Faculty Profiles - MIYAMOTO Shinichi

Published Papers - MIYAMOTO Shinichi

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A study on a secure wireless link creation based on multi-path routing combined with transmit antenna directivity control

Masaaki Yamanaka, Norihiko Morinaga, Shinichi Miyamoto, Seiichi Sampei

Proceedings - 3rd IEEE International Conference on Intelligent Networking and Collaborative Systems, INCoS 2011 526 - 531 2011 [Refereed]

This paper proposes a secure wireless link creation scheme based on a multi-path routing in a single-hop wireless transmission environment, where multiple paths are created by directive transmission using the multipath component of wireless link which the link possesses naturally on its own. Moreover a secret sharing method is employed to divide the transmitted information into pieces of shared information and sending each pieces of information separately through the multiple paths. Computer simulation clarifies that with the proposed scheme, information recovery of the transmitted information can be confined to a limited area in the wireless space, i.e., the transmitted information is less exposed to the adversary around the legitimate terminals. © 2011 IEEE.

DOI

Intensity distribution based space and time division multiple access technique for hybrid-LOS indoor optical wireless communication

Shinichi Miyamoto, Kenji Kawamoto, Seiichi Sampei

FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XXII ( SPIE-INT SOC OPTICAL ENGINEERING ) 7587 7587-31 2010 [Refereed]

This paper proposes a space division and time division multiple access (SD/TDMA) technique based on intensity distributions for hybrid line-of-sight (hybrid-LOS) indoor optical wireless communication system. At first, a novel signal discrimination scheme for the spatially multiplexed optical signals is proposed and it is applied to a space division multiple access (SDMA) in hybrid-LOS system. In the proposed scheme, multiple terminals simultaneously transmit their optical signals to access point (AP) using on-off-keying (OOK) modulation, and the spatially multiplexed optical signals are received by a photodetectors array (PD-array), where multiple PDs are disposed to observe the spatial intensity distribution of optical signals. Because the terminals transmit their data using OOK modulation, the spatial intensity distribution observed by the AP equipped with PD-array is subject to the data transmitted from individual terminals, and the AP can identify the terminals transmitting the optical signal by determining the transmitted intensity distribution. Of course, the transmitted intensity distributions are not orthogonal signal and the discriminability of transmitted intensity distributions is much related to the differences of intensity distributions. This implies that the number of terminals that can simultaneously access to the AP will be limited and it is determined by the differences of the candidate intensity distributions. In order to enhance the discriminability of the transmitted intensity distributions, the proposed signal discrimination scheme is further applied to the SD/TDMA. In the SD/TDMA, the discriminability required to enable SDMA is ensured by introducing a scheduling algorithm in which terminals with higher discriminatory of transmitted intensity distributions are allocated to the same time slot. Numerical results show that SD/TDMA using proposed signal discrimination scheme increases the throughput and the number of terminals that can access to the AP.

DOI

VLSI design of OFDM baseband transceiver with dynamic spectrum access

Masahide Hatanaka, Ryoji Hashimoto, Toshimitsu Tatsuka, Takao Onoye, Hironobu Hatamoto, Shinsuke Ibi, Shinichi Miyamoto, Seiichi Sampei

ISPACS 2010 - 2010 International Symposium on Intelligent Signal Processing and Communication Systems, Proceedings 329 - 332 2010 [Refereed]

The VLSI design of OFDM baseband transceiver is described, which is dedicated to cognitive radio systems. To facilitate dynamic spectrum accessing, this receiver architecture employs a specialized FFT module and a mapping/demapping module. Efficient mechanisms to omit input/output of unused subcarriers are introduced. Also, calculation of spectrum intensity for subcarrier level carrier sensing is successfully integrated to the FFT module. Whole transmitter/receiver modules are implemented by maintaining compatibility with IEEE 802.11g. Implementation results show that the proposed architecture can process OFDM symbols in 60 MHz operation. © 2010 IEEE.

DOI

Dynamic Subcarrier Selection Technique for Cognitive Wireless Mesh Networks Using CSMA/CA

Shinichi Miyamoto, Yuichi Goda, Seiichi Sampei

2008 International Workshop on Smart Info-Media Systems in Bangkok (SISB 2008) 81 - 86 2009.03 [Refereed]

Implementation of OFDM baseband transceiver with dynamic spectrum access for cognitive radio systems

Ryoji Hashimoto, Toshimitsu Tatsuka, Masahide Hatanaka, Takao Onoye, Hironobu Hatamoto, Shinsuke Ibi, Shinichi Miyamoto, Seiichi Sampei

2009 9th International Symposium on Communications and Information Technology, ISCIT 2009 658 - 663 2009 [Refereed]

VLSI architecture for OFDM base-band transceiver is developed, which is dedicated to cognitive radio systems. To facilitate dynamic spectrum access, this transceiver architecture employs a specialized FFT/IFFT module and a mapping/demapping module. Efficient mechanisms to omit input/output of unused subcarriers are introduced. Also, calculation of spectrum intensity for subcarrier level carrier sensing is successfully integrated to the FFT module. Whole transmitter/receiver modules are implemented by keeping compatibility with IEEE 802.11g. A prototype system is constructed by using Xilinx Virtex-II FPGA, which can transmit video sequence in real time. ©2009 IEEE.

