基于功率控制环扰动的DC-DC变换器能量信息一体化研究

针对实现DC-DC变换器之间的信息交互较为复杂的问题,提出了一种基于功率控制环扰动实现其能量信息一体化的方法。通过在DC-DC变换器的传统功率控制环中叠加二进制频移键控(binary frequency shift keying,2FSK)信号作为扰动,将数据信息叠加到传统脉冲宽度调制(pulse-width modulation,PWM)信号中,使得该PWM信号同时包含数据信息,实现能量信息一体化。首先,给出基于2FSK的功率/数据双载波调制以及实时的滑动离散傅里叶变换(sliding discrete Fourier transform,SDFT)解调方案。然后,通过对Buck变换器的能量信息一体化模型进行小信号建模与分析可知,降低输入阻抗可提升通信的信噪比。最后搭建一个由两个Buck变换器并联的实验装置进行验证。实验结果表明在稳态和负载突变的工况下均可实现3 kb/s的稳定通信,验证了所提方法的可行性。该方法使得DC-DC变换器能同时进行功率变换和数据传输,提升数字化和智能化水平。     

时间敏感网络帧抢占时延的混合概率模型

时间敏感网络帧抢占的时延特性相对复杂,难以用单一的标准概率密度函数分析其随机性。针对时间敏感网络帧抢占时延的随机特性分析问题,对帧抢占机制的工作模式和时延影响因素进行了研究,给出了不同可抢占帧长的分阶段抢占时延解析表达式;利用混合概率模型对帧抢占时延的随机特性进行建模,给出了混合概率模型中各个分量及其权重的产生方法;通过数值仿真分析了帧抢占时延的随机性,以及帧长和链路占用率对时延混合概率模型分量权重的影响。研究成果对时间敏感网络帧抢占仿真模型开发和优化设计具有参考价值。     

Broadband hybrid model for relay-aided cooperative MIMO power line communication systems

A hybrid model for broadband multiple-input multiple-output (MIMO) relay-aided indoor power line communications (PLC) system was proposed in this paper. The proposed model combines the top-down and bottom-up approaches and extends to a two-hop relay-aided cooperative system with variable gain relay in amplify-and-forward (AF) mode. Based on the proposed PLC model and generated channel, the channel statistical characteristics are further investigated in 2MHz - 100MHz bandwidth. Simulated results show that the proposed model overcomes the difficulties that the existing models need a lot of topological information of the network or measurements information. It provides a practical simulation analysis method for cooperative relay MIMO-PLC system. The results also show that cooperative MIMO relaying communications can improve the indoor PLC performances and communication reliability.     

基于深度神经网络的无环路由算法

通信网中信息量的迅猛增长,使得网络负载不均衡、 资源利用率低的情况日益加重.当前基于深度学习的智能路由方法在一定程度上克服了此问题,但这些方法在路径选择过程中有一定几率产生环路现象.针对上述问题,提出了一种基于深度神经网络(Deep Neural Network,DNN)的路由方案,利用距离值作为神经网络样本标签,通过...     

Modeling and Realization of Mobile-to-mobile Wideband MIMO Channels Based on the Geometrical Multi-Rings and Multi-Ellipses Stochastic Scattering Model

A geometry-based stochastic scattering model (GBSSM) based on geometrical multiple rings and ellipses is proposed for wideband multiple-input multiple-output (MIMO) mobile-to-mobile (M2M) fading channels. The proposed GBSSM is deployed with cross-polarized antennas and can be applied for the line-of-sight (LOS) and non-LOS (NLOS) scenarios by considering the single-bounced (SB) and double-bounced (DB) components. The channel realization is much more straightforward and concise to study the channel characteristics compared with the too complicated analytical solutions available so far. Based on the proposed GBSSM and realized channel, the channel characteristics and parameters at 2 GHz and 5 GHz with 100 MHz bandwidth are further investigated. The results can be used in the link and system level simulations in mobile-to-mobile radio systems.     

基于自适应遗传算法的PLC信道动态子载波分配

为提高宽带电力线通信(PLC)的传输速率,在2～100MHz的低压宽带电力线信道条件下,提出基于速率最大化(RA)准则的动态子载波分配算法。该算法利用遗传算法比较好的全局搜索能力,将遗传算法与注水算法结合,对正交频分复用系统(OFDM)动态子载波进行自适应分配。新算法先将种群中的个体进行交叉操作,得到两个新的子代群体,对得到的子代种群进行复制和变异操作。仿真结果表明:改进之后的遗传算法与自适应遗传算法相比较,在性能上有较大改善,系统传输速率变快,信道容量变大。     

基础能力培养为目标的VHDL案例教学方法

EDA是电子信息类专业的核心课程。如何提高学生的项目开发能力一直是该课程的重要课题。基础能力是项目开发能力的重要基础。本文以交通灯控制系统设计作为案例,深度剖析案例中的设计方法及知识点,依次完成设计方法中的流程中的功能分析与实现。探索将理论知识实现项目需求中的功能的基本技能,为复杂项目开发奠定基础。文章对硬件描述语言的教学有一定的指导作用。