KEIO RESEARCHERS INFORMATION SYSTEM

Career 【 Display / hide 】

Career 【 Display / hide 】

• 1995.04

  -

  1997.03

  日本学術振興会 ,特別研究員

• 1997.04

  -

  2000.03

  東京工業大学（工学部電気・電子工学科） ,助手

• 2000.04

  -

  2001.03

  株式会社ソニーコンピュータサイエンス研究所 ,アシスタントリサーチャー

• 2001.04

  -

  2004.03

  慶應義塾先端科学技術研究センターリエゾン委員会委員

• 2001.04

  -

  2004.03

  慶應義塾大学専任講師（理工学部電子工学科）

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Academic Background 【 Display / hide 】

Academic Background 【 Display / hide 】

• 1992.03

  Keio University, Faculty of Science and Engineering, 電気工学科

  University, Graduated

• 1995.03

  Other, 工学部電気・計算機工学専修

  －, Graduate School, Completed, Master's course

• 1997.03

  Keio University, Graduate School, Division of Science and Engineeri, 電気工学専攻

  Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide 】

Academic Degrees 【 Display / hide 】

• 工学, Keio University, 1997.03

Books 【 Display / hide 】

Books 【 Display / hide 】

• ソフトウェアで作る無線機の設計法担当

  SANADA YUKITOSHI, 科学情報出版, 2016.09

  Scope: ３章３－７節

• 4G Mobile and Wireless Communications Technologies

  Y. Imaoka, H. Obata, Y. Suzuki, Y. Sanada, River Publishers, 2008.09

  Scope: Chapter entitled "Experimental Investigation of Channel Estimation for IEEE802.11b WLAN System"

• MATLABマルチメディア信号処理

  IKEHARA MASAAKI, SHIMAMURA TETSUYA, SANADA YUKITOSHI, 2004.12

  Scope: 193-276

• マルチメディア通信

  IKEHARA MASAAKI, SANADA YUKITOSHI, 培風館, 2002.12

• Software Radio: Technologies and Services

  R.Kohno, R.Miura, H.Harada, S.Haruyama, Y.Sanada, and L.B.Michael, 2001

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Papers 【 Display / hide 】

Papers 【 Display / hide 】

• User scheduling with beam selection for full digital massive mimo base station

  YATA M., OTSURU G., SANADA Y.

  IEICE Transactions on Communications （IEICE Transactions on Communications)  E104.B （ 4 ） 428 - 435 2021.04

  ISSN  09168516

  　View Summary

  In this paper, user scheduling with beam selection for fulldigital massive multi-input multi-output (MIMO) is proposed. Inter-user interference (IUI) can be canceled by precoding such as zero-forcing at a massive MIMO base station if ideal hardware implementation is assumed. However, owing to the non-ideal characteristics of hardware components, IUI occurs among multiple user terminals allocated on the same resource. Thus, in the proposed scheme, the directions of beams for allocated user terminals are adjusted to maximize the total user throughput. User allocation based on the user throughput after the adjustment of beam directivity is then carried out. Numerical results obtained through computer simulation show that when the number of user terminals in the cell is two and the number of user terminals allocated to one resource block (RB) is two, the throughput per subcarrier per subframe improves by about 3.0 bits. On the other hand, the fairness index (FI) is reduced by 0.03. This is because only the probability in the high throughput region increases as shown in the cumulative distribution function (CDF) of throughput per user. Also, as the number of user terminals in the cell increases, the amount of improvement in throughput decreases. As the number of allocated user terminals increases, more user terminals are allocated to the cell-edge, which reduces the average throughput.

  • Access to Document (DOI)

• Forcible search scheme for mixed gibbs sampling massive mimo detection

  YAMAZAKI K., SANADA Y.

