研究者詳細 - 黒崎　正行

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A Study Real-Time WLAN Sensing System Using Channel State Information 査読有り国際誌

Isshiki R., Tsuji K., Nagao Y., Kurosaki M., Sai B., Ochi H.

Proceedings - IEEE Consumer Communications and Networking Conference, CCNC 2023-January 907 - 908 2023年01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）

Recently, the Wi-Fi human activity recognition (HAR) system has attracted attention, using channel state information (CSI). CSI is a characteristic that indicates the radio propagation environment from transmitter to receiver, indoor environment. Therefore, sensing technology that predicts the indoor environment by calculating backward from the CSI is being considered. We first analyzed CSI in the time direction using singular value decomposition (SVD). In addition, a long short-term memory (LSTM) is applied to the obtained features to classify Absence/Presence. Furthermore, we implemented this system, where software-defined radio (SDR) receiver and common commercial wireless access point.

DOI： 10.1109/CCNC51644.2023.10060556

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Multi-Task Learning with Convolutional Neural Network Approach for Packet Collision Avoidance in 802.11 WLAN 査読有り国際誌

Dody Ichwana Putra, Muhammad Harry Bintang Pratam, Tomoki Nakashima, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proceeings - 2022 9th NAFOSTED Conference on Information and Computer Science 2022年10月

Multi - Task Learning with Convolutional Neural Network for Packet Format Detection and Modulation Classification of Wireless LAN 査読有り国際誌

Dody Ichwana Putra, Muhammad Harry Bintang Pratama, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proceeings - 2022 13th International Conference on Information and Communication Technology Convergence 2022年10月

ns3-ai: Rate Control for Wireless LAN by Deep Q-Network 査読有り国際誌

Tomoki Nakashima, Leonardo Lanante, Muhammad Harry Bintang Pratama, Masayuki Kurosaki, Hiroshi Ochi

Proceedings - International Workshop on Smart Info-Media System in Asia 2022年09月

無線LAN規格IEEE802.11の次世代技術動向と応用査読有り

長尾勇平，黒崎正行，尾知博

映像情報メディア学会誌 ( 一般社団法人　映像情報メディア学会 ) 76 ( 3 ) 337 - 343 2022年05月

FOREWORD Special Section on Smart Multimedia & Communication Systems 査読有り国際誌

OCHI Hiroshi, KUROSAKI Masayuki

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences ( 一般社団法人電子情報通信学会 ) E105.A ( 4 ) 611 - 612 2022年04月

H.264 Scalable Video Coding Transmission on MIMO without CSI Feedback 査読有り

Tiawongsuwan Manthana, Lanante Leonardo, Kurosaki Masayuki, Ochi Hiroshi

信号処理 ( 信号処理学会 ) 26 ( 2 ) 39 - 49 2022年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

In order to meet the current transmission and QoS demands of wireless video transmission, the conventional wireless systems are using Multiple Input Multiple Output (MIMO) technology aided with receiver channel state information (CSI) feedback. The CSI is used by the access point to accurately measure the users' channel quality to decide the best transmission and video encoding parameters possible for each user. However, the CSI feedback has some disadvantages such as the delayed reception at the transmitter, the CSI expiry due to the doppler shift, and finally, hardware complexity making it difficult to be implemented in low power and low cost devices. In this paper, we propose the transmission of H.264/SVC video bitstreams through MIMO system by using the received signal strength indicator (RSSI) instead of CSI. To supplement the RSSI, we implement a look-up table based mechanism to predict the video PSNR for any wireless propagation environment. Aside from being widely supported in all wireless devices, the RSSI can be obtained from the clear to send (CTS) packets in without the need of a sounding process. The results show that our proposed method improves the PSNR by more than 16 dB, and has 6 meters more range compared with the conventional method with fixed encoding ratio and packetization.

DOI： 10.2299/jsp.26.39

Hardware Design of Wireless Video Transmission Using JSCC 査読有り国際誌

Shohei Ochi, Masayuki Kurosaki, Hiroshi Ochi

9th International Joint Symposium on Applied Engineering and Sciences 2021年12月

Noise Reduction for Photon Counting Imaging Using Discrete Wavelet Transform 査読有り

Lee J., Kurosaki M., Cho M., Lee M.C.

Journal of Information and Communication Convergence Engineering 19 ( 4 ) 276 - 283 2021年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, we propose an effective noise reduction method for photon counting imaging using a discrete wavelet transform. Conventional 2D photon counting imaging was used to visualize the object under dark conditions using statistical methods, such as the Poisson random process. The photons in the scene were estimated using a statistical method. However, photons which disturb the visualization and decrease the image quality may occur in the background where there is no object. Although median filters are used to reduce the noise, the noise in the scene remains. To remove the noise effectively, our proposed method uses the discrete wavelet transform, which removes the noise in the scene using a specific thresholding method that utilizes photon counting imaging characteristics. We conducted an optical experiment to demonstrate the denoising performance of the proposed method.

DOI： 10.6109/jicce.2021.19.4.276

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A Study on the Quality Improvement Effects of Using STBC with H.264/SVC Video Transmission 査読有り国際誌

Tiawongsuwan M., Lanante L., Kurosaki M., Ochi H.

ISPACS 2021 - International Symposium on Intelligent Signal Processing and Communication Systems: 5G Dream to Reality, Proceeding 2021年11月

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）

H.264/SVC is a widely used compression standard with a very high lossy compression rate. The completeness of the H.264/SVC bitstream is very crucial in achieving high quality video decompression. This is especially true in regard to the base layer which contains the important coding data. In this paper, we improve the quality of H.264/SVC video transmission by using the Space Time Block Code (STBC) technique. STBC is a technique to increase the reliability of the wireless transmission by transmitting multiple copies of the signal along multiple transmit antennas and is thus suitable for the need of H.264/SVC. We compared STBC with conventional SISO and MIMO techniques using the IEEE 802.11ac standard. The simulation results show that our method which uses STBC has superior performance in terms of both of high PSNR and low BER.

DOI： 10.1109/ISPACS51563.2021.9651122

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Industrial WLAN System with Accurate Time Synchronization on Software Defined Radio 査読有り

Nguyen T.T.T., Toyofuku M., Ito Y., Ishimitsu C., Nagao Y., Kurosaki M., Ochi H.

2021 IEEE International Conference on Communications Workshops, ICC Workshops 2021 - Proceedings 2021年06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）

This paper presents a hardware implementation of low latency and highly accurate time synchronization for Industrial WLAN systems. The design of our media access control (MAC) layer supports both asynchronous and synchronous multi- user transmission protocols. Low overhead Packet Division Multiple Access (PDMA) scheme is utilized for Multi-user Downlink transmission, while Frequency Division Multiple Access (FDMA) is employed for the uplink transmission. The design of the physical (PHY) layer system is developed based on fast and deterministic communication. The proposed industrial WLAN system is developed on Software Defined Radio (SDR). The experimental results show that the wireless control communication can be achieved to control motors with a high accuracy Precision Time Protocol (PTP) in nano-second level from 200 ns to 300 ns which is less than 1 ms compared to PROFINET wireless standard.

DOI： 10.1109/ICCWorkshops50388.2021.9473752

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国際会議開催報告 2020 International Workshop on Smart Info-Media System in Asia 招待有り

黒崎正行, 尾知博

電子情報通信学会基礎・境界ソサイエティ Fundamentals Review 14 ( 4 ) 349 - 350 2021年04月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）

国際会議開催報告
2020 International Workshop on Smart Info-Media System in Asia
（SISA 2020，スマートインフォメディアシステム国際ワークショップ・イン・アジア，https://www.ieice-sisa.org/）Soongsil University, Seoul, Korea（Full Online）2020年12月17日～18日

DOI： essfr.14.4_349

Live demonstration: Null beamforming to self in cooperative MIMO for full-duplex system 査読有り

Kawano M., Nguyen T.T.T., Nagao Y., Lanante L., Kurosaki M., Ochi H.

Proceedings - IEEE International Symposium on Circuits and Systems 2021-May 2021年04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）

We demonstrate a self-interference (SI) cancellation in cooperative multiple-input multiple-output (Co-MIMO) for full-duplex (FD) wireless communication systems by applying the block diagonalization used in multi-user MIMO. The proposed method's implementation uses a field-programmable gate array (FPGA) and software-defined radio (SDR). In the experiment, a total of 33 [dB] SI can cancel with two cooperative APs and two antennas per AP in the IEEE 802.11 system.

DOI： 10.1109/ISCAS51556.2021.9401102

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Null beamforming to self in cooperative MIMO for full-duplex systems 査読有り

Kawano M., Thao Nguyen T.T., Nagao Y., Lanante L., Kurosaki M., Ochi H.

Proceedings - IEEE International Symposium on Circuits and Systems 2021-May 2021年04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）

In this paper, we propose self-interference (SI) cancellation in cooperative multiple-input multiple-output (Co-MIMO) for full-duplex (FD) wireless communication systems. This proposal solves SI by applying the block diagonalization used in multi-user MIMO. Therefore, there is no need for a radio frequency (RF) canceller, which has a large hardware (HW) size and is difficult to extend to MIMO. Furthermore, we can achieve higher throughput by applying Co-MIMO, in which multiple access points (APs) work together to communicate. The proposed method-s implementation uses field-programmable gate array (FPGA) and software-defined radio (SDR). In the experiment, a total of 33 [dB] SI can cancel with two cooperative APs and two antennas per AP in the IEEE 802.11 system.

DOI： 10.1109/ISCAS51556.2021.9401490

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Cooperative MIMO Applied Null Beamforming to Self in Full-Duplex Wireless Communication System and Its Implementation 査読有り国際誌

Kawano M., Nagao Y., Lanante L., Kurosaki M., Ochi H.

International Conference on Advanced Communication Technology, ICACT 2021-February 176 - 181 2021年02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）

This paper proposes a full-duplex wireless communication system applying cooperative multiple-input multiple-output (Co-MIMO). This proposal solves self-interference (SI) in full-duplex wireless communication systems by applying the block diagonalization used in multi-user MIMO (MU-MIMO). Therefore, there is no need for a radio frequency (RF) canceller, which has a large hardware size and is difficult to extend to MIMO. Furthermore, higher throughput can be achieved by applying Co-MIMO, in which multiple access points work together to communicate. We also introduce the implementation of the proposed method using a field-programmable gate array (FPGA) and software-defined radio (SDR) in this paper. It shows that SI cancellation can be realized by using them. The proposed method is implemented based on the IEEE 802.11n frame format as an example. In the experiment, a total of 30 [dB] SI cancellation is confirmed with a transmission power of-12 [dBm]. The SI cancellation amount can be further increased by increasing the transmission power.

DOI： 10.23919/ICACT51234.2021.9370380

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Design of WLAN System for Industrial Communication 査読有り

Ito Y., Toyofuku M., Ishimitsu C., Nguyen T.T.T, Nagao Y., Lanante L., Kurosaki M., Ochi H.

International Workshop on Smart Info-Media System in Asia (SISA 2020) 2020年12月

Power Allocation Scheme for Wireless Video Streaming over Multiuser MIMO Systems 査読有り

Yoshikawa Y., Nagao Y., Kurosaki M., Ochi H.

International Workshop on Smart Info-Media System in Asia (SISA 2020) 2020年12月

Asymmetric Multi-BSS Environment Analytical Model for IEEE 802.11 Based WLANs 査読有り

Kajihara R., Wenkai H., Lanante L., Kurosaki M., Ochi H.

International Workshop on Smart Info-Media System in Asia (SISA 2020) 2020年12月

Software Defined Radio Development of Accurate Time Synchronization for Industrial WLAN Systems 査読有り

Nguyen T.T.T., Toyofuku M., Ito Y., Ishimitsu C., Nagao Y., Kurosaki M., Khai L.D., Ochi H.

IECON Proceedings (Industrial Electronics Conference) 2020-October 2134 - 2139 2020年10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）

© 2020 IEEE. In this paper, we propose a hardware development of a high accuracy Precision Time Protocol (PTP) on Software Defined Radio (SDR) for Industrial WLAN systems. To increase the throughput of the transmission system, we propose a low overhead 3-frames exchange PTP instead of 4-frames transmission as IEEE 1588 PTP protocol. Besides, our hardware-software co-design of the full SoC MAC-PHY can select the PTP timestamp point to remove the random transmission jitters caused by higher layers and the imbalanced timing made by the rugged hardware designs between master and slave. In previous work, the PTP synchronization has been evaluated on the M820-ZYNQ platform with Dummy PHY. In this paper, the proposed PTP system is developed on the SDR platform with real PHY. The SDR platform can reduce the processing delay between software and hardware compared to the previous platform. The result of our demonstration experiments shows that an oscilloscope captures the time synchronization of the proposed system in high accuracy with the nano-second level, which is less than 200 ns.

