IWANAMI Yasunori

写真a

Affiliation Department etc.

Department of Electrical and Mechanical Engineering
Department of Electrical and Mechanical Engineering

Title

Professor

Graduating School

  •  
    -
    1976.03

    Nagoya Institute of Technology   Faculty of Engineering   Graduated

Graduate School

  •  
    -
    1981.03

    Tohoku University  Graduate School, Division of Engineering  Doctor's Course  Completed

  •  
    -
    1978.03

    Nagoya Institute of Technology  Graduate School, Division of Engineering  Master's Course  Completed

Degree

  • Tohoku University -  Doctor of Engineering

  • Nagoya Institute of Technology -  Master of Engineering

Academic Society Affiliations

  •  
     
     

    IEEE(The Instituce of Electrical and Electronics Engineers)

Field of expertise (Grants-in-aid for Scientific Research classification)

  • Communication/Network engineering

 

Research Career

  • Study on very high bit rate data transmission systems on multipathfading environment

    Individual   (not selected)  

    Project Year:   - 

  • Study on coded modulation systems

    Individual   (not selected)  

    Project Year:   - 

  • Study on spread spectrum communications

    Individual   (not selected)  

    Project Year:   - 

Papers

  • Coherent GFSK Receiver on MIMO Frequency Selective Channels

    Kazuki Yoshida, Yasunori Iwanami

    IEEE TENCON 2016 ( IEEE )    1 - 4   2016.11  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    GFSK (Gaussian-filtered Frequency Shift Keying) signal has a constant envelope and is suited to power efficient nonlinear amplification. However, the application of GFSK signal to spectrally efficient and reliable MIMO (Multiple Input Multiple Output) communication schemes has not been so popular up to now. Maybe this comes from the fact that the signal processing for spatially multiplexed MIMO signal is usually done using linear matrix algebra and the application of linear signal processing techniques to nonlinear digital FM signal such as GFSK is difficult. In this paper, we study the coherent detection of GFSK signal based on MLD (Maximum Likelihood Detection) approach on MIMO frequency selective channels. In the proposed receiver, the receive replica signal which is frequency and phase synchronized is generated and the signal distance between the receive signal and the receive replica signal is minimized. By extending the observation length of receive signal, we further improved the BER characteristics. We also reduced the complexity of MLD by using the SE (Schnorr Euchner) algorithm of Sphere Decoding to obtain ML (Maximum Likelihood) solution.

  • A diversity order design of linearly precoded mu-mimo downlink system

    Nobuaki Shimakawa, Yasunori Iwanami

    IEEE TENCON 2016 ( IEEE )    1 - 4   2016.11  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    Recently, Muti-User MIMO (MU-MIMO) downlink system which uses multiple antennas at Base Station (BS) and accommodates multiple users with multiple receive antennas attracts much attention. It can achieve a high channel capacity when the channel state information is known both at BS and each User Equipment (UE). There exist linear and non-linear MU-MIMO downlink schemes, but the linear scheme is considered more easily to be implemented and adjusted. Linear Block Diagonalization (BD) has been proposed in order to cancel the Inter-User Interference (IUI), and combined with the Eigenbeam-Space Division Multiplexing (E-SDM). In this paper, by noting that the block size of each user channel matrix in BD becomes (number of receive antennas of each UE) × (nullity of the matrix constituted by other users), we design the BD + E-SDM scheme based on the down link quality of each UE, i.e., the diversity order. We made simulations for some examples and show the effectiveness of design method based on the diversity order of each UE.

  • A Regenerative Relay Transmission in Linearly Precoded MU-MIMO Downlink

    Yasunori Iwanami, Kentaro Iida

    AICT 2016 ( IARIA )    51 - 56   2016.05  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    Recently, Muti-User MIMO (MU-MIMO) downlink system which uses multiple antennas at base station and accommodates multiple users with multiple receive antennas attracts much attention. In MU-MIMO downlink system, by knowing the Channel State Information (CSI) at the base station, Inter User Interferences (IUI’s) among users are pre-excluded at the base station. By increasing the number of transmit antennas assigned to each user, the transmission quality of each user is improved. In MU-MIMO, there exists linear precoding or nonlinear precoding method, but linear precoding is considered more easily implemented and adjusted than nonlinear precoding. In this paper, we aim the coverage extension and the transmission quality improvement by using a regenerative Detect & Forward (DF) relay in MU-MIMO downlink system. We use Block Diagonalization (BD) + Eigen mode transmission (E-SDM) for linear MU-MIMO scheme. By sharing the BD matrix at both base station and relay, the relay can demodulate the receive signal only with receive CSI and can forward the signal to each user. With this system configuration, we have shown the effectiveness of regenerative relay through simulations.

