雷达极化信息处理技术的研究现状分析

雷达极化技术在防控反导、环境监测、地址观测、资源勘探等领域中有着广泛的应用空间,这使雷达极化信息处理技术成为当前雷达技术研究当中的重要研究领域.文中主要分析雷达极化技术的发展历程,当前雷达极化技术发展现状.     

一种基于CRS插值的频偏估计方法

针对正交频分复用系统对频率偏移异常敏感导致接收机无法正确解调信号的问题,提出了一种小区特定参考信号(Cell-special Reference Signal,CRS)改进的频偏估计方法。首先,对发送的CRS与接收的CRS进行互相关运算,得到信道估计值;然后,对CRS在频域进行插值,使得每个时隙中不同OFDM符号对应子载波位置的参考信号相同;最后,对两个不同OFDM符号中的参考信号部分进行相关性运算,求出频偏。与基于CRS的频偏估计方法相比,该方法用信道估计值做互相关运算,消除了噪声和多径干扰带来的影响;通过对CRS进行插值,提高了频偏估计精度;通过减小计算相关性的两OFDM符号间的距离,使频偏估计范围由\[-1 kHz,1 kHz\]扩大到\[-1.75 kHz,1.75 kHz\]。     

硅基PbSe/BaF_2/CaF_2薄膜及其光电特性

采用分子束外延方法在 Si(111)衬底上生长了 Pb Se/ Ba F2 / Ca F2 薄膜 ,扫描电镜和 X-光衍射分析显示 ,通过生长 Ba F2 / Ca F2 缓冲层的方法 ,在 Si(111)衬底上外延的 Pb Se薄膜晶体质量高 ,Pb Se表面光亮 ,无开裂现象发生 ,X-光衍射峰峰宽窄 (15 3arcs) .外延生长的 Pb Se薄膜被应用于制作光电二极管 ,首次采用热蒸发金属铝膜在 Pb Se表面形成 Al- Pb Se肖特基结光电二极管 ,获得了比 Pb- Pb Se肖特基结更为稳定和理想的电流 -电压特性曲线     

Direction finding using data-supported optimization

A novel data-supported optimization technique for maximum likelihood (ML) direction-of-arrival estimation is proposed. The essence of our approach is to optimize the likelihood function at certaindata-supported points obtained by a resampled root-MUSIC procedure. These points are shown to comprise a small but representative subset of all possible searching points and contain enough information for solving the ML problem.This work was supported in part by grants from the National Sciences and Engineering Research Council of Canada (NSERC), Ministry of Energy, Science and Technology (MEST) of Ontario, Communications and Information Technology Ontario (CITO), and by the Senior Individual Grant Program of the Swedish Foundation for Strategic Research.     

一种循环保护前缀不足的OFDM信道估计算法

在正交频分复用（orthogonal frequency division multiplexing,OFDM）通信系统中,信道估计占有很重要的地位。论文提出了一种在OFDM信号循环保护前缀不足情况下也可应用的盲信道估计算法,它利用循环前缀信号结构采用子空间分解,计算简单。计算机仿真显示其有良好的性能。     

Pulse-driven LED circuit with transformer-based current balance technique

Light emitting diodes (LEDs) have been gradually used for backlight modules for liquid crystal display as a substitute for cold cathode fluorescent lamps. In most of LED applications, it is required to connect several LED strings in parallel to limit the dc voltage level to be applied to the single LED string. Due to considerable current variations through each LED string with inevitable parameter deviations as well as temperature and ageing effects, techniques to balance currents flowing through LED strings are required for LED drivers. This article proposes a pulse-driven LED circuit with transformer-based current balancing scheme, which can simply regulate currents through the LED strings. The transformers are placed in series with the LED strings in such a way that the LED currents are automatically balanced. Since the developed current sharing technique employs no dissipative resistors and no linear-mode transistors, the proposed driver has high efficiency, low power dissipation and reduced thermal problems. In addition, the presented driver with no additional semiconductor devices and no additional controllers can provide a simple and a cost-effective current balancing solution, compared to conventional approaches. Thus, the proposed LED driver can feature a simple, highly efficient, reliable and cost-effective method. The presented LED driver is verified with experimental results.     

大功率半导体激光器驱动电源的设计

设计一种大功率半导体激光器的驱动电源。恒稳电流范围为 0～ 10 A,稳流精度为 1m A,脉冲输出电流频率为 10 KHz,脉冲电流的占空比为 1∶ 10 ,脉冲电流幅值为 0～ 10 A可调     

Fabrication of 0.1 Micron MOSFETs and Their Characteristics

Two innovative techniques for manufacturing 0. 1 micron MOSFETs are described. One is SiO2-resist overetching method, in which an additional SiO2 layer is used to short the gate length; the other is dual-exposure method, according to which two overlapped masks are exposed in a single lithography. Both of them are easy to implement, without any special processing technologies required. The layout used in a real process is introduced. As a result, MOSFETs with minimal channel length of 0.12 micron are obtained. Also, the test results on characteristic are given. Finally, a conclusion is drawn that in 0.1 micron scale, both saturation currents and transconductorance of MOSFETs increase, while substrate currents decrease when channel length diminish.     

战斗机空战效能评估

重点介绍×××国家航空系统研究院 ,在战斗机远距空战和近距空战效能评估方面的观点、方法和仿真计算结果。     

一种快速高效MPEG-4运动估计硬件结构的研究和实现

提出一种高度并行和多流水线处理的硬件结构,实现MPEG-4视频部分的全搜索块匹配运动估计算法.该硬件结构能实时地通过全搜索块匹配运动估计算法来搜索每个像素块最佳匹配运动向量,具有计算速度高、运动向量准确、较少的内置存储器要求、低运行时钟和低功耗等诸多优点,从而可满足移动视频业务和高清晰视频业务的需求.该硬件结构基于富士通的CE66库实现.