Ryuji Kohno | Yokohama National University (original) (raw)
Papers by Ryuji Kohno
IEEE Transactions on Intelligent Transportation Systems, 2007
The Intelligent Transportation Systems Society is an organization within the framework of the IEE... more The Intelligent Transportation Systems Society is an organization within the framework of the IEEE. Members of the IEEE ITS Society have access to the electronic version of this TRANSACTIONS free of charge. Its professional interest is in the application of information technology to transportation. For information on joining the IEEE, please contact the IEEE at the address below. Member copies are for personal use only.
![Research paper thumbnail of Wireless communication technologies: new multimedia systems [Book Review]](https://attachments.academia-assets.com/114109829/thumbnails/1.jpg)
](IEEE Communications Magazine, 2001
BOOK REVIEWS/EDITED BY ANDRZEJ JAJSZCZYK WIRELESS COMMUNICATION TECHNOLO-NORIHIKO MORINAGA, RYUJI... more BOOK REVIEWS/EDITED BY ANDRZEJ JAJSZCZYK WIRELESS COMMUNICATION TECHNOLO-NORIHIKO MORINAGA, RYUJI KOHNO, GIES: NEW MULTIMEDIA SYSTEMS AND SEllCHl SAMPEI (EDITORS), KLUWER ACADEMIC PUBLISHERS, 2000, ISBN 0-7923-7900-4, HARDCOVER, 321 PAGES REVIEWER: ASRAR U. H. SHEIKH This book is the latest in the series of books based on a collection of topics of significance discussed at Personal, Indoor and Mobile Radio Communications (PIMRC) symposia since 1997. This book is divided into two parts. Part I covers new technical trends in wireless multimedia communications, and Part I1 deals with trends in wireless multimedia communication systems. Part I comprises a selection of seven key technologies that are considered the driving forces behind the new emerging multimedia communications systems. Each of the selected technology is described in a standalone chapter, which is written by one or more experts in that technological area. The technologies chosen for Part I are wireless channel modeling, space-time coding, coding for wireless, OFDM, multiuser
2018 3rd International Conference on Computer and Communication Systems (ICCCS), Apr 1, 2018
InTech eBooks, Aug 1, 2011
Proceedings of the Society Conference of IEICE, Aug 30, 2011
IEEE Conference Proceedings, 2017
IEICE Technical Report; IEICE Tech. Rep., May 4, 2017
In this paper, we analyze performance of our error control scheme in a cross-layer design for wir... more In this paper, we analyze performance of our error control scheme in a cross-layer design for wireless body area networks (WBANs). As in our previous work, we have proposed an optimal QoS control scheme that employs a multiplexing layer for priority scheduling and a decomposable error control coding scheme for WBANs. However, a cross-layer approach has not been considered yet. In this paper, we utilize a crosslayer approach at physical (PHY) and medium access control (MAC) layers and analyze performance of our proposed error control scheme and the standard scheme. Numerical results show that our proposed scheme has better performances than the standard scheme. For instance, we show that the proposed system obtains over 6dB gain than the standard about the probability of unsuccessful transmission. Additionally, the case utilizing a schedule access protocol has better performances than a random access protocol.
ABSTRACT This work focused on the theoretical performance evaluation of synchronization for DS-UW... more ABSTRACT This work focused on the theoretical performance evaluation of synchronization for DS-UWB systems using coherent receiver and modeling the system using the probability of false alarm and probability of detection under AWGN channel. We considered a serial packet structure with variable length of spreading code for preamble and data. Theoretical analysis showed that the preamble design affects the synchronization performance. Moreover, there is an optimum value of TNR that maximize the synchronization success rate. A range of TNR improves the synchronization probability and spreads as SNR is increasing. For future perspectives, trade-off between complexity and performance using the proposed system should be evaluated, meanwhile extending to consider multipath fading channel and multiple accesses.
Wireless Personal Communications, Oct 1, 2005
Space-time multiple trellis coded modulation (ST-MTCM) has been introduced in order to achieve ma... more Space-time multiple trellis coded modulation (ST-MTCM) has been introduced in order to achieve maximum transmit diversity gain and larger coding gain with the existence of parallel paths. In our previous research, we designed a new coded modulation scheme for ST-MTCM which simultaneously maximizes the coding gain and diversity gain utilizing Hadamard Matrix giving the maximum determinant. This scheme, however, cannot achieve full transmit rate. In this paper, we extend our research so as to achieve full rate transmission as well as maximum coding and diversity gain. In addition, Super-Orthogonal Space-Time Trellis Code (SO-STTC) is well known for its high coding gain, full diversity gain and full transmit rate. Even though our proposed scheme is essentially the same as SO-STTC, we show in this paper that our proposed code design is different from SO-STTC, and achieves better performance. Our proposed code design utilizes transmit symbol phase rotation at a certain time slot so as to avoid same path transition in trellis, which occurs with conventional SO-STTC scheme. We design codes with different way of phase rotation for different MPSK modulation scheme, and simulation results show the improvements of our proposed codes for MPSK modulation with different number of states.
