Blind Multiuser Channel Identification Based on Rate Doubling and Modulation-Induced Cyclostationarity

1　IntroductionInthemultiuseruplink ,eachuser’ssignalgoesthroughitschanneltothebasestationreceiver,wherethechannelhastobeidentifiedinordertoperformmultiuserdetection .Mostofthemultiuserdetectorsarelinear,includingZeroForcing (ZF)andMinimumMeanSquareError (MMSE)detec tors.Andtheyalldependontheestimationofthemultiuserchannels.Thetraditionalwayofestimat ingchannelsisbytraining .Buttheblindestimationofchannelsareadvantageous;besidesthefactthatitmaysaveagreatdealofbandwidth ,therearesitua ti…     

基于L-M算法的管内流体流量及温度单参数识别

管道内部流量及温度的测量在工业生产和工程应用中具有重要作用。采用高温管道一维稳态导热模型探讨了管道外壁面温度随流体流量及温度的变化规律。基于管道外壁面温度,采用列文伯格-马夸尔特(Levenberg-Marquardt,L-M)算法对管道内流体流量及温度单参数识别进行了研究,并分析了外壁面上的测温点个数对识别结果的影响。结果表明,流体流量或温度与测温点温度之间是一一对应的;流体流量越小,流体温度越高,则流体流量的识别精度越高;流体流量越大,流体温度越高,则流体温度的识别精度越高;无论存在测温误差与否,流体流量及温度的单参数识别结果均非常精确。     

一种新的提高掌纹识别率方法的研究

生物特征识别技术是通过人体本身所固有的、唯一的生理特征来自动地识别一个人。针对掌纹图像具有终身不变性、唯一性、主要特征明显、细节特征唯一等特点,论文提出了一种有效提高掌纹识别率的方法,即结合图像中的主元特征、不变矩特征和线特征的提取方法。该方法与单独使用主元特征提取、不变矩特征提取和线特征提取的方法进行了比较实验,结果证明新方法的识别率有明显提高。     

Self-Tuning Controller for Flow Rate Liquid System

Liquid flowrate control systems are considered one of the most applied systems in industrial processes. This research work deals with the design and practical application of self-tuning PID based pole placement controller of liquid flow delivered out of a variable speed centrifugal pump. The identification of the process parameters is carried out applying the recursive least square method (RLS). The robustness of the proposed controller is examined in the presence of level disturbances applied from pump suction side. Experimental results have shown that the proposed controller offers satisfactory results for a wide range of systems and with different values of time delays because it can be easily dealt with by simply extending the model numerator.     

高加速度下单脉冲测量雷达测速

雷达测速系统在研究目标特性、目标定轨、导弹安全控制中起着重要的作用。根据高加速度下单脉冲测量雷达测速的技术要求，详细地讨论了高加速度情况下的目标回波谱线发散问题，给出了加速度补偿的基本算法和工程实现框图。最后仿真表明，该算法可以完成高加速度下的脉冲多普勒测速。     

Modeling the Rate of Premature Ventricular Contractions and its Response to Lidocaine Infusion

The rate of premature ventricular contractions (PVC rate) and the dynamics of its response to the intravenous infusion of the antiarrhythmic drug lidocaine was modeled to facilitate the design of a closed-loop drug infusion system. An autoregressive moving average model structure with the lidocaine infusion rate as an exogenous input (ARMAX structure) was used. System identification experiments were performed using a canine model of myocardial infarction. The drug infusion rate was varied using a pseudorandom binary sequence (PRBS) test input to excite the system about an operating point established by an exponential infusion regimen. PVC's were detected in real time with a correlation technique. Model parameters were estimated in an offline data analysis. First-order models provided an adequate representation of the PVC rate in eight of ten runs. A second-order model was validated for two runs.     

