Adaptive RAKE receiver in chaos based pilot-added DS-CDMA system

This paper presents the theoretical analysis of adaptive multiuser RAKE receiver scheme in frequency selective fading channel for direct-sequence code division multiple access (DS-CDMA) system. Least mean square (LMS) algorithm is used to estimate the channel coefficients. Chaotic sequences are used as spreading sequence and corresponding bit error rate (BER) in closed form is derived for imperfect channel estimation conditions. Performances of chaotic sequences are compared with pseudorandom noise (PN) sequences. Under perfect synchronization assumption, various simulation results are shown to investigate the performance of the proposed system.     

Extended well-posedness of optimization problems

The well-posedness concept introduced in Ref. 1 for global optimization problems with a unique solution is generalized here to problems with many minimizers, under the name of extended well-posedness. It is shown that this new property can be characterized by metric criteria, which parallel to some extent those known about generalized Tikhonov well-posedness.This work was partially supported by MURST, Fondi 40%, Rome, Italy.     

一类两两NQD列乘积和的Jamison型强稳定性

研究了一类不同分布两两NQD列的Jamison型加权乘积和的强稳定性,推广了不同分布独立列部分和与同分布NQD列部分和情形相类似的结论.     

Spectrum of the Micromaser with Kerr Medium

We have established the master equation for the micromaser with Kerr medium field density operator,studied the spectrum of the micromaser with Kerr medium and analyzed the influence of Kerr effect and the detuning on the spectrum.In the thermal-atom regime,we find that Kerr effect broadens Linewidth D and increases frequency-shift S,and that the detuning Δ narrows linewidth D and increases frequency-shift S as a whole,Moreover Kerr effect leads to oscillatings more rapidly in the resonance peaks,which means that it causes quantum noise,As a whole,with the increase of cavity-length L,the linewidth D and frequency-shift S gradually increase.     

Almost strongly regular matrices and a core theorem for double sequences

The idea of almost convergence for double sequences was introduced by Moricz and Rhoades [Math. Proc. Cambridge Philos. Soc. 104 (1988) 283-294] and they also characterized the four dimensional strong regular matrices. In this paper we define and characterize the almost strongly regular matrices for double sequences and apply these matrices to establish a core theorem.     

两两NQD列大数定律的一个注记

利用两两NQD列三级数定理的思想和Chebyshev不等式,研究了两两NQD列在一类广泛条件下的弱大数定律和一类加强条件下的强大数定律,得到了与独立情形一致的结果,还特别讨论了同分布情形,推广了相关文献的结果．     

半参数回归模型小波估计的弱收敛速度

本文研究了误差为鞅差序列情形下的半参数回归模型.利用小波方法,在相当一般的条件下,得到了参数、非参数估计量的弱收敛速度.     

基于CDMA的布拉格光纤光栅传感系统的仿真分析

讨论了光纤光栅传感系统中常用的复用技术及其限制,阐述了利用CDMA技术实现光纤布拉格光栅阵列波长解调的复用方式,对系统的原理和性能进行了理论分析。在此基础上通过MATLAB做了基于CDMA的光纤光栅传感仿真分析,仿真结果表明该方法能区分反射波长重叠的光栅,从而提高FBG网络复用的频带利用率。     

混合序列部分和的若干收敛性质

本文研究了混合序列部分和的若干收敛性质.利用Serfling不等式推广情形,证明了一类随机变量序列部分和的一个收敛性结果,获得了混合序列部分和的收敛性,并进一步得到了混合序列加权和的强收敛性和完全收敛性,推广并改进了文[2]中有关结果.