Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz（THz） wireless communications. An error control coding scheme based on low density parit...Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz（THz） wireless communications. An error control coding scheme based on low density parity check（LDPC） codes with soft decision decoding algorithm is proposed to improve the bit-error-rate（BER） performance of an on-off keying（OOK） modulated THz signal through atmospheric channel. The THz wave propagation characteristics and channel model in atmosphere is set up. Numerical simulations validate the great performance of LDPC codes against the atmospheric fading and demonstrate the huge potential in future ultra-high speed beyond Gbps THz communications.展开更多
As next generation communication technologies emerge,new high data rate applications and high-definition large-screen video streaming have become very popular.As a result,network traffic has been increasing so much th...As next generation communication technologies emerge,new high data rate applications and high-definition large-screen video streaming have become very popular.As a result,network traffic has been increasing so much that existing backhaul networks soon will not be able to support all traffic demands.To support these needs in future 6G mobile systems,the establishment of an additional backhaul wireless network is considered essential.As one of the solutions,a wireless backhaul network based on an aerial platform has been proposed.In order to explore the potential of aerial platforms as wireless backhaul networks,in this paper,the categories for wireless backhaul networks based on aerial platforms are investigated.This paper includes a survey of the definitions and characteristics of low altitude platforms(LAPs)and high altitude platforms(HAPs),as well as channel models according to the atmosphere.For wireless backhaul network designs based on aerial platforms,altitude and platform selection options,deployment options,energy issues,and security based on target location and performance were considered in the analysis and investigation.展开更多
A wireless body area network (WBAN) allows integration of low power, invasive or noninvasive miniaturized sensors around a human body. WBAN is expected to become a basic infrastructure element for human health monitor...A wireless body area network (WBAN) allows integration of low power, invasive or noninvasive miniaturized sensors around a human body. WBAN is expected to become a basic infrastructure element for human health monitoring. The Task Group 6 of IEEE 802.15 is formed to address specific needs of body area network. It defines a medium access control layer that supports various physical layers. In this work, we analyze the efficiency of simple slotted ALOHA scheme, and then propose a novel allocation scheme that controls the random access period and packet transmission probability to optimize channel efficiency. NS-2 simulations have been carried out to evaluate its performance. The simulation results demonstrate significant performance improvement in latency and throughput using the proposed MAC algorithm.展开更多
基金Project supported by the National Key Basic Research Program of China(Grant No.2014CB339803)the National High Technology Research and Development Program of China(Grant No.2011AA010205)+4 种基金the National Natural Science Foundation of China(Grant Nos.61131006,61321492,and 61204135)the Major National Development Project of Scientific Instrument and Equipment(Grant No.2011YQ150021)the National Science and Technology Major Project(Grant No.2011ZX02707)the International Collaboration and Innovation Program on High Mobility Materials Engineering of the Chinese Academy of Sciencesthe Shanghai Municipal Commission of Science and Technology(Grant No.14530711300)
文摘Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz（THz） wireless communications. An error control coding scheme based on low density parity check（LDPC） codes with soft decision decoding algorithm is proposed to improve the bit-error-rate（BER） performance of an on-off keying（OOK） modulated THz signal through atmospheric channel. The THz wave propagation characteristics and channel model in atmosphere is set up. Numerical simulations validate the great performance of LDPC codes against the atmospheric fading and demonstrate the huge potential in future ultra-high speed beyond Gbps THz communications.
基金This work was supported by Institute for Information&communications Technology Promotion(IITP)grant funded by the Korea government(MSIT)(No.2019-0-00685Free space optical communication based vertical mobile network).
文摘As next generation communication technologies emerge,new high data rate applications and high-definition large-screen video streaming have become very popular.As a result,network traffic has been increasing so much that existing backhaul networks soon will not be able to support all traffic demands.To support these needs in future 6G mobile systems,the establishment of an additional backhaul wireless network is considered essential.As one of the solutions,a wireless backhaul network based on an aerial platform has been proposed.In order to explore the potential of aerial platforms as wireless backhaul networks,in this paper,the categories for wireless backhaul networks based on aerial platforms are investigated.This paper includes a survey of the definitions and characteristics of low altitude platforms(LAPs)and high altitude platforms(HAPs),as well as channel models according to the atmosphere.For wireless backhaul network designs based on aerial platforms,altitude and platform selection options,deployment options,energy issues,and security based on target location and performance were considered in the analysis and investigation.
基金Project(2010-0020163) supported by Inha University Research and by Basic Science Research Program through the National Research Foundation of Korea(NRF) Funded by the Ministry of Education, Korea
文摘A wireless body area network (WBAN) allows integration of low power, invasive or noninvasive miniaturized sensors around a human body. WBAN is expected to become a basic infrastructure element for human health monitoring. The Task Group 6 of IEEE 802.15 is formed to address specific needs of body area network. It defines a medium access control layer that supports various physical layers. In this work, we analyze the efficiency of simple slotted ALOHA scheme, and then propose a novel allocation scheme that controls the random access period and packet transmission probability to optimize channel efficiency. NS-2 simulations have been carried out to evaluate its performance. The simulation results demonstrate significant performance improvement in latency and throughput using the proposed MAC algorithm.
