Driven by the huge demand to explore oceans, underwater wireless communications have been rapidly developed in the past few decades. Due to the complex physical characteristics of water, acoustic wave is the only medi...Driven by the huge demand to explore oceans, underwater wireless communications have been rapidly developed in the past few decades. Due to the complex physical characteristics of water, acoustic wave is the only media available for underwater wireless communication at any distance. As a result, underwater acoustic communication(UAC) is the major research field in underwater wireless communication. In this paper, characteristics of underwater acoustic channels are first introduced and compared with terrestrial communication to demonstrate the difficulties in UAC research. To give a general impression of the UAC, current important research areas are mentioned. Furthermore, different principal modulation-based schemes for short-and medium-range communications with high data rates are investigated and summarized. To evaluate the performance of UAC systems in general,three criteria are presented based on the research publications and our years of experience in high-rate short-to medium-range communications. These three criteria provide useful tools to generally guide the design and evaluate the performance of underwater acoustic communication systems.展开更多
Millimeter-wave(mmWave)radar communication has emerged as an important technique for future wireless systems.However,the interference between the radar signal and communication data is the main issue that should be co...Millimeter-wave(mmWave)radar communication has emerged as an important technique for future wireless systems.However,the interference between the radar signal and communication data is the main issue that should be considered for the joint radar communication system.In this paper,a co-sharing waveform(CSW)is proposed to achieve communication and radar sensing simultaneously.To eliminate the co-interference between the communication and sensing signal,signal splitting and processing methods for communication data demodulation and radar signal processing are given respectively.Simulation results show that the bit error rate(BER)of CSW is close to that of the pure communication waveform.Moreover,the proposed CSW can achieve better performance than the existing waveforms in terms of range and velocity estimation.展开更多
Recently,the importance of vehicle safety supporting system has been highlighted as autonomous driving and platooning has attracted the researchers.To ensure driving safety,each vehicle must broadcast a basic safety m...Recently,the importance of vehicle safety supporting system has been highlighted as autonomous driving and platooning has attracted the researchers.To ensure driving safety,each vehicle must broadcast a basic safety message(BSM)every 100 ms.However,stable BSM exchange is difficult because of the changing environment and limited bandwidth of vehicular wireless communication.The increasing number of vehicles on the road increases the competition to access wireless networks for BSM exchange;this increases the packet collision rate.An increased packet collision rate impairs the transmission and reception of BSM information,which can easily cause a traffic accident.We propose a solution,the vehicular safety support system(V3S),which exchanges BSMs reliably even when many vehicles are on the road.The V3S uses a clustering scheme to decrease network traffic by reducing the amount of data exchanged between a vehicle and the roadside unit(RSU).In addition,the V3S reduces the collision rate of wireless network packets by broadcasting the vehicle’s BSM in an allocated timeslot using the time division multiple access(TDMA)MAC protocol.The V3S also deals with insufficient bandwidth for dedicated short-range communications(DSRC)by changing DSRC channels according to traffic flow.In evaluating the packet error rate for stable BSM packet delivery,the V3S demonstrates an excellent packet error rate of less than 1%,compared to the 802.11p with its packet error rate of 82%.展开更多
This paper introduces infrastructure-to-vehicle and vehicle-to-vehicle communications using VLC.A VLC coupled with a high-speed image sensor is introduced(i.e.,image sensor communication).The high-speed image sensors ...This paper introduces infrastructure-to-vehicle and vehicle-to-vehicle communications using VLC.A VLC coupled with a high-speed image sensor is introduced(i.e.,image sensor communication).The high-speed image sensors provide eyes for autonomous and connected vehicles.VLC imparts data reception capability to image sensors with necessary functions,which can then be provided to autonomous and connected vehicles.In this paper,some of our research on coupling VLC to high-speed image sensors is introduced,including our key findings:the basics of ISC,a vehicle motion model,and range estimation.展开更多
基金Project supported by the National Key R&D Program of China(No.2016YFC1400200)the National Natural Science Foundation of China(Nos.61771396 and 61471298)
文摘Driven by the huge demand to explore oceans, underwater wireless communications have been rapidly developed in the past few decades. Due to the complex physical characteristics of water, acoustic wave is the only media available for underwater wireless communication at any distance. As a result, underwater acoustic communication(UAC) is the major research field in underwater wireless communication. In this paper, characteristics of underwater acoustic channels are first introduced and compared with terrestrial communication to demonstrate the difficulties in UAC research. To give a general impression of the UAC, current important research areas are mentioned. Furthermore, different principal modulation-based schemes for short-and medium-range communications with high data rates are investigated and summarized. To evaluate the performance of UAC systems in general,three criteria are presented based on the research publications and our years of experience in high-rate short-to medium-range communications. These three criteria provide useful tools to generally guide the design and evaluate the performance of underwater acoustic communication systems.
基金supported by the National Natural Science Foundation of China(No.62171052 and No.61971054)the Fundamental Research Funds for the Central Universities(No.24820232023YQTD01).
文摘Millimeter-wave(mmWave)radar communication has emerged as an important technique for future wireless systems.However,the interference between the radar signal and communication data is the main issue that should be considered for the joint radar communication system.In this paper,a co-sharing waveform(CSW)is proposed to achieve communication and radar sensing simultaneously.To eliminate the co-interference between the communication and sensing signal,signal splitting and processing methods for communication data demodulation and radar signal processing are given respectively.Simulation results show that the bit error rate(BER)of CSW is close to that of the pure communication waveform.Moreover,the proposed CSW can achieve better performance than the existing waveforms in terms of range and velocity estimation.
基金This work was supported in part by the Chung-Ang University Research Grants in 2019,and in part by R&D Program for Forest Science Technology(Project No.“2021338C10-2123-CD02)provided by Korea Forest Service(Korea Forestry Promotion Institute).
文摘Recently,the importance of vehicle safety supporting system has been highlighted as autonomous driving and platooning has attracted the researchers.To ensure driving safety,each vehicle must broadcast a basic safety message(BSM)every 100 ms.However,stable BSM exchange is difficult because of the changing environment and limited bandwidth of vehicular wireless communication.The increasing number of vehicles on the road increases the competition to access wireless networks for BSM exchange;this increases the packet collision rate.An increased packet collision rate impairs the transmission and reception of BSM information,which can easily cause a traffic accident.We propose a solution,the vehicular safety support system(V3S),which exchanges BSMs reliably even when many vehicles are on the road.The V3S uses a clustering scheme to decrease network traffic by reducing the amount of data exchanged between a vehicle and the roadside unit(RSU).In addition,the V3S reduces the collision rate of wireless network packets by broadcasting the vehicle’s BSM in an allocated timeslot using the time division multiple access(TDMA)MAC protocol.The V3S also deals with insufficient bandwidth for dedicated short-range communications(DSRC)by changing DSRC channels according to traffic flow.In evaluating the packet error rate for stable BSM packet delivery,the V3S demonstrates an excellent packet error rate of less than 1%,compared to the 802.11p with its packet error rate of 82%.
基金supported in part by Japan Society for the Promotion of Science(JSPS)KAKENHI(No.16H04364).
文摘This paper introduces infrastructure-to-vehicle and vehicle-to-vehicle communications using VLC.A VLC coupled with a high-speed image sensor is introduced(i.e.,image sensor communication).The high-speed image sensors provide eyes for autonomous and connected vehicles.VLC imparts data reception capability to image sensors with necessary functions,which can then be provided to autonomous and connected vehicles.In this paper,some of our research on coupling VLC to high-speed image sensors is introduced,including our key findings:the basics of ISC,a vehicle motion model,and range estimation.
