基于LMMSE的滑动相关信道估计算法

5G NR系统中,接收端信道估计过程一般不可忽略噪声的影响,并且采用传统的线性最小均方误差(LMMSE)信道估计算法的运算量将会变的巨大,所以提出了滑动相关矩阵的方法来降低算法的复杂度。首先,通过仿真得到最优的滑动相关矩阵以及每次滑动所输出的子载波数,然后通过滑动窗依次输出频域子载波的信道估计值从而完成整个信道估计;在时域,通过混合插值方法进一步提升了系统性能。仿真结果表明,算法相比于LMMSE算法误码率升高小于1 dB,但是复杂度降低了99.74%,满足工程需求。     

Adaptive TS‐FNN control for a class of uncertain multi‐time‐delay systems: The exponentially stable sliding mode‐based approach

This paper presents an adaptive Takagi–Sugeno fuzzy neural network (TS‐FNN) control for a class of multiple time‐delay uncertain nonlinear systems. First, we develop a sliding surface guaranteed to achieve exponential stability while considering mismatched uncertainty and unknown delays. This exponential stability result based on a novel Lyapunov–Krasovskii method is an improvement when compared with traditional schemes where only asymptotic stability is achieved. The stability analysis is transformed into a linear matrix inequalities problem independent of time delays. Then, a sliding mode control‐based TS‐FNN control scheme is proposed to achieve asymptotic stability for the controlled system. Since the TS‐FNN combines TS fuzzy rules and a neural network structure, fewer numbers of fuzzy rules and tuning parameters are used compared with the traditional pure TS fuzzy approach. Moreover, all the fuzzy membership functions are tuned on‐line even in the presence of input uncertainty. Finally, simulation results show the control performance of the proposed scheme. Copyright © 2008 John Wiley & Sons, Ltd.     

基于OS-ELM的宽带电力线通信解映射优化算法

针对传统信道估计技术会降低通信系统有效性的缺陷,提出了一种基于在线序贯极限学习机(OS-ELM)的宽带PLC解映射优化算法,用以提高宽带电力线通信系统的通信质量。以我国广东省某小区用户电能表的实际采集数据作为原始数据,搭建了宽带电力线通信系统仿真模型,在实测的500 m四径信道下进行仿真测试并与BP神经网络以及传统的ELM进行性能对比和比较分析。试验结果表明,在各种不同信噪比的通信环境下,引入OS-ELM均表现出更快的训练速度和更好的抗干扰特性。除去信噪比过低的极端恶劣的通信环境以外,该算法均可以有效提高通信质量,降低误码率。     

智能变电站IEC 61588时间同步系统与安全评估

通过介绍智能变电站对时间同步需求和网络时间协议的技术特点、工作原理和组网方式,分析了目前网络时间同步系统在智能变电站应用中的优势与不足。对于IEC 61588网络时间同步系统在系统管理、产品设计和网络结构上存在的安全隐患,提出了一种基于智能变电站网络流量仿真技术的安全测评方法,并利用该方法进行了测评实例分析,保证了IEC 61588时间同步系统智能变电站的安全可靠运行。     

Voltage endurance testing

The medium-voltage ASD stator insulation systems operate under greater stress than those using the sine-wave power. The repetitive short rise-time pulses generated by most ASDs cause an additional stress. The pulses are often increased by the effect of the cable between the ASD and motor. It is incumbent on the user and ASD manufacturer to account for the magnitude, rate of rise, and repetition rate of these pulses. The medium-voltage machines powered by ASDs operate with some level of PD. The machine manufacturer must ensure that the insulation system will provide adequate life in the PD environment. VE testing is a well-understood and accepted method to qualify insulation systems. It is a reliable means to compare new insulation systems with the documented existing ones. The TS describes several qualification procedures based on the knowledge of the converter waveform. These will assure that all parts of the machine insulation system will present acceptable test life.     

参数不确定Chen混沌系统鲁棒模糊控制器的设计

基于TS(Takagi-Sugeno)模糊模型，研究具有参数不确定性Chert混沌系统的鲁棒控制器设计。首先构建含有参数不确定性的TS模糊模型：然后利用并行分布补偿的方法，设计使模糊系统在平衡点附近渐近稳定的鲁棒模糊控制器。该设计通过解一组线性矩阵不等式(LMI)得到局部区域控制器，进而设计TS模糊系统的鲁棒控制器。该鲁棒模糊控制器的渐近稳定性条件更为宽松，能够降低控制器设计的保守性。最后的仿真结果表明所设计的鲁棒模糊控制器对参数不确定Chert混沌系统具有良好的控制效果。     

多跳中继通信网STDM模式链路容量分析

下一代基于中继节点的多跳蜂窝网络将支持更高速率的多媒体移动业务.多跳中继链路能够有效改善无线通信链路的信道质量,有利于系统容量的提高,但是中继节点的引入代价属于额外无线信道资源的消耗,将会降低系统容量.因此本文提出了空间时分复用(STDM)的多跳中继链路模型,使得中继无线信道资源能够空间复用,通过理论分析和数值仿真,在保证一定的链路距离下,与传统严格时间正交的模式相比,STDM模式的链路吞吐量可以成倍的提高.     

