Large intelligent surface(LIS)is considered as a new solution to enhance the performance of wireless networks[1].LIS comprises low-cost passive elements which can be well controlled.In this paper,a LIS is invoked in t...Large intelligent surface(LIS)is considered as a new solution to enhance the performance of wireless networks[1].LIS comprises low-cost passive elements which can be well controlled.In this paper,a LIS is invoked in the vehicular networks.We analyze the system performance under Weibull fading.We derive a novel exact analytical expression for outage probability in closed form.Based on the analytical result,we discuss three special scenarios including high SNR case,low SNR case,as well as weak interference case.The corresponding approximations for three cases are provided,respectively.In order to gain more insights,we obtain the diversity order of outage probability and it is proved that the outage probability at high SNR depends on the interference,threshold and fading parameters which leads to 0 diversity order.Furthermore,we investigate the ergodic achievable rate of LIS-assisted vehicular networks and present the closed-form tight bounds.Similar to the outage performance,three special cases are studied and the asymptotic expressions are provided in simple forms.A rate ceiling is shown for high SNRs due to the existence of interference which results 0 high SNR slope.Finally,we give the energy efficiency of LIS-assisted vehicular network.Numerical results are presented to verify the accuracy of our analysis.It is evident that the performance of LIS-assisted vehicular networks with optimal phase shift scheme exceeds that of traditional vehicular networks and random phase Received:Aug.6,2020 Revised:Nov.17,2020 Editor:Caijun Zhong shift scheme significantly.展开更多
Energy source and circuit cost are two critical challenges for the future development of the Internet of Things(IoT).Backscatter communications offer a potential solution to conveniently obtain power and reduce cost f...Energy source and circuit cost are two critical challenges for the future development of the Internet of Things(IoT).Backscatter communications offer a potential solution to conveniently obtain power and reduce cost for sensors in IoT,and researchers are paying close attention to the technology.Backscatter technology originated from the Second World War and has been widely applied in the logistics domain.Recently,both the academic and industrial worlds are proposing a series of new types of backscatter technologies for communications and IoT.In this paper,we review the history of both IoT and backscatter,describe the new types of backscatter,demonstrate their applications,and discuss the open challenges.展开更多
基金supported by the National Natural Science Foundation of China(No.61701201,61771252,61801244,61801238)the National Key Research and Development Program(No.2020YFB1806608,2019YFB2103004)+1 种基金Six Talent Peaks Project in Jiangsu ProvinceProject of Key Laboratory of Wireless Communications of Jiangsu Province.
文摘Large intelligent surface(LIS)is considered as a new solution to enhance the performance of wireless networks[1].LIS comprises low-cost passive elements which can be well controlled.In this paper,a LIS is invoked in the vehicular networks.We analyze the system performance under Weibull fading.We derive a novel exact analytical expression for outage probability in closed form.Based on the analytical result,we discuss three special scenarios including high SNR case,low SNR case,as well as weak interference case.The corresponding approximations for three cases are provided,respectively.In order to gain more insights,we obtain the diversity order of outage probability and it is proved that the outage probability at high SNR depends on the interference,threshold and fading parameters which leads to 0 diversity order.Furthermore,we investigate the ergodic achievable rate of LIS-assisted vehicular networks and present the closed-form tight bounds.Similar to the outage performance,three special cases are studied and the asymptotic expressions are provided in simple forms.A rate ceiling is shown for high SNRs due to the existence of interference which results 0 high SNR slope.Finally,we give the energy efficiency of LIS-assisted vehicular network.Numerical results are presented to verify the accuracy of our analysis.It is evident that the performance of LIS-assisted vehicular networks with optimal phase shift scheme exceeds that of traditional vehicular networks and random phase Received:Aug.6,2020 Revised:Nov.17,2020 Editor:Caijun Zhong shift scheme significantly.
基金This study was supported in part by the Fundamental Research Funds for the Central Universities(No.2020YJS044)in part by the National Natural Science Foundation of China(Nos.61871026 and U1834210).
文摘Energy source and circuit cost are two critical challenges for the future development of the Internet of Things(IoT).Backscatter communications offer a potential solution to conveniently obtain power and reduce cost for sensors in IoT,and researchers are paying close attention to the technology.Backscatter technology originated from the Second World War and has been widely applied in the logistics domain.Recently,both the academic and industrial worlds are proposing a series of new types of backscatter technologies for communications and IoT.In this paper,we review the history of both IoT and backscatter,describe the new types of backscatter,demonstrate their applications,and discuss the open challenges.
