This paper considers the uumerical method and error analyses for two phase incompresaible miscible displacement in porous media.A time-stepping procedure is introduced using Sckwarz domain decomposition algorithm with...This paper considers the uumerical method and error analyses for two phase incompresaible miscible displacement in porous media.A time-stepping procedure is introduced using Sckwarz domain decomposition algorithm with eded element for the pressure equation and with finite dement for concentration equation. The author has analysed the relationship between convergence rates and discretization parameters,optimal order error estimates are derived under certain constraintes about the discretisation parameters.It is shown that the constraintes can be satisfied by the natural choices of these parameters.展开更多
在MIMO-OFDM水声通信系统中,由于信道间的相互干扰和水声信道严重时延扩展产生的频率选择性衰落,系统的通信误码率较高。针对这一问题,研究了空频编码的MIMO-OFDM通信,提出空频迭代信道估计与均衡(Spatial Frequency Iterative Channel ...在MIMO-OFDM水声通信系统中,由于信道间的相互干扰和水声信道严重时延扩展产生的频率选择性衰落,系统的通信误码率较高。针对这一问题,研究了空频编码的MIMO-OFDM通信,提出空频迭代信道估计与均衡(Spatial Frequency Iterative Channel Estimation and Equalization,SFICEE)方法。该方法通过载波间的空频正交性进行各收发阵元对的信道估计,并通过空频均衡获得符号初始估计,迭代更新信道估计,而后通过符号后验软信息反馈进行迭代空频软均衡。仿真结果表明,当误码率为10^(-3)时,文中所提出的SFICEE方法经过二次迭代与STBC方法相比具有4.8 d B的性能增益,相对于SFBC方法有2.8 d B的性能提升。当输入信噪比相同时,文中所提出方法的星座图更加收敛,可以更好地降低水下通信系统的误码率。展开更多
In this paper,we introduce a domain decomposition method with non-matching grids for solving Dirichlet exterior boundary problems by coupling of finite element method(FEM)and natural boundary element method(BEM).We fi...In this paper,we introduce a domain decomposition method with non-matching grids for solving Dirichlet exterior boundary problems by coupling of finite element method(FEM)and natural boundary element method(BEM).We first derive the optimal energy error estimate of the nonconforming approximation generated by this method.Then we apply a Dirichlet-Neumann(D-N)alternating algorithm to solve the coupled discrete system.It will be shown that such iterative method possesses the optimal convergence.The numerical experiments testify our theoretical results.展开更多
文摘This paper considers the uumerical method and error analyses for two phase incompresaible miscible displacement in porous media.A time-stepping procedure is introduced using Sckwarz domain decomposition algorithm with eded element for the pressure equation and with finite dement for concentration equation. The author has analysed the relationship between convergence rates and discretization parameters,optimal order error estimates are derived under certain constraintes about the discretisation parameters.It is shown that the constraintes can be satisfied by the natural choices of these parameters.
文摘在MIMO-OFDM水声通信系统中,由于信道间的相互干扰和水声信道严重时延扩展产生的频率选择性衰落,系统的通信误码率较高。针对这一问题,研究了空频编码的MIMO-OFDM通信,提出空频迭代信道估计与均衡(Spatial Frequency Iterative Channel Estimation and Equalization,SFICEE)方法。该方法通过载波间的空频正交性进行各收发阵元对的信道估计,并通过空频均衡获得符号初始估计,迭代更新信道估计,而后通过符号后验软信息反馈进行迭代空频软均衡。仿真结果表明,当误码率为10^(-3)时,文中所提出的SFICEE方法经过二次迭代与STBC方法相比具有4.8 d B的性能增益,相对于SFBC方法有2.8 d B的性能提升。当输入信噪比相同时,文中所提出方法的星座图更加收敛,可以更好地降低水下通信系统的误码率。
基金supported by Natural Science Foundation of China(G10371129)supported by the National Basic Research Program of China under the grant G19990328,2005CB321701National Natural Science Foundation of China.
文摘In this paper,we introduce a domain decomposition method with non-matching grids for solving Dirichlet exterior boundary problems by coupling of finite element method(FEM)and natural boundary element method(BEM).We first derive the optimal energy error estimate of the nonconforming approximation generated by this method.Then we apply a Dirichlet-Neumann(D-N)alternating algorithm to solve the coupled discrete system.It will be shown that such iterative method possesses the optimal convergence.The numerical experiments testify our theoretical results.
