研究者詳細 - 侯　亜飛

論文 - 侯　亜飛

分割表示 >> ／全件表示 163 件中 1 - 163 件目

A study for 2-D indoor localization using multiple leaky coaxial cables 査読

Junjie Zhu, Pengcheng Hou, Yafei Hou, Satoshi Denno, Minoru Okada

APSIPA Transactions on Signal and Information Processing 9 1 - 9 2020年10月

Capacity of 4-by-4 MIMO Channel Using One Composite Leaky Coaxial Cable With User Position Information 査読

Yafei Hou, Junjie Zhu, Satoshi Denno, Minoru Okada

IEEE Transactions on Vehicular Technology 68 ( 11 ) 11042 - 11051 2019年11月

Capacity Evaluation of MIMO Channel With One Leaky Coaxial Cable Used as Two Antennas Over Linear-Cell Environments 査読

Yafei Hou, Satoshi Tsukamoto, Sha Li, Takeshi Higashino, Kiyoshi Kobayashi, Minoru Okada

IEEE Transactions on Vehicular Technology 66 ( 6 ) 4636 - 4646 2017年6月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Leaky coaxial (LCX) cable is widely used in wireless communication systems as an antenna, especially for a long and narrow area called the linear-cell environment. The general usage of LCX cable is that it can be treated as one antenna. To configure a multiple-input-multiple-output (MIMO) system, it requires more than one LCX cable. In this paper, we propose a simple design in which one single LCX cable can be used as two antennas. Therefore, the proposal reduces the cost and spacing requirement and releases the space requirement of MIMO deployment for wireless application over linear-cell environments. We will study the capacity of the proposed LCX-MIMO system using equal power (EP) allocation and water-filling power allocation and compare its capacity with the conventional MIMO system using monopole antennas. The capacity results over the 2.4 GHz band and the 5 GHz band show that the proposed LCX-MIMO channel has better capacity than that of using monopole antennas over linear-cell environments. In particular, it can achieve more capacity improvement than that of channel using monopole antennas with the simple EP allocation. The throughput experiments over 5 GHz also show that our proposal can achieve the higher and stable throughput over the radiation coverage of LCX cable.

添付ファイル： 26 IEEETVT 201706.pdf

DOI： 10.1109/TVT.2016.2612683

Overloaded MIMO spatial multiplexing independent of antenna setups 査読

Satoshi Denno, Takumi Sugimoto, Koki Matoba, Yafei Hou

IEICE Transactions on Communications vol.E108-B ( 1 ) 1 - 14 2025年1月

A Linear Search Algorithm for Resource Allocation in Frequency Domain Non-Orthogonal Multiple Access 査読

Satoshi Denno, Yuto Ohba, Yafei Hou

2025 IEEE International Conference on Consumer Electronics (ICCE) 1 - 5 2025年1月

Iterative Colored Noise Cancellation For Overloaded MIMO Systems With Precoding Based on Equal Gain Transform 査読

Satoshi Denno, Takumi Sugimoto, Yafei Hou

17th International Conference on Signal Processing and Communication Systems 1 - 6 2024年12月

Evaluation of Link Quality and Constellation Distance for RIS-Based Spatial Modulation System 査読

Issei Maesaki, Tsuyoshi Inoue, Yafei Hou, Satoshi Denno

2024 IEEE 29th Asia Pacific Conference on Communications (APCC) 77 - 82 2024年11月

Overloaded Multi-User MIMO With Receive Spatial Filters 査読

Kosuke Ota, Satoshi Denno, Yafei Hou

2024 IEEE 29th Asia Pacific Conference on Communications (APCC) 168 - 173 2024年11月

MUSIC Spectrum Based Interference Detection, Localization, and Interference Arrival Prediction for mmWave IRS-MIMO System 査読

Yafei Hou, Kazuto Yano, Norisato Suga, Julian Webber, Satoshi Denno, Toshikazu Sakano

IEEE Access 12 142592 - 142605 2024年10月

Fingerprint-based Indoor Localization for MmWave System With Reconfigurable Intelligent Surface 査読

Souichirou Tada, Haruya Mushiake, Takama Kaito, Yafei Hou, Satoshi Denno

2024 IEEE 13th Global Conference on Consumer Electronics (GCCE) 1 - 2 2024年10月

A Study of BER performance of MmWave RIS Spatial Modulation System Using Genetic Algorithm based Constellations Selection 査読

Tsuyoshi Inoue, Itsusei Maesaki, Yafei Hou, Satoshi Denno

2024 IEEE 13th Global Conference on Consumer Electronics (GCCE) 1 - 2 2024年10月

A Low Complexity Soft-Input Decoding For Overloaded MIMO Systems 査読

K. Matoba, S. Denno, Y. Hou

2024 IEEE 13th Global Conference on Consumer Electronics (GCCE) 1 - 2 2024年10月

Overloaded MIMO Spatial Multiplexing Independent of Antenna Settings 査読

S. Denno, T. Sugimoto, K. Matoba, Y. Hou

2024 IEEE 100th Vehicular Technology Conference (VTC2024-Fall) 1 - 5 2024年10月

Collaborative Amplify-and-Forward Relaying with Relay Selection Based on Doppler Shift Estimation 査読

H. Nishimura, S. Denno, Y. Hou

2024 IEEE 13th Global Conference on Consumer Electronics (GCCE) 1 - 2 2024年10月

Theoretical Analysis on Localization Error Bound for Wireless System Using Leaky Coaxial Cable 査読

Ziying Ji, Junjie Zhu, Yafei Hou, Satoshi Denno

The 17th International Conference on Advanced Computer Theory and Engineering (ICACTE 2024) 1 - 5 2024年9月

On Hyperparameter Determination for GPR-Based Channel Prediction in IRS-Assisted Wireless Communication Systems

Norisato Suga, Kazuto Yano, Yafei Hou, Toshikazu Sakano

IEICE Communications Express 13 ( 8 ) 315 - 318 2024年8月

Low Complexity MU-MIMO Scheduling for B5G Cellular Network 査読

Satoshi Denno, Akihiko Yamada, Yafei Hou

The 3rd international conference on M3 IT Convergence (ICMIC 24) 1 - 5 2024年8月

Low Complexity Overloaded MIMO Non-Linear Detector with Iterative LLR Estimation 査読

Satoshi Denno, Shuhei Makabe, Yafei Hou

IEICE Transactions on Communications E107-B ( 3 ) 339 - 348 2024年3月

WLAN Channel Status Duration Prediction for Audio and Video Services Using Probabilistic Neural Networks.

Yafei Hou, Satoshi Denno

IEEE Access 12 28201 - 28211 2024年

Uplink overloaded MIMO spatial multiplexing with iterative colored noise cancellation in massive MIMO systems 査読

Satoshi Denno, Takumi Sugimoto, Yafei Hou

IEICE Transactions on Communications 1 - 10 2024年

Practical Uplink Multi-User MIMO Scheduling Based on Iterative Heuristic Search 査読

Satoshi Denno, Akihiko Yamada, Yafei Hou

IEICE Transactions on Communications 1 - 10 2024年

Overloaded MIMO Bi-Directional Communication with Physical Layer Network Coding in Heterogeneous Multihop Networks 査読

Satoshi DENNO, Tomoya TANIKAWA, Yafei HOU

IEICE Transactions on Communications E106.B ( 11 ) 1228 - 1236 2023年11月

An Overloaded MIMO 2-Hop Network With Physical Layer Network Coding 査読

Satoshi Denno, Tomoya Tanikawa, Yafei Hou

2023 28th IEEE Asia-Pacific Conference on Communications (APCC 2023) 1 - 5 2023年11月

Multi Stage LLR Estimation With Ordering in A Non-linear Receiver For Overloaded MIMO Systems 査読

Satoshi Denno, Shuhei Makabe, Yafei Hou

26th International Symposium on Wireless Personal Multimedia Communications (WPMC 2023) 1 - 6 2023年11月

Channel Pattern Selection for RIS Based Spatial Modulation System Using Genetic Algorithm 査読

Issei Maesaki, Haruya Mushiake, Yafei Hou, Satoshi Denno

2023 IEEE 12th Global Conference on Consumer Electronics (IEEE GCCE 2023) 1 - 2 2023年10月

Iterative User Scheduling Method for MU-MIMO-OFDM Systems 査読

Akihiko Yamada, Satoshi Denno, Yafei Hou

2023 IEEE 12th Global Conference on Consumer Electronics (IEEE GCCE 2023) 1 - 2 2023年10月

A Lattice Reduction Aided Overloaded Multi-user MIMO 査読

Kazuki Miyata, Satoshi Denno, Yafei Hou

2023 IEEE 98th Vehicular Technology Conference (IEEE VTC-Fall 2023) 1 - 5 2023年10月

Spatial Modulation Proposal for 2-by-2 MIMO System Using Single Leaky Coaxial Cable 査読

Yafei Hou, Soichiro Dake, Yusuke Kawai, Satoshi Denno

2023 IEEE 98th Vehicular Technology Conference (IEEE VTC-Fall 2023) 1 - 5 2023年10月

Characteristics of Frequency Domain Non-Orthogonal Multiple Wireless Access for IoT 査読

Yuto Ohba, Satoshi Denno, Yafei Hou

2023 IEEE 12th Global Conference on Consumer Electronics (IEEE GCCE 2023) 1 - 2 2023年10月

Low Complexity Resource Allocation in Frequency Domain Non-Orthogonal Multiple Access.

Satoshi Denno, Taichi Yamagami, Yafei Hou

IEICE Transactions on Communications 106 ( 10 ) 1004 - 1014 2023年10月

Study on channel prediction in IRS-assisted wireless communication systems

Norisato Suga, Kazuto Yano, Yafei Hou, Toshikazu Sakano

IEICE Communications Express 12 ( 7 ) 374 - 378 2023年7月

Indoor 3-D Localization over LCX-based Wireless Environment Using Particle Filter Approach 査読

Junjie Zhu, Kenda Nagayama, Erika Kouda, Yafei Hou, Satoshi Denno

IEEE Wireless Communications and Networking Conference (WCNC 2023) 1 - 6 2023年3月

Reduced Complexity Resource Allocation For Frequency Domain Non-orthogonal Multiple Access 査読

Satoshi Denno, Taichi Yamagami, Yafei Hou

IEEE Wireless Communications and Networking Conference (WCNC 2023) 1 - 6 2023年3月

MUSIC Spectrum Based Interference Detection and Localization for mmWave RIS-MIMO System 査読

1 - 6 2023年2月

Superposition Signal Input Decoding For Lattice Reduction-aided MIMO Receivers 査読

Satoshi DENNO, Koki KASHIHARA, Yafei HOU

IEICE Transactions on Communications E106-B ( 2 ) 184 - 192 2023年2月

Multi-input Physical Layer Network Coding in Two-Dimensional Wireless Multihop Networks 査読

Hideaki TSUGITA, Satoshi DENNO, Yafei HOU

IEICE Transactions on Communications E106-B ( 2 ) 193 - 202 2023年2月

Simultaneous Localization for Wireless Environments using Leaky Coaxial Cables.

