针对城市移动通信环境,提出了散射体各向异性分布的VMF分布模型.在室外宏小区的移动通信环境下引入散射体群的概念,并结合MIMO多天线Y型阵列(UYA)和圆形阵列(UCA)拓扑结构,使得模型能够估计多径衰落信道的重要信道参数,如UYA和UCA的空...针对城市移动通信环境,提出了散射体各向异性分布的VMF分布模型.在室外宏小区的移动通信环境下引入散射体群的概念,并结合MIMO多天线Y型阵列(UYA)和圆形阵列(UCA)拓扑结构,使得模型能够估计多径衰落信道的重要信道参数,如UYA和UCA的空间衰落相关函数(SFC)、衰落信道模型的信道容量及多天线阵列UYA和UCA对平均余纬的敏感度等,并延伸了SFC在求解信道协方差矩阵的应用.结果表明:M IM O多天线系统的性能不仅取决于天线阵列阵元间距,还与到达角度有关;所提模型的信道参数估计结果适用于实际的城市移动通信环境.针对UYA和UCA的SFC和信道容量研究,拓展了VM F分布模型在三维空间域移动通信领域的应用,对MIMO多天线阵列的信道参数评估和无线通信系统仿真提供了有力的工具.展开更多
Previous porosity models have been shown to be unable to accurately describe the pore-size distribution of rocks and soils.Three new porosity models are developed in this study.Pore-size distributions of soft clay and...Previous porosity models have been shown to be unable to accurately describe the pore-size distribution of rocks and soils.Three new porosity models are developed in this study.Pore-size distributions of soft clay and ecotypic revetment material were obtained using a scanning electron microscope(SEM)in two-dimensional space,and with the mercury intrusion method in three-dimensional space.The results show that the new porosity models are valid in predicting the accumulative porosity of rock and soil samples.Based on the new porosity models,a new microstructure soil consolidation model was developed and the error of the compression strain prediction was less than 0.007 under low pressure.Several models for soil water retention curve were founded,which in form comprise previous models developed by other researchers,and they may be more accurate than previous models because of the valid mean for determining the fractal dimension.In addition,we obtain an expression for the relationship between soil cohesion and the test specimen size,as well as between the bulk density of rocks and soils and the test specimen size.展开更多
文摘针对城市移动通信环境,提出了散射体各向异性分布的VMF分布模型.在室外宏小区的移动通信环境下引入散射体群的概念,并结合MIMO多天线Y型阵列(UYA)和圆形阵列(UCA)拓扑结构,使得模型能够估计多径衰落信道的重要信道参数,如UYA和UCA的空间衰落相关函数(SFC)、衰落信道模型的信道容量及多天线阵列UYA和UCA对平均余纬的敏感度等,并延伸了SFC在求解信道协方差矩阵的应用.结果表明:M IM O多天线系统的性能不仅取决于天线阵列阵元间距,还与到达角度有关;所提模型的信道参数估计结果适用于实际的城市移动通信环境.针对UYA和UCA的SFC和信道容量研究,拓展了VM F分布模型在三维空间域移动通信领域的应用,对MIMO多天线阵列的信道参数评估和无线通信系统仿真提供了有力的工具.
基金supported by the National Natural Science Foundation of China(50778140)the Special Research Foundation of Doctorial Subjects in Universities of China(20070497107)
文摘Previous porosity models have been shown to be unable to accurately describe the pore-size distribution of rocks and soils.Three new porosity models are developed in this study.Pore-size distributions of soft clay and ecotypic revetment material were obtained using a scanning electron microscope(SEM)in two-dimensional space,and with the mercury intrusion method in three-dimensional space.The results show that the new porosity models are valid in predicting the accumulative porosity of rock and soil samples.Based on the new porosity models,a new microstructure soil consolidation model was developed and the error of the compression strain prediction was less than 0.007 under low pressure.Several models for soil water retention curve were founded,which in form comprise previous models developed by other researchers,and they may be more accurate than previous models because of the valid mean for determining the fractal dimension.In addition,we obtain an expression for the relationship between soil cohesion and the test specimen size,as well as between the bulk density of rocks and soils and the test specimen size.