DOI

Proposal of dynamic subcarrier selection technique using CSMA/CA for cognitive wireless mesh networks

Shinichi Miyamoto, Yuichi Goda, Seiichi Sampei

BROADBAND ACCESS COMMUNICATION TECHNOLOGIES III ( SPIE-INT SOC OPTICAL ENGINEERING ) 7234 7234-5 2009 [Refereed] [Invited]

In wireless mesh networks using unlicensed radio frequency band, how to adaptively and efficiently allocate spectrum among multiple wireless nodes according to the surrounding environment is an important issue. Cognitive radio that includes functionalities of radio environmental awareness and intelligent radio resource management in an opportunistic way is regarded as the great candidate to enable the efficient utilization of radio resource. In order to fully exploit radio resources and enhance spectrum efficiency based on cognitive radio to wireless mesh networks, this paper proposes dynamic subcarrier selection technique and CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) based MAC layer protocol for wireless mesh networks. In the proposed technique, based on the detection of available spot-wise subcarriers using the subcarrier-level carrier sense and the estimation of channel conditions, data packet is transmitted using unused discrete subcarriers having good channel conditions. Numerical results confirm that the proposed dynamic subcarrier selection technique is effective in utilizing radio resources and enhance spectrum efficiency. Moreover, because multiple nodes can get the transmission opportunity at the same time, the degradation in transmission performance due to the contention between multiple nodes can be solved.

DOI

Performances of 2.4GHz-band Wireless LAN Systems using Adaptive Multi-code Transmission Technique

Kazuhiro Watanabe, Shinichi Miyamoto, Norihiko Morinaga

電子情報通信学会論文誌 J85-B ( 12 ) 2209 - 2222 2008.11 [Refereed]

A Transmit Antenna Directivity Control Technique for Secure Data Transmission in Ubiquitous Communication Environments

Masaaki Yamanaka, Norihiko Morinaga, Seiichi Sampei, Shinichi Miyamoto

11th International Symposium on Wireless Personal Multimedia Communication (WPMC’08) 2008.09 [Refereed]

Spectrum loading type dynamic spectrum allocation technique for cognitive radio systems

Seiichi Sampei, Shinichi Miyamoto, Shinsuke Fbi

2007 2ND INTERNATIONAL CONFERENCE ON COGNITIVE RADIO ORIENTED WIRELESS NETWORKS AND COMMUNICATIONS ( IEEE ) 535 - 539 2007 [Refereed]

This paper proposes a spectrum loading type dynamic spectrum control technique for broadband cognitive radio systems. In the proposed scheme, based on the detection of available spot-wise spectra, discrete spectrum components of a framed symbol sequence are mapped onto the spot-wise spectra. Two spectrum mapping schemes are proposed; single-RF scheme in which available spot-wise spectra are located so close that the entire spot-wise spectra can be covered by an FFT/IFFT with a reasonable number of FFT points, and multi-RF scheme in which the spot-wise spectra are located far away so that the entire spectra cannot be covered by an FFT/IFFT processor. Computer simulation confirms that the proposed scheme is effective in utilizing spot-wise spectra. Moreover, the proposed scheme is confirmed to be effective in enhancement of co-channel and inter-symbol interference immunity when the number of opportunistically available spot-wise spectra is increased.

Unnecessary power radiation suppression technique using a transmit antenna directivity control in ubiquitous communication environments

Masaaki Yamanaka, Norihiko Morinaga, Seiichi Sampei, Shinichi Miyamoto

2007 IEEE 18TH INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS, VOLS 1-9 ( IEEE ) 1643 - + 2007 [Refereed]

This paper will propose an unnecessary radiation power suppressing technique to electromagnetically restricted areas in ubiquitous communication environments. An adaptive array antenna is employed in each terminal to control a directivity of transmit antenna not to radiate unnecessary power to the electromagnetically restricted areas while keeping sufficient gain to a target terminal. To identify angle of departures to the electromagnetically restricted areas, a radio power sensor network is assumed. Moreover, channel sounding based delay profile estimation is conducted to identify the strongest path direction for the desired signal. Based on the identified strongest path for the desired signal and the direction of the unwanted radiation detected using the radio power sensor network, artificial delay profile for a transmitted signal is created, and antenna directivity for the transmitted signal is created using a deep and wide null creation technique based on the artificial delay profile. Computer simulation confirms that the unnecessary radiation to the electromagnetically restricted areas is sufficiently suppressed while keeping throughput at a satisfactory level.

Proposal of electromagnetic environment-aware wireless network using multi-hop wireless network system

Takashi Tamura, Shinichi Miyamoto, Seiichi Sampei

2006 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1-3, PROCEEDINGS ( IEEE ) 53 - 57 2006

This paper proposes an electromagnetic environment-aware multi-hop wireless network system to achieve a good balance between electromagnetic environment and communications environment. In the proposed system, adaptive transmission route selection and transmission power control are employed to satisfy the requirements concerning the electromagnetic environment-aware. To fuerther enhance throughput, we have introduced transmission rate control in addition to the adaptive route selection and transmission power control. Comuputer simulation confirms that the proposed system is effective to achieve a good balance between electromagnetic environment and communications environment.