Yafei Hou, Erika Kouda, Yusuke Kawai, Satoshi Denno

ICCE-Taiwan 733 - 734 2023年

Genetic Algorithm Based Channel Pattern Selection for Spatial Modulation Using Slots of Leaky Coaxial Cable 査読

Kenda Nagayama, Erika Kouda, Junjie Zhu, Yafei Hou, Satoshi Denno

25th International Symposium on Wireless Personal Multimedia Communications (WPMC 2022), Hybrid (Herning, Denmark & Virtual), Oct. 30- Nov. 2, 2022 1 - 5 2022年10月

Adaptive Collaborative Relaying in High Mobility Environment 査読

Satoshi Denno, Takumi Fujii, Yafei Hou

25th International Symposium on Wireless Personal Multimedia Communications (WPMC 2022), Hybrid (Herning, Denmark & Virtual), Oct. 30- Nov. 2, 2022 1 - 5 2022年10月

Adaptive Resource Allocation Based on Factor Graphs in Non-Orthogonal Multiple Access 査読

Taichi YAMAGAMI, Satoshi DENNO, Yafei HOU

IEICE Transactions on Communications E105-B ( 10 ) 1 - 10 2022年10月

A Low Complexity Non-linear Iterative Receiver for Overloaded MIMO-OFDM Systems 査読

Shuhei Makabe, Satoshi Denno, Yafei Hou

2022 27th Asia Pacific Conference on Communications (APCC 2022), (Jeju Island & Virtual), Oct. 19-21, 2022 1 - 6 2022年10月

Asynchronous Periodic Interference Signals Cancellation in Frequency Domain 査読

Satoshi DENNO, Yafei HOU

IEICE Transactions on Communications E105.B ( 9 ) 1087 - 1096 2022年9月

Low Complexity Soft Decoding With Superposition of Hard Decision Vectors in Lattice Reduction-Aided Linear Receivers 査読

Satoshi Denno, Koki Kashihamra, Yafei Hou

IEEE 33rd Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC 2022), (Virtual), Sept. 12-15, 2022 55 - 59 2022年9月

Particle Filter-Based Indoor Localization and Tracking Method Using Leaky Coaxial Cables 査読

Junjie Zhu, Kenda Nagayama, Erika Kouda, Yafei Hou, Satoshi Denno

IEEE 33rd Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC 2022), (Virtual), Sept. 12-15 595 - 600 2022年8月

Periodic Interference Cancellation With Drift Estimation Based on Super-Resolution Techniques in Frequency Domain 査読

Satoshi Denno, Yafei Hou

2022 IEEE 95th Vehicular Technology Conference: (VTC2022-Spring) 1 - 6 2022年6月

Maximum Doppler Frequency Detection Based on Likelihood Estimation With Theoretical Thresholds 査読

Satoshi DENNO, Kazuma HOTTA, Yafei HOU

IEICE Transactions on Communications E105.B ( 5 ) 657 - 664 2022年5月

Tunable broadband terahertz metamaterial absorber based on vanadium dioxide 査読

Guishuang Yang, Fengping Yan, Xuemei Du, Ting Li, Wei Wang, Yuling Lv, Hong Zhou, Yafei Hou

AIP Advances 12 ( 4 ) 045219 - 045219 2022年4月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AIP Publishing

The special electromagnetic properties of metamaterials have contributed to the development of terahertz technology, and terahertz broadband absorbers for various applications have been investigated. The design of metamaterial absorbers with tunability is in a particularly attractive position. In this work, a tunable broadband terahertz metamaterial absorber is proposed based on the phase transition material vanadium dioxide (VO₂). The simulation results show that an excellent absorption bandwidth reaches 3.78 THz with the absorptivity over 90% under normal incidence. The absorptivity of the proposed structure can be dynamically tuned from 2.7% to 98.9% by changing the conductivity of VO₂, which changes the structure from a perfect reflector to an absorber. An excellent amplitude modulation with the absorptivity is realized. The mechanism of broadband absorption is explored by analyzing the electric field distribution of the absorber based on impedance matching theory. In addition, it also has the advantage of polarization and incident angle insensitivity. The proposed absorber may have a wide range of promising applications in areas such as terahertz imaging, sensing, and detection.

DOI： 10.1063/5.0082295

Indoor Simultaneous TOA Estimation of Multiple Users Using Leaky Coaxial Cable 査読

Junjie Zhu, Erika Kouda, Pengcheng Hou, Kenta Nagayama, Yafei Hou, Satoshi Denno

2022 IEEE 4th Global Conference on Life Sciences and Technologies (LifeTech) 297 - 298 2022年3月

Two-dimensional RSSI-Based Indoor Localization Using Multiple Leaky Coaxial Cables with a Probabilistic Neural Network 査読

Junjie Zhu, Pengcheng Hou, Kenta Nagayama, Yafei Hou, Satoshi Denno, Rian Ferdian

IEEE Access 10 21109 - 21119 2022年3月

Prediction Evaluation for RSSI Data Generated from Leaky Coaxial Cables over Indoor Environment 査読

Pengcheng Hou, Junjie Zhu, Kenta Nagayama, Yafei Hou, Satoshi Denno

2022 IEEE International Conference on Consumer Electronics (ICCE) 1 - 5 2022年1月

Thermally-stable graphene metamaterial absorber with excellent tunability for high-performance refractive index sensing in the terahertz band 査読

Xuemei Du, Fengping Yan, Wei Wang, Luna Zhang, Zhuoya Bai, Hong Zhou, Yafei Hou

Optics and Laser Technology 144 107409 - 107409 2021年12月

RSSI-Based Indoor Localization Using Leaky Coaxial Cable with a PNN Approach 査読

Junjie Zhu, Pengcheng Hou, Kenta Nagayama, Yafei Hou, Satoshi Denno

2021 IEEE 10th Global Conference on Consumer Electronics (GCCE) 220 - 221 2021年10月

Eigenvalue Based Relay Selection for XOR-Physical Layer Network Coding in Bi-Directional Wireless Relaying Networks 査読

Satoshi DENNO, Kazuma YAMAMOTO, Yafei HOU

IEICE Transactions on Communications E104.B ( 10 ) 1336 - 1344 2021年10月

A Broadband Switchable Metamaterial Absorber/Reflector Based On Multi-Laps Graphene Sheets in the Terahertz Band 査読

Xuemei Du, Fengping Yan, Wei Wang, Luna Zhang, Zhuoya Bai, Hong Zhou, Yafei Hou

IEEE Photonics Journal 13 ( 5 ) 1 - 8 2021年10月

Out-of-Bound Signal Demapping for Lattice Reduction-Aided Iterative Linear Receivers in Overloaded MIMO Systems 査読

Takuya FUJIWARA, Satoshi DENNO, Yafei HOU

IEICE Transactions on Communications E104.B ( 8 ) 974 - 982 2021年8月

WLAN Interference Identification Using a Convolutional Neural Network for Factory Environments 査読

Julian Webber, Kazuto Yano, Norisato Suga, Yafei Hou, Eiji Nii, Toshihide Higashimori, Abolfazl Mehbodniya, Yoshinori Suzuki

Journal of Communications 16 ( 7 ) 276 - 283 2021年7月

Modeling and Predictability Analysis on Channel Spectrum Status over Heavy Wireless LAN Traffic Environment 査読

Yafei Hou, Julian Webber, Kazuto Yano, Shun Kawasaki, Satoshi Denno, Yoshinori Suzuki

IEEE Access 9 85795 - 85812 2021年6月

Indoor Localization Using Leaky Coaxial Cable over a Multipath-rich Linear Cell Environment

Junjie Zhu, Kenta Nagayama, Yafei Hou, Satoshi Denno

2021 IEEE 3rd Global Conference on Life Sciences and Technologies (LifeTech) 280 - 281 2021年3月

Partial Perturbation to Alleviate the Performance Degradation of Vector Perturbation With Inaccurate Power Scaling Factors 査読

Yafei Hou, Satoshi Denno

IEEE Transactions on Broadcasting 67 ( 1 ) 324 - 336 2021年3月

Low-Complexity Implementation of Channel Estimation for ESPAR-OFDM Receiver 査読

Yafei Hou, Rian Ferdian, Satoshi Denno, Minoru Okada

IEEE Transactions on Broadcasting 67 ( 1 ) 238 - 252 2021年3月

Busy/Idle Duration Prediction for Video and Audio WLAN Traffics Using Autoregressive Predictor with Data Categorization

Yafei Hou, Shun Kawasaki, Satoshi Denno

2021 23rd International Conference on Advanced Communication Technology (ICACT) 259 - 264 2021年2月

A Study of Throughput Prediction using Convolutional Neural Network over Factory Environment

Yafei Hou, Kazuto Yano, Norisato Suga, Julian Webber, Eiji Nii, Toshihide Higashimori, Satoshi Denno, Yoshinori Suzuki

2021 23rd International Conference on Advanced Communication Technology (ICACT) 2021-February 429 - 434 2021年2月

Frequency domain iterative cancellation of periodic noise

Yuya Furutani, Satoshi Denno, Yafei Hou

2020 International Symposium on Antennas and Propagation, ISAP 2020 289 - 290 2021年1月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Institute of Electrical and Electronics Engineers Inc.

This paper proposes frequency domain iterative cancellation for suppressing a periodic noise. The proposed cancellation alleviates a periodic noise in the desired frequency band by using an interference canceller with a replica of the noise. The proposed iterative canceller achieves superior replica estimation even when the signals in all the frequency bands are collapsed by the periodic noise. The performance of the proposed iterative cancellation is evaluated in terms of the signal power to noise power ratio(SNR) by computer simulations. The proposed cancellation obtains a gain of 25 dB even when the carrier power to noise power ratio(CNR) is about 0 dB by iterating the cancellation 2 times, while the no-iterative cancellation achieves only a gain of 4 dB.

DOI： 10.23919/ISAP47053.2021.9391128

Capacity Loss From Localization Error in MIMO Channel Using Leaky Coaxial Cable 査読

Junjie Zhu, Yafei Hou, Kenta Nagayama, Satoshi Denno

IEEE Access 9 15929 - 15938 2021年1月

Matrix Factorization-Based RSS Interpolation for Radio Environment Prediction 査読

Norisato Suga, Kazuto Yano, Julian Webber, Yafei Hou, Eiji Nii, Toshihide Higashimori, Yoshinori Suzuki

IEEE Wireless Communications Letters 1 - 5 2021年

Cyclic Path Switching for Lattice Reduction-aided Iterative Linear Receivers in Overloaded MIMO Systems 査読

Satoshi Denno, Takuya Fujiwara, Yafei Hou

IEICE Communications Express 10 ( 10 ) 810 - 815 2021年

Non-Orthogonal Packet Access Based on Low Density Signature With Phase Only Adaptive Precoding.

Satoshi Denno, Ryoko Sasaki, Yafei Hou

IEICE Trans. Commun. 104-B ( 3 ) 328 - 337 2021年

Precoded Physical Layer Network Coding with Coded Modulation in MIMO-OFDM Bi-Directional Wireless Relay Systems.

Satoshi Denno, Kazuma Yamamoto, Yafei Hou

IEICE Trans. Commun. 104-B ( 1 ) 99 - 108 2021年

Adaptive Resource Allocation Based on Factor Graphs in Non-Orthogonal Multiple Access

Taichi Yamagami, Satoshi Denno, Yafei Hou

24TH INTERNATIONAL SYMPOSIUM ON WIRELESS PERSONAL MULTIMEDIA COMMUNICATIONS (WPMC 2021): PAVING THE WAY FOR DIGITAL AND WIRELESS TRANSFORMATION 2021年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, we propose a non-orthogonal multiple access with adaptive resource allocation based on factor graphs. The proposed non-orthogonal multiple access assigns multiple frequency resources for each device to send their packet. Even if the number of the devices is more than the frequency resources, the proposed non-orthogonal access allows all the devices to transmit their packets simultaneously for high capacity massive machine type communication (mMTC). Furthermore, this paper proposes adaptive resource allocation based on factor graphs that adaptively allocates the frequency resources to the devices for improvement of the transmission performances. This paper proposes two allocation criteria for the proposed adaptive allocation. This paper shows that the proposed non-orthogonal multiple access achieves superior transmission performance in 4-path Rayleigh fading channel with overloading ratio of 1.5, even without the adaptive resource allocation. The adaptive resource allocation enables the proposed non-orthogonal access to attain a gain of about 5 dB at the BER of 10(-4).

DOI： 10.1109/WPMC52694.2021.9700454

A Study of Throughput Prediction using Convolutional Neural Network over Factory Environment.

