The Experts below are selected from a list of 71721 Experts worldwide ranked by ideXlab platform
Takeo Fujii - One of the best experts on this subject based on the ideXlab platform.
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Packet Delivery Ratio Prediction for V2V Based on Radio Environment Map Considering Hidden Terminal Problem
International Journal of Intelligent Transportation Systems Research, 2020Co-Authors: Ayumu Ueda, Takeo FujiiAbstract:Recently, vehicle-to-vehicle communication has been envisaged to be one of the technologies for realizing highly safe connected and automated driving. One of the approaches for predicting the Radio Environment is the use of a measurement-based spectrum database, which stores various pieces of information on the Radio Environment of data received and collected by vehicles; however, prediction of an accurate packet delivery ratio (PDR) with consideration of packet collisions is difficult if the vehicle density changes after the generation of PDR maps. This paper proposes a method for predicting the PDR with consideration of packet collisions, including the influence of hidden nodes, by using the positions and number of vehicles.
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Radio Environment map updating procedure considering change of surrounding Environment
Wireless Communications and Networking Conference, 2020Co-Authors: Keita Katagiri, Takeo FujiiAbstract:In this paper, we propose a method to update a Radio Environment map (REM) considering change of surrounding Environment. The REM provides statistical Radio information of primary users (PUs) to secondary users (SUs). SUs can utilize the information to design communication parameters for improving communication efficiency. However, if surrounding Environment changes, the newly observed datasets are significantly different from the initially observed datasets. The database server requires to detect change of surrounding Environment and to update the REM based on the detected results. In this paper, we propose a method to update the REM based on hypothesis testing. In the proposed method, sensor nodes observe a received signal strength indicator (RSSI) in each location and report that to the database server. Then, the database server updates the REM using tested results. The simulation results show that the proposed method can detect change of surrounding Environment and accurately predict the average RSSI in each location while significantly reducing the number of the REM updates.
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Radio Environment map construction with joint space frequency interpolation
International Conference on Artificial Intelligence, 2020Co-Authors: Koya Sato, Kei Inage, Takeo FujiiAbstract:In this paper, we propose a Radio Environment map (REM) construction method that interpolates the received signal power over not only the spatial domain but also the frequency domain. REM is a tool for analyzing Radio propagation, which is typically defined as a map that stores the received signal power. Crowdsourcing with spatial interpolation (e.g., Kriging) can accurately construct the REM, and the accurate REM improves the efficiency of spectrum use. However, crowdsourcing can only be performed over frequencies in which the mobile terminals can perform the sensing. Thus, conventional REM construction may only improve the spectral efficiency in the frequency in which the sensing can be performed. Our proposed method focuses on the fact that the average received signal power, which consists of path loss and shadowing, shows a strong correlation over the frequency domain. We show that utilizing correlations over both frequency and spatial domains can construct the REM even if the datasets are not available at the estimated Environment.
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Radio Environment map updating procedure based on hypothesis testing
IEEE International Symposium on Dynamic Spectrum Access Networks, 2019Co-Authors: Keita Katagiri, Takeo FujiiAbstract:In this paper, we propose an updating method of a Radio Environment map (REM) using Welch’s t -test. The REM provides statistical Radio information about primary users (PUs) to secondary users (SUs). By using REM, SUs can predict path loss and shadowing deviation in each location. However, the estimation accuracy of the Radio Environment is degraded if the surrounding Environment changes since the initial REM is constructed. The database server should update the REM by detecting the change of the Radio Environment. Therefore, in this paper, we consider that the database server judges the change of the Radio Environment by using Welch’s t-test, which is one of the hypothesis testings. In the proposed method, the sensor nodes observe the received power in each location and report this information to the database server. The database server tests the difference of the average received power between the initial REM and the new observed datasets and decides the requirement of update of the REM. The simulation results show that the proposed method can detect the change of the Radio Environment and accurately predict the average received power than the updating method using oblivion factor.
