共查询到20条相似文献,搜索用时 15 毫秒
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介绍了在低压电力线上实现数据通信的扩频载波芯片PL2101,以及采用PL2101构成的电力线扩频载波通信系统。 相似文献
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在详细介绍低压电力线载波数据通信的特点和原理及通信方法的基础上,对各种通信方法进行全面的分析比较.对新的低压电力线载波通信方法的研究具有重要的借鉴和指导意义。 相似文献
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To achieve error-free communication on the narrowband power line communication (NB-PLC) channel, there is need for constant measurement campaign and modeling of burst errors resulting from noise, perturbation and disturbances on the channel. This work thus reports a signal level measurement and First-Order Semi-Hidden Fritchman Markov modeling of the three major NB-PLC noise types for a typical South African residential and laboratory indoor low voltage environment. Two distinguishable disturbance scenarios: mildly disturbed and heavily disturbed were considered and Baum–Welch maximum likelihood estimation (MLE) algorithm is used to obtain the most probable model parameters that statistically depict the experimentally measured noise error sequences. 相似文献
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为了抑制脉冲噪声对电力线正交频分复用(OFDM)通信系统的影响,最常用的方法之一是在接收端OFDM解调器之前前置一个置零非线性单元,即传统置零法。然而,由于引入了非线性失真,其性能并不理想。针对传统置零法引起的非线性失真问题,提出了一种基于迭代消除非线性失真的改进置零法。首先,对接收到的时域OFDM信号进行脉冲噪声检测和置零处理;然后,在频域利用已检测的符号来重构时域置零处理引入的非线性失真,并通过迭代提高重构的准确性;最后,从频域接收信号中减去重构的非线性失真。仿真结果表明,所提改进算法与传统置零法相比,有非常大的性能提升,增强了电力线OFDM通信系统对脉冲噪声的抵抗能力。 相似文献
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介绍CDMA扩频通信的基本原理、PL3200型SoC的结构及其载波通信功能模块,提出一种基于PL3200的CDMA扩频电力线载波通信系统的设计方案. 相似文献
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According to the problem that the threshold for traditional blanking depends on the characteristic parameters of noise and exist large deviation,an adaptive noise mitigation algorithm based on peak estimate and feedback compensation(ANMPEFC)in power line communication was proposed.First,SLM mapping preprocessing method was employed to reduce the PAPR of emission signal,peak information was used to estimate the frequency of the received signal and the relationship between peak frequency and impulse characteristics was established.Next,received signal was processed by blanking block and feedback compensation block adaptively according to estimated pulse frequency.Finally, performance of proposed algorithm and existing algorithms were analyzed based on threshold deviation.According to the results from simulation,it is clearly demonstrated that the proposed ANMPEFC can work in power line impulse noise environment without knowing the noise characteristics and has better performance in contrast to existing impulse noise suppression algorithm. 相似文献
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研究电力线通信过程中采样同步效率的优化问题,提出一种计算同步位置的优化策略。首先根据直接同步方法设计先片后位算法,利用片内采样过程完成电力线信号采样,创新地利用片内高低电位的最大差异计算片内位移个数,主要采用高低电位相差数量的最大情况为理想片内同步结果。试验结果表明该算法可以提高40%的时间效率。 相似文献
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提出了采用MSK作为调制解调技术的载波通信系统,设计了基于高速数字信号处理器、大规模可编程器件,数字频率合成、软件解调的全数字通信模块,来实现低压电力线上较为可靠的中低速数据传输。经实测与分析表明,本系统性能优越、抗干扰能力强、可靠性好,可用于配网自动化、自动抄表、工业控制等对通信可靠性要求较高的中、低速数据传输场合。 相似文献
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提出了一种基于电力线信道噪声的真随机数发生器的设计,即通过对电力线信道上的噪声采样的方法来产生随机数。使用EAX加密算法作为后处理算法,消除由于外部干扰产生的偏差和自相关性。通过理论分析和实验验证,可以弥补现有常用真随机数生产法的不足,获得分布均匀、相对独立的随机数。 相似文献
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电力线载波通信技术利用现有的电力传输网络进行数据传输,具有建设成本低,部署快速灵活等特点,被广泛用于局域网本地通信中。但当节点数过多或传输数据量过高时,如每个节点单独将数据传到调控中心,将会给整个通信系统带来巨大的数据量,同时降低通信效率,甚至造成通信拥塞。为降低传输数据量,节省通信传输资源,提升电力线载波接入网络的传输能力,本文提出了基于最小生成树传输路径的电力线载波通信数据融合算法。将所提算法与未使用融合算法带来的数据量进行对比,证明了所提算法的有效性。 相似文献
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为了实现高压电力线的载波通信,提出利用正交频分复用(OFDM)技术实现高压电力线载波通信的系统设计。在研究电力线载波通信和OFDM调制解调技术基本原理的基础上。分析了OFDM技术应用于电力线通信的优缺点,并给出高压电力线载波系统的硬件组成。 相似文献
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The so-called background noise level is a very critical figure in many EMC problems, especially when sensitive radio services are involved. In order to provide a sufficient signal-to-noise ratio (SNR) the minimum signal strength is most commonly calculated on the basis of existing noise levels. On the other hand, if the impact of unwanted emissions on radio services is studied, background noise takes on the function of a reference level. An extensive database of noise levels to be expected is available in the recommendation ITU-R P.372. However, most data concerning man-made noise were already measured in the 1970s. Thus, the significant increase of use of electrical devices with fast digital circuits and various communication systems gives reason to question the validity of the ITU recommendation for today's EMC purposes. This paper deals with different measurement techniques with respect to their suitability for measuring extremely low field strengths in the short wave range and presents measurement results for selected environments. Although the measurements are performed with the constraint of using a mobile measuring setup a considerable sensitivity is reached, leading to the conclusion that the ITU-R P.372 still seems to be valid for estimating noise levels. 相似文献