  IEICE Transactions on Communications （IEICE Transactions on Communications)  E104.B （ 4 ） 419 - 427 2021.04

  ISSN  09168516

  　View Summary

  In this paper, mixed Gibbs sampling multiple-input multiple-output (MIMO) detection with forcible search is proposed. In conventional Gibbs sampling MIMO detection, the problem of stalling occurs under high signal-to-noise ratios (SNRs) which degrades the detection performance. Mixed Gibbs sampling (MGS) is one solution to this problem. In MGS, random sampling is carried out with a constant probability regardless of whether a current search falls into a local minimum. In the proposed scheme, combined with MGS, multiple candidate symbols are forcibly changed when the search is captured by a local minimum. The search restarts away from the local minimum which effectively enlarges the search area in the solution space. Numerical results obtained through computer simulation show that the proposed scheme achieves better performance in a large scale MIMO system with QPSK signals.

  • Access to Document (DOI)

• Low complexity overloaded MIMO detection based on belief propagation with MMSE pre-cancellation

  Imamura T., Sanada Y.

  IEICE Transactions on Communications （IEICE Transactions on Communications)  E104B （ 3 ） 312 - 319 2021.03

  ISSN  09168516

  　View Summary

  In this paper, the application of minimum mean square error (MMSE) pre-cancellation prior to belief propagation (BP) is proposed as a detection scheme for overloaded multiple-input multiple-output (MIMO) systems. In overloaded MIMO systems, the loops in the factor graph degrade the demodulation performance of BP. Therefore, the proposed scheme applies MMSE pre-cancellation prior to BP and reduces the number of loops. Furthermore, it is applied to the selected transmit and receive nodes so that the condition number of an inverse matrix in the MMSE weight matrix is minimized to suppress the residual interference and the noise after MMSE pre-cancellation. Numerical results obtained through computer simulation show that the proposed scheme achieves better bit error rate (BER) performance than BP without MMSE pre-cancellation. The proposed scheme improves the BER performance by 2.9-5.6 dB at a BER of 5.0 × 10− compared with conventional BP. Numerical results also show that MMSE pre-cancellation reduces the complexity of BP by a factor of 896 in terms of the number of multiplication operations. 3

  • Access to Document (DOI)

• Power-Based Criteria for Signal Reconstruction using 1-bit Resolution DACs in Massive MU-MIMO OFDM Downlink

  OKAWA Riki, SANADA Yukitoshi

  IEICE Transactions on Communications （一般社団法人 電子情報通信学会)   2021

  ISSN  0916-8516

  　View Summary

  <p>The sum rate and bit error rate (BER) performance of nonlinier quantized precoding using Gibbs sampling are evaluated in a massive multiuser multiple-input multiple-output (MU-MIMO) system in this paper. Massive MU-MIMO is a key technology to handle the growth of data traffic. In a full digital massive MU-MIMO system, however, the resolution of digital-to-analogue converters (DACs) in transmit antenna branches have to be low to yield acceptable power consumption. Thus, a combinational optimization problem is solved for the nonlinier quantized precoding to determine transmit signals from finite alphabets output from low resolution DACs. A conventional optimization criterion minimizes errors between desired signals and received signals at user equipments (UEs). However, the system sum rate may decrease as it increases the transmit power. This paper proposes two optimization criteria that take the transmit power into account in order to maximize the sum rate. Mixed Gibbs sampling is applied to obtain the suboptimal solution of the nonlinear optimization problem. Numerical results obtained through computer simulations show that the two proposed criteria achieve higher sum rates than the conventional criterion. On the other hand, the sum rate criterion achieves the largest sum rate while it leads to less throughputs than the MMSE criterion on approximately 60% of subcarriers.</p>

  • Access to Document (DOI)