電子情報通信学会総合大会講演論文集, Mar 5, 2013
Abstract We developed a positioning system using impulse radio UWB. The system consists of tags e... more Abstract We developed a positioning system using impulse radio UWB. The system consists of tags equipped only with transmitters and nodes provided with both transmitters and receivers. The system calculates the position of the tags using the TDOA method, whereby ...
IEICE Transactions on Communications, 2009
The medical body area network (MBAN) is an emerging technology to resolve the small area connecti... more The medical body area network (MBAN) is an emerging technology to resolve the small area connection issues around human body, especially for the medical applications. This paper proposes a dynamic TDMA (DTDMA) protocol for MBAN with focus on the dependability and power efficiency. In DTDMA, the slots are allocated by the MBAN coordinator only to the devices which have buffered packets and released to other devices after the current allocation. Through the adaptive allocation of the slots in a DTDMA frame, the MBAN coordinator adjusts the duty cycle adaptively with the traffic load. Comparing with the IEEE 802.15.4 MAC protocol, the DTDMA provides more dependability in terms of lower packet dropping rate and less energy consumption especially for an end device of a MBAN.
Due to rapidly increasing of elderly population all over the world and quickly developing of ente... more Due to rapidly increasing of elderly population all over the world and quickly developing of entertainment devices, wireless body area network (WBAN) attracts attention. For both medical and non-medical applications, a reliability, high energy-efficiency and high throughput of WBAN communication are requested. The well-known cluster-based is proposed to obtain the high energy-efficiency, however the transmission in every cluster is controlled on MAC layer by superframe in order to obtain the high throughput. The performance of original cluster-based, complete control and spatial reuse superframe scenarios is analyzed and compared. The calculation result indicates that the spatial reuse superframe outperforms the original cluster-based when the access probability and/or the total number of sensors are high. Furthermore, there are the optimal number of clusters, the access probabilities and the total number of sensors that achieve the highest throughput. The optimization method of number of spatial reuse superframe (k) is proposed to obtain the highest throughput when another factors change. k increases when another factors of system model increase, excepted the payload. The optimization method of another factors is similar and the proposed method can be applied to not only IEEE802.15.6 WBAN but also another cluster-based wireless sensor networks.
Electronics and communications in Japan, Jul 1, 1991
電子情報通信学会ソサイエティ大会講演論文集, Aug 28, 2012
International Symposium on Information Theory, Dec 15, 2003
IEEE Transactions on Intelligent Transportation Systems, 2007
The Intelligent Transportation Systems Society is an organization within the framework of the IEE... more The Intelligent Transportation Systems Society is an organization within the framework of the IEEE. Members of the IEEE ITS Society have access to the electronic version of this TRANSACTIONS free of charge. Its professional interest is in the application of information technology to transportation. For information on joining the IEEE, please contact the IEEE at the address below. Member copies are for personal use only.
IEEE Communications Magazine, 2001
BOOK REVIEWS/EDITED BY ANDRZEJ JAJSZCZYK WIRELESS COMMUNICATION TECHNOLO-NORIHIKO MORINAGA, RYUJI... more BOOK REVIEWS/EDITED BY ANDRZEJ JAJSZCZYK WIRELESS COMMUNICATION TECHNOLO-NORIHIKO MORINAGA, RYUJI KOHNO, GIES: NEW MULTIMEDIA SYSTEMS AND SEllCHl SAMPEI (EDITORS), KLUWER ACADEMIC PUBLISHERS, 2000, ISBN 0-7923-7900-4, HARDCOVER, 321 PAGES REVIEWER: ASRAR U. H. SHEIKH This book is the latest in the series of books based on a collection of topics of significance discussed at Personal, Indoor and Mobile Radio Communications (PIMRC) symposia since 1997. This book is divided into two parts. Part I covers new technical trends in wireless multimedia communications, and Part I1 deals with trends in wireless multimedia communication systems. Part I comprises a selection of seven key technologies that are considered the driving forces behind the new emerging multimedia communications systems. Each of the selected technology is described in a standalone chapter, which is written by one or more experts in that technological area. The technologies chosen for Part I are wireless channel modeling, space-time coding, coding for wireless, OFDM, multiuser
2018 3rd International Conference on Computer and Communication Systems (ICCCS), Apr 1, 2018
InTech eBooks, Aug 1, 2011
Proceedings of the Society Conference of IEICE, Aug 30, 2011
IEEE Conference Proceedings, 2017
IEICE Technical Report; IEICE Tech. Rep., May 4, 2017
In this paper, we analyze performance of our error control scheme in a cross-layer design for wir... more In this paper, we analyze performance of our error control scheme in a cross-layer design for wireless body area networks (WBANs). As in our previous work, we have proposed an optimal QoS control scheme that employs a multiplexing layer for priority scheduling and a decomposable error control coding scheme for WBANs. However, a cross-layer approach has not been considered yet. In this paper, we utilize a crosslayer approach at physical (PHY) and medium access control (MAC) layers and analyze performance of our proposed error control scheme and the standard scheme. Numerical results show that our proposed scheme has better performances than the standard scheme. For instance, we show that the proposed system obtains over 6dB gain than the standard about the probability of unsuccessful transmission. Additionally, the case utilizing a schedule access protocol has better performances than a random access protocol.
