New Acquisition Algorithm for Direct Sequence Spread Spectrum Signals

Aiming at improving acquisition performance for direct sequence spread spectrum (DSSS) signals, a new acquisition algorithm based on fast Fourier transform (FFT ) is proposed. The code phases are parallel searched throughout the Doppler freq uency domain. Since the influence of Doppler frequency errors on peak-to-avera ge ratios of correlation power shows a pattern similar to the sinc function, it is our belief that by judging on peak-to-average ratios for different Doppler frequency errors false alarm prob...     

相控阵雷达系统并行仿真

在集群环境下,研究了相控阵雷达相干视频并行仿真方法.该方法根据相控阵雷达一个调度间隔多个雷达任务不相关的特点.提出了一种粗粒度MPI并行划分,使雷达任务在集群上并行处理,解决相干视频仿真效率低的问题.实验结果证明了该方法的有效性和可行性.     

基于早迟门位同步环的FPGA实现

位同步环是实现全数字接收机中定时恢复的关键技术,本文设计采用早门、迟门积分对比得到位时钟误差的鉴别方式,对位时钟误差的鉴别结果进行积累滤波,滤波结果实时调整数控振荡器,调节本地位时钟跟踪输入位时钟.文中给出了该住同步环的工作原理、实现框图、资源分析,仿真结果验证了方法的有效性.整个位同步环路基于FPGA实现,易于编程、改进和移植.     

Design of a Radar Signal Simulator Based on Virtex-Ⅱ Series FPGA

The si mulation of radar echo is a dynamic pro-cess,including generation,transmission and process-ing of the radar echo.Many techniques,such assemiconductor,computer and signal processing areusedin the process of si mulation.The si mulation ofradar echo is a combination of the digital si mulationtechnique and the radar technique.Its basic tech-niques include the computer and signal processingtechniques.Its object is to test the algorithmand thequality of theintegrated system,as well as to eval…     

Range Ambiguity Elimination in a Short-Range FMCW Radar System

Modified implementation architecture for sinusoidal frequency modulation is introduced to extract the range information from the received radar echo. Range ambiguity problem arises because the range is calculated from the estimated phase of the received signal which is wrapped into （0, 2π]. By integrating Doppler frequency shifts, the variation of range can be estimated and used as an auxiliary information to help eliminating the corresponding range ambiguity. The performance of the new technique is evaluated by simulations. The results show that this technique is robust to sever phase noise and can be used effectively for ambiguity elimination of the modified sinusoidal frequency modulated continuous wave radar.     

运动点目标空间定位算法研究

提出了一种基于冲激雷达体制的运动点目标空间定位算法,该算法针对冲激雷达的特点,采用距离门等效采样的方式采集各个发射脉冲的回波数据,通过对采集到的数据进行相关处理得到点目标经过各个距离门时不同接收天线间的距离差,并利用TDOA方法实现点目标在各定位点的空间定位。通过对目标运动模型的建立,可进一步通过Kal- man平滑滤波的方法提高运动点目标坐标的估计精度,仿真结果表明该定位算法具有较高的定位精度。     

引信体目标视频回波模拟器专用处理器设计

针对引信体目标视频回波模拟器中实时数字信号处理的要求,给出了基于Virtex-Ⅱ系列现场可编程门阵列(FPGA)设计的专用处理器的方案、方法。该方案充分利用了与FPGA结构相适应的设计优化技术．解决了由于FPGA片内时钟频率过高而产生的瓶颈问题。调试表明,此处理器既有专用ASIC电路的快速性,又有DSP器件的灵活性,完全能满足引信体目标视频回波模拟系统的实际要求。     

遥控遥测系统在靶船上的应用

主要介绍了由主控中心和靶上监控系统组成的遥控遥测系统,该系统对靶载设备实行监测和控制。主控中心发送各种命令到靶上监控系统,并对靶上系统完成相应命令后回传的数据进行处理显示。     

数字锁相环技术在恢复位时钟中的应用

详细介绍了如何在FPGA中利用VHDL语言实现超前滞后型数字锁相环,以便从位流数据中恢复出位时钟;并指出了其结构参数对于环路性能的影响。     

USB2.0高速实时数据采集系统的设计与实现

介绍了一种基于USB2．0的高速实时数据采集系统的硬件及固件程序设计方案,及在不同的DSP、单片机之间移植固件程序的方法和调试过程中可能出现的问题及解决办法。