DOI： 10.1109/IECON43393.2020.9254681

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Performance analysis model of IEEE 802.11 CSMA/CA for Multi-BSS environment 査読有り

Kajihara R., Wenkai H., Lanante L., Kurosaki M., Ochi H.

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2020-August 2020年08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）

© 2020 IEEE. The Markov chain based model by Bianchi for IEEE802.11 distributed controlled access is a highly accurate analytical tool for estimating the system throughput when a single Basic Service Set (BSS) network operates in isolation. However, with the increase of wireless LAN access points being deployed on the same area, an environment with multiple BSS interfering with each other has become the default network scenario. The purpose of this work is to extend the single BSS Markov chain model into a multi-BSS model by incorporating the influence of STAs' interference range and carrier sense range to their own transmission and collision probabilities. We verify the proposed multi-BSS analytical model using the latest version of the ns3 simulator which has recently supported accurate PHY abstractions for multi-BSS simulation. We show that the proposed model has a high accuracy (within 1%) independent of the multi-BSS network topology.

DOI： 10.1109/PIMRC48278.2020.9217235

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Retransmission Diversity with Channel Selectivity for High Reliable and Low Latency Industrial Wireless Control System 査読有り

Kurniawati Astri Maria, Sutisna Nana, Lanante Jr. Leonardo, Nagao Yuhei, Kurosaki Masayuki, Ochi Hiroshi

信号処理 ( 信号処理学会 ) 24 ( 3 ) 81 - 90 2020年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

The emerging applications in the 5th generation (5G) network, such as industrial control system and Machine-to-Machine (M2M) communication require high reliability and low latency communication at the same time. The retransmission scheme is one of the practical approaches to increase system reliability when other diversity techniques are avoided due to hardware complexity or significant transmission delay. In order to address such problems, in this paper, we propose a fast yet reliable retransmission scheme. The proposed retransmission scheme leverages the frequency diversity through simple channel selectivity. The channel selectivity is carried out by employing low complexity subcarrier allocation for selecting other channels in Orthogonal Frequency Division Multiplexing (OFDM) transmission. The evaluation results show that the proposed retransmission method outperforms the conventional scheme. The proposed method can reduce the number of retransmission by up to 30%, corresponding to a success rate of 0.9999 . In addition, it can be employed in an industrial Wireless Local Area Network (iWLAN) system with a large number of users. The achievable control duration is around 52-63 μs, an improvement of approximately 36% compared to the conventional system.

DOI： 10.2299/jsp.24.81

その他リンク： https://ci.nii.ac.jp/naid/130007843050

Hardware Design of Transmitter and Receiver for High Quality Video Transmission 査読有り

Kubo K., Yoshikawa Y., Tashiro K., Lanante L., Kurosaki M., Ochi H.

2020 8th International Electrical Engineering Congress, iEECON 2020 2020年03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）

© 2020 IEEE. The demand for high-resolution wireless video transmission technology is expected to increase greatly as the video resolution increases, and as the Wi-Fi devices spread. Wireless transmission of high-resolution video requires high throughput, therefore it is necessary to use a multiple-input multiple-output (MIMO) system. In this paper, we propose an evaluation platform for video transmission method based on joint source-channel coding (JSCC) that suppresses the degradation of received video by combining source coding and precoding, and efficient hardware software co-design for implementing it on hardware such as field-programmable gate array (FPGA) board. As a result of simulation, beamforming based on eigenbeam-space division multiplexing (E-SDM), one of the precoding method, is performed and the effectiveness of the proposed method has been confirmed.

DOI： 10.1109/iEECON48109.2020.229514

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Multi-Stage MLD with Interference Cancellation in Superposition MIMO Systems for Video Streaming 査読有り

Tashiro K., Kurosaki M., Ochi H.

2020 8th International Electrical Engineering Congress, iEECON 2020 2020年03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）

© 2020 IEEE. Wireless video transmission through multiple-input multiple-output (MIMO) channels has become more and more popular recently. In the superposition MIMO system which non-orthogonally multiplexes several signals in the power domain, the receiver performs non-linear detection to estimate the transmitted signals, which is called postcoding. This paper proposes a multistage postcoder which combines maximum likelihood detection (MLD) with codeword-level interference cancellation (CWIC) to balance the accuracy and complexity. It is shown from simulations that the proposed postcoder outperforms the conventional minimum mean square error-based detection with CWIC, where its improvement in peak signal-to-noise ratio comes up to 11 dB.

DOI： 10.1109/iEECON48109.2020.229510

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Precoder and postcoder design for wireless video streaming with overloaded multiuser MIMO-OFDM systems 査読有り

Tashiro K., Kurosaki M., Ochi H.

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences ( 一般社団法人電子情報通信学会 ) E102A ( 12 ) 1825 - 1833 2019年12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）

Copyright © 2019 The Institute of Electronics, Information and Communication Engineers Mobile video traffic is expected to increase explosively because of the proliferating number of Wi-Fi terminals. An overloaded multiple-input multiple-output (MIMO) technique allows the receiver to implement smaller number of antennas than the transmitter in exchange for degradation in video quality and a large amount of computational complexity for postcoding at the receiver side. This paper proposes a novel linear precoder for high-quality video streaming in overloaded multiuser MIMO systems, which protects visually significant portions of a video stream. A low complexity postcoder is also proposed, which detects some of data symbols by linear detection and the others by a prevoting vector cancellation (PVC) approach. It is shown from simulation results that the combination use of the proposed precoder and postcoder achieves higher-quality video streaming to multiple users in a wider range of signal-to-noise ratio (SNR) than a conventional unequal error protection scheme. The proposed precoder attains 40 dB in peak signal-to-noise ratio even in poor channel conditions such as the SNR of 12 dB. In addition, due to the stepwise acquisition of data symbols by means of linear detection and PVC, the proposed postcoder reduces the number of complex additions by 76% and that of multiplications by 64% compared to the conventional PVC.

DOI： 10.1587/transfun.E102.A.1825

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Wireless Video Transmission over Multiuser MIMO Systems with Fair Power Allocation 査読有り国際誌

Yoshikawa Y., Tashiro K., Kurosaki M., Ochi H.

Proceedings - 2019 International Symposium on Intelligent Signal Processing and Communication Systems, ISPACS 2019 2019年12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）

Taiwan Taipei 2019年12月03日 - 2019年12月06日

© 2019 IEEE. With the spread of mobile devices, image and video transmission is in great demand. The use of multiuser multiple-input multiple-output (MU-MIMO) systems, where multiple data can be sent to multiple users, is highly expected. This paper proposes a novel power allocation scheme for MU-MIMO systems, which minimizes the variance of channel capacities of each spatial stream of all users to achieve user fairness in terms of video quality. In addition to the user fairness, we make the spatial streams which convey visually more important information be high-quality for achieving high video quality. Simulation results show that the proposed power allocation enables to equalize video quality even if the distances between a transmitter and users are different.

DOI： 10.1109/ISPACS48206.2019.8986256

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Power Allocation for Wireless Video Streaming over MIMO Systems with Superposition Coding 査読有り

Tashiro K., Kurosaki M., Ochi H.

International Symposium on Wireless Personal Multimedia Communications, WPMC 2019-November 2019年11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）

Portugal Lisbon 2019年11月24日 - 2019年11月27日

© 2019 IEEE. Recently, video distribution over wireless networks has become more common due to the spread of smart devices. This paper proposes an optimal power allocation algorithm for the transmission of layered video streams over point-to-point multiple-input multiple-output (MIMO) systems combined with superposition coding. The proposed power allocation scheme is derived from the maximization of the weighted sum-rate, where two-step optimization leads to a closed-form solution. First, the power distribution between eigen-channels is optimized, and then the optimal power allocation to quality layers is obtained. Results demonstrate that the proposed scheme attains higher peak signalto-noise ratio on average in a wide range of signal-to-noise ratio than conventional fixed power allocation schemes.

DOI： 10.1109/WPMC48795.2019.9096159

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Development of Factory Automation WLAN System Compatible with Asynchronous Industrial Ethernet 査読有り

Nguyen T., Tsurita M., Toyofuku M., Ito Y., Nagao Y., Kurosaki M., Ochi H.

IEEE International Conference on Emerging Technologies and Factory Automation, ETFA 2019-September 1338 - 1341 2019年09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）

Spain Zaragoza 2019年09月10日 - 2019年09月13日

© 2019 IEEE. In this paper, we propose a design of asynchronous communication for an industrial wireless LAN system. In our design, MAC is synchronous multi-user round-robin transmission protocol. Low overhead Packet Division Multiple Access scheme is utilized for Multi-user Downlink transmission up to 80 MHz, while Frequency Division Multiple Access is employed for the uplink transmission. The designed of PHY system is developed based on a fast and deterministic communication featuring the synchronous multi-user system. In this paper, the industrial robots are not only controlled by synchronous communication but also by asynchronous communication via our industrial WLAN (iWLAN) system. This paper presents the hardware and software cooperative design. In the verification, up to 10 motors can be controlled by our iWLAN system by asynchronous communication, and the delay of each robot measured is 188 μs on average. Besides, the time synchronization captured by oscilloscope is from 40 to 100 ns as in our target.

DOI： 10.1109/ETFA.2019.8868973

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Verification of Symbol Timing Synchronization for Wi-Fi System 査読有り国際誌

Kusunoki I., Nagano K., Sutisna N., Nagao Y., Lanante L., Kurosaki M., Ochi H.

Proceedings - 2019 19th International Symposium on Communications and Information Technologies, ISCIT 2019 167 - 172 2019年09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）

Vietnam Ho Chi Minh City 2019年09月25日 - 2019年09月27日

© 2019 IEEE. In this paper, we propose a system that verifies and corrects the accuracy of symbol timing synchronization processing to determine reception time in Wi-Fi system. Time-of-flight (ToF) based Wi-Fi indoor mobile position estimation uses transmission and reception time stamp of radio waves between the mobile terminal targeted for estimation and fixed Wi-Fi receivers. However, it is known that the accuracy of radio reception time stamp in existing Wi-Fi receivers may be deteriorated due to the influence of multipath environment. Therefore, this paper proposes a system that corrects the accuracy of symbol timing synchronization processing that determines the reception time of radio wave in Wi-Fi system. This will improve the estimation accuracy of Wi-Fi indoor mobile position estimation.

DOI： 10.1109/ISCIT.2019.8905193

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Low-complexity and high-accuracy positioning protocol based on an asynchronous protocol 査読有り

Nan W., Nguyen T., Nagao Y., Lanante L., Kurosaki M., Ochi H.

IEEE Vehicular Technology Conference 2019-September 2019年09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）

USA Honolulu, Hawaii 2019年09月22日 - 2019年09月25日

© 2019 IEEE. Currently, Global Positioning System (GPS) is widely used as a representative position estimation system. However, GPS suffers from poor position estimation accuracy in an indoor environment. Moreover, time synchronization between devices needs to be performed for position estimation which is a resource intensive process. In previous studies, an asynchronous protocol (i.e., no synchronization requirement) called Grid Search was proposed to handle this problem. However, this method also has high complexity and takes a lot of search time to estimate the position. In this paper, we propose a method to narrow the search range using intersecting chord under the condition that generated circles intersect with each other. The proposed position estimation method has low complexity but can achieve accuracy comparable to Grid Search, i.e., a maximum estimation error less than 2 meters with 80% of the trials are within 1 meter. In addition, the calculation time can be reduced up to 6 times compared to the Grid Search when the search range extends to 5 times.

DOI： 10.1109/VTCFall.2019.8891468

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Live demonstration: Accurate time synchronization for industrial wireless LAN systems 査読有り

Tran Thi Thao Nguyen, Yuhei Nagao, Nico Surantha, Masayuki Kurosaki, Hiroshi Ochi

Proceedings - IEEE International Symposium on Circuits and Systems 2019-May 2019年05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）

Japan Sapporo 2019年05月26日 - 2019年05月29日

© 2019 IEEE We demonstrate a precision time protocol (PTP) used to synchronize clocks in industrial wireless local area network (iWLAN) communication systems. The implementation of the system on FPGA boards for accurate verification and to test the feasibility of the system in a real environment. The result has been confirmed that time synchronization is high accuracy from 40 to 100 ns.