• Likelihood-based Metric for Gibbs Sampling Turbo MIMO Detection

  KOBAYASHI Yutaro, SANADA Yukitoshi

  IEICE Transactions on Communications （一般社団法人 電子情報通信学会)   2021

  ISSN  0916-8516

  　View Summary

  <p>In a multiple-input multiple-output (MIMO) system, maximum likelihood detection (MLD) is the best demodulation scheme if no <i>a priori</i> information is available. However, the complexity of MLD increases exponentially with the number of signal streams. Therefore, various demodulation schemes with less complexity have been proposed and some of those schemes show performance close to that of MLD. One kind of those schemes uses a Gibbs sampling (GS) algorithm. GS MIMO detection that combines feedback from turbo decoding has been proposed. In this scheme, the accuracy of GS MIMO detection is improved by feeding back loglikelihood ratios (LLRs) from a turbo decoder. In this paper, GS MIMO detection using only feedback LLRs from a turbo decoder is proposed. Through extrinsic information transfer (EXIT) chart analysis, it is shown that the EXIT curves with and without metrics calculated from received signals overlap as the feedback LLR values increase. Therefore, the proposed scheme calculates the metrics from received signals only for the first GS MIMO detection and the selection probabilities of GS MIMO detection in the following iterations are calculated based only on the LLRs from turbo decoders. Numerical results obtained through computer simulation show that the performance of proposed GS turbo MIMO detection is worse than that of conventional GS turbo MIMO detection when the number of GS iterations is small. However the performance improves as the number of GS iterations increases. When the number of GS iterations is 30 or more, the bit error rate (BER) performance of the proposed scheme is equivalent to that of the conventional scheme. Therefore, the proposed scheme can reduce the computational complexity of selection probability calculation in GS turbo MIMO detection.</p>

  • Access to Document (DOI)

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Papers, etc., Registered in KOARA 【 Display / hide 】

Papers, etc., Registered in KOARA 【 Display / hide 】

• Throughput performance of non-orthogonal multiple access with joint maximum likelihood detection in heterogeneous network

  Sanada, Yukitoshi

  科学研究費補助金研究成果報告書 2018

• Research on low computational complexity signal de-multiplexing schemes for overloaded MIMO systems

  Sanada, Yukitoshi

  科学研究費補助金研究成果報告書 2015

• Research on single receive antenna MIMO-OFDM system

  Sanada, Yukitoshi

  科学研究費補助金研究成果報告書 2012

• Research on signal distortion compensation schemes in a direct conversion receiver

  SANADA, YUKITOSHI

  科学研究費補助金研究成果報告書 2008

Reviews, Commentaries, etc. 【 Display / hide 】

Reviews, Commentaries, etc. 【 Display / hide 】

• Special section on communication quality in wireless networks

  Sanada Y.

  IEICE Transactions on Communications (IEICE Transactions on Communications)  E101B ( 7 )  2018.07

  ISSN  09168516

• 次世代ワイヤレス通信技術　UWBの魅力

  SANADA YUKITOSHI

  Computerworld    pp. 130-133 2004.02

  Introduction and explanation (commerce magazine), Single Work

Presentations 【 Display / hide 】

Presentations 【 Display / hide 】

• Complexity Reduction Schemes for Gibbs Sampling MIMO Detection with Maximum Ratio Combining

  Y. Sanada

  IEEE 87th Vehicular Technology Conference, 2018.06, Oral Presentation(general)

• Throughput Performance of Adaptive Frequency Offset Selection for Amplify-and-Forward Relay in Multiuser Environment

  T. Shiba and Y. Sanada

  IEEE Vehicular Technology Conference 2018 Spring Workshop: TPoC5G 2018, 2018.06, Oral Presentation(general)

• Offloading Effect of Heterogeneous Network with Non-orthogonal Multiple Access

  T. Yukawa and Y. Sanada

  The 23rd Asia-Pasific Conference on Communications, 2017.12, Oral Presentation(general)

• MMSE Interference Rejection Followed by Joint Maximum Likelihood Detection for Distributed Antenna Network

  H. Miyagi and Y. Sanada

  The 23rd Asia-Pasific Conference on Communications, 2017.12, Oral Presentation(general)

• Cyclic Shift Resolution Effects on OFDM System Employing Cyclic-SLM with Delayed Correlation and Matched Filter