基于低码率传输的红外视频编码方法研究

为了满足低速数据链下目标识别的需求,把感兴趣区域(Region of Interest,ROI)编码策略引入红外视频编码。在H.264视频编/解码框架的基础上,通过增加ROI编码的处理,构建基于ROI的视频编/解码框架,并在码率控制过程中调整ROI宏块与非ROI宏块的量化参数,优化了ROI量化模型。实验结果表明,该方法能够节省有限码率,增加ROI目标的细节,提高ROI对象的清晰度,可从整体上提高主观视觉的质量。     

基于多率采样的永磁同步电机控制方法设计

在工业自动化领域,永磁同步电动机在中小功率控制系统中发挥着重要作用。本项目采用多采样率方法构建永磁同步电机控制系统,其主要解决的问题包含多采样率下的速度及参数辨识、永磁同步电机多采样率滑模变结构控制系统设计。     

A Detailed Evolutionary Scrutiny of PEIS with GPS Fleet Tracker and AOMDV-SAPTV Based on Throughput,Delay, Accuracy,Error Rate,and Success Rate

Wireless Personal Communications - Radio Frequency Identification (RFID) technology is projected to address the issue of handling the bulk of nodes for consequently recognized and tracking tags...     

Intelligent modeling, observation, and control for nonlinearsystems

We present identification methods for nonlinear mechatronic systems. First, we consider a system consisting of a known linear part and an unknown static nonlinearity. With this approach, using an intelligent observer, it is possible to identify the nonlinear characteristic and to estimate all unmeasurable system states. The identification result of the nonlinearity and the estimated system states are used to improve the controller performance. Secondly, the first approach is extended to systems where both the linear parameters and the nonlinear characteristic are unknown. This is achieved by implementing the intelligent observer as a structured recurrent neural network     

衰落信道下MFSK信号符号速率估计快速算法

匹配识别在技侦一线业务单位中发挥着重要作用,其对算法的实时性要求较高。多进制频移键控(M-ary frequency-shift keying, MFSK)信号的符号速率为匹配识别中重要的特征参数之一,本文通过分析多径及频偏等衰落信道条件对符号速率估计产生的影响,将调制频率集作为先验信息的情况下,给出了一种衰落信道下MFSK信号符号速率估计的快速算法,该算法通过检测过Goertzel滤波器后输出的最大幅度值,经去毛刺、过零点间隔聚类等处理后完成符号速率的准确估计。仿真结果表明:文中算法具有较强抗噪性能,加入多普勒频移及多径等衰落信道条件仍具有较高的估计精度,且运算量大大减小,非常适合应用于匹配识别中。实际信号处理也表明了该算法的有效性及可行性。      

智能滑套内低频段RFID 标签识别率的研究

实际应用中智能滑套内低频段RFID 标签存在识别率低的问题,从射频识别技术的工作机理出发,借助MATLAB 仿真软件,对低频螺线管天线感应电压特性进行了仿真分析,讨论了读写器天线长度和内径对识别率的影响,提出了基于井下智能滑套的RFID 通信系统最佳天线部署。同时为减弱井下复杂工况环境对标签识别率的影响,设计了读写器天线自适应阻抗匹配系统,建立一套基于井下RFID 通信系统识别率的模拟试验平台,验证仿真设计结果的正确性。     

Capacity, Cutoff Rate, and Coding for a Direct-Detection Optical Channel

It is shown that When Pierce's pulse-position modulation scheme with 2^Lpositions is used on a self-noise-limited directdetection optical communication channel, there results a 2^L-ary erasure channel that is equivalent to the parallel combination ofL"completely correlated" binary erasure channels. The capacity of the full channel is the sum of the capacities of the component channels, but the cutoff rate of the full channel is shown to be much smaller than the sum of the cutoff rates. An interpretation of the cutoff rate is given that suggests a complexity advantage in coding separately on the component channels. It is shown that if short-constraint length convolutional codes with Viterbi decoders are used on the component channels, then the performance and complexity compare favorably with the Reed-Solomon coding system proposed by McEliece for the full channel. The reasons for this unexpectedly fine performance by the convolutional code system are explored in detail, as are various facets of the channel structure.     