  • Coherent MFSK detection on MIMO frequency selective channels

    Rio Abe and Yasunori Iwanami

    IEEE fifth International Conference on Digital Information Processing and Communications (ICDIPC2015) ( IEEE )    77 - 82   2015.10  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    MFSK (M-ary Frequency Shift Keying) signal has a constant envelope and is suited to power efficient nonlinear amplification. However, the application of MFSK signals to spectrally efficient and reliable MIMO (Multiple Input Multiple Output) communication schemes has not been so popular up to now. Maybe this comes from the fact that the signal processing for spatially multiplexed MIMO signal is usually done using linear matrix algebra and the application of linear signal processing techniques to nonlinear FM signals such as MFSK is difficult. In this paper, we study the coherent detection of MFSK signals based on MLD (Maximum Likelihood Detection) approach on MIMO frequency selective channels. In the proposed receiver, the receive replica signal which is frequency and phase synchronized is generated and the signal distance between the receive signal and the receive replica signal is minimized. By extending the observation length of receive signal, we improved the BER characteristics. We also reduced the complexity of MLD by using the SE (Schnorr Euchner) algorithm of Sphere Decoding to obtain ML (Maximum Likelihood) solution.

  • On Type II Hybrid-ARQ with Decode and Forward Relay using Non-Binary Rate-Compatible Punctured LDPC Code on MIMO Frequency Selective Channels

    Sho KATO and Yasunori IWANAMI

    International Journal On Advances in Telecommunications ( IARIA )  vol. 8 ( numbers 1 and 2 ) 74 - 83   2015.06  [Refereed]  [Invited]

    Research paper (scientific journal)   Multiple Authorship

    In this paper, Non-Binary Rate-Compatible Punctured Low Density Parity Check (NB RCP LDPC) code is designed over the extended Galois Field. The designed NB RCP LDPC code is applied to the type II Hybrid Automatic Repeat reQuest (HARQ) with Decode and Forward (DF) relay on Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) channel and MIMO Single Carrier-Frequency Division Multiple Access (SC-FDMA) channel. The designed code enables us to decrease the coding rate with incremental redundancy for each retransmission in HARQ. The retransmission is done from the DF relay after the successful decoding in the relay. We have verified through computer simulations that the proposed type II HARQ scheme with DF relay greatly improves the throughput and average retransmission characteristics compared with the scheme without DF relay. Multiple relay cases are also considered.

  • Complexity Reduced MIMO Interleaved SC-FDMA Receiver with Iterative Detection

    Masaki Tsukamoto, Yasunori Iwanami

    Int. J. Communications, Network and System Sciences, 2014, 7, 508-518   7   508 - 518   2014.12  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    In this paper, we propose the receiver structure for Multiple Input Multiple Output (MIMO) Interleaved Single Carrier-Frequency Division Multiple Access (SC-FDMA) where the Frequency Domain Equalization (FDE) is firstly done for obtaining the tentative decision results and secondly using them the Inter-Symbol Interference (ISI) is cancelled by ISI canceller and then the Maximum Likelihood Detection (MLD) is used for separating the spatially multiplexed signals. Furthermore the output from MLD is fed back to ISI canceller repeatedly. In order to reduce the complexity, we replace the MLD by QR Decomposition with M-Algorithm (QRD-M) or Sphere Decoding (SD).
    Moreover, we add the soft output function to SD using Repeated Tree Search (RTS) algorithm to generate soft replica for ISI cancellation. We also refer to the Single Tree Search (STS) algorithm to further reduce the complexity of RTS. By examining the BER characteristics and the complexity reduction through computer simulations, we have verified the effectiveness of proposed receiver structure.

  • Low complexity MIMO Interleaved SC-FDMA receiver using MRC with iterative detection

    Takamasa TAKAHASHI & Yasunori IWANAMI

    The 2nd IEEE International Symposium on Telecommunication Technologies (ISTT2014)     23 - 27   2014.11  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    In this paper we propose a low complexity receiver structure of MIMO Interleaved SC-FDMA (Multiple Input Multiple Output Interleaved Single Carrier-Frequency Division Multiple Access) on frequency selective channels. The receiver firstly obtains the tentative decision results through FDE (Frequency Domain Equalization) and using the tentative results the ISI (Inter-Symbol Interference) is cancelled by the ISI canceller. Then the MLD (Maximum Likelihood Detection)is utilized to separate the spatially multiplexed signal streams to obtain the decision results. By regarding the decision results as the improved tentative decision results, the ISI cancellation and MLD are iteratively done. However, as the complexity of MLD is quite high, we replace the MLD by the SD (Sphere Decoding). As the complexity of SD is still high for high level modulations, we adopt the combination of IAI (Inter-Antenna Interference)canceller and the MRC (Maximum Ratio Combining)instead of the SD. We examined the BER characteristics and the complexity reduction of proposed receiver structure using the ISI + IAI canceller and MRC with iterative detection and verified the effectiveness of the proposed receiver structure.

