-Loop Transmit Diversity Schemes with Four Antennas in DFT-Precoded OFDMA Using Turbo FDE and Iterative Channel Estimation," IEICE Trans. on Communications, vol.E98-B, no.6, pp. 1065-1077, June 2015.
  6. T. Kawamura, R. Takahashi, H. Numata, N. Miki, and M. Sawahashi, “Performance Evaluation of Joint MLD with Channel Coding Information for Control Signals Using Cyclic Shift CDMA and Block Spread CDMA,” IEICE Trans. on Commun., vol.E95-B, no.12, pp. 3688-3698, Dec. 2012.
  7. S. Nagata, Y. Ofuji, Y. Kishiyama, N. Miki, K. Higuchi, and M. Sawahashi, " Block-Wise Resource Block-Level Distributed Transmission for Shared Data Channel in OFDMA Evolved UTRA Downlink, " IEICE Trans. on Communications, vol. E92-B, no.5, pp. 1660-1668, May 2009.
  8. T. Kawamura, Y. Kishiyama, K. Higuchi, and M. Sawahashi, "Single-Carrier Based Multiplexing of Layer 1 / Layer 2 Control Signals in Evolved UTRA Uplink Using DFT-Spread OFDM, " IEICE Trans. on Communications, vol. E92-B, no.5, pp. 1695-1704, May 2009.
  9. H. Taoka, K. Dai, K. Higuchi, and M. Sawahashi, “Filed Experiments on MIMO Multiplexing with Peak Frequency Efficiency of 50 bit/Second/Hz Using MLD Based Signal Detection for OFDM High-Speed Packet Access,” IEEE Journal on Selected Areas in Communications, vol.26, no. 6, pp.845-856, Aug. 2008.
  10. M. Sawahashi, H. Andoh, K. Higuchi, and F. Adachi, “Experiments on Pilot Symbol-Assisted Coherent Multistage Interference Canceller for DS-CDMA Mobile Radio,” IEEE Journal on Selected Areas in Communications, vol.20, no. 2, pp.433-449, Feb. 2002.
Award 2015 National Invention Award, Commissioner of the Patent Office Award
2012 IEICE Communications Society:Excellent Paper Award
2010 National Invention Award, Prime Minister Invention Award
2007 WPMC2007 Best Paper Award (The 10th International symposium on Wireless Personal Multimedia Communications 2007)
2004 WPMC2004 Regular Paper Award (The 7th International symposium on Wireless Personal Multimedia Communications 2004)
Grant-in-Aid for Scientific Research Support: Japan Society for Promotion of Science (JSPS) https://kaken.nii.ac.jp/ja/search/?kw=%E4%BD%90%E5%92%8C%E6%A9%8B%E8%A1%9B
Recruitment of research assistant(s) No
Affiliated academic society (Membership type) IEEE (Member), IEICE (Fellow)
Education Field (Undergraduate level) Communication engineering, Digital modulation, Coding theory, Communication systems
Education Field (Graduate level) Advanced Communication Systems

Affiliation