  P. Pamungkasari and Y. Sanada

  IEEE TENCON 2017, 2017.11, Oral Presentation(general)

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

Research Projects of Competitive Funds, etc. 【 Display / hide 】

• Multiuser Detection based on Markov chain Monte Carlo Methods

  2019.04

  -

  2022.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, 眞田　幸俊, Grant-in-Aid for Scientific Research (C), Principal Investigator

  　View Summary

  第５世代移動通信システムでは多数のセンサデバイスからの情報を収容し，従来とは違ったアプリケーションのプラットフォームになることが期待されている．そのため基地局では超多素子アンテナを実装し，同時に100以上の信号を受信，復調することが必要である．従来の復調アルゴリズムでは計算量的に同時受信することができる信号数が10程度に限られてしまう．そこで本研究ではマルコフ連鎖モンテカルロ法を用いて100を超える信号を同時に受信し復調するアルゴリズムを検討する．提案アルゴリズムは確率分布の期待値を簡易的に求める手法であるが，これを信号復調に適用する．
  第５世代移動通信システムでは多数のデバイスからの情報を収容し，従来とは違ったアプリケーションのプラットフォームになることが期待されている．基地局では超多素子アンテナを実装し，同時に100以上の信号を受信，復調することが必要である．従来の復調アルゴリズムでは計算量的に同時受信することができる信号数が10程度に限られる．そこで本研究ではマルコフ連鎖モンテカルロ法を用いて100を超える信号を同時に受信し復調するアルゴリズムを検討する．提案アルゴリズムは確率分布の期待値を簡易的に求める手法であるが，これを信号復調に適用する．具体的には(1)提案アルゴリズムによる計算量の削減，(2)想定するチャネルモデルによる復調特性の評価，(3)誤り訂正符号と組み合わせた提案アルゴリズムの特性評価を計算機シミュレーションにより評価する．
  2019年度の研究成果として(1)に関してはマルコフ連鎖モンテカルロ法に並列信号処理を用いた方式を提案した．複数の受信信号間は相互依存しているが，これを無視し並列に処理することにより単位時間当たりの復調回数を増加し，受信特性を改善する．計算機シミュレーションの結果並列数が３のとき最も良い特性を示した．またアルゴリズムが特定のローカルミニマムに停留した場合に強制的に移動させる式も提案した．さらに(3)については１回目の多信号復調のみ受信信号を用いるが，２回目以降誤り訂正後の繰り返し復調に関してはマルコフ連鎖モンテカルロ法の出力のみを用いる方式を提案した．これにより受信信号を用いた復調処理部分の計算量を削減し，従来方式と同等の誤り率を達成できた．
  またマルコフ連鎖モンテカルロ法を超多素子アンテナの別の形態である分散アンテナに用い，ユーザに対するアンテナと周波数リソース割り当て最適化も検討し，少ない計算量で最適手法に近い周波数利用効率を実現できることを明らかにした．
  当初の研究計画では(1)提案アルゴリズムによる計算量の削減，(2)想定するチャネルモデルによる復調特性の評価，(3)誤り訂正符号と組み合わせた提案アルゴリズムの特性評価を検討項目に挙げた．このうち(1)および(3)に関しては想定通りの計算量削減効果を得られた．これに対して(2)に関しては，受信アンテナ間の相関のあるチャネル応答を想定したマルコフ連鎖モンテカルロ法による受信信号の復調を試みたが，想定以上に特性が劣化した．
  当初計画(2)想定するチャネルモデルによる復調特性の評価に関して，2020年度においては格子基底縮小を用いてアンテナ間の相関を低減し，マルコフ連鎖モンテカルロ法を適用することを検討する．この組み合わせによる復調方式はすでに提案されているが本研究では特に並列信号処理を用いて等価的にマルコフ連鎖モンテカルロ法の繰り返し処理回数を増加した場合の特性について検討する予定である．また通信路応答の大小により受信アンテナをグループ化し，それぞれのグループに対して個別の拡張係数を適応することによる効果を検討する．さらにマルコフ連鎖モンテカルロ法をチャネル推定にも適用し信号復調と同時にチャネル推定精度を改善する方法を検討する．