DOI： 10.1109/ISCAS.2019.8702192

Kyutacar

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High Precision Industrial Wireless LAN System with Asynchronous Communication 査読有り

Tran Thi Thao Nguyen, Makoto Tsurita, Kyoshiro Sakamoto, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

International Conference on Advanced Communication Technology, ICACT 2019-February 222 - 227 2019年04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）

Korea Pyeongchang 2019年02月17日 - 2019年02月20日

© 2019 Global IT Research Institute (GIRI). In this paper, we propose an industrial Wireless Local Area Network (iWLAN) system compatible with asynchronous communication for industrial robots (iRBs) control in factory automation (FA) environments. The design of our media access control layer is synchronous multi-user round-robin transmission protocol. Low overhead Packet Division Multiple Access (PDMA) scheme is utilized for Multi-user Downlink transmission up to 80 MHz, while Frequency Division Multiple Access (FDMA) is employed for the uplink transmission. The system is developed based on a fast and deterministic communication featuring the synchronous multi-user system. In general, the iRBs are not only controlled by synchronous communication but also by asynchronous communication via this iWLAN system. In this paper, we present the Field-programmable gate array (FPGA) implementation are carried out to confirm that our iWLAN system by asynchronous communication can control up to four motors. Based on the result of FPGA implementation, the time synchronization of the proposed system in high accuracy from 40 to 100 ns is also captured by an oscilloscope.

DOI： 10.23919/ICACT.2019.8701902

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Asynchronous Indoor Positioning System and Its FPGA Implementation 査読有り

Kotaro Nagano, Yuhei Nagao, Leonardo Lanante Jr, Masayuki Kurosaki, Hiroshi Ochi

Proceedings of 7th Japan-Korea Joint Workshop on Complex Communication Sciences (JKCCS'19) 2019年01月

Industrial Wireless LAN System Compatible with EtherCAT 査読有り

Kyoshiro Sakamoto, Makoto Tsurita, Yuhei Nagao, Mizuki Toyofuku, Yoshiki Itou, Tran Thi Thao Nguyen, Tatsumi Uwai, Masayuki Kurosaki, Hiroshi Ochi

Proceedings of 7th Japan-Korea Joint Workshop on Complex Communication Sciences (JKCCS'19) 2019年01月

Performance Evaluation of MU-MIMO Channel Emulator 査読有り

Kyosuke Kubo, Tran Thi Thao Nguyen, Leonardo Lanante Jr, Masayuki Kurosaki, Hiroshi Ochi

Proceedings of 7th Japan-Korea Joint Workshop on Complex Communication Sciences (JKCCS'19) 2019年01月

High Precision Localization by Shrinking Circle based on An Asynchronous Protocol 査読有り

Nan Wang, Leonardo Lanante Jr, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proceedings of 7th Japan-Korea Joint Workshop on Complex Communication Sciences (JKCCS'19) 2019年01月

FPGA Implementation of Wireless LAN System for Factory Automation 査読有り

Tran Thi Thao Nguyen, Yuhei Nagao, Tatsumi Uwai, Nana Sutisna, Masayuki Kurosaki, Hiroshi Ochi, Baiko Sai

International Conference on Advanced Technologies for Communications 2018-October 78 - 83 2018年12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）

Vietnam Ho Chi MInh City 2018年10月18日 - 2018年10月20日

© 2018 IEEE. A design of wireless communication system, particularly Media Access Control (MAC) and Physical layer system (PHY) for Factory Automation (FA) system based on Wireless Local Area Network (WLAN) communication system, is proposed in this paper. The designed of MAC is synchronous multi-user round-robin transmission protocol. Low overhead Packet Division Multiple Access (PDMA) scheme is utilized for Multi-user Downlink transmission up to 80 MHz, while Frequency Division Multiple Access (FDMA) is employed for the uplink transmission. The designed of PHY system is developed based on a fast and deterministic communication featuring the synchronous multi-user system. For efficient of multi-user transmission in the proposed protocol, the transmission time of the proposed iWLAN with 40 MHz bandwidth can achieve 500% better than PROFINET wireless standard. Furthermore, the implementation results of MAC and PHY layer of the proposed system show that FPGA logic utilization can fit with the target FPGA which is promising for a full implementation and evaluation combining with radio frequency.

DOI： 10.1109/ATC.2018.8587479

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Optimized Packetization of H.264 SVC Bitstreams for MIMO Wireless Video Streaming 査読有り

Tiawongsuwan M., Tashiro K., Kurosaki M., Ochi H.

ISCIT 2018 - 18th International Symposium on Communication and Information Technology 355 - 358 2018年12月

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）

© 2018 IEEE. Wireless video transmission over multiple-input multiple-output (MIMO) systems is a challenging theme. Eigen beam-space division multiplexing (E-SDM) is an optimal beamforming technique in terms of channel capacity when the transmitter and receiver can share channel state information. E-SDM sorts the channel quality from the highest signal-To-noise ratio (SNR) to the lowest one. This paper presents the video transmission scheme for H.264 scalable video streams over MIMO E-SDM with optimized packetization. The proposed method controls the ratio of a base layer and enhancement layers contained in a packet. The result shows that the optimized ratio is obtained when a packet consists of the lowest base layer ratio. This ratio provides the 39.9 dB of peak-signal-To-noise ratio after decoding while no frame can be decoded with the other ratio at SNR of 10 dB.

DOI： 10.1109/ISCIT.2018.8587974

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Greedy Power Allocation for Wireless Video Streaming with Overloaded MIMO Systems 査読有り

Koji Tashiro, Masayuki Kurosaki, Hiroshi Ochi

Proc. 2018 International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS) 2018年11月

Industrial Wireless LAN System Compatible with Asynchronous Communication 査読有り

Makoto Tsurita, Kyoshiro Sakamoto, Mizuki Toyofuku, Yoshiki Itou, Tran Thi Thao Nguyen, Tatsumi Uwai, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. 2018 International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS) 2018年11月

Greedy Power Allocation for Wireless Video Streaming with Overloaded MIMO Systems 査読有り

Tashiro K., Kurosaki M., Ochi H.

ISPACS 2018 - 2018 International Symposium on Intelligent Signal Processing and Communication Systems 155 - 160 2018年11月

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）

© 2018 IEEE. In recent years, wireless video streaming has become very popular due to the widespread of Wi-Fi terminals supporting multiple-input multiple-output (MIMO) techniques. High-quality video streaming in wireless networks is a challenging topic. This paper proposes a greedy power allocation algorithm (GPA) for video streaming by overloaded MIMO systems. The proposed GPA adaptively controls power distribution based on received signal-to-noise ratio (SNR) so that the required bit error rate can be achieved. Simulation results demonstrate that GPA shows better performance than a conventional equal power allocation (EPA) scheme in terms of peak-signal-to-noise ratio (PSNR). The minimum SNR for achieving 35 dB in PSNR is 6 dB with GPA while EPA requires 10 dB in SNR to achieve 35 dB in PSNR.

DOI： 10.1109/ISPACS.2018.8923194

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Industrial Wireless LAN System Compatible with Asynchronous Communication 査読有り

Tsurita M., Ochi H., Sakamoto K., Toyofuku M., Itou Y., Nguyen T.T.T., Uwai T., Nagao Y., Kurosaki M., Sai B.

ISPACS 2018 - 2018 International Symposium on Intelligent Signal Processing and Communication Systems 168 - 172 2018年11月

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）

© 2018 IEEE. In this research, we propose an industrial Wireless Local Area Network (iWLAN) system compatible with asynchronous communication for industrial robots (iRBs) control in factory automation (FA) environments. In FA, iRBs are not only controlled by synchronous communication but also by asynchronous communication. As our conventional system is not compatible with asynchronous communication, it causes delay when iRBs are controlled by asynchronous communication. In order to target iRBs using asynchronous communication, we propose the utilization of specific memory writing technique. The register transfer level (RTL) simulation results show that our proposals can communicate with iRBs in faster throughput, better than the conventional system. Furthermore, the field-programmable gate array (FPGA) implementation are carried out to confirm that motors can be controlled by our iWLAN system compatible with asynchronous communication.

DOI： 10.1109/ISPACS.2018.8923192

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Efficient MIMO video transmission scheme for the scalable video coding extension of HEVC 査読有り

Manthana Tiawongsuwan, Koji Tashiro, Leonardo Lanante, Masayuki Kurosaki, Hiroshi Ochi

2018 International Workshop on Advanced Image Technology, IWAIT 2018 1 - 3 2018年05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）

© 2018 IEEE. High efficiency video coding (HEVC) is the newest video coding standard of the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. The introduction of multiple-input multiple-output (MIMO) eigenbeam-space division multiplexing (E-SDM) systems makes it possible to increase data rate by multiplexing different data streams on multiple parallel eigen-channels. In this paper, we propose a MIMO video transmission scheme for scalable high efficiency video coding (SHVC), which is the scalable extension of H.265/HEVC. Simulation results show that our video transmission scheme has more potential to broadcast video streams efficiently than conventional MIMO systems.

DOI： 10.1109/IWAIT.2018.8369630

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Energy efficient industrial wireless system through cross layer optimization 査読有り

Kurniawati Astri Maria, Nana Sutisna, Tran Thi Thao Nguyen, Duc Khai Lam, Yuhei Nagao, Leonardo Lanante, MasayukiKurosaki, Hiroshi Ochi

Proc. IEEE International Conference on Industrial Technology (ICIT) 2018-February 1586 - 1591 2018年02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）

France Lyon 2018年02月20日 - 2018年02月22日

Industrial wireless system has been considered as a potential application in the upcoming wireless system (e.g. 5G and IoT era). The main requirements of this application are ultra-reliable low-latency and low-power massive machine type communication. Satisfying all these requirements at the same time is still big technical challenge, since many aspects from different layers of network system are inter-dependent in affecting overall system performance. Therefore, system design and optimization are difficult and could not be carried out solely in one part. To overcome these issues, this paper presents cross-layer optimization in order to achieve energy-efficient wireless system, while maintaining low-latency and high-reliability requirements. The cross-layer optimization is performed within Medium Access Layer (MAC) and Physical Layer (PHY), which are devoted as the backbone for radio access. The optimizations include system level design, low-power aware protocol and resource management design, signal processing algorithm design and circuit design techniques of transceiver system. Furthermore, the implementation of overall PHY-MAC hardware design for industrial wireless LAN system is presented. The proposed design offers an advantage, in terms of energy-efficient wireless system, as compared to the other classes of low-power wireless systems (e.g. Bluetooth, Zigbee) and the conventional WLAN systems.

DOI： 10.1109/ICIT.2018.8352418

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A hybrid HW/SW 802.11ac/ax system design platform with ASIP implementation 査読有り

Naotaka Yoshida, Leonardo Lanante, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

2017 International Symposium on Intelligent Signal Processing and Communication Systems, ISPACS 2017 - Proceedings 2018-January 827 - 831 2018年01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）

Chaina Xiamen 2017年11月06日 - 2017年11月09日

© 2017 IEEE. Current and next generation WLAN devices have an increasing need for processing power to support new WLAN features that require high computation complexity. In this paper, we present our design for an 802.11ac/ax system with an application specific instruction-set processor (ASIP) to implement multiple disjoint system tasks at much faster speed compared to a general purpose processor. As a proof of concept, we implemented the channel SVD, channel compression/decompression and beam-forming weight computations at the same time in the embedded ASIP core to support the 802.11ac MU-MIMO beamforming feature. In addition, the design was synthesized in the Zynq zc706 evaluation board programmable logic (PL) along with the rest of the PHY. The actual task to be done by the ASIP core at any given time can be programmed via the zc706 processing system (PS) resulting in a very high hardware savings compared to an all hardware implementation.

DOI： 10.1109/ISPACS.2017.8266590

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Efficient MIMO Video Transmission Scheme for the Scalable Video Coding Extension of HEVC 査読有り

Manthana Tiawongsuwan, Koji Tashiro, Leonardo Lanante, Masayuki Kurosaki, Hiroshi Ochi

Proc.International Workshop on Advance Image Technology 2018 (IWAIT2018) 2018年01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）

Thailand Chiang Mai 2018年01月07日 - 2018年01月10日

High efficiency video coding (HEVC) is the newest video coding standard of the ITU-T video coding experts group and the ISO/IEC moving picture experts group. The introduction of multiple-input multiple-output (MIMO) eigenbeam-space division multiplexing (E-SDM) systems makes it possible to increase data rate by multiplexing different data streams on multiple parallel eigen-channels. In this paper, we propose a MIMO video transmission scheme for scalable high efficiency video coding (SHVC), which is the scalable extension of H.265/HEVC. Simulation results show that our video transmission scheme has more potential to broadcast video streams efficiently than conventional MIMO systems.