Yafei Hou, Kazuto Yano, Norisato Suga, Julian L. Webber, Eiji Nii, Toshihide Higashimori, Satoshi Denno, Yoshinori Suzuki

23rd International Conference on Advanced Communication Technology(ICACT) 429 - 434 2021年

Busy/Idle Duration Prediction for Video and Audio WLAN Traffics Using Autoregressive Predictor with Data Categorization.

Yafei Hou, Shun Kawasaki, Satoshi Denno

23rd International Conference on Advanced Communication Technology(ICACT) 259 - 264 2021年

User Mobility Estimation Through Maximum Doppler Frequency Detection.

Satoshi Denno, Kazuma Hotta, Yafei Hou

15th International Conference on Signal Processing and Communication Systems(ICSPCS) 1 - 5 2021年

Channel Status Prediction using Auto-regressive and Auto-regressive Integrated Predictors over WLAN Channel 査読

Yafei Hou, Naoya Hokimoto, Satoshi Denno

International Journal of Computer & Software Engineering 5 ( 2 ) 1 - 9 2020年12月

A polarization- and angle-insensitive broadband tunable metamaterial absorber using patterned graphene resonators in the terahertz band 査読

Xuemei Du, Fengping Yan, Wei Wang, Siyu Tan, Luna Zhang, Zhuoya Bai, Hong Zhou, Yafei Hou

Optics and Laser Technology 132 2020年12月

An SMLB-based OFDM receiver over impulsive noise environment 査読

Chengbo Liu, Na Chen, Minoru Okada, Yafei Hou

APSIPA Transactions on Signal and Information Processing 9 1 - 8 2020年11月

Low Complexity Soft Input Decoding in an Iterative Linear Receiver for Overloaded MIMO 査読

Satoshi Denno, Tsubasa Inoue, Yuta Kawaguchi, Takuya Fujiwara, Yafei Hou

IEICE Transactions on Communications E103B ( 5 ) 600 - 608 2020年5月

Enhancing sensing capacity of terahertz metamaterial absorbers with a surface-relief design 査読

Wei Wang, Fengping Yan, Siyu Tan, Haisu Li, Xuemei Du, Luna Zhang, Zhuoya Bai, Dan Cheng, Hong Zhou, Yafei Hou

PHOTONICS RESEARCH 8 ( 4 ) 519 - 527 2020年4月

Estimation of Probability Density Function Using Multi-bandwidth Kernel Density Estimation for Throughput. 査読

Norisato Suga, Kazuto Yano, Julian Webber, Yafei Hou, Toshihide Higashimori, Yoshinori Suzuki

2020 International Conference on Artificial Intelligence in Information and Communication (ICAIIC) 171 - 176 2020年

Busy/Idle Duration Models of Video and Audio WLAN Traffics and Their Prediction Performance. 査読

Yafei Hou, Shun Kawasaki, Satoshi Denno

2020 IEEE 2nd Global Conference on Life Sciences and Technologies (LifeTech) 202 - 203 2020年

Low Complexity Soft Decoding For Physical Layer Network Coding With Coded Modulation.

Satoshi Denno, Tomoya Tanikawa, Hideaki Tsugita, Yafei Hou

14th International Conference on Signal Processing and Communication Systems(ICSPCS) 1 - 5 2020年

Two Dimensional Indoor Localization with Multiple Leaky Coaxial Cables.

Junjie Zhu, Pengcheng Hou, Yafei Hou, Satoshi Denno, Minoru Okada

9th IEEE Global Conference on Consumer Electronics(GCCE) 626 - 627 2020年

Bit Stream Decorrelation in An Iterative Overloaded MIMO Receiver for Higher-Order QAMs.

Takuya Fujiwara, Satoshi Denno, Yafei Hou

23rd International Symposium on Wireless Personal Multimedia Communications(WPMC) 1 - 5 2020年

Graphene-embedded broadband tunable metamaterial absorber in terahertz band

Xue-mei Du, Feng-ping Yan, Wei Wang, Si-yu Tan, Lu-na Zhang, Zhuo-ya Bai, Hong Zhou, Ya-fei Hou

Journal of Optics (United Kingdom) 22 ( 1 ) 2020年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP Publishing Ltd

Numerous studies have been conducted to design terahertz broadband metamaterial absorbers for various applications, such as electromagnetic stealth, photodetection, and broadband communications. It remains a hot research topic to design metamaterial absorbers (MAs) to achieve broadband absorption while maintaining a wide range of tunability. Here, we present a novel design of graphene-embedded metamaterial functioning as a broadband tunable absorber based on the field reinforcement effect and plasmon resonance of graphene. With a stacked configuration, the absorptivity of the MA proposed in this paper can be as high as 90% in a wide range of 1.2 THz. By comparative analysis, we exhibit that the MA shows a relatively wider absorption bandwidth than the one without the embedded graphene, which discloses the significance of integrating graphene layer in our design. The detailed numerical calculations of the surface currents and electric field distributions are presented in this paper to better uncover the physical mechanisms of the broadband and multi-band absorption. Moreover, further numerical calculations show that the designed MA also demonstrates several other excellent properties, such as tunability, polarization insensitivity, incident angle insensitivity and outstanding structural parameters tolerance. The proposed graphene-embedded MA can be used in various promising applications, like smart sensors, broadband absorber and imaging devices.

DOI： 10.1088/2040-8986/ab56c0

Symmetry Breaking and Resonances Hybridization in Vertical Split Ring Resonator Metamaterials and the Excellent Sensing Potential 査読

Wei Wang, Fengping Yan, Siyu Tan, Haisu Li, Xuemei Du, Luna Zhang, Zhuoya Bai, Dan Cheng, Hong Zhou, Yafei Hou

IEEE/OSA Journal of Lightwave Technology 37 ( 19 ) 5149 - 5157 2019年10月

A Study of Capacity Loss from Localization Error in MIMO Channel Using Leaky Coaxial Cable. 査読

Junjie Zhu, Yafei Hou, Satoshi Denno, Minoru Okada

2019 IEEE 8th Global Conference on Consumer Electronics (GCCE) 1002 - 1003 2019年10月

XOR Physical Layer Network Coding with Non-Linear Precoding for Quadrature Amplitude Modulations in Bi-Directional MIMO Relay Systems 査読

Satoshi Denno, Yuto Nagai, Yafei Hou

IEICE TRANSACTIONS ON COMMUNICATIONS E102B ( 10 ) 2073 - 2081 2019年10月

Numerical Analysis of Magnetic Plasmonic Resonance Modes in Three-Dimension Split Ring Resonator Metamaterials 査読

Wei Wang, Feng-Ping Yan, Si-Yu Tan, Hai-Su Li, Xue-Mei Du, Hong Zhou, Yafei Hou

IEEE Photonics Journal 11 ( 4 ) 1 - 10 2019年8月

A Novel Low Complexity Lattice Reduction-Aided Iterative Receiver for Overloaded MIMO 査読

Satoshi Denno, Yuta Kawaguchi, Tsubasa Inoue, Yafei Hou

IEICE TRANSACTIONS ON COMMUNICATIONS E102B ( 5 ) 1045 - 1054 2019年5月

Near Optimum User Selection for Minimum Mean Square Error Based Tomlinson Harashima Precoding

Satoshi Denno, Tomoyuki Baba, Kenta Asaka, Yafei Hou

International Journal of Computer & Software Engineering 4 ( 1 ) 2019年1月

Prediction of QoS Outage Probability for Wireless Communication in Factory Environments. 査読

Norisato Suga, Kazuto Yano, Julian Webber, Yafei Hou, Toshihide Higashimori, Yoshinori Suzuki

2019 International Conference on Internet of Things, Embedded Systems and Communications (IINTEC) 124 - 129 2019年

Iterative Soft Input Decoding with Assistance of Lattice Reduction for Overloaded MIMO. 査読

Satoshi Denno, Tsubasa Inoue, Takuya Fujiwara, Yafei Hou

2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall) 1 - 5 2019年

Low Density Signature based Packet Access with Phase Only Adaptive Precoding 査読

Satoshi Denno, Ryoko Sasaki, Yafei Hou

2019 IEEE 89TH VEHICULAR TECHNOLOGY CONFERENCE (VTC2019-SPRING) 1 - 5 2019年

Coded Quadrature Amplitude Modulations For XOR Physical Layer Network Coding With Precoding. 査読

Satoshi Denno, Kazuma Yamamoto, Yafei Hou

2019 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC) 1 - 6 2019年

Optical Radio Channel Propagation in Wireless Communication Systems with LEDs 査読

Satoshi Denno, Shunsuke Fujitaka, Yafei Hou, Shigeru Tomisato, Kazuhiro Uehara

2019 12TH GLOBAL SYMPOSIUM ON MILLIMETER WAVES (GSMM 2019) 50 - 52 2019年

Machine Learning-based RSSI Prediction in Factory Environments. 査読

Julian Webber, Norisato Suga, Susumu Ano, Yafei Hou, Abolfazl Mehbodniya, Toshihide Higashimori, Kazuto Yano, Yoshinori Suzuki

2019 25th Asia-Pacific Conference on Communications (APCC) 195 - 200 2019年

Time-Domain Signal Recovery for OFDM System in the Industrial Environment 査読

Chengbo Liu, Na Chen, Yafei Hou, Minoru Okada

2019 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA ASC) 1847 - 1851 2019年

Relay Selection for Bi-directional Relay Systems with XOR-Phisical Layer Network Coding 査読

Kazuma Yamamoto, Satoshi Denno, Yafei Hou

2019 IEEE VTS ASIA PACIFIC WIRELESS COMMUNICATIONS SYMPOSIUM (APWCS 2019) 1 - 5 2019年

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

XOR-physical layer network coding is known to achieve superior performance in terms of an end-to-end throughput and frequency utilization efficiency. This paper proposes a novel relay selection technique to further improve transmission performance. We introduce a relay selection criteria that is defined as an end-to-end BER performance in the relay network. The proposed technique select a group of relays that maximizes the criteria. This paper applies lattice reduction-aided precoding in order to improve the transmission performance and to reduce computational complexity of the relay selection. The performance of the proposed relay selection is evaluated in a 2x2 MIMO bidirectional wireless relay system. The proposed selection attains a gain of about 13dB at the BER of 10(-4).

DOI： 10.1109/VTS-APWCS.2019.8851618

その他リンク： https://dblp.uni-trier.de/db/conf/apwcs2/apwcs2019.html#YamamotoDH19

Single weakly tilted FBG in 2-μm band capable of measuring temperature, axial strain, and surrounding refractive index

Dan Cheng, Fengping Yan, Ting Feng, Zhuoya Bai, Luna Zhang, Wei Wang, Shuo Liu, Hong Zhou, Yafei Hou

Optical Engineering 57 ( 9 ) 2018年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPIE

Optical fiber devices and applications in the 2-μm band have been investigated extensively due to its unique advantages, such as eye safety. A fiber sensor based on tilted fiber Bragg grating with a grating plane angle of 2 deg is fabricated and experimentally tested. To the best of the authors' knowledge, this is the first tilted fiber Bragg grating sensor to realize simultaneous measurements of temperature, axial strain, and a certain range of surrounding refractive index (SRI) at the 2-μm band. This paper uses the wavelength detection method and selects three independent resonant wavelengths as the investigated parameters. Results show that perturbations of temperature, axial strain, and SRI can shift the wavelengths of the core mode resonance and cladding mode resonance to some degree. The temperature sensitivities of the core mode and cladding mode are nearly the same, but their axial-strain sensitivities are different. Furthermore, the core mode is insensitive to the change in SRI. The sensitivities of SRI, temperature, and strain can thus be obtained by experimentally determining the wavelength shifts of the three independent resonance peaks. A 3 × 3 matrix containing the relationship coefficients between the disturbances of temperature, axial strain, and SRI and wavelength shifts is constructed. By reversely solving the matrix equation, variations in temperature, strain, and SRI can be obtained using the experimental determination of wavelength drifts.

