In this paper,an improved Susceptible-Infected-Susceptible(SIS) epidemic spreading model is proposed in order to provide a theoretical method to analyze and predict the spreading of diseases.This model is based on the...In this paper,an improved Susceptible-Infected-Susceptible(SIS) epidemic spreading model is proposed in order to provide a theoretical method to analyze and predict the spreading of diseases.This model is based on the following ideas:in social networks,the contact probability between nodes is decided by their social distances and their active degrees.The contact probability of two indirectly connected nodes is decided by the shortest path between them.Theoretical analysis and simulation experiment were conducted to evaluate the performance of this improved model.Because the proposed model is independent of the network structure,simulation experiments were done in several kinds of networks,namely the ER network,the random regular network,the WS small world network,and the BA scale-free network,in order to study the influences of certain factors have on the epidemic spreading,such as the social contact active degree,the network structure,the average degree,etc.This improved model provides an idea for studying the spreading rule of computer virus,attitudes,fashion styles and public opinions in social networks.展开更多
As the key technology of the 5th generation （5G）, 3-dimensional （3D） massive multi-input and multi-output （MIMO） is expected to be widely used in small cell network （SCN）. In this paper, in order to investigat...As the key technology of the 5th generation （5G）, 3-dimensional （3D） massive multi-input and multi-output （MIMO） is expected to be widely used in small cell network （SCN）. In this paper, in order to investigated the tradeoff between limited size in SCN and the capacity gain from increasing antenna elements, the spatial performances of 3D massive MIMO based on a 512×16 MIMO channel measurements at 6 GHz in urban microcell （UMi） scenario are studied. Enormous channel impulse responses （CIR） are collected and reconstructed, which enables us to present comparative results of the capacity and the eigenvalue spread （ES）. Furthermore, the impacts of antenna element number and spacing on system performance are investigated, i. e. , 32, 64, 128 elements are selected from the 512 transmitter （Tx） array with elevation interval spacing being 0.5, 1 and 2 wavelengths for each. Interestingly, the capacity gap can be obviously observed on the comparison between the 1 and 2 wavelength antenna spacing cases, which implies that correlation cannot be ignored when the antenna spacing is larger than 1 wavelength when massive antennas are equipped. The contrast results show that the capacities are enlarged with the increasing of antenna elements number, and larger antenna spacing will lead to higher channel capacity as expected. However, the capacity gains brought by the increasing of antenna spacing will descend to certain degrees as the antenna number increases. Collectively, these results will provide further insights into 3D massive MIMO utilization.展开更多
基金supported by National Natural Science Foundation of China 61301091Shaanxi Province Science and Technology Project 2015GY015
文摘In this paper,an improved Susceptible-Infected-Susceptible(SIS) epidemic spreading model is proposed in order to provide a theoretical method to analyze and predict the spreading of diseases.This model is based on the following ideas:in social networks,the contact probability between nodes is decided by their social distances and their active degrees.The contact probability of two indirectly connected nodes is decided by the shortest path between them.Theoretical analysis and simulation experiment were conducted to evaluate the performance of this improved model.Because the proposed model is independent of the network structure,simulation experiments were done in several kinds of networks,namely the ER network,the random regular network,the WS small world network,and the BA scale-free network,in order to study the influences of certain factors have on the epidemic spreading,such as the social contact active degree,the network structure,the average degree,etc.This improved model provides an idea for studying the spreading rule of computer virus,attitudes,fashion styles and public opinions in social networks.
基金supported by the National Natural Science Foundation of China (61322110)the Key Program of Beijing Municipal Natural Science Foundation (17L20052)+2 种基金the National Science and Technology Major Program of the Ministry of Science and Technology (2018ZX030122001)the Ministry of Education-China Mobile Research Fund (MCM20160105)Huawei Technologies Co. ,Ltd
文摘As the key technology of the 5th generation （5G）, 3-dimensional （3D） massive multi-input and multi-output （MIMO） is expected to be widely used in small cell network （SCN）. In this paper, in order to investigated the tradeoff between limited size in SCN and the capacity gain from increasing antenna elements, the spatial performances of 3D massive MIMO based on a 512×16 MIMO channel measurements at 6 GHz in urban microcell （UMi） scenario are studied. Enormous channel impulse responses （CIR） are collected and reconstructed, which enables us to present comparative results of the capacity and the eigenvalue spread （ES）. Furthermore, the impacts of antenna element number and spacing on system performance are investigated, i. e. , 32, 64, 128 elements are selected from the 512 transmitter （Tx） array with elevation interval spacing being 0.5, 1 and 2 wavelengths for each. Interestingly, the capacity gap can be obviously observed on the comparison between the 1 and 2 wavelength antenna spacing cases, which implies that correlation cannot be ignored when the antenna spacing is larger than 1 wavelength when massive antennas are equipped. The contrast results show that the capacities are enlarged with the increasing of antenna elements number, and larger antenna spacing will lead to higher channel capacity as expected. However, the capacity gains brought by the increasing of antenna spacing will descend to certain degrees as the antenna number increases. Collectively, these results will provide further insights into 3D massive MIMO utilization.