High-Accuracy Positioning System based on ToA for Industrial Wireless LAN 査読有り

Tran Thi Thao Nguyen, Khairunisa Ahmad Denney, Ohhara Syuhei, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. 2017 4th NAFOSTED Conference on Information and Computer Science 2017-January 37 - 41 2017年11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）

Vietnam Hanoi 2017年11月24日 - 2017年11月25日

In this paper, we propose a positioning system using a time-synchronized wireless network that can achieve high positioning accuracy without being dependent on any global positioning system (GPS) devices with cm-level accuracy as the main goal and objective. The proposed system utilizes time of arrival (ToA) method to estimate the target's position. Based on the results, we can achieve time synchronization with less than 1ns accuracy with the average offset error of 0.05ns and cm-level positioning accuracy with the position error of 1.23cm through our simulation. Furthermore, increasing the number or measuring device in positioning system will increase the accuracy of positioning a target. High accuracy time synchronization is achievable by deploying proposed PTP with a high number of iteration performed inside the synchronization period. In this research, we aim to deploy the proposed system in industrial wireless LAN. It is applicable by embedding the system into customized wireless LAN chip with positioning ability.

DOI： 10.1109/NAFOSTED.2017.8108035

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Joint transmission and coding scheme for high-resolution video streams over multiuser MIMO-OFDM systems 査読有り

Koji Tashiro, Leonardo Lanante, Masayuki Kurosaki, Hiroshi Ochi

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences ( 一般社団法人電子情報通信学会 ) E100-A ( 11 ) 2304 - 2313 2017年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

High-resolution image and video communication in home networks is highly expected to proliferate with the spread of Wi-Fi devices and the introduction of multiple-input multiple-output (MIMO) systems. This paper proposes a joint transmission and coding scheme for broadcasting high-resolution video streams over multiuser MIMO systems with an eigenbeam-space division multiplexing (E-SDM) technique. Scalable video coding makes it possible to produce the code stream comprised of multiple layers having unequal contribution to image quality. The proposed scheme jointly assigns the data of scalable code streams to subcarriers and spatial streams based on their signal-to-noise ratio (SNR) values in order to transmit visually important data with high reliability. Simulation results show that the proposed scheme surpasses the conventional unequal power allocation (UPA) approach in terms of both peak signal-to-noise ratio (PSNR) of received images and correct decoding probability. PSNR performance of the proposed scheme exceeds 35dB with the probability of over 95% when received SNR is higher than 6dB. The improvement in average PSNR by the proposed scheme compared to the conventional UPA comes up to approx. 20dB at received SNR of 6dB. Furthermore, correct decoding probability reaches 95% when received SNR is greater than 4dB.

DOI： 10.1587/transfun.E100.A.2304

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Channel Selectivity Schemes for Re-transmission Diversity in Industrial Wireless System 査読有り

Astri Maria Kurniawati, Nana Sutisna, Yuhei Nagao, Leonardo Lanante Jr, Masayuki Kurosaki, Baiko Sai, Hiroshi Ochi

Proc. International Symposium on Electronics and Smart Devices (ISESD) 2018-January 207 - 212 2017年10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）

Indonseia Yogyakarta 2017年10月17日 - 2017年10月19日

The new use case of 5G network, such as industrial wireless control system and Machine-to-Machine (M2M) communication system, requires high reliability and real-time communication (ultra low-latency) at the same time. To increase system reliability, re-transmission scheme is one of popular technique, but it introduces a significant communication latency. To address this latency introduced by conventional re-transmission scheme, this paper presents re-transmission diversity through channel selectivity. Adjacent channel selection and random channel selection are the two channel selectivity schemes that are being considered as fast and low-latency channel selection method. The performance comparison of these two schemes are evaluated in an industrial wireless system. Evaluation results show that channel selectivity based on adjacent channel selection gives a better performance as compared with random channel selection. Furthermore, the impact of channel selectivity in different channel models are also presented to evaluate its effectiveness and to provide an insight for final deployment.

DOI： 10.1109/ISESD.2017.8253333

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Unified HW/SW System-Level Simulation Framework for Next Generation Wireless System 査読有り

Nana Sutisna, Leeonardo Lanante Jr., Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. 2017 30th IEEE International System-on-Chip Conference (SOCC) 2017-September 322 - 327 2017年09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）

Germay Munich 2017年09月05日 - 2017年09月08日

Recently, wireless technology experiences a fast growth to meet user demand and push toward the boundary limit of system performance. The simulation and verification framework play important role for accelerating investigation of technology proof of concept, field-trial, and large-scale commercial prototyping. In this paper, we present system-level simulation of heterogeneous model and unified HW/SW framework, particularly for next generation wireless system. The proposed framework includes a unified HW/SW co-evaluation methodology, the flexible HW/SW architecture, and fast HW/SW co-evaluation. The co-evaluation is carried out by employing hardware-in-the loop scheme that covers various abstraction level of simulation, from algorithm-level into physical-level simulation, with respect to system level simulation. The proposed co-verification framework allows a comprehensive system evaluation for a wireless system, involving various system parameters, hardware impairments, different channel conditions and cross-layer evaluations with fast run-time evaluations. Additionally, we also show an application example of multi-user wireless communication system and its experimental evaluations.

DOI： 10.1109/SOCC.2017.8226070

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Precoding and postcosing schemes for wireless video transmission in overloded MIMO systems 査読有り

Koji Tashiro, Leonardo Lanante, Masayuki Kurosaki, Hiroshi Ochi

Proc. IEEE International Conference on Image Processing (ICIP 2017) 2017-September 1920 - 1924 2017年09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）

China Beijing 2017年09月17日 - 2017年09月20日

Image and video transmission is highly expected to proliferate with the wide spread of Wi-Fi devices and the introduction of multiple-input multiple-output (MIMO) systems. This paper proposes a novel precoder for video transmission in overloaded MIMO systems, which is based on an eigenbeam space division multiplexing (E-SDM) technique. This paper also proposes a low complexity postcoder, which detects some of data symbols by a linear approach and the others by a prevoting vector cancellation (PVC) approach. It is shown from simulation results that the proposed precoder and postcoder achieve 40 dB in peak signal-to-noise ratio while reducing the computational complexity by over 61 compared to the conventional PVC-based detection when received signal-to-noise ratio is higher than 10 dB.

DOI： 10.1109/ICIP.2017.8296616

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Analysis of Finite Retry Limit on Uplink OFDMA Random Access 査読有り

Tomoyasu Irikida, Tatsumi Uwai, Leonardo Lanante Jr., Masayuki Kurosaki, Hiroshi Ochi

Proc. 2017 International Workshop on Smart Info-Media Systems in Asia (SISA 2017) 2017年09月

Scalable Copyright Protection using Lossless Information Hiding 査読有り

Koichi Araki, Tsubasa Sonezaki, Masayuki Kurosaki, Hiroshi Ochi

Proc. 2017 International Workshop on Smart Info-Media Systems in Asia (SISA 2017) 2017年09月

OFDMAランダムアクセスのマルコフ連鎖モデル化とその性能解析査読有り

上井竜己, 長尾勇平, ラナンテジュニア, 黒崎正行, 尾知博

電子情報通信学会論文誌B 通信 ( 電子情報通信学会 ) J100-B ( 7 ) 492 - 504 2017年07月

記述言語：日本語掲載種別：研究論文（学術雑誌）

次世代無線LAN規格IEEE 802.11axにおいて採用が決定しているUplink-Multi User送信では，Orthogonal Frequency Division Multiple Access (OFDMA)ランダムアクセスが検討されている．本論文ではOFDMAランダムアクセスのマルコフ連鎖モデルを提案し，提案モデルがIEEE 802.11規格におけるDistributed Coordination Functionの性能解析モデルとして基本的なモデルであるBianchiモデルの拡張モデルとみなせることを示す．提案モデルを用いてOFDMAランダムアクセスの通信効率とスループットを解析し，解析結果と計算機シミュレーション結果の比較を通して，稠密環境におけるOFDMAランダムアクセスの性能を高精度に解析可能であることを示す．更に，OFDMAランダムアクセスの通信効率をMedium Access Control (MAC)パラメータに着目して解析し，環境に応じてMACパラメータを設定することで，通信効率が向上することを示す．

DOI： 10.14923/transcomj.2016wfp0005

Interleaved Domain Interference Canceller for Low Latency IDMA System and Its VLSI Implementation 査読有り

Tran Thi Thao Nguyen, Leonardo Lanante, Yuhei Nagao, Masayuki Kurosaki, Shingo Yoshizawa, Hiroshi Ochi

Proc. 2017 IEEE 85th Vehicular Technology Conference (VTC Spring) 2017-June 2017年06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）

Australia Sydney 2017年06月04日 - 2017年06月07日

Interleave division multiple access (IDMA) is a potential candidate for the future fifth generation (5G) systems. In this paper, we propose a novel architecture for IDMA system with low latency while maintaining low complexity. In the conventional architecture, the IDMA receiver sequentially processes deinterleaving, despreading, spreading and interleaving for multiuser detection. The proposed architecture, which is called the interleaved domain, can perform multi-user detection directly without deinterleaving the received frame. Because of this, the interleaving is no longer needed in the interference cancellation loop resulting in the decrease of latency by half and the increase of throughput by twice. In VLSI implementation results, the proposed architecture has reduced circuit area and power consumption by 53% and 58% compared to the conventional architecture on the same throughput condition.

DOI： 10.1109/VTCSpring.2017.8108683

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Performance analysis of the 802.11ax UL OFDMA random access protocol in dense networks 査読有り

Leonardo Lanante, Hiroshi Ochi, Tatsumi Uwai, Yuhei Nagao, Masayuki Kurosaki, Chittabratta Ghosh

Proc. 2017 IEEE International Conference on Communications (ICC) 1 - 6 2017年05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）

France Paris 2017年05月21日 - 2017年05月25日

Recently, 802.11ax has introduced uplink Orthogonal Frequency Division Multiple Access (UL OFDMA)-based random access transmission to provide uplink multiuser capability to stations (STA) with unknown buffer status. These STAs include those that are waking up from sleep and unassociated STAs trying to establish connection for the first time. Due to the absence of carrier sensing per resource unit, this procedure has a maximum efficiency of only about 37% for high number of STAs. The efficiency will decrease further without properly choosing the random access parameters. In this paper, we first build an analytical model of the performance of UL OFDMA random access transmission and verify it using simulations. In addition, we propose methods to optimize various random access parameters to maintain a system efficiency near the 37% limit. Simulation results show that our optimization methods can increase the throughput of UL OFDMA random access by as much as 39% when compared to randomly chosen parameters.

DOI： 10.1109/ICC.2017.7997340

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85028300693&origin=inward

Re-transmission diversity with fast channel selectivity for reliable industrial WLAN system 査読有り

Maria K., Nagao Y., Lanante L., Kurosaki M., Ochi H.

Proceedings of the IEEE International Conference on Industrial Technology 1189 - 1194 2017年04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）

Canada Toronto 2017年03月22日 - 2017年03月25日

© 2017 IEEE. This paper proposes a fast and low-complexity retransmission scheme for Industrial WLAN system. The proposed scheme exploits the frequency diversity and employs channel selectivity in order to achieve high-reliability and low-latency communication. The channel selectivity is carried out instantly by re-scheduling sub-carrier allocation during OFDM transmission in order to obtain diversity gain. Evaluation results show that the performance of the proposed scheme in terms of system-error rate and achievable transmission throughput rate, are significantly improved from the conventional re-transmission scheme. Furthermore, the proposed method only need a minor modification in both of communication protocol and transceiver design from the existing Industrial WLAN system. Hence, the low-complexity transmission scheme could be realized in current OFDM-based wireless system.

DOI： 10.1109/ICIT.2017.7915531

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Low latency Interleave Division Multiple Access System 査読有り国際誌

Nguyen T., Lanante L., Nagao Y., Kurosaki M., Yoshizawa S., Ochi H.