DOI： 10.1117/1.OE.57.9.096107

Ultrasensitive sensing with three-dimensional terahertz metamaterial absorber 査読

Siyu Tan, Fengping Yan, Wei Wang, Hong Zhou, Yafei Hou

JOURNAL OF OPTICS 20 ( 5 ) 2018年5月

Safeguarding 5G Networks through Physical Layer Security Technologies 査読

Li Sun, Kamel Tourki, Yafei Hou, Lu Wei

WIRELESS COMMUNICATIONS & MOBILE COMPUTING 2018 7503735 - 2 2018年

Partial Layered Division Multiplexing with STBC for ISDB-T and Next Generation DTTB Systems 査読

Ryan Paderna, Yafei Hou, Duong Quang Thang, Takeshi Higashino, Minoru Okada

ITE TRANSACTIONS ON MEDIA TECHNOLOGY AND APPLICATIONS 6 ( 1 ) 98 - 109 2018年

Low-complexity Power Allocation with Positional Information for 4-by-4 MIMO Channel using One Composite Leaky Coaxial Cable 査読

Junjie Zhu, Yafei Hou, Satoshi Denno, Minoru Okada

2018 IEEE 7TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE 2018) 841 - 842 2018年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Leaky coaxial (LCX) cable can be used as antenna for wireless communication system and wireless power transfer which can be widely applied for many application scenarios including wireless service for IoT, automated factory using a large number of wireless devices. We have designed that one LCX cable can be used as two antennas which can releases the space requirement of MIMO deployment for wireless application. In this paper, we will further evaluate the 4-by-4 LCX-MIMO channel using one composite cable with two LCX cables. In addition, we also propose a low-complexity power allocation method for the LCX-MIMO system with the user's positional information (PI). The results show that the capacity is promising when the spacing between LCX cables is small as to 2cm. In addition, our proposed low-complexity power allocation has better capacity than that of using equal power allocation when SNR value is over the low range.

DOI： 10.1109/GCCE.2018.8574729

その他リンク： https://dblp.uni-trier.de/db/conf/gcce/gcce2018.html#ZhuHDO18

Performance Analysis of Low complexity Lattice Reduction-aided Iterative Receiver for Overloaded MIMO 査読

Satoshi Denno, Yuta Kawaguchi, Tsubasa Inoue, Hou Yafei

2018 12TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS) 1 - 5 2018年

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a novel low complexity lattice reduction-aided iterative receiver for overloaded MIMO. Novel noise cancellation is proposed that increases an equivalent channel gain with a scalar gain introduced in this paper, which results in the improvement of the signal to noise power ratio (SNR). The performance of the proposed receiver is theoretically analyzed that the lattice reduction guarantees the SNR of the detector to be more than a value proportional to the scalar gain, when the LenstraLenstraLovas (LLL) algorithm is applied to implement the lattice reduction. The proposed receiver attains a gain of about 5dB at the BER of 10(-4) in a 6 x 2 overloaded MIMO channel.

DOI： 10.1109/ICSPCS.2018.8631747

その他リンク： https://dblp.uni-trier.de/db/conf/icspcs/icspcs2018.html#DennoKIH18

Adaptive Sideband Selection for Periodic Interference Cancellation 査読

Yuya Kimura, Satoshi Denno, Yafei Hou

2018 ASIA-PACIFIC MICROWAVE CONFERENCE PROCEEDINGS (APMC) 156 - 158 2018年

担当区分：最終著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes adaptive sideband selection for periodic interference cancellation using digital signal processing. The proposed selection enables the periodic interference cancellation to attain better performance by providing sideband signals having higher ICNR(interference to carrier and noise power ratio). An algorithm that selects such sideband signals is shown in this paper. The proposed selection achieves 18dB better SINR(output signal to interference and noise power ratio) performance than random selection in the channel with CIR(carrier to interference power ratio) of 10dB and CNR(carrier to noise power ratio) of 30dB.

Busy/Idle Duration Model for WLAN Traffic and Its Prediction Performance using Autoregressive Method 査読

Yafei Hou, Yusuke Tanaka, Julian Webber, Kazuto Yano, Satoshi Denno, Tomoaki Kumagai

2018 ASIA-PACIFIC MICROWAVE CONFERENCE PROCEEDINGS (APMC) 893 - 895 2018年

Ultrasensitive terahertz metamaterial sensor based on vertical split ring resonators 査読

Wei Wang, Fengping Yan, Siyu Tan, Hong Zhou, Yafei Hou

PHOTONICS RESEARCH 5 ( 6 ) 571 - 577 2017年12月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：OPTICAL SOC AMER

An ultrasensitive metamaterial sensor based on double- slot vertical split ring resonators (DVSRRs) is designed and numerically calculated in the terahertz frequency. This DVSRR design produces a fundament LC resonance with a quality factor of about 20 when the incidence magnetic field component normal to the DVSRR array. The resonant characteristics and sensing performance of the DVSRR array design are systematically analyzed employing a contrast method among three similar vertical split ring resonator (SRRs) structures. The research results show that the elimination of bianisotropy, induced by the structural symmetry of the DVSRR design, helps to achieve LC resonance of a high quality factor. Lifting the SRRs up from the substrate sharply reduces the dielectric loss introduced by the substrate. All these factors jointly result in superior sensitivity of the DVSRR to the attributes of analytes. The maximum refractive index sensitivity is 788 GHz/RIU or 1.04 x 10(5) nm/RIU. Also, the DVSRR sensor maintains its superior sensing performance for fabrication tolerance ranging from -4% to 4% and wide range incidence angles up to 50 degrees under both TE and TM illuminations. (C) 2017 Chinese Laser Press

DOI： 10.1364/PRJ.5.000571

Simultaneous measurement of refractive index and conductivity based on metamaterial absorber

Wei Wang, Feng-Ping Yan, Si-Yu Tan, Lu-Na Zhang, Zhuo-Ya Bai, Dan Cheng, Hong Zhou, Ya-Fei Hou

Journal of Optics (United Kingdom) 19 ( 11 ) 2017年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP Publishing Ltd

An algorithm for the metamaterial sensors to simultaneously measure the refractive index (RI) and conductivity of the analyte is introduced. To verify the algorithm, a square ring metamaterial absorber is numerically calculated as a specific example in the terahertz frequency. Firstly, the sensing performances of the absorber on the RI and conductivity are evaluated separately. Then the relationship expressions between dual variables (frequency shift (FS) and amplitude modulation (AM)) and two arguments (RI and conductivity) can be obtained through mathematical fitting process. By reversely solving this equations set, the conductivity and RI of the analyte can be expressed as another equations set that can be solved easily. The proposed algorithm offers an effective method to determine RI and conductivity of the analyte by measuring the AM and FS of the reflection dip of the absorber sensor. To validate the effectiveness and accuracy of the algorithm, the FS and AM obtained from the simulations are plugged into the reverse equations set. Then the calculated n and σ are compared to their responding original values. The maximum percentage error between them are both less than 0.83%, which are small enough to illustrate the rightness of the proposed method.

DOI： 10.1088/2040-8986/aa8fc1

Research on transmission characteristics of phase-shifted CFBG in 2 mu m band 査読

Luna Zhang, Fengping Yan, Zhuoya Bai, Yan Bai, Shuo Liu, Hong Zhou, Yafei Hou, Ning Zhang

OPTICAL FIBER TECHNOLOGY 36 428 - 437 2017年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE INC

Principles of single-and multi-phase-shifted chirped fiber Bragg grating (CFBG) in 2 mu m band are analyzed with transmission matrix method, and transmission characteristics, including transmissivity, wavelength and bandwidth performance, of single-and multi-phase-shifted CFBG in 2 mu m band with different grating parameters are discussed by simulation. It is found that phase-shifted position, grating length, chirped coefficient and refractive index modulation amplitude all have impacts on bandwidth of phase-shifted transmission peak. The transmission peak bandwidths of single-, dual-and tri-phase-shifted CFBG can reach to 0.0270, 0.0172 and 0.0112 nm respectively. The experiment of phase-shifted CFBG verifies the correctness of the simulation, and the bandwidths of 0.0901 and 0.0480 nm are acquired for single-and dual-phase-shifted CFBG respectively, which are narrower than previous filters based on fiber Bragg grating in 2 mu m band multi-wavelength fiber laser system. (C) 2017 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.yofte.2017.06.001

2-mu m numerical analysis of linear-cavity FP structures based on fiber Bragg gratings 査読

Zhuoya Bai, Fengping Yan, Luna Zhang, Yan Bai, Shuo Liu, Hong Zhou, Yafei Hou, Ning Zhang

OPTICAL ENGINEERING 56 ( 5 ) 2017年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS

The linewidth performance of all-fiber, linear-cavity Fabry-Perot structures based on fiber Bragg gratings operating at 2-mu m band has been investigated numerically. The output linewidth performance of two symmetrical and asymmetrical cavities has been theoretically studied and comprehensively compared. The numerical analysis is based on the transmission matrix method with the simplified parameters. The simulation results show that cavity lengths, cavity lengths ratio, grating lengths, grating lengths ratio, as well as index modulation depths, affect the output linewidth performance. The tolerance ability of the asymmetrical structure is first proposed and investigated under 1 mm accuracy, and single-frequency output can be realized by properly adjusting the properties of the proposed composite linear cavity structure. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

DOI： 10.1117/1.OE.56.5.056107

Single-polarization noise-like pulse generation from a hybrid mode-locked thulium-doped fiber laser 査読

Shuo Liu, Feng-Ping Yan, Ting Feng, Lu-Na Zhang, Zhuo-Ya Bai, Hong Zhou, Yafei Hou, Ning Zhang

JOURNAL OF OPTICS 19 ( 4 ) 2017年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IOP PUBLISHING LTD

A hybrid mode-locked thulium-doped fiber laser incorporating a nonlinear optical loop mirror and a nonlinear polarization rotation effect is proposed in the 2 mu m band for the first time. By adjusting two polarization controllers, a stable single-polarization noise-like (SPNL) pulse operation is obtained. The SPNL pulse could work steadily for at least 400 min. At a launched pump power of 3.52 W, the hybrid mode-locked SPNL pulse centers at 2007 nm with an optical full width at half maximum of 20 nm, a polarization extinction ratio of 26.3 dB, a coherence spike width of 258 fs and a pulse energy of 42.11 nJ, respectively.

DOI： 10.1088/2040-8986/aa6267

Switchable SP Dual-Wavelength Mode-Locked TDFL Incorporating a PM-FBG and SESAM 査読

Shuo Liu, Fengping Yan, Luna Zhang, Zhuoya Bai, Hong Zhou, Yafei Hou, Ning Zhang

IEEE PHOTONICS TECHNOLOGY LETTERS 29 ( 6 ) 551 - 554 2017年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

A switchable single-polarization (SP) dualwavelength mode-locked thulium-doped fiber laser using the polarization maintaining fiber Bragg grating and semiconductor saturable absorber mirror is proposed in 2-mu m band. By adjusting the polarization controller, stable dual-wavelength pulse lasing operation and SP single-wavelength pulse lasing operation are obtained. The dual-wavelength pulse lasing operation is obtained at 1940.97 and 1941.73 nm. In the SP single-wavelength pulse lasing state, the polarization extinction ratios are higher than 30 dB, the SP pulse duration are 3.75 and 3.73 ps.