  • On Type II Hybrid-ARQ with Decode and Forward Relay using Non-Binary Rate-Compatible Punctured LDPC Code on MIMO SC-FDMA up-link

    Tomotaka Hamada & Yasunori Iwanami

    ICWMC 2014 : The Tenth International Conference on Wireless and Mobile Communications     112 - 117   2014.06  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    In this paper, Non-Binary Rate-Compatible Punctured Low Density Parity Check (NB RCP LDPC) code is designed over the extended Galois Field. The designed NB RCP LDPC code is applied to the type II Hybrid Automatic Repeat reQuest (HARQ) with Decode and Forward (DF) relay on Multiple Input Multiple Output (MIMO) Single Carrier-Frequency Division Multiple Access (SC-FDMA) up-links. The designed code enables us to decrease the coding rate with incremental redundancy for each retransmission in HARQ. The retransmission is done from the DF relay after the successful decoding in the relay. We have verified through computer simulations that the proposed type II HARQ scheme with DF relay greatly improves the throughput and average retransmission characteristics compared with the scheme without DF relay. Multiple relay cases are also considered.

  • Iterative Detection of M-FSK Signal on MIMO Frequency Selective Fading Channels

    Yuichi Yamane and Yasunori Iwanami

    The Ninth Advanced International Conference on Telecommunications, AICT2013     38 - 43   2013.06  [Refereed]

    Research paper (international conference proceedings)   Multiple Authorship

    In this paper, we have proposed the novel demodulation scheme of M-FSK (M-ary Frequency Shift Keying) signal on MIMO (Multiple Input Multiple Output) frequency selective channels. As for this demodulation scheme, there exists almost no investigation except a few reports. The proposed scheme uses FDE (Frequency Domain Equalization) and ISI (Inter-Symbol Interference) canceller plus MLD (Maximum Likelihood Detection). We further reduced the BER by using iterative feedback of detected results. The novelty in this paper is the integration of those techniques for detecting MIMO M-FSK signal. Through computer simulation, we have verified that the proposed scheme using FDE and ISI canceller plus MLD with iterative feedback exhibits the excellent BER characteristics compared with previously reported FDE detector.

  • Performance of AF Relay Networks with Multiple Relays and Multiple Antennas at Destination Using MRC Combining

    Solimanzoy Fayeqa Haider, Cong Li, Yasunori Iwanami

    Int'l J. of Communications, Network and System Sciences   Volume 6 ( Number 5 ) 197 - 203   2013.05  [Refereed]

    Research paper (scientific journal)   Multiple Authorship

    Cooperative networking schemes in wireless networks provide cooperative diversity gain using differently located an- tennas that combat fadings induced by multipath propagation. In this paper, we present the optimal weight design for the destination in AF (Amplify and Forward) relay system, where the optimally designed MRC (Maximum Ratio Com- bining) is employed at the destination for S→D link (direct link between source and destination) and R→D links (indi- rect links between relays and destination). We investigate the BER performance of 1S→NR→LD system composed of one source, N relay nodes equipped with single antenna and one destination node equipped with L antennas, which also includes 1S→1R→LD and 1S→NR→1D. Simulation and numerical results are presented to verify our analysis.

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Books

  • Digital communications

    (Part: Single Author )

    Corona Publishing CO., LTD.  2007.10 ISBN: 9784339027112

Review Papers

  • On Coded MIMO-OFDM Schemes

    Yasunori Iwanami

    The journal of the Institute of Electronics, Information and Communication Engineers ( The Institute of Electronics, Information and Communication Engineers )  Vol.94 ( No.8 ) 728 - 734   2011.08

    Introduction and explanation (international conference proceedings)   Single Author

Presentations

  • A study on the deployment of RRH in MU-MIMO downlink with distributed antenna

    Nobuaki Shimakawa, Yasunori Iwanami

    2017.09  -  2017.09 

  • MU-MIMO DFリレー伝送方式におけるBS送信アンテナ数に関する検討、B-5-140

    島川展明、岩波保則

    2017年電子情報通信学会総合大会  (名城大学)  2017.03  -  2017.03  電子情報通信学会

  • A study on coherent GFSK detection on MIMO frequency selective channels

    Rio Abe, Yasunori Iwanami

    2016.03  -  2016.03 

  • A design of user communication quality in linearly precoded MU-MIMO downlink system

    Zhang Guoyu, Yasunori Iwanami

    2016.03  -  2016.03 

  • A study of regenerative relay in linearly precoded MU-MIMO downlink

    Kentaro Ida, Yasunori Iwanami

    2016.03  -  2016.03 

  • A study on Type II Hybrid-ARQ multiple relaying scheme using Non-Binary Rate-Compatible-Punctured LDPC codes with MIMO-OFDM

    2015.09  -  2015.09 

  • A study on Amplify & Forward relaying scheme using multiple receive antennas

    2015.03  -  2015.03 

  • A study on multi-user MIMO relay transmission scheme using block diagonalization and MRC

    2015.03  -  2015.03 

  • BER estimation of MIMO FDE receivers with channel measurement

    2015.03  -  2015.03 

  • A study on coherent MFSK detection on MIMO frequency selective channels

    2015.03  -  2015.03 

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