International Conference on Information Networking 7 - 12 2017年04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）

Vietnam Da Nang 2017年01月11日 - 2017年01月13日

© 2017 IEEE. In this paper, we propose a novel architecture for IDMA system with low latency and high throughput for the uplink multi-user wireless system. The throughput of the proposed IDMA system can be improved to about double compared to the conventional IDMA system while the hardware complexity remains unchanged. To achieve this, the proposed system utilizes the interleaver/de-interleaver-less architecture to minimize the latency of the interference canceller in IDMA receiver. In the conventional architecture, the IDMA receiver sequentially processes the de-interleaving, interleaving, de-spreading and spreading that cause high latency. The proposed architecture can perform these sequential processes at the same time resulting in a reduction of interference cancellation operation cycles in half.

DOI： 10.1109/ICOIN.2017.7899444

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85018302531&origin=inward

An area-efficient multimode FFT circuit for IEEE 802.11 ax WLAN devices 査読有り国際誌

Dinh P., Lanante L., Nguyen M., Kurosaki M., Ochi H.

International Conference on Advanced Communication Technology, ICACT 735 - 739 2017年03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）

Korea Pyongchang 2017年02月19日 - 2017年02月22日

© 2017 Global IT Research Institute - GiRI. Multi-mode fast Fourier Transform (FFT) circuits are essential in orthogonal frequency domain (OFDM) based systems which supports multiple bandwidth. Typically, hardware implementation employs a single FFT circuit for the highest supported bandwidth and using oversampling, the same FFT circuit is used to support lower bandwidth. For the new 802.11ax wireless local area network (WLAN) standard whose frame consists of the regular 3.2us length symbol as well as a longer 12.8us symbol, a fast switchable double-mode FFT circuit is required. In addition, the 802.11ax SIG-B symbol contains a maximum of two independent symbol streams that requires two FFT circuits for the 3.2us symbol length. Our proposed FFT architecture is optimized to support the 802.11ax standard with low latency, area and power requirements. FPGA implementation results show that our proposed circuit has efficiency 13.7% lower area compared to conventional architecture.

DOI： 10.23919/ICACT.2017.7890190

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85018460543&origin=inward

Performance evaluation of OFDMA random access in IEEE802.11ax 査読有り国際誌

Uwai T., Miyamoto T., Nagao Y., Lanante L., Kurosaki M., Ochi H.

2016 International Symposium on Intelligent Signal Processing and Communication Systems, ISPACS 2016 2017年01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）

© 2016 IEEE. Random access Orthogonal Frequency Division Multiple Access (OFDMA), a method for uplink multi-user transmission (UL-MU) for STAs with unknown transmit buffer has been adopted in the upcoming IEEE802.11ax next generation wireless LAN standard. In this paper, we propose a performance analysis model which use bidimensional Markov chain model of OFDMA random access. Via computer simulation, we show the usefulness of the proposed method even in the case of dense environment. In addition, we present a method in calculating the optimal number of resource units, which in 802.11ax refer to a subset of subcarriers to assign the user for OFDMA random access from numerical results.

DOI： 10.1109/ISPACS.2016.7824740

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85015004832&origin=inward

ToA-based positioning system for industrial wireless LAN 査読有り

Denney K., Hamada M., Nagao Y., Kurosaki M., Ochi H.

2016 International Symposium on Intelligent Signal Processing and Communication Systems, ISPACS 2016 2017年01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）

Thailand Phulket 2016年10月24日 - 2016年10月27日

© 2016 IEEE. In this paper, we propose an alternative positioning system using time-synchronized wireless network that can achieve high positioning accuracy without being dependent to any global positioning system (GPS) devices with cm-level accuracy as the main goal and objective. The proposed system utilizes time of arrival (ToA) method in order to estimate the target's position. Based on the results, we can achieve time synchronization with less than 1ns (average offset error of 0.05ns) accuracy and cm-level (position error of 1.23cm) positioning accuracy through our simulation. Furthermore, increasing the number or measuring device in positioning system will increase the accuracy of positioning a target. High accuracy time synchronization is achievable by deploying proposed PTP with high number of iteration in synchronization period. In this research, we aim to deploy the proposed system in industrial wireless LAN. It is applicable by embedding the system into customized wireless LAN chip with positioning ability.

DOI： 10.1109/ISPACS.2016.7824744

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85015004753&origin=inward

Unified HW/SW framework for efficient system level simulation 査読有り

Sutisna N., Lanante L., Nagao Y., Kurosaki M., Ochi H.

2016 IEEE Asia Pacific Conference on Circuits and Systems, APCCAS 2016 518 - 521 2017年01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）

South Korea Jeju 2016年10月25日 - 2016年10月28日

© 2016 IEEE. In this paper, we present unified Hardware (HW)/Software (SW) framework for efficient system level simulation of complex circuits, particularly high throughput wireless communication system. The proposed framework include a unified methodology covering both of system level simulation (e.g. MATLAB or C/C++) and physical level verification (e.g FPGA). It allows performing fast HW/SW evaluation in the context of system level performance and also covering large number of verification scenarios within acceptable time. Experimental evaluations show the example design case achieves improvement of simulation time several orders of magnitude faster than pure software simulation and also capable to run in near real-time processing. Moreover, the proposed verification platform can be used for complete performance characterization of a MIMO wireless system under various system parameters, hardware impairments and channel model.

DOI： 10.1109/APCCAS.2016.7804018

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85011031730&origin=inward

Adaptive backoff mechanism for OFDMA random access with finite service period in IEEE802.11ax 査読有り国際誌

Uwai T., Miyamoto T., Nagao Y., Lanante L., Kurosaki M., Ochi H.

2016 IEEE Conference on Standards for Communications and Networking, CSCN 2016 2016年12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）

Germany Berlin 2016年10月31日 - 2016年11月02日

© 2016 IEEE. In next generation wireless LAN standard which is called IEEE802.11ax, Orthogonal Frequency Division Multiple Access (OFDMA) random access has been adopted as an uplink multi-user transmission technology. In this paper, we propose an adaptive backoff algorithm for OFDMA random access. Due to the finite service period defined by the standard, random access OFDMA sessions are discontinuous in time which may result in performance degradation when naive implementations are performed. Via computer simulations, we show that near maximum throughput is consistently achieved even in the case of dense environment. In addition, we explain a method for accurately estimating the number of OFDMA random access users, a key parameter in the proposed adaptive method.

DOI： 10.1109/CSCN.2016.7785174

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85010303856&origin=inward

Performance Evaluation of OFDMA Random Access in IEEE802.11ax 査読有り

Tatsumi Uwai, Takuma Miyamoto, Yuhei Nagao, Leonardo Lanante Jr., Masayuki Kurosaki, Hiroshi Ochi

Proc. IEEE International Symposium on Intelligent Signal Processing and Communication Systems 2016年10月

Design of WLAN based system for fast protocol factory automation system 査読有り

Maria K., Lam D., Lanante L., Nagao Y., Kurosaki M., Ochi H., Areni I.

Proceedings - Asia-Pacific Conference on Communications, APCC 2016 430 - 435 2016年10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）

Indonesia Yogyakarta 2016年08月25日 - 2016年08月27日

© 2016 IEEE. This paper proposes a design of wireless communication system, particularly physical layer system (PHY) for Factory Automation (FA) system based on Wireless Local Area Network (WLAN) communication system. The designed PHY system is developed based on a fast and deterministic communication featuring a synchronous multi user round robin transmission protocol. Low overhead Packet Division Multiple Access (PDMA) scheme is utilized for Multi-user Downlink transmission, while the Frequency Division Multiple Access (FDMA) is employed for the uplink transmission. For efficient PHY implementation, several approaches on architectural aspects are also introduced. Implementation results show that the optimized design of transmitter and receiver have efficient logic resource while maintain required processing speed and error performance.

DOI： 10.1109/APCC.2016.7581430

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84994655892&origin=inward

Overview of Next Generation Wireless LAN IEEE 802.11ax 査読有り

Yuhei Nagao, Leonardo Lanante, Tatsumi Uwai, Masayuki Kurosaki, Hiroshi Ochi

Proc. International Workshop on Smart Info-Media Systems in Asia 248 - 253 2016年09月

MU-MIMO channel emulator with automatic channel sounding feedback for IEEE 802.11ac 査読有り

Nguyen T., Lanante L., Nagao Y., Kurosaki M., Ochi H.

IEEE Wireless Communications and Networking Conference, WCNC 2016-September 2016年09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）

Qatar Doha 2016年04月03日 - 2016年04月06日

© 2016 IEEE. This paper proposes a 4×4 MU-MIMO channel emulator with automatic channel sounding feedback used for beam-forming and MU-MIMO precoding features of IEEE 802.11ac. The main contribution of this paper is the design of a MU-MIMO channel emulator capable of sending channel feedback automatically to the AP from the generated channel coefficients after a programmable time duration. This function helps to evaluate the precoding algorithms without channel estimation error and uses very minimal MAC features. The second contribution is the design of single path implementation with serial processing which plays an important role on reducing the hardware complexity. The design choice makes it possible to generate channel coefficients for very high sampling rate systems with little increase in complexity. In addition, single path implementation allows the addition of the feedback channel output with only few additional nonsequential elements which would otherwise double in a parallel implementation. To demonstrate the functionality of our MU-MIMO channel emulator, we present actual hardware emulator results of precoded receive signal constellation on oscilloscope.

DOI： 10.1109/WCNC.2016.7564942

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84989854391&origin=inward

Fast design exploration with unified HW/SW co-verification framework for high throughput wireless communication system 査読有り国際誌

Sutisna N., Hongyo R., Lanante L., Nagao Y., Kurosaki M., Ochi H.

IEEE Joint Conference - International Conference on IC Design and Technology, ICICDT 2016 and Solid State Systems Symposium, 4S 2016 2016年08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）

© 2016 IEEE. This paper presents fast design exploration with unified HW/SW co-verification framework, particularly for high throughput wireless communication system. Design exploration is an important task during design development in order to obtain optimum design with various possible methods/algorithms of implementation and also under various design constraints. The fast design exploration is enabled by employing co-operation between model-based RTL design and proposed unified HW/SW co-verification platform. Fast design exploration and unified HW/SW co-verification of MIMO MLD Decoder is selected as design example to show the effectiveness employed methodology and proposed platform. This approach gives significant improvement on reducing hardware design and verification time as compared with conventional approach, as well as provides reliable design.

DOI： 10.1109/ICICDT.2016.7542059

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84988354356&origin=inward

Unified HW/SW co-verification methodology for high throughput wireless communication system 査読有り

Sutisna N., Hongyo R., Lanante L., Nagao Y., Kurosaki M., Ochi H.

IPSJ Transactions on System LSI Design Methodology ( 一般社団法人情報処理学会 ) 9 ( 0 ) 61 - 71 2016年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 Information Processing Society of Japan. As complexity of system LSI design is increased significantly, efficient verification methodology is mandatory to achieve reliable system and to speed up development time. HW/SW co-verification, nowadays, is interesting and practical as a tool for system verification because it allows covering large number of verification scenarios in acceptable time. In this paper, we present an efficient and unified framework of HW/SW co-verification methodology for large scale system, particularly high throughput wireless communication system. The proposed methodology combine system level simulation (e.g., MATLAB or C/C++) and physical level verification (e.g., FPGA). It allows performing fast HW/SW verification, as well as fast turn-around design exploration. The proposed methodology has been successfully employed to our case study which is 4x4 MIMO wireless communication system. Experimental results show that our case study is able to run in near real-time processing, resulting in an improvement of simulation time orders of magnitude faster than software based simulation. Moreover, the proposed verification platform can be used for complete characterization of communication performance of a MIMO wireless system employing MLD MIMO decoder for various operation modes and channel models.

