Let (Ω, A, P) be a probability space, X(t, ω) a random function continuous in probability for t∈[0,+∞) or (-∞,+∞)(ω∈Ω), and F(t) a positive function continuous for t∈[0,+∞) or (-∞, +∞). If X(t, ω) and F(...Let (Ω, A, P) be a probability space, X(t, ω) a random function continuous in probability for t∈[0,+∞) or (-∞,+∞)(ω∈Ω), and F(t) a positive function continuous for t∈[0,+∞) or (-∞, +∞). If X(t, ω) and F(t) verify certain conditions, then there exists a sequence {Qn(t,ω)} of random polynomials such that we have almost surely: for t∈[0,+∞) or (-∞, +∞), lim|X(t, ω)-Qn(t, ω)|/F(t)=0.展开更多
We consider Jackson inequality in L^2 （B^d×T, Wκ,μ^B （x））, where the weight function Wκ,μ^B （X） is defined on the ball B^d and related to reflection group, and obtain the sharp Jackson inequalityEn-1,m-...We consider Jackson inequality in L^2 （B^d×T, Wκ,μ^B （x））, where the weight function Wκ,μ^B （X） is defined on the ball B^d and related to reflection group, and obtain the sharp Jackson inequalityEn-1,m-1（f）2≤κn,m（τ,r）ωr（f,t）2,τ≥2τn,λ,where Tn,λ is the first positive zero of the Gegenbauer cosine polynomial Cn^λ （cos θ）（n ∈ N）.展开更多
In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to...In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to construct the confidence interval of f(y|x) .展开更多
In this note, the random weighting approximations for empirical process indexed by abounded class of functions are obtained, and the strong uniform convergence rates of ran-dom weighting empirical processes are given....In this note, the random weighting approximations for empirical process indexed by abounded class of functions are obtained, and the strong uniform convergence rates of ran-dom weighting empirical processes are given. When unknown multivariate underlingdistributions are not confined by any additional condition, we obtain the random weightingapproximations for multivariate Von Mises statistics and their projection pursuits (PP). Thisresult is also true for the bootstrap approximation of empirical processes.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
文摘Let (Ω, A, P) be a probability space, X(t, ω) a random function continuous in probability for t∈[0,+∞) or (-∞,+∞)(ω∈Ω), and F(t) a positive function continuous for t∈[0,+∞) or (-∞, +∞). If X(t, ω) and F(t) verify certain conditions, then there exists a sequence {Qn(t,ω)} of random polynomials such that we have almost surely: for t∈[0,+∞) or (-∞, +∞), lim|X(t, ω)-Qn(t, ω)|/F(t)=0.
基金supported by National Natural Science Foundation of China(11071019)Beijing Natural Science Foundation(1132001)
文摘We consider Jackson inequality in L^2 （B^d×T, Wκ,μ^B （x））, where the weight function Wκ,μ^B （X） is defined on the ball B^d and related to reflection group, and obtain the sharp Jackson inequalityEn-1,m-1（f）2≤κn,m（τ,r）ωr（f,t）2,τ≥2τn,λ,where Tn,λ is the first positive zero of the Gegenbauer cosine polynomial Cn^λ （cos θ）（n ∈ N）.
基金Supported by Natural Science Foundation of Beijing City and National Natural Science Foundation ofChina(2 2 30 4 1 0 0 1 30 1
文摘In this paper, the normal approximation rate and the random weighting approximation rate of error distribution of the kernel estimator of conditional density function f(y|x) are studied. The results may be used to construct the confidence interval of f(y|x) .
基金Project supported by the National Natural Science Foundation of China.
文摘In this note, the random weighting approximations for empirical process indexed by abounded class of functions are obtained, and the strong uniform convergence rates of ran-dom weighting empirical processes are given. When unknown multivariate underlingdistributions are not confined by any additional condition, we obtain the random weightingapproximations for multivariate Von Mises statistics and their projection pursuits (PP). Thisresult is also true for the bootstrap approximation of empirical processes.
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。
