【作者】 程忠良；

【导师】 贾振红； 覃锡忠；

【作者基本信息】 新疆大学 ， 信号与信息处理， 2010， 硕士

【摘要】 目前对电力线通信的研究已相当广泛,但离产品的大规模商用化还有一定的距离,电力线信道的噪声去除技术成为其制约因素之一,且还在不断的探究之中。本文重点对电力线信道中噪声如何更加有效去除的问题进行了分析和研究,鉴于同步技术在电力线通信中的重要作用,还提出了一种适合于电力线信道的OFDM盲同步算法。文中通过模拟低压电力线信道噪声环境,在改进阈值平移不变量去噪法中首次采用一种新的阈值函数,使阈值的变化与噪声的小波变换随尺度的变化特性相一致。二者仿真实验表明,改进的盲同步算法具有良好的定时估计和频率偏移估计性能;而改进的平移不变量去噪算法能够有效改善信号的信噪比,减小原始信号和估计信号之间的均方根误差,去噪效果更好。更多还原

【Abstract】 Power line communication has been widely researched up to now, but there is a stretch to go on to adopt on a large scale, the de-noising methods in the power line channel become one of the restriction factor and is probed deeply into constantly. The de-noising in the power line channel is analyzed and researched in this paper. Considering the importance of synchronization, a modified blind OFDM synchronization algorithm is proposed. Through simulating the noise condition, the improved threshold function is firstly adopted, which makes the threshold’s changes be consistent with the noise’s property according to the decomposing scale. The computer simulation results show that the perfect blind OFDM synchronization algorithm performs well in the estimation of the timing, and the method based on the amended translation invariant wavelet can effectively improve the signal-noise ratio, reduce the root mean square error between the original signal and the estimated signal, and has a better de-noising effect.更多还原