基于PC104与C8051F120的水下机器人环境监测系统设计

为了实现对水下机器人周围环境的监测,提出了一种基于PC104与C8051F120的水下机器人环境监测系统设计方案,并完成系统的软硬件设计.该系统的硬件部分主要是采集下潜深度传感器、姿态传感器、温湿度传感器的数据,软件部分采用用Visual C＋＋ 6.0设计了监控界面.该系统能够实时显示视频和各传感器数据.实际测试表明,该系统具有稳定性高、准确性高的特点,达到了设计要求.     

基于DSP的开发/高速处理系统的设计

在简要介绍TMS320C32芯片特点的基础上，讨论了由PC机与该芯片构成的主从系统框架。在力求实现实时性和用户专用性设计的原则下，设计完成了以TMS320C32为数字信号处理运算核心，以微机为控制系统，由DSP目标板和微机构成的一个高速数字信号处理系统。详细介绍了DSP开发／高速处理系统的基本原理，描述了系统的工作过程，介绍了利用该开发高速处理板形成两种用户系统的方法。     

GPS远端定位监控系统的设计

分析了定位监控系统的设计,该系统由信息处理模块、GSM(全球移动通信系统)模块、GPS(全球定位系统)模块以及中心台等部分组成。重点介绍利用GPS接收模块接收GPS信息,并对接收到的数据进行处理,提取经纬度等信息,通过GSM网络发送到控制台,然后在监控中心利用导航软件根据传送来的信息实行定位、调度、监控等功能。介绍了利用TI16C554实现多路串口通信,并设计了一种利用TI16C554实现多路串口通信的硬件应用电路。     

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。     

显微镜图像采集控制系统设计

介绍了基于AT89C2051单片机的显微镜图像采集控制系统设计方案，给出了通过RS-232接口实现计算机与单片机通信，进行完成单片机驱动步进电动机的驱动，从而以实现采集显微图像的系统结构及设计方法。该设计采用单片机控制手段并结合计算机技术、通信技术和控制技术来实现整个系统的设计。     

基于TMS320C50的通信保密机硬件设计

介绍了以数字信号处理器芯片TMS320C50为核心的保密机实现方案。围绕C50这一中心将系统分为C50及外围逻辑电路、存储器、TLC32044及外围电路和电话接口电路4部分硬件设计。该方案采用一片TMS320C50即可完成所有的加解密、回波抵消运算，并为密钥控制、自适应均衡等运算保留了系统资源。     

控制局域网(CAN)中的数据转换的设计与实现

给出了一种实现CAN总线与RS232之间数据的转换的方法及过程．主控单元为单片机P89C51，其中涉及到CAN芯片SJA1000以及串口扩展芯片ST16C654的应用。作者分别以设计原理、硬件设计及软件设计三部分来介绍．并着重介绍了软件部分的功能实现过程，其中CAN接口部分按照CAN的2．0B协议来执行。     

无线通信芯片nRF903与89C51的接11设计

介绍了无线通信芯片nRF903的主要特点和工作原理，在此基础上设计了nRF903与单片机89C51的硬件接口电路。单片机89C51可以通过其I／O控制nRF903的工作状态、工作频率和发射功率等参数，并能实现半双工无线通信。为了保证可靠通信，设计了一个简单的通信协议．该通信协议数据帧由包头、地址、数据和校验码4部分组成，采用固定帧长度。文中给出了无线通信的接收和发射软件流程。所设计的软硬件接口非常适合在ISM频段的无线通信系统中应用。     

基于单片机的温度控制系统的设计与实现

针对需要进行温度控制的复杂非线性系统，介绍了一种基于单片机AT89C51实现的高精度实用型饮水机温度控制系统。首先介绍了其总体设计方案，然后详细给出了各部分硬件设计电路，简述了其软件设计与实现。测试结果表明，该控制系统能较好地满足温湿度智能控制的要求，具有较高的测量精度和控制精度。     

基于PIC16F877A和TL16C754的异步通信串口扩展及实现

文章介绍了基于PIC16F877A单片机和TL16C754异步通信芯片实现异步通信串口扩展的整体方案。该系统主要由PIC16F877A单片机、TL16C754及SN54LS245驱动芯片构成,通过开展相应的试验,证明了该处理方案的有效性,并在某工程项目中应用。     

Experimental demonstration of an improved EPON architecture using OFDMA for bandwidth scalable LAN emulation

We propose and demonstrate an improved Ethernet passive optical network (EPON) architecture supporting bandwidth-scalable physical layer local area network (LAN) emulation. Due to the use of orthogonal frequency division multiple access (OFDMA) technology for the LAN traffic transmission, there is no need to change the existing EPON architecture. Only one receiver at each optical network unit (ONU) is required to detect both LAN traffic and EPON downstream traffic, which makes the proposed system simple and cost-effective. Moreover, flexible assignment of LAN traffic bandwidth is realized by allocating different number of subcarriers or using different modulation formats. The 250 Mb/s 4-quadrature amplitude modulation (4-QAM) and 500 Mb/s 16-QAM OFDM LAN traffic are successfully emulated with the EPON traffic in our experiment.     

基于PROTEUS的数据采集系统的设计与仿真

基于PROTEUS的数据采集系统,结合Keil C51软件,实现了对单片机系统进行硬件设计和软件仿真功能,不仅可将许多单片机实例功能形象化,也可将许多单片机实例运行过程形象化.实验表明,使用PROTUES对单片机的数据采集系统进行设计和仿真,结果正确可靠,而且可以有效提高开发效率.     

A new bound and algorithm for Star 16-QAM carrier phase estimation

The true Cramer-Rao lower bound (CRLB) is derived and evaluated for the estimation of carrier phase of Star 16-quadrature amplitude modulation (QAM) and can be simply applied to carrier frequency estimation. Different geometries are investigated by varying the ring ratio (RR). For signal-to-noise ratios (SNRs) between 6-15 dB, the CRLB with RR=3 is lower than that of Square 16-QAM. A modified phase estimator is presented, which closely follows the new CRLB. Investigation of symbol error performance in short packet length reveals Star 16-QAM to be superior to Square 16-QAM for SNR<13 dB, which is a reasonable operating range for a coded system. Although Square 16-QAM and Star RR=1.8 are optimum for a perfect receiver, when the effect of phase estimation is considered, we find Star RR=3 to be better for SNR below 10 dB.     

A multidelay whitening approach to blind identification andequalization of SIMO channels

Blind channel estimation and blind equalization of single-input multiple-output communications channels is considered using only the second-order statistics of the data. Estimation of (partial) channel impulse response and design of finite-length minimum mean-square error blind equalizers is investigated. The basis of the approach is the design of multiple zero-forcing equalizers that whiten the noise-free data at multiple delays. In the past such an approach has been considered using just one zero-forcing equalizer at zero-delay. Infinite-impulse response channels are allowed. The proposed approach also works when the "subchannel" transfer functions have common zeros so long as the common zeros are minimum-phase zeros. The channel length or model orders need not be known. Three illustrative simulation examples using 4-QAM and 16-QAM signals are provided where the proposed approach is compared with several existing approaches     

Cochannel and intersymbol interferences in QAM system

The method of Ho and Yeh, with some modifications, is employed to analyse the performance of the QAM system in the presence of jammers and band-limiting. Results are presented for a 16-QAM system using the TDMA INTELSAT V communication system specifications.     

A new lattice polynomial perceptron and its applications tofrequency-selective fading channel equalization and ACI suppression

It is expected that the available spectrum for the proposed personal communication networks will soon be at a premium as the user population increases, and using multilevel quadrature amplitude modulation (MQAM), an bandwidth efficient transmission method for digital signals, may significantly ease the problem. A new lattice polynomial perceptron (LPP), with faster and less input signal-dependent convergence behavior, is presented and applied to frequency-selective slow fading channel equalization and adjacent-channel interference (ACI) suppression in a 16-QAM system. Computer simulation results are given, which shows that, in a 16-QAM system, the performance of LPP is clearly superior to that of the other structures     

Radio-Over-Fiber 16-QAM, 100-km Transmission at 5 Gb/s Using DSB-SC Transmitter and Remote Heterodyne Detection

By using a double-sideband suppressed carrier (DSB-SC) optical transmitter and a remote self-heterodyned (RSH) detection method, we experimentally and analytically proved the feasibility of a radio-over-fiber system using a 16-QAM signal at 5 Gb/s and 18 GHz, with a transmission distance of 100 km between a mobile service center and a base station. The transmission system performance was carefully analyzed by considering optical amplifier noise, fiber nonlinearity, phase noise, frequency response, and analog-to-digital converter (ADC) quantization noise. The 18-GHz, 16-QAM signal can be radiated from the base station to a remote antenna port without any upconverter, and the remote antenna port consists of a downconverter and high-speed digital signal processors (DSPs) to recover the 16-QAM signal. The high-speed DSP, which partially compensates the intersymbol-interference (ISI) and phase-noise-induced system penalties, was enabled by 20-Gs/s ADCs. The algorithms used in the DSP blocks were also described in details.     

改进的16进制正交幅度调制码的相位估计算法

相干光通信系统中的相位恢复是克服信号收发端和传输过程中产生的相位噪声的必要步骤。为获得低的运算复杂度和良好的相位估计效果,本文对传统的四次方相位估计算法进行了改进,使之具有自适应的数据块长度控制功能。通过理论分析以及Matlab数值仿真方法验证改进的效果。对于16进制正交幅度调制码（16QAM）,改进后的算法在几乎不增...     

DESIGN OF INTERPOLATION FILTER FOR ALL DIGITAL RECEIVER-ON THE INTERPOLATION PROBLEM OF FULL RESPONSE MODULATION SIGNALS

All digital implementation of receiver is a main topic on digital communication recently. The design of interpolation filter is one of the important problems for all digital implementation of receiver. In this paper, for full response linear modulation signal, a interpolation criterion is proposed. An interpolation formula is presented on bandwidth-limited transmission signal. For example, using the raised cosine roll off function as the system pulse response, the feasibility and effectiveness on the interpolation formula are certified by theoretical and numerical analysis. The computer simulation result on 16-QAM signal is given.