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Crowdsourcing-Assisted Radio Environment Database for V2V Communication
Sensors, 2018Co-Authors: Keita Katagiri, Koya Sato, Takeo FujiiAbstract:In order to realize reliable Vehicle-to-Vehicle (V2V) communication systems for autonomous driving, the recognition of Radio propagation becomes an important technology. However, in the current wireless distributed network systems, it is difficult to accurately estimate the Radio propagation characteristics because of the locality of the Radio propagation caused by surrounding buildings and geographical features. In this paper, we propose a measurement-based Radio Environment database for improving the accuracy of the Radio Environment estimation in the V2V communication systems. The database first gathers measurement datasets of the received signal strength indicator (RSSI) related to the transmission/reception locations from V2V systems. By using the datasets, the average received power maps linked with transmitter and receiver locations are generated. We have performed measurement campaigns of V2V communications in the real Environment to observe RSSI for the database construction. Our results show that the proposed method has higher accuracy of the Radio propagation estimation than the conventional path loss model-based estimation.
Yangyang Zhang - One of the best experts on this subject based on the ideXlab platform.
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a vision to smart Radio Environment surface wave communication superhighways
IEEE Wireless Communications, 2021Co-Authors: Kaikit Wong, Kinfai Tong, Zhiyuan Chu, Yangyang ZhangAbstract:Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart Radio Environment by using software-defined materials or programmable metasurfaces for establishing favorable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on intelligent surfaces for future smart Radio Environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off Radio waves intelligently toward intended user terminals. In the proposed SW vision, energy efficiency can be much higher, due to more desirable propagation characteristics compared to open-space Radio propagation. The fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-less data access. We shall outline the opportunities and challenges arising from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways.
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a vision to smart Radio Environment surface wave communication superhighways
arXiv: Signal Processing, 2020Co-Authors: Kaikit Wong, Kinfai Tong, Zhiyuan Chu, Yangyang ZhangAbstract:Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart Radio Environment by using software-defined materials or programmable metasurfaces for establishing favourable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on "smart surfaces" for future smart Radio Environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off Radio waves intelligently towards intended user terminals. In this vision, energy efficiency will be ultra-high, due to much less pathloss compared to free space propagation, and the fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-free data access. We shall outline the opportunities and associated challenges arisen from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways.
Kaikit Wong - One of the best experts on this subject based on the ideXlab platform.
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a vision to smart Radio Environment surface wave communication superhighways
IEEE Wireless Communications, 2021Co-Authors: Kaikit Wong, Kinfai Tong, Zhiyuan Chu, Yangyang ZhangAbstract:Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart Radio Environment by using software-defined materials or programmable metasurfaces for establishing favorable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on intelligent surfaces for future smart Radio Environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off Radio waves intelligently toward intended user terminals. In the proposed SW vision, energy efficiency can be much higher, due to more desirable propagation characteristics compared to open-space Radio propagation. The fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-less data access. We shall outline the opportunities and challenges arising from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways.
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a vision to smart Radio Environment surface wave communication superhighways
arXiv: Signal Processing, 2020Co-Authors: Kaikit Wong, Kinfai Tong, Zhiyuan Chu, Yangyang ZhangAbstract:Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart Radio Environment by using software-defined materials or programmable metasurfaces for establishing favourable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on "smart surfaces" for future smart Radio Environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off Radio waves intelligently towards intended user terminals. In this vision, energy efficiency will be ultra-high, due to much less pathloss compared to free space propagation, and the fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-free data access. We shall outline the opportunities and associated challenges arisen from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways.
Keita Katagiri - One of the best experts on this subject based on the ideXlab platform.
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Radio Environment map updating procedure considering change of surrounding Environment
Wireless Communications and Networking Conference, 2020Co-Authors: Keita Katagiri, Takeo FujiiAbstract:In this paper, we propose a method to update a Radio Environment map (REM) considering change of surrounding Environment. The REM provides statistical Radio information of primary users (PUs) to secondary users (SUs). SUs can utilize the information to design communication parameters for improving communication efficiency. However, if surrounding Environment changes, the newly observed datasets are significantly different from the initially observed datasets. The database server requires to detect change of surrounding Environment and to update the REM based on the detected results. In this paper, we propose a method to update the REM based on hypothesis testing. In the proposed method, sensor nodes observe a received signal strength indicator (RSSI) in each location and report that to the database server. Then, the database server updates the REM using tested results. The simulation results show that the proposed method can detect change of surrounding Environment and accurately predict the average RSSI in each location while significantly reducing the number of the REM updates.