DOI： 10.2197/ipsjtsldm.9.61

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84992616475&origin=inward

Fast Design Exploration with Unified HW/SW co-verification Framework for High Throughput Wireless Communication System 査読有り

Nana Sutisna, Reina Hongyo, Leonardo Lanante Jr., Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEEE International Conference on IC Design and Technology 2016年07月

FPGA Implementation of Multiprocessor SoC for Industrial Wireless LAN Systems 査読有り

Yushi Matsunaga, Mitsuru Hamada, Nico Surantha, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi,

International Technical Conference on Circuits/Systems, Computers and Communications 411 - 414 2016年07月

RTL Design of FA-WLAN System and its Verification 査読有り

Mitsuru Hamada, Duc Khai Lam, Keishi Yamaguchi, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

International Technical Conference on Circuits/Systems, Computers and Communications 245 - 248 2016年07月

A Secure and Fast Industrial WLAN System with Zero-Delay Roaming 査読有り

Keishi Yamaguchi, Mitsuru Hamada, Duc Khai Lam, Nico Surantha, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. IEEE International Conference on Industrial Technology 2016年03月

An Improved Precision Time Protocol for Industrial WLAN Communication Systems 査読有り

Duc Khai Lam, Keishi Yamaguchi, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. IEEE International Conference on Industrial Technology 2016年03月

A Fast and Safe Industrial WLAN Communication Protocol for Factory Automation Control Systems 査読有り

Duc Khai Lam, Yasuhiro Shinozaki, Keishi Yamaguchi, Satoshi Morita, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

ISCIE Transaction of the Institute of Systems, Control and Information Engineers ( 一般社団法人システム制御情報学会 ) 29 ( 1 ) 29 - 39 2016年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

In this work, an industrial Wireless Local Area Network (iWLAN) system used to control industrial robots (iRBs) in factory automation (FA) environments is addressed. For fast and safe communications, we first propose a synchronous multi-user round-robin transmission protocol. To reduce the overhead caused by the conventional multi-user downlink transmission technique, we then propose a low overhead Packet Division Multiple Access (PDMA) transmission technique. The numerical and simulation results indicate that our approaches increase speed of 100% and 300% throughput compared to the conventional industrial Point Coordination Function (iPCF) and Space Division Multiple Access (SDMA) approaches, respectively. Besides, our approaches also provide lower system error rate (SER) than conventional ones. In particular, the control duration per iRB in our iWLAN system is faster than 100μsec. Therefore, our proposed schemes can achieve fast and safe performance for FA communication systems.

DOI： 10.5687/iscie.29.29

その他リンク： http://id.ndl.go.jp/bib/027040186

Power Saving Techniques for Wireless Communication Systems Using Cross Layer Designs 査読有り

Yuya Haraguchi, Tatsuya Yamamoto, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. IEEE the 15th International Symposium on Communications and Information Technologies 2015年10月

A Fast Industrial WLAN Protocol and its MAC Implementation for Factory Communication Systems 査読有り

Duc Khai Lam, Keishi Yamaguchi, Yasuhiro Shinozaki, Satoshi Morita, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEEE International Conference on Emerging Technologies and Factory Automation 1 - 6 2015年09月

High-definition Video Transmission over MU-MIMO E-SDM Systemication Systems 査読有り

Koji Tashiro, Leonardo Lanante Jr., Masayuki Kurosaki, Hiroshi Ochi

2015 International Workshop on Smart Info-Media Systems in Asia 2015年08月

A Fast and Safety Industrial WLAN Protocol for Factory Communication Systems 査読有り

Duc Khai Lam, Yasuhiro Shinozaki, Keishi Yamaguchi, Satoshi Morita, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEEE International Conference on Industrial Technology 1808 - 1813 2015年03月

Proposal of a switching power supply noise mitigation technique on industrial power supply overlaid communication system, 査読有り

Hidetsugu Koga, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Journal of Signal Processing 19 ( 2 ) 43 - 53 2015年03月

A joint time synchronization concept for wireless communication system 査読有り

Setiawan H., Kurosaki M., Ochi H.

Proceedings - 2014 International Conference on Advanced Informatics: Concept, Theory and Application, ICAICTA 2014 255 - 259 2015年01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）

© 2014 IEEE. This paper presents a concept of common timing detection for three different wireless communication standards i.e. WLAN, WiMAX and LTE. We propose a system consists of sample rate conversion, symmetry-based auto-correlation, and peak detector. The correlation part consists of a single 256-tap symmetric-based auto-correlation circuit and a peak detector with an adaptive threshold value. The fixed point simulation results show that the proposed system has satisfied the minimum receiver sensitivity requirements that specified by the standards. Moreover, the proposed system has fitted for FPGA Virtex-5 XC5VTX240T implementation by utilizing 50 percent of total look up table (LUT) in the FPGA, and can reach the clock frequency up to 76.7MHz.

DOI： 10.1109/ICAICTA.2014.7005950

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84961309522&origin=inward

FPGA Implementation of a MIMO Channel Emulator for the IEEE802.11n/ac 査読有り

Tran Thi Thao Nguyen, Yuhei Nagao, Leonardo Lanante, Masayuki Kurosaki, Hiroshi Ochi

he 2015 Vietnam-Japan International Symposium on Antennas and Propagation 77 - 82 2015年01月

Very high throughput WLAN system for ultra HD 4K video streaming 査読有り

Syafei W., Kurosaki M., Ochi H.

2014 1st International Conference on Information Technology, Computer, and Electrical Engineering: Green Technology and Its Applications for a Better Future, ICITACEE 2014 - Proceedings 177 - 182 2015年01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）

© 2014 IEEE. We have been developing a very high throughput WLAN system based on IEEE802.11ac's criteria. It combines MIMO and OFDM technology to provide throughput over 1 Gbps for 150 feet propagation distance by using 80MHz of bandiwdth on 5GHz frequency band. 4 by 5 antennas MIMO is set to get 2 nd -order diversity gain to maintain high throughput and performance. Greenfield preamble with novel phase rotation is employed to mitigate the overhead problem while reducing the peak to average power ratio of the signals. Run test to broadcast the ultra high definition video which resolution 4096 × 1714 pixels/frame with 30 frame/second under in-door channel model demonstrates an excellent performance of the developed system.

DOI： 10.1109/ICITACEE.2014.7065737

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84927947333&origin=inward

ASIC design of 7.7 Gbps multi-mode LDPC decoder for IEEE 802.11ac 査読有り

Tran T., Nagao Y., Ochi H., Kurosaki M.

14th International Symposium on Communications and Information Technologies, ISCIT 2014 259 - 263 2015年01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）

© 2014 IEEE. In this paper, we propose a multi-mode low density parity check (LDPC) decoder architecture for high throughput wireless communication systems. Throughput of our decoder depends on code rate. The main blocks of our architecture are independent from value of the check matrix. Based on the proposed architecture, we design a twelve-mode Min-Sum LDPC decoder for IEEE 802.11ac system and synthesize it in ASIC 90nm technology. The ASIC synthesis results show that our decoder achieves up to 15.4 bits/cycle (bpc) or 7.7 Gbps at 500 MHz operating frequency, and has the best efficiency which is 1.89 (bpc/mm2) as compared to the previous works. In this paper, we also propose an efficient quantization method that can significantly improve the PER performance. The floating point and fixed point simulation results show that PER performance of the 802.11ac system is improved by at least 1 dB if using LDPC instead of BCC. Furthermore, the proposed quantization method can improve the LDPC PER performance up to 1.7 dB.

DOI： 10.1109/ISCIT.2014.7011912

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84922885090&origin=inward

産業用機器向け電力重畳型通信システムにおけるスイッチング電源雑音の軽減方式の提案査読有り

古賀英嗣, 長尾勇平, 黒崎正行, 尾知博

Journal of Signal Processing 19 ( 2 ) 43 - 53 2015年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, we present a method of reducing the effect of switching noise generated from the switching power supply using a GaN (gallium nitride) device for controlling industrial equipment communication signal. We point out the noise power with its peak at the resonance frequency determined by the parasitic impedance and circuit constants. We propose a contorted communication timing where the guard interval of the communication signal and the switching noise are overlapping. Then, we propose to select the dedicated LLR (log-likelihood ratio) calculation instantaneously when the switching noise overlaps the guard interval of the communication signal in the proposed timing. Using the proposed contorted communication timing, we have improved the SNR (signal-to-noise ratio) vs BER (bit error rate) from 1.0×10-1 to 2.5×10-2 at the SNR of 20[dB]. In addition using the proposed LLR calculation method, the SNR vs BER is improved by more than 5 [dB] while the SNR vs PER(packet error ratio) is improved by 10[dB] at the SNR of 20[dB].

DOI： 10.2299/jsp.19.43

その他リンク： http://ci.nii.ac.jp/naid/130004849326

A Novel Wireless LAN Protocol for Factory Automation Control 査読有り

Duc Khai Lam, Hisaya Urabe, Yasuhiro Shinozaki, Keishi Yamaguchi, Satoshi Morita, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

International Conference on Robotics and Biomimetics 2014年12月

Live demonstration : hardware-software co-verification for very large scale SoC using synopsys HAPS platform 査読有り

Nana Sutisna, Leonardo Lanante Jr., Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. 2014 IEEE Asia Pacific Conference on Circuits and Systems 171 - 172 2014年11月

Lossless data hiding method using error correction code 査読有り

Tsubasa Nobeoka, Leonardo Lanante Jr., Masayuki Kurosaki, Hiroshi Ochi

Proc. 2014 IEEE Asia Pacific Conference on Circuits and Systems 539 - 542 2014年11月

LLR calculation technique for lossless data hiding method using LDPC code 査読有り

Tsubasa Nobeoka, Leonardo Lanante Jr, Masayuki Kurosaki, Hiroshi Ochi

Proc. International Workshop on Smart Info-Media Systems in Asia 2014年10月

The power saving using variable time reservation-less sleep control for wireless LAN access points 査読有り

Yuya Haraguchi, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. International Workshop on Smart Info-Media Systems in Asia 2014年10月

High-resolution image transmission over MIMO-OFDM E-SDM system with JSCC 査読有り

Koji Tashiro, Leonardo Lanante Jr., Masayuki Kurosaki, Hiroshi Ochi

Proc. The 4th IEEE International Conference on Consumer Electronics - Berlin 379 - 383 2014年09月

High Definition Video Transmission System using Channel Characteristics

Daiki Sakata , Koji Tashiro, Masafumi Ito, Masayuki Kurosaki, Hiroshi Ochi

2014 International Symposium on Dependable Integrated Systems 2014年03月

THPマルチユーザMIMOシステムにおけるチャネル推定誤差の影響の低減手法 (通信技術の革新を担う学生論文特集) 査読有り

藤田尚吾, ラナンテレオナルドジュニア, 長尾勇平, 黒崎正行, 尾知博

電子情報通信学会論文誌. B, 通信 ( 一般社団法人電子情報通信学会 ) 97 ( 2 ) 174 - 181 2014年02月

担当区分：責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

マルチユーザMIMO(MU-MIMO)システムにおいてTomlinson Harashima Precoding(THP)手法は良好な伝送性能を示す非線形プリコーディングとして注目されている.しかしながらチャネル情報(CSI)に誤差が存在する場合,THPのBER特性は大きく劣化する.本報告では,THPにおいて受信機側でチャネル推定値の実数のみで復号を行うことにより,CSI誤差による雑音強調の影響を低減する手法を提案する.THP手法におけるチャネル推定誤差の影響を算出し,計算機シミュレーションにより提案手法の有効性を示す.

その他リンク： https://ci.nii.ac.jp/naid/110009766808

PWM noise reductionin OFDM-based power supply overlaid communication system for industrial machine control 査読有り

Hidetsugu Koga, Masayuki Kurosaki, Hiroshi Ochi

AETA 2013: Recent Advances in Electrical Engineering and Related Sciences, Lecture Notes in Electrical Engineering 282 247 - 257 2013年11月

An Adaptive Frame Aggregation Algorithm for High Throughput Wireless LAN 査読有り

Yuki Chosokabe, Tatsumi Uwai, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

The International Symposium on Electrical-Electronics Engineering 2013年10月

Watermarking Method using QR Decomposition for JPEG 2000 Wireless Transmission 査読有り

Masayuki Kurosaki, Hiroshi Ochi

International Workshop on Smart Info-Media Systems in Asia 2013年10月

A Computationally Efficient Sampling Frequency Offset Estimation for OFDM based Digital Terrestrial Television System 査読有り

Nico Surantha, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEEE 24th International Symposium on Personal, Indoor, and Mobile Radio Communications 662 - 666 2013年09月

Channel Estimation for MISO DVB-T2 System in High-Speed Environment 査読有り

Nico Surantha, Tatsumi Uwai, Yuhei Nagao, Masayuki Kurosaki, Baiko Sai, Hiroshi Ochi

RISP Journal of Signal Processing 17 ( 5 ) 179 - 188 2013年09月

Implementation of 2.6Gbps Super-high Speed AES-CCM Security Protocol for IEEE802.11i 査読有り

Khoa Nguyen, Leoardo Lanante, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEEE International Symposium on Communication and Information Technology 2013年09月

Novel THP Scheme with Minimum Noise Enhancement for Multi-User MIMO Systems 査読有り

Shogo Fujita, Leonardo Lanante Jr., Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E96-A ( 6 ) 1340 - 1347 2013年06月

Sampling Frequency Offset Estimation for Digital Terrestrial Television Broadcasting System 査読有り

Nico Surantha, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEICE Communication Express 2 ( 5 ) 224 - 230 2013年05月

JPEG 2000 wireless image transmission system using encryption domain authentication 査読有り

Ito R., Matsuo M., Miyaoka Y., Inoue K., Eguchi S., Kurosaki M., Ochi H., Kuroki Y., Miyazaki A.