DOI： 10.1109/LPT.2017.2669210

Low-Complexity Compressed Sensing-Based Channel Estimation With Virtual Oversampling for Digital Terrestrial Television Broadcasting 査読

Ryan Paderna, Duong Quang Thang, Yafei Hou, Takeshi Higashino, Minoru Okada

IEEE Transactions on Broadcasting 63 ( 1 ) 82 - 91 2017年3月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

This paper proposes a low-complexity compressed sensing (CS)-based time domain channel estimation with virtual oversampling for OFDM-based DTTB system. CS technique is first applied to sparse channel estimation in integrated services digital broadcasting-terrestrial (ISDB-T) system. Unfortunately, the CS-based time-domain channel estimation suffers from a performance degradation under the existence of fractional delay. Fractional delay is a common issue in time domain-based channel estimation due to sampling imperfection of channel delay time. Therefore, we propose virtual oversampling to deal with the fractional delay without increasing the signal bandwidth. Furthermore, exploiting the fact that the rate of change of path delay is slower than the path gain, a modified orthogonal matching pursuit is also proposed to reduce computational complexity. Numerical analyses of bit error rate and computational complexity are given to verify effectiveness of the proposed scheme.

添付ファイル： 23 IEEETBCRyan20170301.pdf

DOI： 10.1109/TBC.2016.2606938

A Low-Complexity Hardware Implementation of Compressed Sensing-Based Channel Estimation for ISDB-T System 査読

Rian Ferdian, Yafei Hou, Minoru Okada

IEEE Transactions on Broadcasting 63 ( 1 ) 92 - 102 2017年3月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Compressed sensing (CS) is one of the hottest research topics in the sparse signal reconstruction problem. But CS implementation has a drawback of high computational complexity due to calculation between large size of matrices. In this paper, we will propose a low-complexity CS hardware realization for channel estimation in the integrated services digital broadcasting-terrestrial (ISDB-T) system using several optimization methods to reduce the implementation complexity of CS usage. Since the ISDB-T is based on orthogonal frequency division and multiplexing system, the measurement matrix of CS computation is a truncated discrete Fourier transform (DFT) matrix. We can exploit the symmetrical property of this DFT matrix to significantly reduce its multiplication complexity and random access memory usage. To achieve fast reconstruction period, this paper also provides a hardware architecture for the proposed method and its realization in field programmable gate array. The simulation results show that the proposed methods can achieve lower complexity CS-based channel estimation with almost the identical system performance with the conventional method. Moreover, the realized hardware can achieve the fastest execution time compare to that of other existing methods.

添付ファイル： 22 IEEETBCRian201701.pdf

DOI： 10.1109/TBC.2016.2617286

Stability wavelength-spacing-tunable single-longitudinal-mode dual-wavelength erbium-doped fiber laser based on nonlinear amplifying loop mirror 査読

Shuo Liu, Fengping Yan, Siyu Tan, Yan Bai, Chang Fei, Hong Zhou, Yafei Hou, Ning Zhang

OPTICAL AND QUANTUM ELECTRONICS 49 ( 1 ) 2017年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER

A simple linear cavity configuration for a stability wavelength-spacing-tunable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber laser based on a nonlinear amplifying loop mirror (NALM) is proposed. The gain competition in the erbium-doped fiber (EDF) has been suppressed by the intensity dependent loss introduced by the NALM. The SLM operation is guaranteed by a section of unpumped EDF as saturable absorber. A stable dual-wavelength SLM fiber laser with a wavelength-spacing of 11.35 nm is experimentally realized. The optical signal-to-noise ratio is over 47 dB and the linewidths of two wavelengths measured by delayed self-heterodyne method are 1.1 and 1.0125 kHz, respectively. The tuning range of wavelength-spacing is 9.09-11.35 nm, correspondingly, and the THz signal is from 1.235 to 1.416 THz.

DOI： 10.1007/s11082-016-0863-9

Study on Idle Slot Availability Prediction for WLAN using a Probabilistic Neural Network 査読

Julian Webber, Abolfazl Mehbodniya, Yafei Hou, Kazuto Yano, Tomoaki Kumagai

2017 23RD ASIA-PACIFIC CONFERENCE ON COMMUNICATIONS (APCC): BRIDGING THE METROPOLITAN AND THE REMOTE 162 - 167 2017年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

We have recently proposed a multi-band wireless local area network (WLAN) system as a solution to the increasingly crowded frequency space. Efficiency can be improved by an agile transceiver that transmits on an idle channel on either or both bands concurrently, and a busy/idle (B/I) predictor will form part of the sensing unit for such a system. A probabilistic neural network (PNN) is studied here for predicting upcoming WLAN B/I status based on pattern matching and classification of previous state patterns. IEEE 802.11 wireless data frames were captured at two hot-spots on multiple channels and the B/I status estimated. The prediction performance is compared for two different locations, channels, prediction matrix dimensions, B/I vs channel occupancy ratio (COR) input types, and frequency of retraining. Results show that the PNN has good potential to estimate the number of idle slots in the upcoming 20 slots and the performance improves with regular retraining.

DOI： 10.23919/APCC.2017.8304030

その他リンク： https://dblp.uni-trier.de/db/conf/apcc/apcc2017.html#WebberMHYK17

Noise-like pulse generation from a thulium-doped fiber laser using nonlinear polarization rotation with different net anomalous dispersion 査読

Shuo Liu, Fengping Yan, Yang Li, Luna Zhang, Zhuoya Bai, Hong Zhou, Yafei Hou

PHOTONICS RESEARCH 4 ( 6 ) 318 - 321 2016年12月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：OPTICAL SOC AMER

A mode-locked thulium-doped fiber laser (TDFL) based on nonlinear polarization rotation (NPR) with different net anomalous dispersion is demonstrated. When the cavity dispersion is -1.425 ps(2), the noise-like (NL) pulse with coherence spike width of 406 fs and pulse energy of 12.342 nJ is generated at a center wavelength of 2003.2 nm with 3 dB spectral bandwidth of 23.20 nm. In the experimental period of 400 min, the 3 dB spectral bandwidth variation, the output power fluctuation, and the central wavelength shift are less than 0.06 nm, 0.04 dB, and 0.4 nm, respectively, indicating that the NPR-based TDFL operating in the NL regime holds good long-term stability. (C) 2016 Chinese Laser Press

DOI： 10.1364/PRJ.4.000318

Low-Complexity Channel Estimation and Detection for MIMO-OFDM Receiver With ESPAR Antenna 査読

Diego Javier Reinoso Chisaguano, Yafei Hou, Takeshi Higashino, Minoru Okada

IEEE Transactions on Vehicular Technology 65 ( 10 ) 8297 - 8308 2016年10月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Multiple-input-multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) receivers with an electronically steerable passive array radiator (ESPAR) antenna can improve bit error rate (BER) performance and obtain additional diversity gain without increasing the number of radio-frequency (RF) front-end circuits. In this scheme, a minimum-mean-square-error (MMSE) channel estimator is employed for obtaining the channel state information. However, its drawbacks include insufficient estimation accuracy and high computational complexity due to the inverse matrix calculation. In this paper, we propose using a low-complexity compressed-sensing-based channel estimation for the MIMO-OFDM receiver with an ESPAR antenna. We also propose a low-complexity detection scheme to further reduce the computational cost required for the detection. The simulation results show that with using the proposed channel estimation method, the BER performance is improved, while its complexity is reduced. The simulations also show that the proposed detection scheme successfully reduces the required computational cost while minimizing the degradation in the BER.

添付ファイル： 18 IEEETVT 201610 Low-ComplexityChannelEstimationandDetectionforMIMO-OFDMReceiverWithESPARAntenna.pdf

DOI： 10.1109/TVT.2015.2506782

Quality-Based Channel Allocation Scheme with Predistortion in Multi-Channel Radio over Fiber System 査読

Withawat Tangtrongpairoj, Yafei Hou, Takeshi Higashino, Minoru Okada

IEICE TRANSACTIONS ON ELECTRONICS E99C ( 5 ) 563 - 573 2016年5月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

Radio over Fiber (RoF) is a promising solution for providing wireless access services. Heterogeneous radio signals are transferred via an optical fiber link using an analog transmission technique. When the RoF and the radio frequency (RF) devices have a nonlinear characteristic, these will create the intermodulation products (IMPs) in the system and generate the intermodulation distortion (IMD). In this paper, the IMD interference in the uplink RF signals from the coupling effect between the downlink and the uplink antennas has been addressed. We propose a method using the dynamic channel allocation (DCA) algorithm with the predistortion (PD) technique to improve the throughput performance of the multi-channel RoF system. The carrier to distortion plus noise power ratio (CDNR) is evaluated for all channel allocation combinations; then the best channel combination is assigned as a set of active channels to minimize the effect of IMD. The results show that the DCA with PD has the lowest IMD and obtains a better throughput performance.

DOI： 10.1587/transele.E99.C.563

A Proposal of Wireless Sensor Network System for Slope Failure Detection Using Smartphones

Yafei Hou, Manato Fujimoto, Hirohiko Suwa, Yutaka Arakawa, Julian Webber, Kazuto Yano, Satoshi Tsukamoto, Tomoaki Kumagai(ATR, Michinori Hatayama, Kyoto, Uni

The 2016 Vietnam-Japan International Symposium on Antennas and Propagation 2016年2月

Downhill: BLE-based Multi-Hop Communication Using Smartphones for Detecting Slope Failures 査読

Manato Fujimoto, Seigi Matsumoto, John Noel Victorino, Hirohiko Suwa, Yutaka Arakawa, Yafei Hou, Julian Webber, Kazuto Yano, Satoshi Tsukamoto, Michinori Hatayama

The 17th International Workshop on Mobile Computing Systems and Applications (ACM HotMobile 2016) 16 - 21 2016年2月

Fast and Low-complexity Orthogonal Matching Pursuit Based Channel Estimation in ISDB-T Receiver with 3-element ESPAR Antenna 査読

Rian Ferdian, Yafei Hou, Minoru Okada

2016 IEEE INTERNATIONAL SYMPOSIUM ON BROADBAND MULTIMEDIA SYSTEMS AND BROADCASTING (BMSB) 1 - 4 2016年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In a mobile integrated service digital broadcasting-terrestrial (ISDB-T) system, the usage of a 3-elements electrical steerable parasitic array radiator (ESPAR) antenna can be a solution to gain diversity while keeping low power consumption and compact hardware size. But, the ESPAR antenna also increases the channel estimation difficulty as the received signal from each element will interfere each others. Orthogonal matching pursuit (OMP) can become an alternative in obtaining channel information for the system with ESPAR antenna. However, the OMP technique has a drawback in huge matrix inner product in its computation. In this paper, we propose a 3-column OMP with measurement matrix strength reduction technique to reduce the complexity in the inner product computation. The propose method overall result can achieve more than 90% complexity reduction.

DOI： 10.1109/BMSB.2016.7521988

A Proposal of Half-Symbol Parallel Combinatory Multicarrier Modulation for One-Seg Service of ISDB-T System 査読

Chengbo Liu, Yafei Hou, Takeshi Higashino, Minoru Okada

2016 IEEE INTERNATIONAL SYMPOSIUM ON BROADBAND MULTIMEDIA SYSTEMS AND BROADCASTING (BMSB) 1 - 4 2016年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

One-Seg service is a mobile terrestrial digital audio/video and data broadcasting service in Japan and many other countries. It transmits QPSK modulated symbols to achieve about 416 kbit/s transmission rate for mobile receivers with 428 kHz of bandwidth at UHF band. To further improve the transmission quality and spectrum efficiency, the system design must consider some major issues such as performance degradation from large Doppler shift and small size hardware for receivers which limit the system only to use low-order M-QAM modulation like BPSK or QPSK and small size of power amplifier with a low dynamic range of peak-to-average power ratio (PAPR). To reduce these impacts on the performance of One-Seg service, this paper proposes a BPSK modulated multicarrier system using parallel combinatory (PC) code. The proposed system achieves better BER performance and better PAPR characteristics with a comparable bandwidth efficiency (BWE) compared to that of the corresponding M-QAM modulated OFDM systems.

