Blind CFR Estimation for SIMO SC-FDE Systems

提出了一种基于线性预测的单输入多输出单载波频域均衡系统频域信道响应(也称为信道频率响应,Cfr)盲估计算法。与传统的线性预测时域信道估计方法不同,提出的算法不需要计算新息以及新息和输出序列的互相关,而是直接从预测滤波器系数获得频域信道响应估计的闭式解。算法仅采用输出序列的二阶统计量,对信道阶次过估计具有鲁棒性,并且估计性能优于传统的线性预测时域信道估计方法。计算机仿真结果验证了理论分析的正确性。A blind scheme to estimate frequency-domain channel response(is also called channel frequency response,CFR) in single-input multiple-output(SIMO) single-carrier frequency-domain equalization(SC-FDE) systems based on linear prediction algorithm(LPA) was presented.Compared with conventional LPA based time-domain channel estimation approach,this method obtains the closed-form solution for channel estimation in frequency-domain directly from tap weights of the prediction filter,rather than Cross-correlation of innovation and measurements.It exploits merely secon-dorder statistics(SOS),and is robust to channel order overestimation.Furthermore,the performance of the proposal is better than conventional LPA based time-domain channel estimation approach.Finally,computer simulations confirm the theoretical analysis.863国家高科技计划资助项目(2006AA09Z108);国家自然基金项目(60672046);湖南省教育厅科研项目(08C196)资

数字光纤通信接收机灵敏度、信号波形及判决电平的分析

在设计数字光通信系统时,必须先选定通信系统中所传输的光脉冲波形、选定输至判决器的脉冲波形及计算接收机灵敏度。本文根据S.D.Personick所提出的公式绘制出在实用上易于使用的曲线,并用这些曲线计算接收灵敏度,从而确定所需脉冲波形。判决电平也是用Personick公式计算的,虽然误差较大,但仍可作为参考

光纤带宽与光源谱宽的关系

本文重点讨论了用长、短波长的发光管作光源时系统的带宽问题以及它对中继距离的影响。虽然此时的带宽与用激光器作光源的系统相比要窄很多,但采取一定的措施,可以得到适当弥补。另一方面,它对光纤带宽的要求却降低了,加之发光管有造价低、寿命长、使用维护方便等优点,因此在一般市话中继通信系统中使用发光管作光源还是有其广阔前景的

注入锁定型激光放大器的FM噪声

本文研究了半导体注入锁定型（IL）激光放大器（LA）的FM噪声性能,给出了一般的FM噪声功率谱的解析表达式,并分为注入锁定和FM信号放大两种情况,探讨了FM噪声功率谱及FM噪声功率的限制因子。理论计算和实验结果是一致的,都证明注入锁定可以大大抑制半导体激光器的FM噪声

Subband Method for Wideband Adaptive Beamforming

提出一种基于通用参数滤波器组的宽带自适应波束形成子带实现方法.宽带接收信号经分析滤波器组分成若干子带信号,每个子带信号经各自的子带阵列处理器处理后由综合滤波器组恢复成宽带信号.因子带信号工作在更低的采样速率下,且每个子带信号处理器并行工作.有效降低了算法计算量.提高了阵列处理器效率.结果表明。与传统宽带处理方法相比,此子带方法除了输出信号均方误差略有增加外。能有效提高权值收敛速度。显著增强干扰抑制能力;与使用同样通道数目的正交镜像滤波器组的子带方法相比,该方法进一步提高了干扰抑制能力并可减小均方误差.A subband method with general-parameter-filter banks(GPFB)for wideband array adaptive beamforming is proposed.The received wideband signal is divided into multiple subband signals by the analytical filter bank.Each of the subband signals is then fed into its corresponding subband array pro- cessor,of which the outputs are combined by the synthesis filter bank and recovered into wideband sig- nal.As subbands are running at down-sampling rate and in parallel manner,the loads of computational processing can be effectively alleviated,and the efficiency of array improved.The simulation results show that the convergence speed of weights and deep suppression of the interference are enhanced with the subband method except for a little worse mean square error(MSE)of the output signal.In addi- tion,compared to the subband method using quadrature-mirror-filter(QMF)banks with the same number of channels,this method possesses a superior ability of interference suppression,and it is also capable of reducing the MSE significantly.国家“863计划”项目(2006AA09Z108

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies