C8051F020单片机在磁致伸缩位移传感器中的应用

介绍了一种基于C8051F020单片机的数据采集系统,叙述了磁致伸缩线性位移传感器的工作原理、C8051F020单片机性能等,通过C8051F020单片机组成的硬件电路对磁致位移传感器数据进行采集,将采集到的位移数据进行滤波、放大、转换并在液晶显示器上显示出来。     

利用C8051F020系列单片机实现智能仪器开发

简单介绍C8051F020系列混合信号单片机,简述利用该单片机进行智能仪器开发的基本方法.并在此基础上简要介绍一种利用C8051F020单片机实现的基于Ka、Ku、X三个波段的简易一次雷达系统构成的用于测量特定物质燃烧火焰特性的微波测量系统,及简述该系统的组成、工作原理以及实现方法.     

基于C8051F020的天线参数自动测量系统

给出一种基于C8051F020单片机的天线参数自动测量系统,该系统以C8051F020单片机为核心,由自动控制模块、信号采集模块、数据显示与存储模块三部分组成。从实验结果来看,设计实现了天线方向图的测量,并通过方向图计算出天线的主瓣宽度、旁瓣电平值等特征参数。系统着眼于低成本设计,同时又易于移动和操作,可以较好地满足小型天线生产厂商天线测量的实际需求。     

基于C8051F020的晶体管V-I特性测量仪设计

提出了一种基于C8051F020单片机的便携式晶体管特性曲线图示仪.该仪器能显示NPN、PNP等晶体管的输出特性曲线,并能在屏幕上直接显示hFE值.在硬件设计上,充分利用了C8051F020单片机的I/O引脚和片内外设,使仪器简化了电路,降低了成本.     

基于C8051F020单片机的实时测控装置设计

为了实现某型电子装备研制中对于时序控制和多路数据采集的实时性要求,设计了一种基于C8051F020单片机的实时测控装置。采用多单片机系统实现了多路模数混合信号的实时采集,完成复杂的时序控制,准确地输出各种控制信号。将采集的数据进行综合分析计算,利用硬件逻辑判决电路对单片机的计算结果和传感器的参考信号进行优先级判断,最终输出系统所需的触发信号。该装置采用多个单片机和功能模块,构建了多数入多输出的数据采集和控制系统,利用RS 485协议实现多机串行通信,完成了系统预定功能。     

基于C8051F020单片机的电机变频遥控控制系统

本文介绍了以C8051F020单片机为核心的遥控控制系统,该系统主要由遥控发射器和C8051F020单片机控制的接收电路以及输入检测、输出控制电路组成。系统结构灵活、成本低,易于扩充和修改。     

用C8051F020主控的液晶显示模块FM12232C及其应用

介绍了C8051F020单片机和图形点阵液晶显示模块FM12232C的性能特点，分析了在单片机C8051F020主控下FM12232C的硬件接口电路和软件设计方法，利用该方法可成功实现对液晶模块的控制和汉字显示。     

基于C8051F020单片机的温度湿度气压采集系统

本设计是以C8051F020单片机作为控制器的温度、湿度、气压采集系统,主要元件有C8051F020单片机、温度湿度传感器（罗卓尼克HC2-S）、压力传感器MS5534C等。经过试验验证,该系统可实时的显示温度、湿度和气压数据,工作稳定可靠。     

无绝缘移频自动闭塞系统中采集系统设计

介绍一种基于C8051F020单片机及CPLD芯片EPM3256ATC144-10实现的多种信号采集系统,其主要功能是对ZPW-2000R型移频自动闭塞系统中各种频率信号及交流模拟量、数字量进行采集处理,并与上位机进行数据通信。系统以单片机为核心,利用C8051F020内部ADC完成交流模拟信号的采集,通过两片CPLD实现高精度频率采集和数字信号采集;所有的数据运算处理均由单片机完成,再通过CAN总线等传送至上位机。该系统利用简单的电路设计及较低的成本,很好地满足了实际应用和生产需要;系统中所需控制时序及地址译码等电路均由CPLD产生,所有处理结果均存入RAM。CPU可随时从RAM读取数据,并传送至上位机,为数据的实时性采集和处理提供了有力保证。     

基于C8051F330D单片机的多路数据采集系统设计

介绍了数据采集系统的结构和工作原理,并应用C8051F330D单片机设计了一个多路数据采集系统。该系统硬件由4部分组成：电源电路、主控制芯片、按键电路、显示电路。每部分都做了相应的设计;系统软件采用汇编语言开发实现,选用编译工具——keil编译器完成C8051F330D单片机与计算机之间的连接,从而对采集系统进行一系列的调试。最后的实验表明该采集系统精度高、操作性能良好,应用成本较低,因此可用于多种环境下的温度、压力等物理量的采集、转换及显示。     

基于FPGA的精密时间间隔测量仪设计

介绍一种基于FPGA的精密时间间隔测量仪的研制过程。精密时间间隔测量仪是应科学试验中高可靠性、高精密度和多通道等测量要求而研制的。精密时间间隔测量仪以PXI接口为平台设计成为虚拟仪器,一个PXI系统可插多个精密时间间隔测量仪板卡,每个板卡可对1个起始通道与8个停止通道的脉冲信号进行时间间隔测量,同时测量停止脉冲的脉冲宽度。精密时间间隔测量仪以FPGA为测时核心,利用锁相环倍频和时钟分相技术,测量分辨力可达到1ns,测时范围可达10ns-10ms。     

多路射频信号相位差现场测量系统设计与实现

设计并实现了四路射频信号相位差测量系统,采用模拟乘法器芯片AD8302测量二路射频信号的相位差。设计了特殊的电路,将基于AD8302的相位差测量系统的测量范围从180°扩展到360°。采用基于CAN总线的数据采集系统实现相位差的现场测量。该系统的相位差测量范围为0°～360°,相位差测量精度为0．1°,误差约为±1°。该系统工作频带宽、电路简单、易于实现,可用于需要实现远距离测量多路射频信号间的相位差的场合。     

一种改进的基于频率选路的DWDM-ROF系统

设计了一个基于频率选路的DWDM-ROF系统。通过30 GHz射频信号驱动相位调制器,对4个间隔为100 GHz的光信道进行双边带调制,产生12个光信道。采用分插复用器将边带分成两组,一组边带分别加载2.5 Gb/s的数据,另一组不做任何变化,然后两路共同耦合进入下行光纤传输50 km,此方案最多可以解复用至6个基站分别接收毫米波信号后供天线发射,并且可以对任意信道进行选路复用。结果表明,通过4路的信道产生6路的毫米波信号,具有较高的频谱效率,同时系统信道间串扰对系统影响不大。     

基于AT89S51单片机的数显表的研制

工业现场有大量的模拟信号或脉冲频率信号需要测量显示,市场上现有的数显表功能单一,校正困难,抗干扰差,难以显示真实工程量值。介绍一种用于工业现场信号测量的数显表,该表以AT89S51单片机为核心,采用的模拟信号测量技术和脉冲信号测量技术,可以精确测量模拟信号或频率信号,通过给单片机设定不同的参数,对所测量的模拟信号或脉冲信号进行换算,从而显示现场的工程量值。该数显表一表多用,可广泛应用于液位、流量、温度、压力、速度等的测量显示。     

Multidimensional signal space partitioning using a minimal set ofhyperplanes for detecting ISI-corrupted symbols

A signal space partitioning technique is presented for detecting symbols transmitted through intersymbol interference channels. The decision boundary is piecewise linear and is made up of several hyperplanes. The goal here is to minimize the number of hyperplanes for a given performance measure, namely, the minimum distance between any signal and the decision boundary, Unlike in Voronoi partitioning, individual hyperplanes are chosen to separate signal clusters rather than signal pairs. The convex regions associated with individual signals, which together form the overall decision region, generally overlap or coincide among in-class signals. The technique leads to an asymptotically optimum detector when the target distance is set at half the minimum distance associated with the maximum-likelihood sequence detector. Complexity and performance can be easily traded as the target distance is a flexible design parameter     

基于相位和强度调制的微波测频技术研究

为了更好地对微波信号进行频率测量，采用了一种基于相位调制和强度调制相结合的瞬时测频方法。一束连续波光源通过耦合器被分成两路，未知微波信号分别同时经过相位调制器和强度调制器从而对载波进行调制，之后进入两段长距离的单模光纤中。在光纤中由于色散引起的微波功率损耗的特点，可以获得单调变化的频率-幅度的映射关系，继而通过光电探测的微波信号输出功率比得到幅度比较函数；另外还分析与实现了测频范围与测频精确度的优化。结果表明，该方案结构简易，能够快速精准地测量出未知信号的频率，测量范围可以达到0.5GHz~53GHz，测量误差小于±200MHz。该方法可以有效地测量微波信号频率，可靠性强，适用范围广。     

Real-time multichannel computerized electrogastrograph

The purpose of this study was to develop a real-time multichannel computerized electrogastrograph (EGG) to measure and analyze electrical signals from the human abdominal surface. A soft-contact matrix composed of 25 cutaneous electrodes is embedded evenly in a latex mat. The mat can be firmly attached to the abdominal surface by drawing a vacuum between the matrix and the stomach. Twenty-five high-amplification filter/amplifiers provide a high signal-to-noise ratio and flat amplitude response for a signal between 0.02 and 0.12 Hz (1.2-7.2 cpm). The computer program provides waveform and frequency analysis for any chosen channel and mapping analyses for all 25 channels. A two-dimensional propagation exploration program was also developed. Using four different mapping analysis program subroutines, the optimal points for analyzing the EGG signals can be reliably found and variability of these locations can be observed easily. Results show differences in the EGG mappings of normal and abnormal subjects     

Target spatial and frequency scattering diversity property for diversity MIMO radar

Statistical multiple-input multiple-output (MIMO) radar, e.g., frequency diversity MIMO radar (FDMR) and spatial diversity MIMO radar (SDMR), can exploit signal diversity to improve target detection performance. The statistical property of target echo signals received in diversity channels is an important concern in designing signal processing algorithms for an FDMR and an SDMR, which is studied in this paper by using a round shaped scatterers centre target model. A uniform formula is derived to estimate the correlation coefficients of target echo signals in diversity channels for both an FDMR and an SDMR. The theoretical correlation coefficients are testified by numerical experiments.     

基于FPGA的多路信号源设计与实现

某型号遥测数据采集器在实验和测试时,需要开发一种能够产生多种输入信号的信号源。由单片机作为控制核心,基于FPGA、利用直接频率合成技术产生8路正弦信号。信号源各路信号的频率和幅度均可调,通过键盘设置可以5Hz为一个步进设定各个正弦信号的频率,液晶显示器能够显示当前状态和各个信号的频率。此信号源能同时实现多路信号的输出,信号精度高,在其他测试实验中也具有良好的应用前景。     

Signal Design for Bandwidth Efficient Multiple Access under Asymptotic Effective Energy Constraints

The problem of signal design for bandwidth-efficient multiple access (BEMA) over additive white Gaussian noise (AWGN) channels is addressed under quality of service (QoS) requirements specified by asymptotic effective energies (AEEs). The AEE characterizes the bit error rate (BER) in the low-noise regime, but in contrast to BER, it is tractable and amenable to analysis and signal design. We adopt the BEMA strategy of bandwidth conservation where users are detected successively using minimum mean-squared error decision feedback (MMSE-DF) detection and where signals are designed in a greedy fashion for one user at a time, in the reverse order in which the users are detected. The signal design method proposed here is based on an exact characterization of how a signal update for one user affects the issue of preserving bandwidth with the addition of signals for subsequent users. A geometric insight in the construction of good signal sets and significant improvements in bandwidth over full-rank or orthogonal signaling are obtained. The main result of this paper can hence be seen as providing a tight upper bound on the minimum signature sequence dimension or rank (and hence bandwidth) needed to satisfy individual, possibly distinct user QoS constraints specified in terms of the AEE measure.