ABSTRACT This work focused on the theoretical performance evaluation of synchronization for DS-UW... more ABSTRACT This work focused on the theoretical performance evaluation of synchronization for DS-UWB systems using coherent receiver and modeling the system using the probability of false alarm and probability of detection under AWGN channel. We considered a serial packet structure with variable length of spreading code for preamble and data. Theoretical analysis showed that the preamble design affects the synchronization performance. Moreover, there is an optimum value of TNR that maximize the synchronization success rate. A range of TNR improves the synchronization probability and spreads as SNR is increasing. For future perspectives, trade-off between complexity and performance using the proposed system should be evaluated, meanwhile extending to consider multipath fading channel and multiple accesses.
Wireless Personal Communications, Oct 1, 2005
Space-time multiple trellis coded modulation (ST-MTCM) has been introduced in order to achieve ma... more Space-time multiple trellis coded modulation (ST-MTCM) has been introduced in order to achieve maximum transmit diversity gain and larger coding gain with the existence of parallel paths. In our previous research, we designed a new coded modulation scheme for ST-MTCM which simultaneously maximizes the coding gain and diversity gain utilizing Hadamard Matrix giving the maximum determinant. This scheme, however, cannot achieve full transmit rate. In this paper, we extend our research so as to achieve full rate transmission as well as maximum coding and diversity gain. In addition, Super-Orthogonal Space-Time Trellis Code (SO-STTC) is well known for its high coding gain, full diversity gain and full transmit rate. Even though our proposed scheme is essentially the same as SO-STTC, we show in this paper that our proposed code design is different from SO-STTC, and achieves better performance. Our proposed code design utilizes transmit symbol phase rotation at a certain time slot so as to avoid same path transition in trellis, which occurs with conventional SO-STTC scheme. We design codes with different way of phase rotation for different MPSK modulation scheme, and simulation results show the improvements of our proposed codes for MPSK modulation with different number of states.
電子情報通信学会総合大会講演論文集, Mar 5, 2013
Abstract We developed a positioning system using impulse radio UWB. The system consists of tags e... more Abstract We developed a positioning system using impulse radio UWB. The system consists of tags equipped only with transmitters and nodes provided with both transmitters and receivers. The system calculates the position of the tags using the TDOA method, whereby ...
IEICE Transactions on Communications, 2009
The medical body area network (MBAN) is an emerging technology to resolve the small area connecti... more The medical body area network (MBAN) is an emerging technology to resolve the small area connection issues around human body, especially for the medical applications. This paper proposes a dynamic TDMA (DTDMA) protocol for MBAN with focus on the dependability and power efficiency. In DTDMA, the slots are allocated by the MBAN coordinator only to the devices which have buffered packets and released to other devices after the current allocation. Through the adaptive allocation of the slots in a DTDMA frame, the MBAN coordinator adjusts the duty cycle adaptively with the traffic load. Comparing with the IEEE 802.15.4 MAC protocol, the DTDMA provides more dependability in terms of lower packet dropping rate and less energy consumption especially for an end device of a MBAN.
Due to rapidly increasing of elderly population all over the world and quickly developing of ente... more Due to rapidly increasing of elderly population all over the world and quickly developing of entertainment devices, wireless body area network (WBAN) attracts attention. For both medical and non-medical applications, a reliability, high energy-efficiency and high throughput of WBAN communication are requested. The well-known cluster-based is proposed to obtain the high energy-efficiency, however the transmission in every cluster is controlled on MAC layer by superframe in order to obtain the high throughput. The performance of original cluster-based, complete control and spatial reuse superframe scenarios is analyzed and compared. The calculation result indicates that the spatial reuse superframe outperforms the original cluster-based when the access probability and/or the total number of sensors are high. Furthermore, there are the optimal number of clusters, the access probabilities and the total number of sensors that achieve the highest throughput. The optimization method of number of spatial reuse superframe (k) is proposed to obtain the highest throughput when another factors change. k increases when another factors of system model increase, excepted the payload. The optimization method of another factors is similar and the proposed method can be applied to not only IEEE802.15.6 WBAN but also another cluster-based wireless sensor networks.
Electronics and communications in Japan, Jul 1, 1991
電子情報通信学会ソサイエティ大会講演論文集, Aug 28, 2012
International Symposium on Information Theory, Dec 15, 2003