DOI： 10.1109/BMSB.2016.7521993

Diversity Gain Analysis of SFN-STBC Digital Terrestrial TV System Using Dual Polarized MIMO Antenna 査読

Ryan Paderna, Duong Quang Thang, Yafei Hou, Takeshi Higashino, Minoru Okada

2016 IEEE INTERNATIONAL SYMPOSIUM ON BROADBAND MULTIMEDIA SYSTEMS AND BROADCASTING (BMSB) 1 - 4 2016年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a Modified Orthogonal Matching Pursuit (MOMP)-assisted MIMO-OFDM receiver for next generation DTTV with Single Frequency Network- Space Time Block Coding (SFN-STBC). The receiver uses dual polarized antennas which can receive signals from different transmitters. In this paper, we investigate the BER performance if the transmitters transmit signals with different signal power where the receiver is in near-far effect with different receive power from different transmitter. In addition, we also examine the performance of the SFN system using MOMP for channel estimation with near-far effect. The simulation shows that the BER decreases if the received signal power from different transmitters are almost equal. And also, the MOMP BER performance is about 1 dB closer compared to ideal channel information in the range of SNR Eb/No=l5dB to Eb/No=25dB region.

DOI： 10.1109/BMSB.2016.7521981

Orthogonal Parallel Combinatory Amplitude Shift Keying Modulated Multicarrier System 査読

Chengbo Liu, Yafei Hou, Takeshi Higashino, Minoru Okada

2016 16TH INTERNATIONAL SYMPOSIUM ON COMMUNICATIONS AND INFORMATION TECHNOLOGIES (ISCIT) 7 - 10 2016年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

For some scenarios where high received power cannot be guaranteed due to user moving, the OFDM system with low order M-QAM such as BPSK/QPSK is promising. This paper will propose an orthogonal parallel combinatory ASK modulated multicarrier system to achieve flexible bandwidth efficiency (BWE) using low order ASK modulation and parallel combinatory (PC) code. PC code has been shown that it can achieve flexible BWE and better peak-to-average power ratio (PAPR) performance. Our proposal will utilize PC code for both I-phase and Q-phase of frequency-domain OFDM symbol which further improve the BWE of PC-OFDM system. The proposed system can obtain better BER performance and better PAPR performance using low order ASK modulation. Therefore, the proposed system can simplify the receiver design and provide the design freedom degree with a flexible range of BWE for system design or adaptive modulation and code control.

DOI： 10.1109/ISCIT.2016.7751581

Compressed Sensing based Channel Impulse Response Estimation for Space Time Block Coding Single Frequency Network in DTV System

PADERNA Ryan, THANG Duong Quang, HOU Yafei, HIGASHINO Takeshi, OKADA Minoru

映像情報メディア学会技術報告 40 21 - 24 2016年

記述言語：英語出版者・発行元：一般社団法人映像情報メディア学会

This system uses a low complexity channel estimation for Space Time Coding in a Single Frequency Network Digital Terrestrial Television System. The receiver employs a MIMO system with vertical and horizontal antennas. The channel estimator uses a compressed sensing in time domain which exploits the sparsity of the channel impulse response. The algorithm for estimating the delay and channel gain is Orthogonal Matching Pursuit (OMP). The BER performance shows that OMP is very close to the ideal channel estimation. In addition, the OMP performance outperforms the linear interpolation method.

DOI： 10.11485/itetr.40.4.0_21

Compressed Sensing Based Channel Estimation in ISDB-T System without Cyclic Prefix

FERDIAN Rian, HOU Yafei, OKADA minoru

映像情報メディア学会技術報告 40 29 - 32 2016年

記述言語：英語出版者・発行元：一般社団法人映像情報メディア学会

Integrated Service Digital Broadcasting Terrestrial (ISDB-T) transmission system is based on OFDM technique which requires cyclic prefix (CP) and pilot tones for channel estimation. Beside data sub-carriers, the usage of CP and pilot tones occupies the ISDB-T bandwidth up to 25%. However, CP is required to mitigate the inter-symbol interference (ISI) and interblock interference (IBI) and pilot tones are required to estimate the channel response information in order to equalize the multipath effect. Recently, a wireless communication scheme without CP by using chained turbo of equalization (CHATUE) technique was proposed. Furthermore, in term of channel estimation, compressed sensing (CS) has become a prominent technique that offers better performance with less pilot tones. In this paper, we proposed a channel estimation scheme for ISDB-T system without CP using CS technique. The pilot tones are inserted at several lowest value intersections location in the previous and post symbol interferences. The final result provides an ISDB-T system with more than 90% spectrum efficiency.

DOI： 10.11485/itetr.40.4.0_29

Erratum: Quality-Based Channel Allocation Scheme with Predistortion in Multi-Channel Radio over Fiber System [IEICE Transactions on Electronics Vol. E99.C (2016) No. 5 pp. 563-573]

TANGTRONGPAIROJ Withawat, HOU Yafei, HIGASHINO Takeshi, OKADA Minoru

IEICE Transactions on Electronics 99 ( 10 ) 1226_e1 - 1226_e1 2016年

Realization of 4-by-4 MIMO Channel Using One Composite Leaky Coaxial Cable 査読

Yafei Hou, Satoshi Tsukamoto, Takahiro Maeda, Masayuki Ariyoshi, Kiyoshi Kobayashi, Tomoaki Kumagai, Atsuhiko Niwa, Fumio Suzuki, Minoru Okada

2015 12TH ANNUAL IEEE CONSUMER COMMUNICATIONS AND NETWORKING CONFERENCE 97 - 102 2015年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Leaky coaxial cable (LCX) is widely used for wireless communication systems as an antenna for a linear-cell, which covers long and shallow areas. Since one LCX is usually utilized as one antenna, more than one LCX is required to configure a multi-input multi-output (MIMO) system. It means it is costly and space-consuming. To resolve these problems, we proposed a novel MIMO method for LCX. In this paper, we propose the method to utilize one composite cable, which consists of a pair of LCXs with different radiation characteristics, to configure a 4 x 4 MIMO channel. The measurement results confirmed that the proposed composite cable can realize a good channel condition for 4 x 4 MIMO transmission even if it is put in an anechoic chamber where no reflection path exists. On the other hand, the results also confirmed that it has good channel condition even if the spacing between a pair of LCX is as small as 2cm for the SGHz band. Therefore the proposed system can reduce the space requirement for MIMO deployment for wireless application over linear-cell environments to cope with the high rapid increase of consumer electronics devices.

DOI： 10.1109/CCNC.2015.7157953

Improved Compressed Sensing based Channel Estimation for Terrestrial DTV using Auxiliary Pilot Channel 査読

Ryan Paderna, Yafei Hou, Takeshi Higashino, Minoru Okada

2015 15TH INTERNATIONAL SYMPOSIUM ON COMMUNICATIONS AND INFORMATION TECHNOLOGIES (ISCIT) 213 - 216 2015年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposed a scattered auxiliary channel subcarriers for OFDM as additional pilots. This will improve the performance of compressed sensing based channel estimation for digital terrestrial TV. The auxiliary channel is designed to convey additional information on modulating signal transmission. The simulation shows that the proposed system has less bit-error-rate compared with the system without scattered auxiliary channel subcarriers. That is because the channel estimation will detect the correct position of the channel impulses with sufficient pilots.

DOI： 10.1109/ISCIT.2015.7458345

A Study of Capacity of 4-by-4 MIMO Channel Using Leaky Coaxial Cables for Linear-cells 査読

Sha Li, Yafei Hou, Takeshi Higashino, Minoru Okada

2015 15TH INTERNATIONAL SYMPOSIUM ON COMMUNICATIONS AND INFORMATION TECHNOLOGIES (ISCIT) 253 - 256 2015年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Leaky coaxial (LCX) cable is widely used in wireless transmission communication systems as antenna for a long and narrow area called as linear-cell. We have proposed that one single LCX cable can be used as two antennas and the method to utilize one composite cable, which consists of a pair of LCXs with different radiation characteristics, to configure a multiple input and multiple-output (MIMO) system. In this paper, we will study capacity of the proposed 4-by-4 LCX-MIMO system and compare its capacity with conventional MIMO system using omnidirectional antennas over 2.4GHz band. We also investigate the capacity difference if the spacing of two LCX cable is changed over 5GHz band. The results over 2.4GHz band show that the proposed system can reduce the space requirement for MIMO deployment for wireless application over linear-cell environments. The capacity results show that proposed LCX-MIMO channel has larger capacity than that of using monopole antennas at both sides. Over 5GHz band, the proposed LCX-MIMO channel using WF allocation scheme can have the capacity near to that of independent and identically distributed (i.i.d.) channel. It has good channel capacity even if the spacing between the pair of LCXs is as small as 2cm. On the other hand, the capacity can be largely improved using the simple EP allocation scheme if the system utilize LCX cables to configure MIMO systems for both 2.4GHz and 5GHz bands.

DOI： 10.1109/ISCIT.2015.7458355

Effective VLSI Architecture for Compressed Sensing Based Channel Estimation in ISDB-T System 査読

Rian Ferdian, Yafei Hou, Minoru Okada

2015 15TH INTERNATIONAL SYMPOSIUM ON COMMUNICATIONS AND INFORMATION TECHNOLOGIES (ISCIT) 273 - 276 2015年

担当区分：責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Compressed Sensing (CS) based channel estimation has been proven to give a better reconstruction results compared to conventional method. Despite promising a better result, CS based channel estimation still suffers from high complexity computations due to huge matrix multiplication and matrix inversion operations. This paper will propose an effective CS based channel estimation VLSI architecture for ISDB-T system. Since ISDBT system is using orthogonal frequency division multiplexing (OFDM) technique for its transmission, its CS channel estimation will utilize a measurement matrix which is formed by parts of Discrete Fourier Transform (DFT) matrix. By exploiting the fact that the measurement matrix will inherit some symmetrical properties from DFT matrix, we can achieve a low complexity CS based channel estimation for practical implementation.

DOI： 10.1109/ISCIT.2015.7458360

Configuration of MIMO system using single leaky coaxial cable for linear cell environments 査読

Yafei Hou, Satoshi Tsukamoto, Takahiro Maeda, Masayuki Ariyoshi, Kiyoshi Kobayashi, Tomoaki Kumagai, Minoru Okada

IEICE COMMUNICATIONS EXPRESS 4 ( 5 ) 143 - 148 2015年

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

It has been conventionally assumed that a single leaky coaxial (LCX) cable only is utilized as one antenna to configure a multiple-input multiple-output (MIMO) system. In this letter, we show one single LCX cable can be used as two antennas to configure a MIMO system owing to the designed intersection angle between the different radiation directivities of both input signals. The measurement results of 2 x 2 LCX-MIMO channel quality confirm that our proposed LCX-MIMO can realize a promising channel condition over 5 GHz frequency band. It also points out that the intersection angle between radiation directivities of LCX cable needs to be considered carefully to reduce the channel degradation at the both edge portions of the LCX cable.

DOI： 10.1587/comex.4.143

[Paper] ISDB-T Diversity Receiver using a 4-element ESPAR Antenna with Periodically Alternating Directivity

Reinoso Chisaguano Diego Javier, Hou Yafei, Higashino Takeshi, Okada Minoru

ITE Transactions on Media Technology and Applications 3 ( 4 ) 268 - 278 2015年

記述言語：英語出版者・発行元：一般社団法人映像情報メディア学会

Antenna diversity is one of the solutions to multipath fading but with the cost of additional hardware for every RF chain. In mobile reception application, it is difficult to install the additional antennas and cables to the vehicle due to limitations in installation cost and features. In this paper, we propose an Integrated Services Digital Broadcasting - Terrestrial (ISDB-T) diversity receiver using a 4-element electronically steerable passive array radiator (ESPAR) antenna with periodically alternating directivity. The proposed receiver obtains diversity gain requiring only a single-RF front-end and cable, thus reducing the hardware complexity compared to conventional antenna diversity receivers. The receiver utilizes compressed sensing-based channel estimation that recovers the channel state information (CSI) with good accuracy. The simulation results show that with perfect CSI, the proposed ISDB-T receiver is capable of obtaining a diversity gain of about 15 dB for a bit error rate of 10^-3.