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Radio Environment map updating procedure based on hypothesis testing
IEEE International Symposium on Dynamic Spectrum Access Networks, 2019Co-Authors: Keita Katagiri, Takeo FujiiAbstract:In this paper, we propose an updating method of a Radio Environment map (REM) using Welch’s t -test. The REM provides statistical Radio information about primary users (PUs) to secondary users (SUs). By using REM, SUs can predict path loss and shadowing deviation in each location. However, the estimation accuracy of the Radio Environment is degraded if the surrounding Environment changes since the initial REM is constructed. The database server should update the REM by detecting the change of the Radio Environment. Therefore, in this paper, we consider that the database server judges the change of the Radio Environment by using Welch’s t-test, which is one of the hypothesis testings. In the proposed method, the sensor nodes observe the received power in each location and report this information to the database server. The database server tests the difference of the average received power between the initial REM and the new observed datasets and decides the requirement of update of the REM. The simulation results show that the proposed method can detect the change of the Radio Environment and accurately predict the average received power than the updating method using oblivion factor.
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Crowdsourcing-Assisted Radio Environment Database for V2V Communication
Sensors, 2018Co-Authors: Keita Katagiri, Koya Sato, Takeo FujiiAbstract:In order to realize reliable Vehicle-to-Vehicle (V2V) communication systems for autonomous driving, the recognition of Radio propagation becomes an important technology. However, in the current wireless distributed network systems, it is difficult to accurately estimate the Radio propagation characteristics because of the locality of the Radio propagation caused by surrounding buildings and geographical features. In this paper, we propose a measurement-based Radio Environment database for improving the accuracy of the Radio Environment estimation in the V2V communication systems. The database first gathers measurement datasets of the received signal strength indicator (RSSI) related to the transmission/reception locations from V2V systems. By using the datasets, the average received power maps linked with transmitter and receiver locations are generated. We have performed measurement campaigns of V2V communications in the real Environment to observe RSSI for the database construction. Our results show that the proposed method has higher accuracy of the Radio propagation estimation than the conventional path loss model-based estimation.
Kinfai Tong - One of the best experts on this subject based on the ideXlab platform.
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a vision to smart Radio Environment surface wave communication superhighways
IEEE Wireless Communications, 2021Co-Authors: Kaikit Wong, Kinfai Tong, Zhiyuan Chu, Yangyang ZhangAbstract:Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart Radio Environment by using software-defined materials or programmable metasurfaces for establishing favorable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on intelligent surfaces for future smart Radio Environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off Radio waves intelligently toward intended user terminals. In the proposed SW vision, energy efficiency can be much higher, due to more desirable propagation characteristics compared to open-space Radio propagation. The fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-less data access. We shall outline the opportunities and challenges arising from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways.
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a vision to smart Radio Environment surface wave communication superhighways
arXiv: Signal Processing, 2020Co-Authors: Kaikit Wong, Kinfai Tong, Zhiyuan Chu, Yangyang ZhangAbstract:Complementary to traditional approaches that focus on transceiver design for bringing the best out of unstable, lossy fading channels, one radical development in wireless communications that has recently emerged is to pursue a smart Radio Environment by using software-defined materials or programmable metasurfaces for establishing favourable propagation conditions. This article portraits a vision of communication superhighways enabled by surface wave (SW) propagation on "smart surfaces" for future smart Radio Environments. The concept differs from the mainstream efforts of using passive elements on a large surface for bouncing off Radio waves intelligently towards intended user terminals. In this vision, energy efficiency will be ultra-high, due to much less pathloss compared to free space propagation, and the fact that SW is inherently confined to the smart surface not only greatly simplifies the task of interference management, but also makes possible exceptionally localized high-speed interference-free data access. We shall outline the opportunities and associated challenges arisen from the SW paradigm. We shall also attempt to shed light on several key enabling technologies that make this realizable. One important technology which will be discussed is a software-controlled fluidic waveguiding architecture that permits dynamic creation of high-throughput data highways.