Adaptive Channel Selection Technique for Dual-band Wireless LAN System

Proceedings of 2005 Wireless Personal Multimedia Communications 2005

Performance of 2.4GHz-band wireless LAN system using orthogonal frequency division multiplexing scheme under microwave oven noise environment

S Miyamoto, S Harada, N Morinaga

EMC 2005: IEEE International Symposium on Electromagnetic Compatibility, Vols 1-3, Proceedings ( IEEE ) 157 - 162 2005

2.4GHz-band wireless LAN system based on IEEE 802.11g standard has been taking a great attention as it provides the attractive features such as low cost and high speed transmission rate up to 54 Mbps using Orthogonal Frequency Division Multiplexing (OFDM) transmission scheme. However, 2.4GHz radio frequency band is also used for Industrial, Scientific and Medical (ISM) devices, and the man-made noise leaked from ISM devices will degrade the performance of 2.4GHz-band wireless LAN system. In this paper, we investigate the performances of 2.4GHz-band Wireless LAN system based on IEEE 802.11g standard (IEEE 802.11g WLAN system) under microwave oven noise environment. Numerical results show that the performances of IEEE 802.11g WLAN system are much degraded by the influence of man-made noise emitted from microwave oven.

DOI

Performance of 2.4GHz-band Wireless LAN System with IEEE 802.11e Polling Based Channel Access under Man-made Noise Environment

Proceeding of Pan-Pacific EMC Joint Meeting 2005 2005

Adaptive Packet Transmission Technique for 2.4GHz-band Wireless LAN System under Bluetooth Coexistence Environment

2004 Korea-Japan AP/EMC/EMT Joint Conference 2004

Dynamic Band Selection Technique for Dual-band Wireless LAN System

2004 Korea-Japan AP/EMC/EMT Joint Conference 2004

Adaptive multi-code transmission with adaptive multilevel modulation for 2.4 GHz-band wireless LAN systems

K Watanabe, S Miyamoto, N Morinaga

ELECTRONICS LETTERS ( IEE-INST ELEC ENG ) 39 ( 1 ) 168 - 169 2003.01 [Refereed]

DOI

Parameter estimation and bit error rate of optimum receiver in a class-A impulsive radio noise environment

H Kanemoto, S Miyamoto, N Morinaga

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS ( SCRIPTA TECHNICA-JOHN WILEY & SONS ) 86 ( 8 ) 68 - 78 2003 [Refereed]

Since most of the noise generated by electronic equipment using high-frequency devices has statistical properties that are quite different from Gaussian noise, the bit error rate of conventional receivers is greatly degraded in a man-made noise environment, because they are designed with the presumption of Gaussian noise. One of the methods of providing a better bit error rate in such a noise environment is the use of an optimum receiver. This optimum receiver attains a high bit error rate by using maximum likelihood symbol detection based on the statistical properties of the noise, and the statistical properties of the noise must be known a priori for optimum reception. In this paper, we use the Middleton class-A impulsive radio noise model as the statistical model of the noise and study the parameter estimation and bit error rate of an optimum receiver in a class-A impulsive radio noise environment. First, we evaluate the effect of errors in parameter estimation on the bit error rate of the optimum receiver in a class-A impulsive radio noise environment, and show that to improve the performance of the optimum receiver in this noise environment, we should use parameters that express the statistics of the noise. Next we study the relationship between the number of noise samples used in estimation and the parameter estimation accuracy, and demonstrate that large numbers of noise samples are needed for highly accurate parameter estimation. However, it is shown that a quite good bit error rate can be obtained by the optimum receiver in the noise environment even if parameter estimation is based on a somewhat smaller number of noise samples (for example, about 700 samples for an impulsive index A = 0.05 and a Gaussian component ratio Gamma' = 0.05). (C) 2003 Wiley Periodicals, Inc.

DOI

A Proposal of the Indoor Infrared Wireless LAN System using Infrared Wireless Repeater

MIYAOKA Katsuya, MIYAMOTO Shinichi, MORINAGA Norihiko

ITE Technical Report ( The Institute of Image Information and Television Engineers ) 26 45 - 50 2002

A directed line-of-sight (LOS) system achives the highest speed communication by directional control of transmitter and receiver in the indoor infrared wireless LAN system. However, for utilizing a LOS chanel between transmitter and receiver, the performance is affected by the partition. In this paper, we discuss the probability of terminal accommodation and the transmission power in the environment with the partition and propose the system using some infrared wireless repeaters in order to reduce a loss with the partition. These results lead to validity of the proposed system by decreasing effect of a loss with the partition.

DOI

Adaptive Immunity Control of 2.4GHz-band DS-SS Wireless LAN System under Man-made Noise and Multipath Fading Environment

Shinichi Miyamoto, Norihiko Morinaga

2001 Asia-Pacific Radio Science Conference (AP-RASC'01) E6-05 2001.08 [Refereed] [Invited]

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Published Papers - MIYAMOTO Shinichi