Automatic fault detection, isolation, and recovery in transparentall-optical networks

Network fault identification is an important network management function, which is closely related to fault management and has an impact on other network management functions such as configuration management, and performance management. This paper investigates fault surveillance and fault identification mechanisms for a transparent optical network in which data travels optically from the source node to the destination node without going through any optical-to-electrical (O/E) or electrical-to-optical (E/O) conversion. Mechanisms and algorithms are proposed to detect and isolate faults such as fiber cuts, laser, receiver, or router failures. These mechanisms allow nonintrusive device monitoring without requiring any prior knowledge of the actual protocols being used in the data transmission     

Development and Preliminary Validation of Heart Rate and Breathing Rate Detection Using a Passive, Ballistocardiography-Based Sleep Monitoring System

Techniques such as ballistocardiography (BCG) that can provide noninvasive long-term physiological monitoring have gained interest due to a growing recognition of adverse effects from poor sleep and sleep disorders. The noninvasive analysis of physiological signals (NAPS) system is a BCG-based monitoring system developed to measure heart rate, breathing rate, and musculoskeletal movement that shows promise as a general sleep analysis tool. Overnight sleep studies were conducted on 40 healthy subjects during a clinical trial at the University of Virginia. The NAPS system's measures of heart rate and breathing rate were compared to ECG, pulse oximetry, and respiratory inductance plethysmography (RIP). The subjects were split into a training dataset and a validation dataset, maintaining similar demographics in each set. The NAPS system accurately detected heart rate, averaged over the prescribed 30-s epochs, to within less than 2.72 beats per minute of ECG, and accurately detected breathing rate, averaged over the same epochs, to within 2.10 breaths per minute of RIP bands used in polysomnography.     

Thermal ink jet dynamics: modeling, simulation, and testing

In this paper, we present a cinematographic measuring technique for visualization and characterization of dynamics in micro electro mechanical systems for the example of a thermal ink jet printhead. Furthermore, we derive a model for identification and simulation of dynamic phenomena in the thermal pneumatic microactuator of a thermal ink jet. Using this model we calculate the pressure propagation in the bubble by identifying the mathematical model with position measurements extracted from cinematographic image sequences which have been taken with our visualization equipment. The identification of the model was performed with minimizing the sum of quadratic deviations between simulated and measured values. Parameter studies with the identified model predict the behavior of the microactuator at outer pressures higher than 1 bar.     

Growth, spectroscopy, and lasing of titanium-doped sapphire

The growth, spectroscopy, and lasing of titanium-doped sapphire are discussed. Particular attention is given to the problems of achieving high-quality laser material and to the identification and elimination of defects that currently limit Ti:Al2O3laser performance.     

Amplify-and-Forward in Wireless Relay Networks: Rate, Diversity, and Network Size

A wireless network with fading and a single source-destination pair is considered. The information reaches the destination via multiple hops through a sequence of layers of single-antenna relays. At high signal-to-noise ratio (SNR), the simple amplify-and-forward strategy is shown to be optimal in terms of degrees of freedom, because it achieves the degrees of freedom equal to a point-to-point multiple-input multiple-output (MIMO) system. Hence, the lack of coordination in relay nodes does not reduce the achievable degrees of freedom. The performance of this amplify-and-forward strategy degrades with increasing network size. This phenomenon is analyzed by finding the tradeoffs between network size, rate, and diversity. A lower bound on the diversity-multiplexing tradeoff for concatenation of multiple random Gaussian matrices is obtained. Also, it is shown that achievable network size in the outage formulation (short codes) is a lot smaller than the ergodic formulation (long codes).     

深入理解失效率和瞬时失效率

对失效率λ(t)和瞬时失效率h(t)所具有的实际含义和表征内容进行了深入的探讨。同时详解了失效密度函数f(t)在可靠性工程计算中具有将随机失效数转变为连续变化量的作用。对这几个可靠性参量在工程应用和计算时的适用场合作了分析。通过简洁易懂的论述和实际的计算实例,重点说明了瞬时失效率的3个特点,希望在可靠性基础理论的学习中正确地理解失效率和瞬时失效率的意义。