A tabu search approach to fault section estimation in power systems

In this paper, a new method for fault section estimation in power systems based upon the set covering theory and tabu search (TS) technique is proposed. First, a new mathematical model for the fault section estimation problem is developed based upon the simulation of protection system behavior and the well developed parsimonious set covering theory. Secondly, a new method is presented to solve this problem using a TS based method, in order to find the global optimal solution(s) efficiently. Finally, a sample power system is used to demonstrate the feasibility and efficiency of the developed method. The comparison between the developed TS based and the existing genetic algorithm (GA) based approaches to the fault section estimation problem has also been carried out, and many simulation results show that the TS based approach is more efficient than the GA based approach. The key features of this proposed method are that it can deal with very complicated fault scenarios and can find multiple global optimal solutions directly and very efficiently in a single run. Test results suggest that the developed TS based method is very efficient and of promise for on-line applications.     

基于时分处理的BOC信号通道时延标定算法

卫星导航信号发射通道的设备自身时延是星地组合时延的一个部分,卫星在地面测试中必须进行通道时延标定。针对导航卫星BOC（binary offset carrier）调制导航信号发射通道绝对时延,提出了一种采用时分处理的时延标定算法。在完成导航卫星输出BOC导航信号和时间保持系统产生的秒脉冲信号双通道同步采样后,在数字域对BOC采样信号进行预处理和串并变换,将高速数据流变换为多路低速率数据流,对每路信号频率码相位捕获,从而得到BOC信号发射通道绝对时延。计算机仿真表明在采样率10 Gsa/s时提出算法的标定不确定度优于0.2 ns。     

宽带电力线载波OFDM信道估计

正交频分复用（OFDM）是电力线高速数据传输的有效调制技术.而电力线信道的时频双选择性造成OFDM系统的频率偏移,导致载波间干扰（inter-carrier interference,ICI）.为准确掌握信道特性,提出了基于离散长球序列-基扩展模型（DPSS-BEM）的宽带电力线载波OFDM信道估计方法.采用二维DPSS-BEM对电力线信道进行建模,将电力线信道视为二维正交分量的线性加权,并利用导频位置的训练信息和最小二乘法估计权值.仿真表明,该方法能有效地跟踪电力线信道变化,改善信道的归一化均方误差和误码率性能,以便有针对性地采取措施,减少载波间的相互干扰.     

Distribution system temperature adaptive load transfer using colored Petri net approach

This paper derives appropriate decisions for load transfer among distribution feeders by switching operations to improve system operating performance by combining the load characteristics and the variations among customers as a result of temperature increases using a switching operation decision inference mechanism based on a colored Petri net (CPN) approach. A practical distribution system with 19 feeders, daily load profiles, and corresponding data on temperature sensitivity (TS) is used to perform computer simulations to demonstrate the effectiveness of the proposed methodology. It is concluded that the proposed CPN inference mechanism can enhance the system operating performance with the proper switching operation by considering the TS of customer power consumption served in each service zone of distribution feeders.     

Fuzzy bilinear state feedback control design based on TS fuzzy bilinear model for DC–DC converters

This paper proposes a fuzzy bilinear state feedback controller based on Tagaki–Sugeno (TS) fuzzy bilinear model for DC–DC converters. The DC–DC converters can be approximated to bilinear model via Taylor series expansion. For achieving the output voltage regulation, we formulate the extended system of bilinear DC–DC converter model, one of whose state variables is the error between the output voltage and the reference output voltage. The extended system can be described to TS fuzzy bilinear model. We design a fuzzy bilinear state feedback controller to track the reference output voltage. The closed loop system is globally asymptotically stable via the proposed controller. Lyapunov theory is employed to guarantee the stability of the closed loop system. Numerical examples are given to demonstrate the validity of our proposed control approach with comparative results.     

暗原先验算法在天空区域的处理与改进

暗原先验算法在天空区域去雾过程中会造成噪声过度放大和晕环现象,针对这个问题提出了依据天空隶属系数调整天空区域透射率的方法。求得有雾图像相应位置天空隶属度系数,自适应改变透射率调整幅度,并利用二次函数特性,对隶属度小值区域进行压缩,减弱近景透射率有效区域的调整,最后通过大气散射模型得到复原图像。大量实验结果表明,该方法得到的复原图像清晰自然,特别是在天空区域,保留部分浓雾区域去雾程度的同时抑制了天空区域的噪声和晕环现象,取得了很好的去雾效果。相对暗原先验算法,改进算法在天空区域得到更加准确的透射率估计,复原图像效果更佳。     

一种数字电视传输流监测系统的设计与实现

提出了一种基于PCI Express总线采集数字电视传输流(TS)并实时完成TS数据分析的监测系统方案,设计并实现了PCI-E接口板卡的硬件设计、驱动软件及TS数据分析软件。测试表明该系统性能稳定,可以实时完成传输率最高为200Mb/s的TS码流分析,能够满足有线数字电视系统的实际需求。     