International Conference on Advanced Communication Technology, ICACT 179 - 183 2013年04月

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）

Korea Phenix Park 2013年01月 - 2013年01月

In this paper, we propose a wireless high resolution video transmission system with encryption and authentication. The proposed system is implemented by JPEG 2000 coding. We implement JPEG 2000 coder by GPU in CUDA which is an integrated development environment for GPU, or by JPEG 2000 codec LSI. Moreover, the authentication system can check the user information in encrypted domain using Paillier encryption. Therefore, this system is more secure than conventional systems. We show that the proposed system can achieve 4K size coding by 2.34fps with CUDA, and HD size coding by 29.98 fps with LSI codec. In addition, we demonstrate that the authentication using Paillier encryption is successful. © 2013 GIRI.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84876247645&origin=inward

Hardware design of spatial mapper for 1.73Gbps multi-user MIMO system of IEEE802.11ac 査読有り

Setiawan H., Lanante L., Kurosaki M., Ochi H.

Proc. of 2013 3rd Int. Conf. on Instrumentation, Communications, Information Technol., and Biomedical Engineering: Science and Technol. for Improvement of Health, Safety, and Environ., ICICI-BME 2013 111 - 114 2013年01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）

This paper presents a spatial mapper hardware design using model based RTL provided by Synphony HLS. It is a part of a transmitter system based on IEEE 802.11ac. The speed target is 160MHz in the FPGA Altera Stratix IV EP4SE820H35C3. For spatial mapper, this speed can be achieved by two stages pipelining. The first pipeline puts inside of the complex multiplier, while the other is after the complex multiplier processing. The compilation result shows that the spatial mapper design can reach up to 203.7MHz and requires 1658 combinational circuits, 2113 ALMs, 3216 registers. © 2013 IEEE.

DOI： 10.1109/ICICI-BME.2013.6698475

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84893561701&origin=inward

Derivation of log-likelihood ratio for M-ary non-orthogonal FSK wireless system 査読有り

Nojima D., Nagao Y., Kurosaki M., Ochi H.

IEEE Vehicular Technology Conference 2012年12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）

Canada Quebec 2012年09月 - 2012年09月

In a soft decision Viterbi decoder, the log-likelihood ratio (LLR) metric is used to improve the performance of the error correction. On linear systems under additive white gaussian noise channel, this is straightforward as the error distribution at the input of the Viterbi decoder is also gaussian. In non-linear systems such as the M-ary non-coherent non-orthogonal frequency shift keying (FSK), this is generally not true. However, non-orthogonal non-coherent FSK LLR has not yet been proposed in literature. In this paper we derived the LLR for the M-ary non-orthogonal FSK mathematically and verified it using simulations. © 2012 IEEE.

DOI： 10.1109/VTCFall.2012.6399141

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84878896252&origin=inward

RTL design of high-speed sorted QR decomposition for MIMO decoder 査読有り

Miyaoka Y., Nagao Y., Kurosaki M., Ochi H.

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E95-A ( 11 ) 1991 - 1997 2012年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

In this paper, we propose a hardware architecture of high-speed sorted QR decomposition for 4x4 MIMO wireless communication systems. QR decomposition (QRD) is commonly used in many MIMO de-tection algorithms. In particular, sorted QR decomposition (SQRD) is the advanced algorithm to improve MIMO detection performance. We design an SQRD hardware architecture by using a modified Gram-Schmidt algo-rithm with pipelining and recursive processing. In addition, we propose an extended architecture which can decompose an augmented channel matrix for MMSE MIMO detection. These architecture can be applied in high-throughput MIMO-OFDM system such as IEEE802.11n which supports data throughput of up to 600 Mbps. We implement the proposed SQRD architecture and the proposed MMSE-SQRD architecture with 179k and 334k gates in 90 nm CMOS technology. These proposed design can achieve a high performance of up to 40.8 and 50.0 million 4x4 SQRD operations per second with the maximum operating frequency of 245 and 300 MHz. Copyright © 2012 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transfun.E95.A.1991

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84868338880&origin=inward

Power Supply Overlaid Real Time Communication System with OFDM for Industrial Robot Control 査読有り

Hidetsugu Koga, Masayuki Kurosaki, Hiroshi Ochi

Proc. IEEE 2012 International Symposium on Communications and Information Technologies 215 - 220 2012年10月

Modified Tomlinson Harashima Precoding Using Square Root for Multi-User MIMO Systems 査読有り

Shogo Fujita, Leonardo Lanante Jr., Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEEE Vehicular Technology Conference 2012-Fall 2012年09月

Hardware Design of 1.3Gbps Multi-User MIMO System for IEEE802.11ac with LDPC decoder 査読有り

Leonardo Lanante Jr., Yuji Yokota, Yuhei Nagao, Baiko Sai, Masayuki Kurosaki, Hiroshi Ochi

International Workshop on Smart Info-Media Systems in Asia 82 - 87 2012年09月

Pilot Aided Channel Estimation for a 2x2 MIMO DVB-T2 system in High Speed Mobile Environment 査読有り

Nico Surantha, Tatsumi Uwai, Yuhei Nagao, Masayuki Kurosaki, Baiko Sai, Hiroshi Ochi

IEEE Vehicular Technology Conference 2012-Fall 2012年09月

Hardware Design of 1.3Gbps Multi-User MIMO System for IEEE802.11ac 査読有り

Leonardo Lanante Jr., Shogo Fujita, Yuji Yokota, Yuhei Nagao, Baiko Sai, Masayuki Kurosaki

IEEE Vehicular Technology Society Asia Pacific Wireless Communications Symposium 2012年08月

Model-based Design Method for Wireless System VLSI with Synopsys Synphony Tool 査読有り

Thi Hong Tran, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi, Baiko Sai

he 2nd Solid-State Systems Symposium - VLSI & Related Technologies 283 - 289 2012年08月

JPEG 2000 Image Transmission using Encryption Domain Authentication by Paillier Cryptosystem 査読有り

Muneaki Matsuo, Masayuki Kurosaki, Akio Miyazaki, Hiroshi Ochi

IEEE International Conference on Communications 2012年06月

Sorted QR Decomposition for High-Speed MMSE MIMO Detection Based Wireless Communication Systems 査読有り

Yuya Miyaoka, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. 2012 IEEE International Symposium on Circuits and Systems (ISCAS2012) 2857 - 2860 2012年05月

Hardware Implementation of High Throughput RC4 Algorithm 査読有り

Thi Hong Tran, Leonardo Lanante, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

2012 IEEE International Symposium on Circuits and Systems (ISCAS-2012) 77 - 80 2012年05月

RTL Design of Joint CFO and IQ-Imbalance Compensator for Narrow-Band Wireless System 査読有り

Takuro Yoshida, Daisuke Nojima, Leonardo Lanante Jr. Yuhei Nagao, Masayuki Kurosaki, Baiko Sai, Hiroshi Ochi

ECTI Transaction on Computer and Infomation Technology 6 ( 1 ) 54 - 61 2012年05月

Packet Delayed Lattice Reduction Algorithm for High Performance MIMO Decoder 査読有り

Leonardo Lanante Jr., Arumjeni Mitayani, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

IEEE Wireless Communications and Networking Conference (WCNC 2012) 236 - 240 2012年04月

IEEE 802.11n physical layer implementation on field programmable gate array 査読有り

Setiawan H., Nagao Y., Kurosaki M., Ochi H.

Telkomnika 10 ( 1 ) 67 - 74 2012年03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）

Register transfer level (RTL) development is a time cost step that requires high diligence and fidelity to get the valid interpretation of abstraction function of digital circuit. In this research, we introduce and prove that Model-Based Design Process (MBDP) is an effective and efficient way to develop a RTL complex system such as wireless communication. Using MBDP flow, we interpret, develop, and verify the physical layer RTL of a new standard that ratified on the end 2009, i.e. IEEE 802.11n wireless local area network (WLAN). The result of this research is a prototyping FPGA StratixII EP2S180 that has properly worked as a 2x2 MIMO WLAN with maximum throughput 144 Mbps. © 2012 Universitas Ahmad Dahlan.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84883601671&origin=inward

ASIC design of 600Mbps 4×4 MIMO wireless LAN system 査読有り

Thi Hong Tran, Yuhei Nagao, Masayuki Kurosaki, Baiko Sai, Hiroshi Ochi

Proc. The 15th International Conference on Advanced Communication Technology (ICACT2012) 360 - 363 CD-ROM 2012年02月

Performance Evaluation for Multi-User MIMO IEEE 802.11acWireless LAN System 査読有り

Daisuke NOJIMA, Leonardo Lanante Jr., Yuhei NAGAO, Masayuki KUROSAKI, Hiroshi OCHI

Proc. The 15th International Conference on Advanced Communication Technology (ICACT2012) 804 - 808 CD-ROM 2012年02月

Performance Evaluation of π/4 DQPSK Direct-conversion Wireless Communication System 査読有り

Yuji YOKOTA, Takuro YOSHIDA, Daisuke NOJIMA, Yuhei NAGAO, Masayuki KUROSAKI, Hiroshi OCHI

Proc. The 15th International Conference on Advanced Communication Technology (ICACT2012) 788 - 793 CD-ROM 2012年02月

Low Complexity Compensation of Frequency Dependent I/Q Imbalance and Carrier Frequency Offset for Direct Conversion Receivers 査読有り

Leonardo LANANTE Jr., Masayuki KUROSAKI, Hiroshi OCH

IEICE TRANSACTIONS on Communications E95-B ( 2 ) 484 - 492 2012年02月

A high throughput MAC layer for 600Mbps IEEE802.11n wireless LAN 査読有り

Khine T., Nagao Y., Kurosaki M., Ochi H.

APSIPA ASC 2011 - Asia-Pacific Signal and Information Processing Association Annual Summit and Conference 2011 469 - 472 2011年12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）

This correspondence presents a fast and systematic architecture for realizing an efficient 4-stream IEEE802.11n based hardware/software co-design Medium Access Control( MAC) Layer, which can achieve near theoretical MAC throughput for burst data transmission while complying with a strict channel access time requirements. As a design result, the proposed MAC system architecture can achieve 462Mbps for which 77% efficiency of maximum 4-stream Physical Layer(PHY) transmission rate 600Mbps is obtained. This result is verified with both SystemVerilog software simulation and hardware prototyping on a Xilinx FPGA board. Furthermore, a SoC architecture for one-chip implementation with MIPS/ARM/Power PC CPUs is also shown. In this SoC, IEEE802.11e as well as 11i functions are also included.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84866882508&origin=inward

Real time 2D-DWT of JPEG 2000 for Digital Cinema using CUDA 4.0 査読有り

Inoue K., Kuroki Y., Kurosaki M., Nagao Y., Ochi H.

2011 International Symposium on Intelligent Signal Processing and Communications Systems: "The Decade of Intelligent and Green Signal Processing and Communications", ISPACS 2011 2011年12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）

The Specifications of the Digital Cinema system released by Digital Cinema Initiatives decide to encode so-called 2K or 4K images by JPEG 2000. The JPEG 2000 codec provides high compression rates and error tolerance, but this codec is burden for both encoding and decoding. The parallel computing architecture named CUDA receives a lot of attention recently. In this paper, we attempt to realize real-time implementation of the two dimensional discrete wavelet transform (2D-DWT) of JPEG 2000 by using the newest developmental environment CUDA 4.0. © 2011 IEEE.

DOI： 10.1109/ISPACS.2011.6146127

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84857247328&origin=inward

An ASIC implementation of puncture and spatial stream parser for MIMO Wireless LAN system 査読有り

Ardiansyah A., Nagao Y., Kurosaki M., Ochi H.