DOI： 10.3169/mta.3.268

Introducing Dual Regularization Parameters into Regularized Channel Inversion (RCI)-Based Vector Perturbation for Modulo Loss Reduction 査読

Yafei Hou, Satoshi Tsukamoto, Kazuto Yano, Masahiro Uno, Kiyoshi Kobayashi

2014 16TH INTERNATIONAL CONFERENCE ON ADVANCED COMMUNICATION TECHNOLOGY (ICACT) 361 - + 2014年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a method to reduce the symbol error caused by modulo operator for regularized channel inversion (RCI)-based vector perturbation (RCI-VP). The proposed method introduces dual regularization parameters of RCI precoding matrix. First regularization parameter alpha(1) is set so as to maximize the signal to interference plus noise ratio (SINR) value of each stream to find the optimal perturbation vector. The second regularization parameter alpha(2) is set so as to minimize the total MSE between the transmitted perturbation vector and received perturbation vector to reduce the symbol error caused by modulo operator. The simulated results confirm that the proposed method can improve the performance of RCI-VP over i.i.d. MIMO channel and frequency-selective fading MIMO channel.

Performance Comparison for 2 by 2 MIMO System Using Single Leaky Coaxial Cable over WLAN Frequency Band 査読

Yafei Hou, Satoshi Tsukamoto, Masayuki Ariyoshi, Kiyoshi Kobayashi, Tomoaki Kumagai, Minoru Okada

2014 ASIA-PACIFIC SIGNAL AND INFORMATION PROCESSING ASSOCIATION ANNUAL SUMMIT AND CONFERENCE (APSIPA) 1 - 5 2014年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In linear service areas such as a tunnel and along railways, leaky coaxial cable (LCX) is widely used as antenna for radio communication. Usually, one LCX is utilized as one antenna. Therefore it requires more than one LCX to configure an multi-input multi-output (MIMO) system. We have recently proposed a method that one single LCX can be utilized as two antennas by feeding different RF transmit signals to each end of the proposed cable. In this paper, we compare 2x 2 MIMO system performance using the proposed LCX and using conventional monopole antennas over 2.4GHz band for WLAN appliances. The results confirm that our proposed 2x 2 MIMO channel using a single LCX can realize a good channel condition and bit error ratio (BER) performance for MIMO transmission even within a highly correlated propagation condition. On the other hand, it also shows that the proposed LCX MIMO is promising technique for communications over linear-cell environments from the simulated results which considering the path loss and radiation pattern of LCX characteristics.

DOI： 10.1109/APSIPA.2014.7041735

An experimental evaluation of 2 × 2 MIMO system using closely-spaced leaky coaxial cables. 査読

Satoshi Tsukamoto, Takahiro Maeda, Masayuki Ariyoshi, Yafei Hou, Kiyoshi Kobayashi, Tomoaki Kumagai

Asia-Pacific Signal and Information Processing Association Annual Summit and Conference, APSIPA 2014, Chiang Mai, Thailand, December 9-12, 2014 1 - 5 2014年

4-by-4 MIMO Channel Using Two Leaky Coaxial Cables (LCXs) for Wireless Applications over Linear-cell 査読

Yafei Hou, Satoshi Tsukamoto, Masayuki Ariyoshi, Kiyoshi Kobayashi, Minoru Okadat

2014 IEEE 3RD GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE) 125 - 126 2014年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

We have recently proposed a novel 2 x 2 multipleinput multiple-output (MIMO) system that utilizes a single leaky coaxial cable (LCX) as two antennas. In this paper, we further propose a 4 x 4 MIMO system by combining two LCXs that have different radiation characteristics into one composite cable and evaluate characteristics of the channel with different spacing between the LCXs. Since the different radiation characteristics create different propagation paths, the proposed system with small spacing between LCXs can realize an efficient channel condition for 4 x 4 MIMO transmission. As a result of measurement at 2.4 GHz band, the smaller spacing as to 1 em between LCXs makes better 4 x 4 MIMO channel condition for transmission. This result indicates that the proposed system can reduce the space requirement for system deployment.

DOI： 10.1109/GCCE.2014.7031177

2 by 2 MIMO System Using Single Leaky Coaxial Cable for Linear-cells 査読

Yafei Hou, Satoshi Tsukamoto, Masayuki Ariyoshi, Kiyoshi Kobayashi, Minoru Okada

2014 IEEE 25TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATION (PIMRC) 327 - 331 2014年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Leaky coaxial cables (LCX) have been widely used as antennas to form linear service areas for radio communication systems. Such services of linear cells have been deployed inside tunnels, along railways, and so on. Usually, one LCX is utilized as one antenna. Therefore it requires more than one LCX to configure an multi-input multi-output (MIMO) system. In this paper, we propose a MIMO system using single LCX, which can be utilized as two antennas. When different RF transmit signals are fed to each end of the proposed cable, single LCX can work as two antennas. To confirm the feasibility of the proposed MIMO system, we conduct experiments to measure the characteristics of 2 x 2 MIMO channel using single LCX. The results confirm that our proposed 2 x 2 MIMO channel using single LCX can realize a good channel condition for MIMO transmission even within a highly correlated propagation condition. The proposed MIMO system using LCX will release the space requirement and reduce the cost of system for configuration of LCX MIMO system especially with large number of LCXs. It benefits the design and configuration of LCX-MIMO system for many scenarios of linear-cell.

DOI： 10.1109/PIMRC.2014.7136184

Introduction of Dual Regularization Parameters to Improve the Performance of MMSE Based Vector Perturbation 査読

Yafei Hou, Satoshi Sonobe, Satoshi Tsukamoto, Kazuto Yano, Masahiro Uno, Kiyoshi Kobayashi

2013 15TH INTERNATIONAL CONFERENCE ON ADVANCED COMMUNICATION TECHNOLOGY (ICACT) 558 - 562 2013年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a method to improve the performance of minimum-mean square error (MMSE) based vector perturbation (MMSE-VP) by introducing dual regularization parameters of MMSE precoding matrix. First regularization parameter alpha(1) is set so as to maximize the signal to interference plus noise ratio (SINR) value of each stream to find the optimal perturbation vector. The second regularization parameter alpha(2) is set as to minimize the total MSE between the transmitted perturbation vector and received perturbation vector to precancel the interference among the streams. The simulated results confirm that the proposed method can improve the performance of MMSE-VP over i.i.d. MIMO channel and indoor correlated frequency-selective fading MIMO channel.

Impact of CSI variation in subband on performance of vector perturbation based MU MIMO-OFDM system

Hou Yafei, Sonobe Satoshi, Tsukamoto Satoshi, Yano Kazuto, Uno Masahiro, Kobayashi Kiyoshi

IEICE Communications Express 2 ( 3 ) 86 - 92 2013年

記述言語：英語出版者・発行元：The Institute of Electronics, Information and Communication Engineers

Because of limitation of channel state information (CSI) feedback resource, multiuser (MU) MIMO-OFDM system usually divides all usable subcarriers into several subbands and the CSI of middle subcarrier of each subband is fed back. This feedback style generates CSI error among each subband. Due to this CSI error, a MU MIMO-OFDM system based on vector perturbation (VP) yields inefficient perturbation vectors (PVs) and mismatched spatial filters, which cause severe performance degradation. In this letter, we show that the performance degradation is mainly caused from the mismatched spatial filters rather than the inefficient PVs. This result is useful to design of a computational complexity reduction for the VP based system by reducing the matrix operations for PV search.

DOI： 10.1587/comex.2.86

A Simple Method of Transmitting Stream Adaptation for Fixed-Matrix-Size Precoding on MU-MIMO Transmission 査読

Yafei Hou, Satoshi Sonobe, Kazuto Yano, Masahiro Uno, Kiyoshi Kobayashi

2012 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC) 136 - 141 2012年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

During the operation of multiuser multiple-input-multiple output (MU-MIMO) algorithms, some antennas of BS or UEs may neither transmit nor receive signals due to the long distance or unexpected damages. Therefore, the BS cannot obtain the channel state information (CSI) from/to these antennas. Without these CSI, the performance of algorithm is degraded. We call this effect as 'broken antenna effect (BAE).' To cope with this issue, this paper proposes a process to regularize the channel matrix by replacing the missing CSI with zero(s) and setting non-zero values to diagonal elements. Then, it is confirmed through computer simulation that the proposed method can adjust the number of transmitting parallel streams according to the number of 'broken' antennas, and provide MU-MIMO transmission with maximum diversity order without any change of the precoding process.

DOI： 10.1109/WCNC.2012.6213993

Channel Estimation Improvement with Frequency Domain MMSE Equalization for PCP-SC System 査読

Yafei Hou, Tomohiro Hase

IEICE TRANSACTIONS ON COMMUNICATIONS E94B ( 6 ) 1690 - 1698 2011年6月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

In this paper, we propose a simple but effective way of improving the performance of channel estimation (CE) for pilot cyclic prefixed single carrier (PCP-SC) system. The proposed method utilizes the property that the shifting signal of the PCP pilot signal can also be utilized to estimate the channel information. The receiver can continuously estimate the channel information by just shifting the received pilot signal. Regardless of the signal-to-noise ratio (SNR) and the pilot type, the proposed method can achieve about a 1.72 dB performance gain in terms of the mean squared error (MSE) of channel estimation with a slight increase in computational complexity. The BER performance with the proposed CE improvement are evaluated in a multipath fading channel using a zero-forcing (ZF) equalizer and an minmum mean squared error (MMSE) equalizer by computer simulation. It is shown that the proposed CE improvment method using an MMSE equalizer which has an unbiased vlaue of noise variance (NV) estimator gives a promising BER performance. The proposed method also benefits the estimation of the SNR for the single carrier system.

DOI： 10.1587/transcom.E94.B.1690

Channel Estimation Improvement for MIMO Single-Carrier Block Transmission System 査読

Yafei Hou, Tomohiro Hase

2011 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC) 2011年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, we propose an effective way of improving the performance of channel estimation for MIMO single-carrier block transmission (SCBT) systems. The proposed method utilizes the property that the shift of the cyclic pilot signal of each antenna branch can also be utilized to catch the channel information as a new pilot for MIMO SCBT systems. The receiver can continuously estimate the channel information by just shifting the received pilot signal. The channel estimation performance is improved by averaging all channel estimators since this averaging process can reduce the power of noise component. Regardless of the signal-to-noise ratio (SNR) and the pilot type, the proposed method can achieve about a 1.72 dB performance gain in term of the mean squared error (MSE) of channel estimation for each antenna branch with slightly computational complexity. The proposed method can be also utilized to most channel estimation methods for the MIMO SCBT system.

Channel and Noise Variance Estimation Improvement for PCP-SC System 査読

Yafei Hou, Tomohiro Hase

2010 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC 2010) 2010年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, we propose a simple but effective way of improving the performance of channel estimation and catching the noise variance for pilot cyclic prefixed single carrier (PCP-SC) system. The proposed method utilizes the property that the shift of the PCP pilot signal can also be utilized to catch the channel information as a new pilot. Regardless of the signal-to-noise ratio (SNR) and the pilot type, the proposed method can achieve about a 1.72 dB performance gain for the mean squared error (MSE) of channel estimation with slightly additional computational complexity. In addition, regardless of the pilot type, the receiver can generate a new random signal from the pilot signal. The new signal has an identical variance value to that of the mixed AWGN noise. The proposed estimation method for noise variance is independent of channel estimation errors. Therefore it simplifies the receiver design and improves the system performance.