A tabu search based hybrid optimization approach for a fuzzy modelled unit commitment problem

This article presents a solution model for the unit commitment problem (UCP) using fuzzy logic to address uncertainties in the problem. Hybrid tabu search (TS), particle swarm optimization (PSO) and sequential quadratic programming (SQP) technique (hybrid TS–PSO–SQP) is used to schedule the generating units based on the fuzzy logic decisions. The fitness function for the hybrid TS–PSO–SQP is formulated by combining the objective function of UCP and a penalty calculated from the fuzzy logic decisions. Fuzzy decisions are made based on the statistics of the load demand error and spinning reserve maintained at each hour. TS are used to solve the combinatorial sub-problem of the UCP. An improved random perturbation scheme and a simple method for generating initial feasible commitment schedule are proposed for the TS method. The non-linear programming sub-problem of the UCP is solved using the hybrid PSO–SQP technique. Simulation results on a practical Neyveli Thermal Power Station system (NTPS) in India and several example systems validate, the presented UCP model is reasonable by ensuring quality solution with sufficient level of spinning reserve throughout the scheduling horizon for secure operation of the system.     

风电场出力随机扰动下的电网概率脆弱性评估

在风电大规模接入电力系统的发展趋势下,系统将经受更复杂的随机性影响,给系统的可靠稳定运行带来极大挑战。在综合考虑了不同规模和不同并网点的风电场随机扰动性、发电机的随机故障停运率以及负荷的随机波动的前提下,基于半不变量和Gram-Charlier级数(CGC)的输电网概率潮流方法,并结合系统的临界电压和极限传输功率,提出一种新的概率脆弱性评估方法,以此来筛选出风电场并网后电力系统的脆弱节点和脆弱支路。对所提方法在IEEE-30母线系统中通过不同规模风电场、不同接入点条件下进行仿真验证,及其与基于支路势能函数法的传统评估方法进行对比,结果证明该方法能够给出可靠有效的评估结论,有助于为进一步探索不同规模风电场并网下的电力系统脆弱性提供思路。     

复杂环境下双向协作通信研究

双向协作通信应用于航空自组网、车联网等未来无线通信,面临着高速运动环境下信道状态变化导致通信质量大幅下降问题。利用随机信道建模方式,考虑通信过程前后子阶段信道状态信息相关性,推导了信道状态联合概率密度闭式表达式;提出了以最小化系统中断概率为目标的最优功率分配策略以改善双向协作通信系统的中断性能。蒙特卡罗仿真结果表明在不同的系统平均信噪比、信道相关系数（与通信节点运动速度相关）下最优功率分配相比于等功率分配可有效提高系统中断性能。基于最优功率分配的双向协作通信能克服高速运动环境下信道状态变化问题,具有高可靠高速率特点,能为航空自组网、车联网等未来无线通信应用提供技术支撑。     

泥浆信道数据压缩和纠错联合编码研究

泥浆脉冲通信是无线随钻测井系统中主用通信方式,泥浆信道本身衰减较大,且信道噪声复杂.针对泥浆信道及噪声特性进行分析,提出了一种适用于泥浆脉冲信号的联合编码方法,其在对信号进行无损压缩的同时可针对突发错误和随机错误进行纠正,保证传输效率的同时降低系统误码率,且不会增加设备复杂度.最后以现场测井数据为基础,表明LZW的最大压缩比可达3:1,并通过仿真实验证明该联合编码方法具有良好的抗噪声性能,能较好地重构测井数据,验证了其有效性.     

电力系统相量测量装置最优配置混合算法的研究

以电力系统状态完全可观测和相量测量装置(PMU)配置数目最小为目标,形成了PMU最优配置问题。将遗传算法和禁忌算法有效结合形成禁忌遗传算法,该算法在改进交叉和变异算子的基础上,继承和发展了遗传算法基于多点搜索、鲁棒性强等诸多优点,每当群体有出现早熟而陷入局部最优解的趋势时,利用禁忌搜索增强算法的爬山能力,避免算法早熟而陷入局部最优解,增强算法的全局收敛能力和收敛速度。与遗传算法和禁忌搜索方法相比,禁忌遗传算法具有更好的全局收敛能力和收敛速度。最后采用IEEE14,IEEE30和IEEE57节点系统对算法的有效性进行了验证。     

5G TM 信号无线信道测量平台研究与实现

为了研究第五代移动通信（5G）系统无线信道，获得准确的5G无线信道特性和信道模型，提出了一种基于5G新空口（NR）测试模式（TM）信号的无线信道测量平台。开展了TM无线信道测量平台的总体架构及测量信号接收处理算法设计，并基于软件无线电设备和高性能计算设备搭建测量平台。针对功率谱平坦度、峰均功率比和相关性等指标，对多种TM信号的测量性能进行评估。根据性能评估结果，选择适合作为测量波形的TM信号。采用射频馈线直连、多径信道模拟和静态空口实测3种方法对TM无线信道测量平台进行验证，该平台不仅可以实现准确的信道测量，同时能够对矢量幅度误差和误比特率等传输性能进行测试。