Proceedings - International Conference on Instrumentation, Communication, Information Technology and Biomedical Engineering 2011, ICICI-BME 2011 87 - 91 2011年12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）

This paper discus an ASIC implementation of puncture and SSP for MIMO IEEE 802.11n 4x4 MIMO Wireless LAN system. We also describe its receiver counterpart block, which is SSDP and Depuncture. The biggest challenge of this work is 72 modes operation that need to be supported. The design is implemented on 90nm ASIC CMOS technology. Synthesis result for puncture and SSP reveal that the logic area is 0.025 mm 2 . The correspond gates count is 4.535 KGE. Circuit power consumption is 0.736 mW. The design can work at very high frequency up to 1000MHz (1GHz). Thus, it could be implemented for very high data rate applications that use MIMO OFDM techniques up to 3,750 Mbps, such as digital cinema and HDTV over wireless transmission. Meanwhile, SSDP and Depuncture synthesis shows that the logic area is 0.0309 mm 2 which is equivalent with 5.581 gates. The maximum operating frequency is lower than its transmitter counterparts, only 250 MHz. Circuit power consumption is 0.209 mW. © 2011 IEEE.

DOI： 10.1109/ICICI-BME.2011.6108600

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84855913067&origin=inward

Low-Latency Normalization Method for Multi-User MIMO Systems Using Vector Perturbation Precoder 査読有り

Shogo Fujita, Leonardo Lanante Jr., Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Proc. IEEE Third International Conference on Intelligent Networking and Collaborative Systems (INCOS 2011) CD-ROM 2011年11月

A CUDA Implementation of DWT for JPEG 2000 Codec 査読有り

Masayuki KUROSAKI, Masateru MATSUO, Yoshimatsu KUROKI, Yuhei NAGAO, Baiko Sai, Hiroshi OCHI

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences E94-A ( 11 ) 2358 - 2360 2011年11月

Power Supply Overlaid Communication System with OFDM Modulation for Robot Control 査読有り

Yusuke YAMAGUCHI, Hidetsugu KOGA, Masayuki KUROSAKI, Hiroshi OCHI

2011 International Workshop on Smart Info-Media Systems in Asia (SISA2011) CD-ROM 2011年10月

Image Transmission using Encryption Domain Authentication for Mesh Network 招待有り査読有り

Muneaki MATSUO, Masayuki KUROSAKI, Akio MIYAZAKI, Hiroshi OCHI

2011 International Workshop on Smart Info-Media Systems in Asia (SISA2011) CD-ROM 2011年10月

Joint CFO and IQ-Imbalance Compensator for Narrow-Band Wireless System 査読有り

Takuro YOSHIDA, Daisuke NOJIMA, Yuhei NAGAO, Masayuki KUROSAKI, Hiroshi OCHI

Asia Pacific Signal and Information Processing Association (APSIPA) ASC 2011 ( Thu-PM.PS3 ) CD-ROM 2011年10月

Complexity Reduction Technique of Vector Perturbation Algorithm for Multiuser MIMO Systems 査読有り

Muneaki MATSUO, Ryuta IMASHIOYA, Yuhei NAGAO, Masayuki KUROSAKI, Hiroshi OCHI

The 11th IEEE International Symposium on Communications and Information Technologies (ISCIT 2011) CD-ROM 2011年10月

LTE physical layer identity detection: Frequency vs time domain schemes 査読有り

Setiawan H., Kurosaki M., Ochi H.

IEEE International Conference on Communications 2011年09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）

Long Term Evolution (LTE) physical layer identity can be recognized either in frequency domain or time domain. In this paper we serve some comparisons in term of complexity, latency, and recognition probability. As a result, frequency domain detection has superiority on performance for SNR higher than 3dB on all channel models, as well as lower latency than time domain scheme one. However, it requires huge computation resources that might meet difficulty for mobile devices implementation. © 2011 IEEE.

DOI： 10.1109/icc.2011.5962766

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=80052177952&origin=inward

High-Speed Sorted QR Decomposition for MIMO Wireless Communication Systems 査読有り

Yuya MIYAOKA, Yuhei NAGAO, Masayuki KUROSAKI, Hiroshi OCHI

IEEE Asia Pacific Wireless Communication Symposium (APWCS2011) ( 36 ) CD-ROM 2011年08月

FPGA Implementation of Joint CFO and IQ-Imbalance Compensator for Narrow-Band Wireless System 査読有り

Takuro YOSHIDA, Daisuke NOJIMA, Yuhei NAGAO, Masayuki KUROSAKI, Hiroshi OCHI

International Conference on Advanced Technologies for Communications (ATC) CD-ROM 2011年08月

Wireless Transmission of JPEG 2000 Compressed Video 査読有り

Masateru Matsuo,Ryo ito,Masayuki Kurosaki,Baiko Sai,Yoshimitsu Kuroki,Akio Miyazaki,Hiroshi Ochi

Proc. The 13th International Conference of Advanced Communication Technology (ICACT2011) ( 08A-04 ) 2011年02月

Symbol timing synchronization ISDB-T System in Multipath Fading Channel 査読有り

Nico Surantha,Tatsumi UWAI,Yuhei Nagao,Masayuki Kurosaki,Hiroshi Ochi

Proc. The 13th International Conference of Advanced Communication Technology (ICACT2011) ( 10C-01 ) 2011年02月

Non-Linear Precoding for Next Generation Multi-User MIMO Wireless LAN Systems 査読有り

Leonardo Lanante Jr.,Masayuki Kurosaki,Hiroshi Ochi

Proc. The 13th International Conference of Advanced Communication Technology (ICACT2011) ( 09A-02 ) 2011年02月

RTL Design of Joint CFO and IQ-Imbalance Compensator for Narrow-BandWireless System 査読有り国際誌

Takuro Yoshida, Daisuke Nojima, Yuhei Nagao, Masayuki Kurosaki, Hiroshi Ochi

Int. Conf. Embedded Systems and Intelligent Technology (ICESIT2011) 2011年02月

A Proposition of 600Mbps WLAN-like System with Low-Complexity MIMO Decoder for FPGA Implementation 査読有り

Wahyul Amien Syafei,Yuhei NAGAO,Msayuki KUROSAKI,Baiko SAI,Hiroshi OCHI

IEICE Transactions on Communications E94-B ( 2 ) 1745 - 1345 2011年02月

Performance Improvement Method for ISDB-T Receiver Under Fast Fading Channel 査読有り

Tatsumi UWAI,Nico Surantha,Yuhei Nagao,Masayuki Kurosaki,Hiroshi Ochi

IEEE Consumer Communications and Networking Conference (CCNC2011) 2011年01月

HDTV over MIMO Wireless Transmission System 査読有り

Masateru Matsuo,Msasyuki Kurosaki,Yuhei Nagao,Sai Baiko,Yoshimitsu Kuroki,Akio Miyazaki,Hiroshi Ochi

IEEE Consumer Communications and Networking Conference (CCNC2011) 2011年01月

RAM based physical-layer identity detector for 3GPP long term evolution 査読有り

Setiawan H., Kurosaki M., Ochi H.

IEEE Region 10 Annual International Conference, Proceedings/TENCON 1362 - 1367 2010年12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）

Employing OFDMA and scalable bandwidth scheme in Long Term Evolution (LTE) downlink access impact on increasing complexity in frequency domain physical layer identity detection. Therefore, in this paper, we propose time domain detection instead of frequency domain using finite impulse response (FIR) filter and partial cross-correlation. Moreover, we implement RAM based architecture instead of multipliers and registers in filtering and cross-correlation computation. As result, the proposed system complexity is less than 128 point FFT. As addition, more than 95% physical layer identity can be detected correctly in SNR = 0 dB or higher for AWGN channel condition. ©2010 IEEE.

DOI： 10.1109/TENCON.2010.5686058

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79951656455&origin=inward

A Feasibility Study on Physical Implementation of Global Wireless Communication Services Recognition System 査読有り

Hendra Setiawan,Masayuki Kurosaki,Hiroshi Ochi

IEEE Globecom 2010 Workshop on Advances in Communications and Networks 2010年12月

4K Digital Cinema Home Theater over High Throughput Wireless Transmission System 査読有り

Masayuki Kurosaki,Masateru Matsuo,Kuroki Yoshimitsu,Ryuta Imashioya,Sai Baiko,Hiroshi Ochi

IEEE Globecom 2010 Workshop on Multimedia Communications and Services 2010年12月

Joint Time-and-Frequency Synchronization for ISDB-T Receiver in Multipath Fading Channel 査読有り

Nico Surantha,Tatsumi Uwai,Yuhei Nagao,Masayuki KUROSAKI,Hiroshi Ochi

Smart Info-Media System Conference in Asia (SISA) 2010 2010年09月

Dirty Paper Coding for Next Generation Multi-User MIMO Wireless LAN Systems 査読有り

Leonardo Alisasis Lanante Jr,Tohru Oyama,Masayuki KUROSAKI,Hiroshi Ochi

Smart Info-Media System Conference in Asia (SISA) 2010 2010年09月

Log Likelihood Ratio for FSK Demodulation Using Frequency Discriminator 査読有り

Daisuke Nojima,Yuhei Nagao,Masayuki KUROSAKI,Hiroshi Ochi

Smart Info-Media System Conference in Asia (SISA) 2010 2010年09月

Analysis of RAM Based Cross-Correlation Architecture 査読有り

Hendra Setiawan,Masayuki KUROSAKI,Hiroshi Ochi

Smart Info-Media System Conference in Asia (SISA) 2010 2010年09月

A Design of Gigabit Wireless LAN with Backward Compatibility 査読有り

Aidilla Pradini,Wahyul Amien Syafei,Yuhei Nagao,Ryuta Imashioya,Shin Chon Park,Masayuki KUROSAKI,Hiroshi Ochi

Smart Info-Media System Conference in Asia (SISA) 2010 2010年09月

Performance Improvement Method for Digital Terrestrial Television Broadcasting Under Fast Fading Channel 査読有り

Tatsumi Uwai,Nico Surantha,Yuhei Nagao,Masayuki KUROSAKI,Hiroshi Ochi

Smart Info-Media System Conference in Asia (SISA) 2010 2010年09月

A CUDA Implementation of JPEG 2000 Codec for 4K Digital Cinema Wireless Transmission System 査読有り

Yoshimitsu Kuroki, Masateru Matsuo, Yuhie Nagao, Baiko Sai, Akio Miyazaki, Masayuki Kurosaki, Hiroshi Ochi

Proc. Smart Info-Media System Conference in Asia (SISA) 2010 ( SSW2-1 ) 2010年09月

PAPR Reduction Technique for Next Generation Gigabit WLAN 査読有り

Wahyul Amien Syafei,Yuhei NAGAO,Msayuki KUROSAKI,Baiko SAI,Hiroshi OCHI

Journal of Signal Processing 14 ( 5 ) 381 - 386 2010年09月

HDTV Wireless Streaming Using IEEE802.11ac 4x5 MIMO WLAN System 査読有り

Masayuki KUROSAKI,Masateru Matsuo,Yoshimitsu Kuroki,Akio Miyazaki,Hiroshi Ochi

2010 International Workshop on Information Communication Technology 2010年08月

A Study on Performance Improvement of Digital Terrestrial Television Broadcasting Under Fast Fading Channel 査読有り

Tatsumi Uwai,Nico Surantha,Yuhei Nagao,Masayuki KUROSAKI,Hiroshi Ochi

The Third International Conference on Communications and Electronics (ICCE 2010) 57 - 57 2010年08月

Soft Decision Viterbi Decoder for FSK Demodulation Under Fast Fading Channel 査読有り

Daisuke Nojima,Yuhei Nagao,Masayuki KUROSAKI,Hiroshi Ochi

The Third International Conference on Communications and Electronics (ICCE 2010) 36 - 36 2010年08月

A design of next generation Gigabit MIMO wireless LAN system 査読有り

Syafei W., Nagao Y., Kurosaki M., Sai B., Ochi H.

International Conference on Advanced Communication Technology, ICACT 2 941 - 946 2010年05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）

Korea Phoenix Park 2010年02月07日 - 2010年02月10日

This paper deals with a design of next generation Gigabit WLAN system based on IEEE802.11TGac's functional requirements. It achieves 1.1 Gbps throughput for 45 meter propagation distance with 80 MHz bandwidth on 5 GHz band. The proposed preamble ensures backward compatibility with the IEEE802.11a/n systems and has lower PAPR and comparable preamble efficiencywith IEEE802.11n's preamble. It uses MIMO architecture to maintain both the high throughput and the high performance. Two options of channel encoder, binary convolutional code and low density parity check code are available to enhance the performance. Run test under in-door channel model demonstrates the excellent performance of the proposed system.