Flexible Parallel Combinatory OFDM System 査読

Yafei Hou, Tomohiro Hase

2ND IEEE INTERNATIONAL CONFERENCE ON ADVANCED COMPUTER CONTROL (ICACC 2010), VOL. 1 436 - 441 2010年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

In this paper, combining the parallel combinatory (PC) code and the a flexible OFDM structure [7], we report the design of a new OFDM system with PC code for various applications with a moderate transmission rate. The system can select appropriate phase sets for all modulated subcarriers for each PC code for different design requirements such as peak-to-average power ratio (PAPR) reduction or HER performance improvement. The proposed system will achieve better PAPR characteristics and promising HER performance. In addition, due to the flexible OFDM structure, the proposed PC-OFDM system will also have properties of high adaptability and compatibility.

New OFDM Structure with Parallel Combinatory Code 査読

Yafei Hou, Tomohiro Hase

IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 55 ( 4 ) 1854 - 1859 2009年11月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

We have introduced a flexible OFDM structure based on a promising property of IFFT operation [7]. This structure can support uplink applications which include many transmitters using different numbers of subcarriers and one receiver with just one IFFT/FFT module with the subcarriers of the least common multiple (LCM) for the number of subcarriers of all the transmitters. In this paper, combining the Parallel combinatory (PC) code and the proposed flexible OFDM structure, we report the design of a new OFDM system with PC code for various applications with a moderate transmission rate. The system can select appropriate Phase sets for all modulated subcarriers for each PC code for different design requirements such ay peak-to-average power ratio (PAPR) reduction or BER performance improvement. The proposed system will achieve better PAPR characteristics and promising BER performance. In addition, due to the flexible OFDM structure, the proposed PC-OFDM system will also have properties of high adaptability and compatibility(1).

DOI： 10.1109/TCE.2009.5373742

Improvement on the Channel Estimation of Pilot Cyclic Prefixed Single Carrier (PCP-SC) System 査読

Yafei Hou, Tomohiro Hase

IEEE SIGNAL PROCESSING LETTERS 16 ( 8 ) 719 - 722 2009年8月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

The pilot cyclic prefixed single carrier (PCP-SC) system has the ability to achieve channel estimation in a fast-fading environment. It also enables symbol recovery even when the frequency domain of the channel has nulls. This letter proposes a simple but effective way of improving the performance of channel estimation. Regardless of the signal-to-noise ratio (SNR) and the pilot type, the receiver can achieve about a 1.72 dB performance gain for the mean squared error (MSE) of channel estimation if it implements the proposed method with slightly additional computational complexity. The proposed method can also be utilized in any type of pilot in PCP-SC and MIMO systems.

DOI： 10.1109/LSP.2009.2023953

New Flexible OFDM Structure for Consumer Electronics Communication Systems 査読

Yafei Hou, Tomohiro Hase

IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 55 ( 1 ) 191 - 198 2009年2月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

This paper introduces a promising property in which the transmitter of an OFDM system can utilize an N-point IFFT operation to build the time-domain symbols of a KN-point IFFT operation. Based on this property, we propose a flexible OFDM structure. This structure will support uplink applications which include many transmitters using different numbers of subcarriers and one receiver with just one IFFT/FFT module with the subcarriers of least common multiple (LCM) for the number of subcarriers of all the transmitters. Therefore it reduces the design complexities of the receiver and increases the compatible characteristics for consumer electronics (CE). Compared with the original OFDM system, the proposed system improves the performance of the packet error ratio (PER) and the bit error ratio (BER) performance by using the appropriate K. In addition, the proposed structure can be designed to enlarge the bandwidth efficiency of the system and improve the performance of channel estimation compared with the OFDM/TDM system.(1)

DOI： 10.1109/TCE.2009.4814434

Parallel Combinatory OFDM/TDM System 査読

Yafei Hou, Tomohiro Hase

ISCE: 2009 IEEE 13TH INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2 165 - + 2009年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Combined with OFDM with time division multiplexing (OFDM/TDM) system and parallel combinatory (PC) code, we propose a new OFDM system which can be utilized to the communication systems of consumer electronics. Compared with the original OFDM system, the proposed system will achieve promising BER performance and better PAPR characteristics.

Improvement on the Channel Estimation of Pilot Cyclic Prefixed Single Carrier (PCP-SC) System 査読

Yafei Hou, Tomohiro Hase

2009 IEEE 70TH VEHICULAR TECHNOLOGY CONFERENCE FALL, VOLS 1-4 708 - + 2009年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper will propose a simple hut effective way to improve the performance of channel estimation of pilot cyclic prefixed single carrier (PCP-SC) system. The proposed method utilizes the property that the shift of pilot cyclic prefixed signal can also be utilized to catch the channel information as a new pilot. The receiver can continuously estimate the channel information by just shifting the received signal. Regardless or signal-to-noise ratio (SNR) and pilot type, the receiver can achieve about 1.72 dB performance gain for MSE of channel estimation if it implements the proposed method with a slight additional computational complexity. The proposed method can also be utilized in any types of pilot in PCP-SC and MIMO system.

New OFDM System without Guard Interval 査読

Yafei Hou, Tomohiro Hase

2009 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS 159 - 160 2009年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new OFDM system without a guard interval (GI) based on the useful characteristics of IFFT operation. The system utilizes the pilot signal to capture the channel information as well as GI does. Therefore, the bandwidth efficiency of the system can be improved. In addition, it achieves promising peak-to-average power ratio (PAPR) characteristics which also decrease the cost of handsets.

OFDM transmitter structure with low PAPR 査読

Yafei Hou, Tomohiro Hase

2008 IEEE INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2 590 - + 2008年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new OFDM transmitter structure which can be realized by a smaller FFT chip based on the useful characteristics of IFFT operation. The proposed system benefits the design of handsets. In addition, it achieves promising peak-to-average power ratio (PAPR) characteristics which also decreases the cost of handsets.

Collision-captured multicarrier modulation system 査読

Yafei Hou, Tomohiro Hase

2008 IEEE SARNOFF SYMPOSIUM 345 - + 2008年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new system called the collision-captured multicarrier modulation system which can realize the capture of a packet collision. Based on the OFDM system using partial symbol transmission, the transmitter can select a specific duration to achieve promising PAPR characteristics and realize the capture of a packet collision. The simulated results show that over 90% collision occurrences and the correct position of the collided part can be captured even in severe near-far situations. The proposed system can also achieve a PAPR reduction with an acceptable BER performance degradation.

Collision-Recovery Method for Collided OFDM Based Packets 査読

Yafei Hou, Tomohiro Hase

2008 IEEE 19TH INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS 688 - 693 2008年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

We present an effective method of collision recovery for orthogonal frequency division multiplexing (OFDM)-based communications. For the OFDM system, the modulated message data can be demodulated using the partial time-domain OFDM symbol. Therefore, the partial time-domain symbol can be adopted to reconstruct the whole OFDM time-domain symbol with estimated channel information. This property can be utilized to recover packets from the collisions. Since most collisions are cases in which a long packet collides with short packets, the collided part is assumed to be short. The simulated results show that the method can recover all packets with different specific probabilities and can be developed to solve the problem of hidden terminals.

OFDM system for capturing collision 査読

Yafei Hou, Tomohiro Hase

2008 IEEE INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2 601 - + 2008年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new system called the collision-captured OFDM system which can realize the capture of a packet collision based on the OFDM system using partial symbol transmission. The simulated results show that over 90% of collision occurrences and the correct position of the collided part can be captured even in severe near-far situations.

A new way of PAPR reduction for OFDM system 査読

Yafei Hou, Tomohiro Hase

2008 IEEE INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2 586 - + 2008年

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

This paper proposes a new peak-to-average power ratio (PAPR) reduction technique for OFDM systems. The proposed system selects the specific duration of each time-domain OFDM symbol which can achieve a promising PAPR, to transmit equal bits of data. Compared with the OFDM system using amplitude clipping, PST can obtain comparable PAPR performance and achieve a 0.5 - 3 dB BER performance gain by choosing the appropriate parameters. In addition, PST does not need any complex modules to fix the original phases of the clipped samples, so it decreases the cost of transmitters.

A novel modulation with parallel combinatory and high compaction multi-carrier modulation 査読

Yafei Hou, Masanori Hamamura

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E90A ( 11 ) 2556 - 2567 2007年11月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

In this paper, we propose a new modulation named parallel combinatory/high compaction multi-carrier modulation (PC/HC-MCM) using the techniques of parallel combinatory orthogonal frequency division multiplexing (PC-OFDM) and high compaction multi-carrier modulation (HC-MCM). Two types of PC/HC-MCM systems, which are named as modulated PC/HC-MCM system and (unmodulated) PC/HC-MCM system, can be designed. The modulated PC/HC-MCM system achieves better bit-error rate (BER) performance than that of HC-MCM system with equal bandwidth efficiency (BWE). The PC/HC-MCM system can obtain the better peak-to-average power ratio (PAPR) characteristics by selecting appropriate constellation for each subcarrier. On the other hand, since PC/HC-MCM can divide the PC-OFDM symbol duration into multiple time-slots, the advantages of frequency hopping (FH) can be applied in the PC/HC-MCM system. Therefore, we also combine the PC/HC-MCM and frequency hopping multiple access (FHMA) to propose a novel multiple access (MA) system. It can simultaneously transmit multiple users' data within one symbol duration of PC-OFDM.

DOI： 10.1093/ietfec/e90-a.11.2556

Collision recovery for OFDM system over wireless channel 査読

Yafei Hou, Masanori Hamamura

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E90A ( 7 ) 1312 - 1322 2007年7月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

We present an effective method of collision recovery for orthogonal frequency division multiplexing (OFDM)-based communications. For the OFDM system, the modulated message data can be demodulated using the partial time-domain OFDM signal. Therefore, the partial time-domain signal can be adopted to reconstruct the whole OFDM time-domain signal with estimated channel information. This property can be utilized to recover packets from the collisions. Since most collisions are cases in which a long packet collides with a short packet, the collided part is assumed to be short. The simulated results show that the method can recover the two collided packets with a certain probability and can be developed to solve the problem of hidden terminals. This method will dramatically benefit the protocol design of wireless networks, including ad hoc and sensor networks.

DOI： 10.1093/ietfec/e90-a.7.1312

Fast index for XML data 査読

Ping Yi, Yafei Hou, Yue Wu, Jianhua Li

Journal of Computational Information Systems 3 ( 1 ) 97 - 107 2007年2月

Novel parallel combinatory system with high compaction multicarrier modulation 査読

Journal on Communications 28 ( 1 ) 69 - 74 2007年1月

Flooding attack and defence in ad hoc networks 査読

Journal of Systems Engineering and Electronics 17 ( 2 ) 410 - 416 2006年6月

Performance tradeoff with adaptive frame length and modulation in wireless network

Yafei Hou, Masanori Hamamura, Shiyong Zhang

Proceedings - Fifth International Conference on Computer and Information Technology, CIT 2005 2005 490 - 494 2005年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this paper, we present the results of analysis which shows that there is much to be gained from variable frame length, different modulations in terms of goodput, range and energy consumption for wireless channel. Using those results, then we obtain three useful rules for the tradeoff with goodput, range and energy consumption with different modulations. © 2005 IEEE.

A novel way of saving power in CSMA/CD

Yafei Hou, Masanori Hamamura

2005 2nd IEEE Consumer Communications and Networking Conference, CCNC2005 2005 582 - 584 2005年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

In this paper, a new way of saving power is expounded. With the different modulation, the different energy levels are needed, and then the constant length of packet can be changed to the different length of symbol. Therefore it changes the average length of symbols of all users. At the same time, the variable length of symbol can influence the throughput and delay of system. But using CSMA/CD, the influence can be least. In our paper, we found that the power can be saved and the throughput can be improved by increasing the average length of symbol in some degree. © 2004 IEEE.

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