• 非直交多元接続を用いたヘテロジニアスネットワークのスループット特性

  2016.04

  -

  2019.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, 眞田　幸俊, Grant-in-Aid for Scientific Research (C), Principal Investigator

Intellectual Property Rights, etc. 【 Display / hide 】

Intellectual Property Rights, etc. 【 Display / hide 】

• 通信装置、復調方法及びプログラム

  Application No.： 特願2015－49558  2015.03 

  Patent, Single, National application

• マルチキャリアシステム

  Application No.： 2008－176119  2008.07 

  Registration No.： 5305305  2013.07

  Patent, Joint

• ＯＦＤＭ受信装置

  Application No.： 特願2008－053847  2008.03 

  Announcement No.： 特開2009-212835  2009.09 

  Patent, Joint, National application

• ＯＦＤＭ受信装置

  Application No.： 特願2008ー045323  2008.02 

  Announcement No.： 特開2009-206668  2009.09 

  Patent, Joint, National application

• 無線通信装置

  Application No.： 特願2007-108046  2007.03 

  Announcement No.： 特開2008-219671  2008.09 

  Patent, Joint, National application

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Awards 【 Display / hide 】

Awards 【 Display / hide 】

• IEICE Fellow

  2017.03, IEICE

• 電子情報通信学会フェロー

  2017.03, 電子情報通信学会

  Type of Award： Other Awards

• 電子情報通信学会通信ソサイエティ活動功労賞

  2015.09

  Type of Award： Awards of National Conference, Council and Symposium

• 電子情報通信学会通信ソサイエティ活動功労賞

  2015.09

  Type of Award： Awards of National Conference, Council and Symposium

• 電子情報通信学会通信ソサイエティ活動功労賞

  2015.09

  Type of Award： Awards of National Conference, Council and Symposium

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Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• WIRELESS COMMUNICATIONS

  2021

• RECITATION IN ELECTRONICS AND INFORMATION ENGINEERING

  2021

• LABORATORIES IN ELECTRONICS AND INFORMATION ENGINEERING(2)

  2021

• INFORMATION ENGINEERING

  2021

• INDEPENDENT STUDY ON INTEGRATED DESIGN ENGINEERING

  2021

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Social Activities 【 Display / hide 】

Social Activities 【 Display / hide 】

• 株式会社トランザクション・メディア・ネットワークス

  2020.06

  -

  Present

  　View Summary

  社外取締役

• ARIB

  2013.05

  -

  2014.05

  　View Summary

  MMAC部会委員長
  UWB-WG主任
  UWB作業班主任

• 総務省情報通信審議会UWB無線システム作業班携帯電話アドホック委員会

  2012.12

  -

  2013.05

• 自営無線ブロードバンドシステム導入のための周波数共用に関する調査検討会

  2011.05

  -

  2012.03

• 独立行政法人情報通信研究機構研究活動に関する外部評価委員会

  2008.10

  -

  2011.03

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Memberships in Academic Societies 【 Display / hide 】

Memberships in Academic Societies 【 Display / hide 】

• IEICE, 

  1995

  -

  Present

• The Institute of Electrical and Electronics Engineers, Inc.

  　

Committee Experiences 【 Display / hide 】

Committee Experiences 【 Display / hide 】

• 2020.06

  -

  Present

  委員, 電子情報通信学会国際委員会

• 2018.06

  -

  Present

  委員, 電子情報通信学会無線通信システム研究専門委員会

• 2018.06

  -

  2020.05

  調査理事, 電子情報通信学会

• 2018.06

  -

  2020.05

  幹事, IEICE

• 2018.06

  -

  2020.05

  幹事, IEICE

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